Association between Air Pollutants and Asthma Emergency Room Visits and Hospital Admissions in Time Series Studies: A Systematic Review and Meta-Analysis

Assessing the impact of specific PM2.5-Bound metallic elements on asthma emergency department visits: A case-crossover study in Taiwan

OBJECTIVES

This study aims to assess the specific PM2.5-bound metallic elements that contribute to asthma emergency department visits by using a case-crossover study design.

METHODS

This study analyzed data from 11,410 asthma emergency department visits as case group and 22,820 non-asthma onset dates occurring one week and two weeks preceding the case day as controls from 2017 to 2020. PM2.5 monitoring data and 35 PM.2.5-bound metallic elements from six different regions in Taiwan were collected. Conditional logistic regression models were used to assess the relationship between asthma and PM2.5-bound metallic elements.

RESULTS

Our investigation revealed a statistically significant risk of asthma emergency department visits associated with PM2.5 exposure at lag 0, 1, 2, and 3 during autumn. Additionally, PM2.5-bound hafnium (Hf), thallium (Tl), rubidium (Rb), and aluminum (Al) exhibited a consistently significant positive correlation with asthma emergency department visits at lags 1, 2, and 3. In stratified analyses by area, age, and sex, PM2.5-bound Hf showed a significant and consistent correlation.

CONCLUSIONS

This study provides evidence of PM2.5-bound metallic elements effects in asthma exacerbations, particularly for Hf. It emphasizes the importance of understanding the origins of these metallic elements and pursuing emission reductions to mitigate regional health risks.

Assessing environmental injustice in Kansas City by linking paediatric asthma to local sources of pollution: a cross-sectional study

OBJECTIVE

A grassroots environmental-justice organisation in Kansas City has been examining the disproportionate exposure to air pollution experienced by residents living fenceline to the largest classification railyard in the USA. Prior analyses showed limited increased risk for asthma exacerbation for patients with asthma living closer to toxic release inventory (TRI) facilities and railyards. In this study, we assessed geographical asthma and environmental disparities, to further explore community-level disparities.

DESIGN

This is a cross-sectional study of population-level asthma rates, which included rates for all asthma encounters and acute asthma encounters (urgent care, emergency department, inpatient admission). Distances from census-tract centroids to nearest TRI facilities, railyards and highways were calculated. The association between asthma rates and distances was examined using Kendall's τ correlation and multivariable Poisson regression models.

SETTING

We used electronic medical record data from the regional paediatric hospital, census and Environmental Protection Agency (EPA) air monitoring data.

PARTICIPANTS

Patients with 2+ asthma encounters during the EPA study timeframe were identified.

RESULTS

Residential distance from railyards exhibited a significant negative correlation with overall (-0.36 (CI -0.41 to -0.32)) and acute (-0.27 (CI -0.32 to -0.22)) asthma rates. Asthma rates were elevated among tracts north of the closest railyard (incident rate ratio: 1.38; CI 1.35 to 1.41) when compared with southern directionality. An increased distance from the nearest railyard of 3 km was associated with a decrease in overall asthma rates of 26%.

CONCLUSION

Significant negative associations between proximity to all pollution source types and asthma rates were observed. This community-level research has served as a tool for community engagement and will be used to support proposed local policy. Environmental justice work addresses local concerns involving small, limited datasets, if the data exist at all. The academic epidemiological platform may reconsider acceptable approaches to small population research in order to better serve communities with the most need.

Assessing the Impact of Non-Exhaust Emissions on the Asthmatic Airway (IONA) Protocol for a Randomised Three-Exposure Crossover Study

BACKGROUND

People living with asthma are disproportionately affected by air pollution, with increased symptoms, medication usage, hospital admissions, and the risk of death. To date, there has been a focus on exhaust emissions, but traffic-related air pollution (TRAP) can also arise from the mechanical abrasion of tyres, brakes, and road surfaces. We therefore created a study with the aim of investigating the acute impacts of non-exhaust emissions (NEEs) on the lung function and airway immune status of asthmatic adults.

METHODS

A randomised three-condition crossover panel design will expose adults with asthma using a 2.5 h intermittent cycling protocol in a random order at three locations in London, selected to provide the greatest contrast in the NEE components within TRAP. Lung function will be monitored using oscillometry, fractional exhaled nitric oxide, and spirometry (the primary outcome is the forced expiratory volume in one second). Biomarkers of inflammation and airborne metal exposure will be measured in the upper airway using nasal lavage. Symptom responses will be monitored using questionnaires. Sources of exhaust and non-exhaust concentrations will be established using source apportionment via the positive matrix factorisation of high-time resolution chemical measures conducted at the exposure sites.

DISCUSSION

Collectively, this study will provide us with valuable information on the health effects of NEE components within ambient PM2.5 and PM10, whilst establishing a biological mechanism to help contextualise current epidemiological observations.

Contemporary Concise Review 2023: Environmental and occupational lung diseases

Air pollutants have various effects on human health in environmental and occupational settings. Air pollutants can be a risk factor for incidence, exacerbation/aggravation and death due to various lung diseases, including asthma, chronic obstructive pulmonary disease (COPD), hypersensitivity pneumonitis or pneumonia (HP), pulmonary fibrosis such as pneumoconiosis and malignant respiratory diseases such as lung cancer and malignant pleural mesothelioma. Environmental and occupational respiratory diseases are crucial clinical and social issues worldwide, although the burden of respiratory disease due to environmental and occupational causes varies depending on country/region, demographic variables, geographical location, industrial structure and socioeconomic situation. The correct recognition of environmental and occupational lung diseases and taking appropriate measures are essential to their effective prevention.

Predicting the daily number of patients for allergic diseases using PM10 concentration based on spatiotemporal graph convolutional networks

Air pollution causes and exacerbates allergic diseases including asthma, allergic rhinitis, and atopic dermatitis. Precise prediction of the number of patients afflicted with these diseases and analysis of the environmental conditions that contribute to disease outbreaks play crucial roles in the effective management of hospital services. Therefore, this study aims to predict the daily number of patients with these allergic diseases and determine the impact of particulate matter (PM10) on each disease. To analyze the spatiotemporal correlations between allergic diseases (asthma, atopic dermatitis, and allergic rhinitis) and PM10 concentrations, we propose a multi-variable spatiotemporal graph convolutional network (MST-GCN)-based disease prediction model. Data on the number of patients were collected from the National Health Insurance Service from January 2013 to December 2017, and the PM10 data were collected from Airkorea during the same period. As a result, the proposed disease prediction model showed higher performance (R2 0.87) than the other deep-learning baseline methods. The synergic effect of spatial and temporal analyses improved the prediction performance of the number of patients. The prediction accuracies for allergic rhinitis, asthma, and atopic dermatitis achieved R2 scores of 0.96, 0.92, and 0.86, respectively. In the ablation study of environmental factors, PM10 improved the prediction accuracy by 10.13%, based on the R2 score.

Relation between air quality and asthma in high-altitude places, La Paz, Bolivia (3,600 m a.s.l.)

Introduction. Asthma is a chronic disease affecting millions of people around the world. Air quality is a major factor in triggering asthma symptoms. Objective. To analyze air quality and asthma in high-altitude residents of La Paz, Bolivia. Materials and methods. In this analytical, descriptive, and retrospective study, we collected data from patients diagnosed with asthma at the Instituto Nacional del Tórax and the Instituto Boliviano de Biología de Altura. In addition, air quality monitoring of particulate matter was carried out at the stations of the Red de Monitoreo de la Calidad del Aire. Results. Women represented 56.9% of cases at the Instituto Nacional del Tórax and the Instituto Boliviano de Biología de Altura. In both institutions, the average age was 47 years and patients were overweight or obese. Increases in PM2.5 were recorded in autumn, winter and spring from 2014, 2016 to 2019 and 2015 in all four seasons. PM10 showed increases in autumn and winter from 2014 to 2020 within the established limits. We observed a positive and significant association between PM2,5 concentration and the spirometry parameters of forced vital capacity, peak expiratory flow, and “reversibility percentage” or “bronchodilator response percentage”. The association of PM10 and forced vital capacity, forced expiratory volume in the first second, and peak expiratory flow, was also statistically significant. Conclusion. Asthma cases occur on average at 47 years of age in overweight or obese people. We observed a positive association between particles PM2,5 and PM10 with spirometric parameters, stronger with particulate matter PM2,5.

Risk Factors for Acute Asthma Exacerbations in Adults With Mild Asthma

BACKGROUND

Although individuals with mild asthma account for 30% to 40% of acute asthma exacerbations (AAEs), relatively little attention has been paid to risk factors for AAEs in this population.

OBJECTIVE

To identify risk factors associated with AAEs in patients with mild asthma.

METHODS

This was a retrospective cohort study. We used administrative data from a large managed care organization to identify 199,010 adults aged 18 to 85 years who met study criteria for mild asthma between 2013 and 2018. An asthma-coded qualifying visit (index visit) was identified for each patient. We then used information at the index visit or from the year before the index visit to measure potential risk factors for AAEs in the subsequent year. An AAE was defined as either an asthma-coded hospitalization or emergency department visit, or an asthma-related systemic corticosteroid administration (intramuscular or intravenous) or oral corticosteroid dispensing. Poisson regression models with robust SEs were used to estimate the adjusted risk ratios for future AAEs.

RESULTS

In the study cohort, mean age was 44 years and 64% were female; 6.5% had AAEs within 1 year after the index visit. In multivariate models, age, sex, race, ethnicity, smoking status, body mass index, prior acute asthma care, and a variety of comorbidities and other clinical characteristics were significant predictors for future AAE risk.

CONCLUSION

Population-based disease management strategies for asthma should be expanded to include people with mild asthma in addition to those with moderate to severe disease.

Does socioeconomic and environmental burden affect vulnerability to extreme air pollution and heat? A case-crossover study of mortality in California

BACKGROUND

Extreme heat and air pollution is associated with increased mortality. Recent evidence suggests the combined effects of both is greater than the effects of each individual exposure. Low neighborhood socioeconomic status ("socioeconomic burden") has also been associated with increased exposure and vulnerability to both heat and air pollution. We investigated if neighborhood socioeconomic burden or the combination of socioeconomic and environmental exposures ("socioenvironmental burden") modified the effect of combined exposure to extreme heat and particulate air pollution on mortality in California.

METHODS

We used a time-stratified case-crossover design to assess the impact of daily exposure to extreme particulate matter <2.5 μm (PM2.5) and heat on cardiovascular, respiratory, and all-cause mortality in California 2014-2019. Daily average PM2.5 and maximum temperatures based on decedent's residential census tract were dichotomized as extreme or not. Census tract-level socioenvironmental and socioeconomic burden was assessed with the CalEnviroScreen (CES) score and a social deprivation index (SDI), and individual educational attainment was derived from death certificates. Conditional logistic regression was used to estimate associations of heat and PM2.5 with mortality with a product term used to evaluate effect measure modification.

RESULTS

During the study period 1,514,292 all-cause deaths could be assigned residential exposures. Extreme heat and air pollution alone and combined were associated with increased mortality, matching prior reports. Decedents in census tracts with higher socioenvironmental and socioeconomic burden experienced more days with extreme PM2.5 exposure. However, we found no consistent effect measure modification by CES or SDI on combined or separate extreme heat and PM2.5 exposure on odds of total, cardiovascular or respiratory mortality. No effect measure modification was observed for individual education attainment.

CONCLUSION

We did not find evidence that neighborhood socioenvironmental- or socioeconomic burden significantly influenced the individual or combined impact of extreme exposures to heat and PM2.5 on mortality in California.

IMPACT

We investigated the effect measure modification by socioeconomic and socioenvironmental of the co-occurrence of heat and PM2.5, which adds support to the limited previous literature on effect measure modification by socioeconomic and socioenvironmental burden of heat alone and PM2.5 alone. We found no consistent effect measure modification by neighborhood socioenvironmental and socioeconomic burden or individual level SES of the mortality association with extreme heat and PM2.5 co-exposure. However, we did find increased number of days with extreme PM2.5 exposure in neighborhoods with high socioenvironmental and socioeconomic burden. We evaluated multiple area-level and an individual-level SES and socioenvironmental burden metrics, each estimating socioenvironmental factors differently, making our conclusion more robust.

Outdoor air pollution and near-fatal/fatal asthma attacks in children: A systematic review

BACKGROUND

Globally, observational studies have demonstrated an association between high levels of air pollution and asthma attacks in children. It remains unclear whether and to what extent exposure may be associated with increased near-fatal/fatal attacks.

OBJECTIVE

To systematically review the evidence for an association between ambient outdoor air pollution and fatal and/or near-fatal asthma (NFA).

METHODS

Following Cochrane methodology, we searched MEDLINE, EMBASE, Web of Science, Scopus, and Open Grey electronic databases for studies reporting the association of fatal/NFA and air pollution (particulate matter [PM], sulfur dioxide, nitrogen dioxide, black carbon and ozone [O3]) in children. NFA was defined as requiring intensive care unit (ICU) management.

RESULTS

Two reviewers independently screened 1358 papers. A total of 276 studies identified asthma attacks related to air pollution, 272 did not meet inclusion criteria after full-text review. Four observational studies described fatal/NFA, of which three addressed NFA. PM2.5 (per 12.5 µg/m3 increase) and O3 (per 22 ppb increase) were associated with NFA in one study (PM2.5, relative risk: 1.26, confidence interval [CI] [1.10-1.44]), O3 (1.19 [1.01-1.40]). PM10 was associated with ICU admission in the context of thunderstorm asthma. Elemental carbon was associated equally with NFA that did not require an ICU admission (p = 0.67). Studies of fatal asthma including children did not demarcate age within the analysis.

CONCLUSIONS

Ozone and PM2.5 have been associated with NFA in children but synthesis is limited by the paucity of studies and methodological heterogeneity. Poor reporting of severities of asthma attacks hinders the assessment of whether outdoor air pollution is associated with an increased number of NFA/fatal attacks in children.

Air pollutants contribute to epithelial barrier dysfunction and allergic diseases

Air pollution is a global problem associated with various health conditions, causing elevated rates of morbidity and mortality. Major sources of air pollutants include industrial emissions, traffic-related pollutants, and household biomass combustion, in addition to indoor pollutants from chemicals and tobacco. Various types of air pollutants originate from both human activities and natural sources. These include particulate matter, pollen, greenhouse gases, and other harmful gases. Air pollution is linked to allergic diseases, including atopic dermatitis, allergic rhinitis, allergic conjunctivitis, food allergy, and bronchial asthma. These pollutants lead to epithelial barrier dysfunction, dysbiosis, and immune dysregulation. In addition, climate change and global warming may contribute to the exacerbation and the development of allergic diseases related to air pollutants. Epigenetic changes associated with air pollutants have also been connected to the onset of allergic diseases. Furthermore, these changes can be passed down through subsequent generations, causing a higher prevalence of allergic diseases in offspring. Modulation of the aryl hydrocarbon receptor could be a valuable strategy for alleviating air pollutant-induced epidermal barrier dysfunction and atopic dermatitis. A more effective approach to preventing allergic diseases triggered by air pollutants is to reduce exposure to them. Implementing public policies aimed at safeguarding individuals from air pollutant exposure may prove to be the most efficient solution. A pressing need exists for global policy initiatives that prioritize efforts to reduce the production of air pollutants.

Air pollution and childhood respiratory consultations in primary care: a systematic review

BACKGROUND

Outdoor air pollution is a known risk factor for respiratory morbidity worldwide. Compared with the adult population, there are fewer studies that analyse the association between short-term exposure to air pollution and respiratory morbidity in children in primary care.

OBJECTIVE

To evaluate whether children in a primary care setting exposed to outdoor air pollutants during short-term intervals are at increased risk of respiratory diagnoses.

METHODS

A search in Medline, the Cochrane Library, Web of Science and Embase databases throughout March 2023. Percentage change or risk ratios with corresponding 95% CI for the association between air pollutants and respiratory diseases were retrieved from individual studies. Risk of bias assessment was conducted with the Newcastle-Ottawa Scale (NOS) for cohort or case-control studies and an adjusted NOS for time series studies.

RESULTS

From 1366 studies, 14 were identified as meeting the inclusion criteria. Most studies had intermediate or high quality. A meta-analysis was not conducted due to heterogeneity in exposure and health outcome. Overall, studies on short-term exposure to air pollutants (carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2) and particulate matter ≤10 µm (PM10)) were associated with increased childhood respiratory consultations in primary care. In general, exposure to ozone was associated with a reduction in respiratory consultations.

CONCLUSIONS

The evidence suggests CO, SO2, NO2, PM10 and PM2.5 are risk factors for respiratory diseases in children in primary care in the short term. However, given the heterogeneity of the studies, interpretation of these findings must be done with caution.

PROSPERO REGISTRATION NUMBER

CRD42022259279.

The association between air pollutions and emergency hospitalizations due to COPD and asthma across 16 Polish cities: population-based study

OBJECTIVES

In recent years numerous initiatives aimed at reducing air pollution have been undertaken in Poland. The general objective was to examine the correlation between air pollution measured by the level of particulate matter ≤10 μm in diameter (PM10) and emergency hospitalizations due to chronic obstructive pulmonary disease (COPD) and asthma in 16 Polish cities (capitals of the regions).

MATERIAL AND METHODS

The authors aimed to diagnose the situation across 16 cities over a 5‑year period (2014-2019). Data on the number of hospitalizations was retrieved from the national public insurance system, the National Health Fund. A total number of 22 600 emergency hospitalizations was analyzed (12 000 and 10 600 in 2014 and 2019, respectively). The data on air pollution was accessed via the public register of the Chief Inspectorate for Environmental Protection air quality database. The authors of this article have used the data on PM10 daily exposure in each of the 16 cities in 2014 and 2019. Statistical methods included: non-parametric tests, a 2-stage modelling approach for time-series data, and multivariate meta-analysis of the results.

RESULTS

The results indicated that there was a statistically significant decrease in PM10 concentration in 2019 in comparison to 2014 in all cities, mainly in the autumn and winter season. However, the correlation between the improvement in the air quality and a decrease in emergency hospitalizations due to asthma and COPD turned out to not be as strong as expected. The authors observed a strong correlation between PM10 concentrations and hospitalizations due to asthma and COPD, but only when air quality norms were significantly above acceptable levels.

CONCLUSIONS

Air pollution measured by PM10 concentration might be used as one of the predictors of the asthma and COPD emergency hospitalization risk, yet other factors like respiratory tract infection, health care organizational aspect, patient self-control, compliance and comorbidities should also be taken into consideration. Int J Occup Med Environ Health. 2024;37(1):110-27.

Short-term effects of air pollutants on hospital admissions for asthma among older adults: a multi-city time series study in Southwest, China

Background

This study aimed to explore the relationship between air pollution and hospital admissions for asthma in older adults, and to further assess the health and economic burden of asthma admissions attributable to air pollution.

Methods

We collected information on asthma cases in people over 65 years of age from nine cities in Sichuan province, as well as air pollution and meteorological data. The relationship between short-term air pollutant exposure and daily asthma hospitalizations was analyzed using the generalized additive model (GAM), and stratified by gender, age, and season. In addition, we assessed the economic burden of hospitalization for air pollution-related asthma in older adults using the cost of disease approach.

Results

The single pollutant model showed that every 1 mg/m3 increase in CO was linked with an increase in daily hospitalizations for older adults with asthma, with relative risk values of 1.327 (95% CI: 1.116-1.577) at lag7. Each 10 μg/m3 increase in NO2, O3, PM10, PM2.5 and SO2, on asthma hospitalization, with relative risk values of 1.044 (95% CI: 1.011-1.078), 1.018 (95% CI: 1.002-1.034), 1.013 (95% CI: 1.004-1.022), 1.015 (95% CI: 1.003-1.028) and 1.13 (95% CI: 1.041-1.227), respectively. Stratified analysis shows that stronger associations between air pollution and asthma HAs among older adult in females, those aged 65-69 years, and in the warm season, although all of the differences between subgroups did not reach statistical significance. During the study period, the number of asthma hospitalizations attributable to PM2.5, PM10, and NO2 pollution was 764, 581 and 95, respectively, which resulted in a total economic cost of 6.222 million CNY, 4.73 million CNY and 0.776 million CNY, respectively.

Conclusion

This study suggests that short-term exposure to air pollutants is positively associated with an increase in numbers of asthma of people over 65 years of age in Sichuan province, and short-term exposure to excessive PM and NO2 brings health and economic burden to individuals and society.

Exploring the link between particulate matter pollution and acute respiratory infection risk in children using generalized estimating equations analysis: a robust statistical approach

BACKGROUND

India is facing a burdensome public health challenge due to air pollution, with a particularly high burden of acute respiratory infections (ARI) among children. To address this issue, our study aims to evaluate the association between exposure to fine particulate matter (PM2.5) and ARI incidence in young children in India.

MATERIALS AND METHODS

Our study used PM2.5 data provided by the Atmospheric Composition Analysis Group at Washington University to assess the association between PM2.5 exposure and ARI incidence in 223,375 children sampled from the 2019-2021 Demographic Health Survey in India. We employed the generalized estimating equation and reported odds ratios and 95% confidence intervals for a 10 µg/m3 increase in PM2.5 and quartiles of PM2.5 exposure.

RESULTS

Each 10 µg/m3 increase in PM2.5 levels was associated with an increased odds of ARI (OR: 1.23, 95% CI: 1.19-1.27). A change from the first quartile of PM2.5 (2.5-34.4 µg/m3) to the second quartile (34.5-51.5 µg/m3) of PM2.5 was associated with a two-fold change (OR: 2.06, 95% CI: 1.60-2.66) in the odds of developing ARI. Similarly, comparing the first quartile to the fourth quartile of PM2.5 exposure (78.3-128.9 µg/m3) resulted in an over four-fold increase in the odds of ARI (OR: 4.45, 95% CI: 3.37-5.87).

CONCLUSION

Mitigation efforts must be continued implementing higher restrictions in India and to bring new interventions to ensure safe levels of air for reducing the burden of disease and mortality associated with air pollution in India.

Impact of family socioeconomic position on childhood asthma outcomes, severity, and specialist referral - a Danish nationwide study

BACKGROUND

Asthma is the most common chronic illness in children, carrying a major burden. Socioeconomic position (SEP) affects adult asthma outcomes, but its impact on childhood asthma, particularly in primary versus specialist care, has not been studied thoroughly.

METHODS

In a Danish cohort consisting of all children aged 2-17 years redeeming inhaled corticosteroids in 2015, parental SEP impact on asthma outcomes was investigated. Workforce attachment, income, education, and metropolitan residence were chosen as covariates in logistic regression. Outcomes were uncontrolled (excessive use of short-acting beta2-agonists), exacerbating (oral corticosteroid use or hospitalization), and severe asthma (according to GINA 2020).

RESULTS

The cohort comprised 29,851 children (median age 8.0, 59% boys). 16% had uncontrolled asthma, 8% had ≥1 exacerbation. Lower income and metropolitan residence correlated with higher odds of poor control, exacerbations, and severe asthma. Lower education correlated with worse asthma outcomes. Education and income were protective factors in primary care, but not in specialist care. Metropolitan residence was the sole factor linked to specialist care referral for severe asthma.

CONCLUSION

Low parental SEP and metropolitan residence associated with poor asthma outcomes. However, specialist care often mitigated these effects, though such care was less likely for at-risk children in non-metropolitan areas.

Relationship between air quality and asthma-related emergency hospital admissions in Mexico City 2017-2019

BACKGROUND

Previous studies found exposure to air pollution leads to exacerbations of asthma in paediatric and adult patients and increases asthma-related emergency hospital admissions (AREHA).

METHODS

AREHAs and levels of air pollutants (PM10, PM2.5 and NO2) were obtained from Mexico City for the period 2017-2019. A time-series approach was used to explore the relationship between air pollutants and AREHA. Relative risks of AREHA were estimated using a negative binomial regression in young children (less than 5 years) and adults (greater than 18 years).

RESULTS

There was a positive association between AREHA and PM10, PM2.5 and NO2 in adults, which remained after mutual adjustment for these pollutants. The relative risk (RR) of admission in adults increased by 3% (95% CI 1% to 4%) for a 10 µg/m3 increase in PM10, 1% (0.03% to 3%) for a 5 µg/m3 increase in PM2.5 and by 1% (0.06% to 2%) for a 5 µg/m3 increase in NO2. In contrast, in young children, AREHAs were negatively associated with PM10 after adjustment for NO2 (RR 0.97 (0.95 to 0.99) for a 10 µg/m3 and with NO2 after adjustment for PM10 and PM2.5 (RR 0.98 (0.96 to 0.99) and 0.97 (0.96 to 0.99), respectively, for a 5 µg/m3 increase in NO2). AREHAs in children were not associated with PM2.5 after adjustment for NO2.

CONCLUSIONS

Ambient air pollution, within the previous week, was associated with emergency hospital admissions for asthma to public hospitals in adults in Mexico City. The relationship in children was less consistent. Further work is needed to explore why differences between adults and children exist to inform appropriate interventions to benefit public health.

Childhood asthma in the Bronx, NY; the impact of pollutants on length of hospital stay

OBJECTIVE

The length of hospital stay (LOS) is a proxy of asthma exacerbation severity and healthcare cost. The study aims to estimate the effect of ambient air pollution on pediatric asthma LOS in the Bronx, NY.

METHODS

A total of 1,920 children admitted to the hospital in Bronx, NY due to asthma during 2017-2019 period were included in the study. Demographic and clinical parameters were obtained from medical records. Daily ozone (O3) and fine particulate matter (PM2.5) measurements were obtained from local air quality networks. Poisson regression adjusting for gender, age, weight status, respiratory infections including influenza, and ambient temperature was applied to determine whether there was an association of air pollution with length of hospital stay.

RESULTS

The mean LOS varied by age, sex, weight status, influenza vaccination status, respiratory viral panel (RVP) results, asthma controller use, and asthma classification. After controlling for these factors in Poisson regression, the mean LOS increased up to 10.62% (95%CI: 0.78-21.41; p = 0.03) for an increase of 10 μg/m3 of PM2.5 exposure on admission day, and 3.90% (95%CI = 0.06-7.88; p = 0.05) for an increase of 10 ppbv of O3 concentration during the previous day.

CONCLUSION

Ambient particulate and ozone pollution is associated with lengthier hospital stays for pediatric asthma, potentially indicating more severe asthma exacerbations.

The impact of air pollution on neurocognitive development: Adverse effects and health disparities

Air pollution is recognized as a major public health concern. The number of deaths related to ambient air pollution has increased in recent years and is projected to continue rising. Additionally, both short- and long-term air pollution exposure has been linked with deleterious effects on neurocognitive function and development. While air pollution poses as a threat to everyone, people of color and individuals of lower socioeconomic status are often exposed to elevated levels of air pollution as a function of systemic racism and classism. Further, given additional disparities in access to healthcare and other compounding stressors, adverse effects of air pollution on neurocognitive health are exacerbated among individuals who hold marginalized identities-making effects both less likely to be detected and treated. This review examines evidence of the effects of air pollution on neurocognitive development across the lifespan and incorporates an environmental justice perspective to highlight disparities in air pollution exposure across race and socioeconomic status. Last, upon the reviewed evidence, limitations of past research and recommendations for policy are discussed.

Impact of air pollution changes and meteorology on asthma outpatient visits in a megacity in North China Plain

The effects of air pollution and meteorology on asthma is less studied in North China Plain. In the last decade, air quality in this region is markedly mitigated. This study compared the short-term effects of air pollutants on daily asthma outpatient visits (AOV) within different sex and age groups from 2014 to 2016 and 2017-2019 in Tianjin, with the application of distributed lag nonlinear model. Moreover, relative humidity (RH) and temperature as well as the synergistic impact with air pollutants were assessed. Air pollutants-associated risk with linear (different reference values were used) and non-linear assumptions were compared. In 2014-2016, PM10 and PM2.5 exhibited a larger impact on AOV, with the corresponding cumulative excess risks (ER) for every 10 μg/m3 increase at 1.04 % (95%CI:0.67-1.40 %, similarly hereafter) and 0.79 % (0.35-1.23 %), as well as increased to 43 % (26-63 %) and 20 % (10-31 %) at severe pollution. In 2017-2019, NO2 and MDA8 O3 exhibited a larger impact on AOV, with a cumulative ER for every 10 μg/m3 increase at 1.0 (0.63-1.4 %) and 0.36 % (0.15-0.57 %), with corresponding values of 7.9 % (4.8-11 %) and 5.6 % (2.3-9.0 %), at severe pollution. SO2 associated risk was only significant from 2014 to 2016. Cold effect, including extremely low temperature exposure and sharp temperature drop could generate a pronounced increase in AOV at 9.6 % (3.8-16 %) and 24 % (9.1-41 %), respectively. Moderate low temperature combined with air pollutants can enhance AOV during winter. Higher temperature in spring and autumn could trigger asthma by increasing pollen levels. Low RH resulted in AOV increase by 4.6 % (2.4-6.9), while higher RH generated AOV increase by 3.4 % (1.6-5.3). Females, children, and older adults tended to have a higher risk for air pollution, non-optimum temperature, and RH. As air pollution-associated risks on AOV tends to be weaker due to air quality improvement in recent years, the impact of extreme meteorological condition amidst climate change on asthma visits warrants further attention.

The association between PM2.5 concentration and the severity of acute asthmatic exacerbation in hospitalized children: A retrospective study in Chongqing, China

BACKGROUND

Ambient PM2.5 is associated with asthma exacerbation. The association between the concentration of PM2.5 and the severity of asthma exacerbation has yet to be thoroughly clarified. The study aims to explore the association between the piror 30 days average concentration of PM2.5 and the severity of acute asthma exacerbation in hospitalized children.

METHODS

A total of 269 children with acute exacerbation of asthma were enrolled and divided into three groups according to the PM2.5 exposure concentrations: group 1 (PM2.5: <37.5 μg/m3 ), group 2 (PM2.5: 37.5-75 μg/m3 ), group 3 (PM2.5: ≥75 μg/m3 ), respectively. The ordered logistic regression modeling was conducted to explore the influence of daily PM2.5 concentration on the clinical severity of children's asthma exacerbation. Multiple linear regression was conducted to explore the association between the concentration of PM2.5 and the length of stay in the hospital (LOS). We also conducted a receiver operating characteristic (ROC) curve analysis to explore the cutoff value of PM2.5 to predict the children's asthma exacerbation.

RESULTS

There was no statistical difference among the three groups of children in gender, age, body mass index, ethnicity, the first diagnosis of asthma, allergic history, passive smoke exposure, or family history of asthma. There was a statistically significant difference in many hospitalization characteristics (p < 0.05) among the three groups of children. Significant differences were found in terms of accessory muscles of respiration (p = 0.005), respiratory failure (p = 0.012), low respiratory tract infectious (p = 0.020), and the severity of asthma exacerbation (p < 0.001) among the three groups. PM2.5 concentration was primarily positively correlated to neutrophile inflammation. The ordered multivariate logistic regression model showed that higher PM2.5 concentrations were significantly associated with greater odds of more severe asthma exacerbation in one and two-pollutant models. The adjusted odds ratio of severe asthma exacerbation was 1.029 (1.009, 1.049) in the one-pollutant model. The most significant odds ratio of severe asthma exacerbation was 1.050 (1.027, 1.073) when controlling NO2 in the two-pollutant models. Multiple linear regression showed that PM2.5 concentration was significantly associated with longer LOS in both one-pollutant and two-pollutant models. By performing ROC analysis, the average daily concentration of 44.5 µg/m3 of PM2.5 (AUC = 0.622, p = 0.002) provided the best performance to predict severe asthma of children exacerbation with a sensitivity of 59.2% and a specificity of 63.8%.

CONCLUSION

The increased prior 30 days average concentration of PM2.5 was associated with greater asthma exacerbation severity and longer length of stay in the hospital of children with asthma exacerbation.

Analyzing and Forecasting Pediatric Fever Clinic Visits in High Frequency Using Ensemble Time-Series Methods After the COVID-19 Pandemic in Hangzhou, China: Retrospective Study

BACKGROUND

The COVID-19 pandemic has significantly altered the global health and medical landscape. In response to the outbreak, Chinese hospitals have established 24-hour fever clinics to serve patients with COVID-19. The emergence of these clinics and the impact of successive epidemics have led to a surge in visits, placing pressure on hospital resource allocation and scheduling. Therefore, accurate prediction of outpatient visits is essential for informed decision-making in hospital management.

OBJECTIVE

Hourly visits to fever clinics can be characterized as a long-sequence time series in high frequency, which also exhibits distinct patterns due to the particularity of pediatric treatment behavior in an epidemic context. This study aimed to build models to forecast fever clinic visit with outstanding prediction accuracy and robust generalization in forecast horizons. In addition, this study hopes to provide a research paradigm for time-series forecasting problems, which involves an exploratory analysis revealing data patterns before model development.

METHODS

An exploratory analysis, including graphical analysis, autocorrelation analysis, and seasonal-trend decomposition, was conducted to reveal the seasonality and structural patterns of the retrospective fever clinic visit data. The data were found to exhibit multiseasonality and nonlinearity. On the basis of these results, an ensemble of time-series analysis methods, including individual models and their combinations, was validated on the data set. Root mean square error and mean absolute error were used as accuracy metrics, with the cross-validation of rolling forecasting origin conducted across different forecast horizons.

RESULTS

Hybrid models generally outperformed individual models across most forecast horizons. A novel model combination, the hybrid neural network autoregressive (NNAR)-seasonal and trend decomposition using Loess forecasting (STLF), was identified as the optimal model for our forecasting task, with the best performance in all accuracy metrics (root mean square error=20.1, mean absolute error=14.3) for the 15-days-ahead forecasts and an overall advantage for forecast horizons that were 1 to 30 days ahead.

CONCLUSIONS

Although forecast accuracy tends to decline with an increasing forecast horizon, the hybrid NNAR-STLF model is applicable for short-, medium-, and long-term forecasts owing to its ability to fit multiseasonality (captured by the STLF component) and nonlinearity (captured by the NNAR component). The model identified in this study is also applicable to hospitals in other regions with similar epidemic outpatient configurations or forecasting tasks whose data conform to long-sequence time series in high frequency exhibiting multiseasonal and nonlinear patterns. However, as external variables and disruptive events were not accounted for, the model performance declined slightly following changes in the COVID-19 containment policy in China. Future work may seek to improve accuracy by incorporating external variables that characterize moving events or other factors as well as by adding data from different organizations to enhance algorithm generalization.

Ozone Pollution and Acute Exacerbation of Asthma in Residents of China: An Ecological Study

Purpose

The evidence for a causal relationship between high-level ozone (O3) exposure and acute exacerbation of asthma among adults is limited, and the conclusions are less definitive.

Patients and methods

Here we collected the daily data on asthma cases, O3 exposure, and meteorological factors from 2010 to 2016 in Shijiazhuang, China. We investigated the risk of asthma exacerbation associated with high-level ozone exposure using a polynomial distributed lag model (PDLM). Using a generalized additive model (GAM), we estimated the interactive effects between O3 and other pollutants as well as meteorological factors on asthma exacerbation.

Results

A total of 7270 patients with asthma were enrolled from 22 governmental hospitals in 13 counties. Each 10 μg/m3 increase in O3 concentration on the exacerbation of asthma was associated with a 1.92% (95% CI = 0.80-3.03%) higher risk of asthma exacerbation on day lag 7. The cumulative risk of O3 on asthma exacerbation increased by 18.9% (95% CI = 12.8-25.4%) on the 14th day. High consecutive levels of O3 increase the risk of asthma exacerbation, and the interactive effect of O3 and sulfur dioxide (SO2) appears before the exacerbation onset.

Conclusion

These findings suggested that O3 should be an important risk factor for asthma exacerbation, and health benefits in reducing asthma exacerbation risk would be gained with continued efforts to improve the air quality in China.

Neighborhood violence and socioeconomic deprivation influence associations between acute air pollution and temperature on childhood asthma in New York city

Ambient air pollution, temperature, and social stressor exposures are linked with asthma risk, with potential synergistic effects. We examined associations for acute pollution and temperature exposures, with modification by neighborhood violent crime and socioeconomic deprivation, on asthma morbidity among children aged 5-17 years year-round in New York City. Using conditional logistic regression in a time-stratified, case-crossover design, we quantified percent excess risk of asthma event per 10-unit increase in daily, residence-specific exposures to PM2.5, NO2, SO2, O3, and minimum daily temperature (Tmin). Data on 145,834 asthma cases presenting to NYC emergency departments from 2005 to 2011 were obtained from the New York Statewide Planning and Research Cooperative System (SPARCS). Residence- and day-specific spatiotemporal exposures were assigned using the NYC Community Air Survey (NYCCAS) spatial data and daily EPA pollution and NOAA weather data. Point-level NYPD violent crime data for 2009 (study midpoint) was aggregated, and Socioeconomic Deprivation Index (SDI) scores assigned, by census tract. Separate models were fit for each pollutant or temperature exposure for lag days 0-6, controlling for co-exposures and humidity, and mutually-adjusted interactions (modification) by quintile of violent crime and SDI were assessed. We observed stronger main effects for PM2.5 and SO2 in the cold season on lag day 1 [4.90% (95% CI: 3.77-6.04) and 8.57% (5.99-11.21), respectively]; Tmin in the cold season on lag day 0 [2.26% (1.25-3.28)]; and NO2 and O3 in the warm season on lag days 1 [7.86% (6.66-9.07)] and 2 [4.75% (3.53-5.97)], respectively. Violence and SDI modified the main effects in a non-linear manner; contrary to hypotheses, we found stronger associations in lower-violence and -deprivation quintiles. At very high stressor exposures, although asthma exacerbations were highly prevalent, pollution effects were less apparent-suggesting potential saturation effects in socio-environmental synergism.

The Impact of Climate Change on Asthma and Allergic-Immunologic Disease

PURPOSE OF REVIEW

This review discusses climate change-related impacts on asthma and allergic-immunologic disease, relevant US public health efforts, and healthcare professional resources.

RECENT FINDINGS

Climate change can impact people with asthma and allergic-immunologic disease through various pathways, including increased exposure to asthma triggers (e.g., aeroallergens, ground-level ozone). Climate change-related disasters (e.g., wildfires, floods) disrupting healthcare access can complicate management of any allergic-immunologic disease. Climate change disproportionately affects some communities, which can exacerbate disparities in climate-sensitive diseases like asthma. Public health efforts include implementing a national strategic framework to help communities track, prevent, and respond to climate change-related health threats. Healthcare professionals can use resources or tools to help patients with asthma and allergic-immunologic disease prevent climate change-related health impacts. Climate change can affect people with asthma and allergic-immunologic disease and exacerbate health disparities. Resources and tools are available to help prevent climate change-related health impacts at the community and individual level.

Increase in daily asthma medication sales in association with air pollution levels in Greater Stockholm

Daily air pollution levels are known to influence the number of patients with acute asthma. We investigated the short-term effects of air pollution exposure on the daily number of asthma medication purchases in the Greater Stockholm area, Sweden.

Methods

We conducted a time-series study with data on asthma medication purchases and daily mean values of particulate matter ≤10 µm (PM10), nitrogen oxides (NOx), and ozone during 2018-2019. We used nonlinear distributed lag quasi-Poisson regression models to estimate the associations between air pollution levels and medication purchases, adjusting for meteorological variables, pollen levels, day of the week, and long-term trends. The models established linear relationships between air pollutants and the outcome, and potential delayed effects were smoothed with a spline across a lag period of 2 weeks. We applied separate models for each municipality (n = 21) in Greater Stockholm, and calculated pooled estimates to achieve combined results for the whole region.

Results

We observed associations between daily levels of air pollution and purchases of asthma medications, most clearly for PM10. The pooled estimates of the relative risks for asthma medication purchases across all 21 municipalities associated with a 10 μg m-3 increase in PM10 the same day (lag 0) was 1.7% [95% confidence interval (CI): 1.2%, 2.1%], a cumulative increase of 4.6% (95% CI: 3.7%, 5.6%) over one week (lag 0-6), and a 6.5% (95% CI: 5%, 8%) increase over 2 weeks (lag 0-13). The corresponding pooled effect per 10 μg m-3 increase in NOx and ozone were 2.8% (95% CI: 1.6%, 4.1%) and 0.7% (95% CI: 0%, 1.4%) over 2 weeks (lag 0-13), respectively.

Conclusions

Our study revealed short-term associations between air pollution, especially PM10, and purchases of asthma medications.

Effects of Ambient Air Pollutants on Hospital Admissions among Children Due to Asthma and Wheezing-Associated Lower Respiratory Infections in Mysore, India: A Time Series Study

Air pollutants are known to trigger asthma and wheezing-associated lower respiratory infections in children, but evidence regarding their effect on hospital admissions in India is limited. We conducted a time-series study over a period of five years to assess the role of ambient air pollutants in daily asthma-related hospital admissions in children in Mysore, India. Daily asthma and wheeze (associated with lower respiratory infections) admissions were modelled using a generalised additive model (GAM) to examine the non-linear effects and generalised linear models (GLM) for linear effects, if any. Models were adjusted by day of the week and lag days, with smooth terms for time, maximum temperature, and relative humidity, and they were stratified by sex and age group. Of the 362 children admitted, more than 50% were boys, and the mean age was 5.34 years (±4.66). The GAMs showed non-linear associations between NO2, PM2.5, and NH3. For example, a 10 µgm-3 (or 10%) increase in NO2 increased admissions by 2.42. These non-linear effects were more pronounced in boys. A linear effect was detected for PM10 with a relative risk (95% CI) of 1.028, 1.013, and 1.043 with admission. Further research is needed to explore whether these findings can be replicated in different cities in India. Air pollution needs to be controlled, and policies that focus on lower cut-off levels for vulnerable populations are necessary.

Long-term exposure to outdoor air pollution and asthma in low-and middle-income countries: A systematic review protocol

BACKGROUND

Several epidemiological studies have examined the risk of asthma and respiratory diseases in association with long-term exposure to outdoor air pollution. However, little is known regarding the adverse effects of long-term exposure to outdoor air pollution on the development of these outcomes in low- and middle-income countries (LMICs). Our study aims to investigate the association between long-term exposure to outdoor air pollution and asthma and respiratory diseases in LMICs through a systematic review with meta-analysis.

METHODS

This systematic review and meta-analysis will follow the PRISMA (Preferred Reporting for Systematic Reviews and Meta-Analyses) checklist and flowchart guidelines. The inclusion criteria that will be used in our study are 1) Original research articles with full text in English; 2) Studies including adult humans; 3) Studies with long-term air pollution assessment in LMICs, air pollutants including nitrogen oxide (NO2), sulfur oxide (SO2), particulate matter (PM2.5 and PM10), carbon monoxide (CO) and ozone (O3); 4) cohort and cross-sectional studies; 5) Studies reporting associations between air pollution and asthma and respiratory symptoms. A comprehensive search strategy will be used to identify studies published up till August 2022 and indexed in Embase, Medline, and Web of Science. Three reviewers will independently screen records retrieved from the database searches. Where there are enough studies with similar exposure and outcomes, we will calculate, and report pooled effect estimates using meta-analysis.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022311326.

DISCUSSION

Findings from the health effects of long-term exposure to outdoor air pollution may be of importance for policymakers. This review will also identify any gaps in the current literature on this topic in LMICs and provide direction for future research.

The clinical characteristics of patients with asthma exposed to different environmental risk factors: A cross-sectional study

BACKGROUND

Smoking, biomass, and occupational exposure are the main environmental risk factors for asthma. The purpose of this study was to analyze the clinical characteristics of exposure to these risk factors in patients with asthma.

METHODS

This cross-sectional study enrolled patients with asthma from an outpatient department according to the Global Initiative for Asthma. Demographics, forced expiratory volume in 1 s (FEV1), FEV1%pred, FEV1/forced vital capacity (FVC), laboratory tests, asthma control test (ACT), asthma control questionnaire (ACQ) scores, and the inhaled corticosteroid (ICS) dose were recorded. A generalized linear mixed model was used to adjust for potential confounders.

RESULTS

A total of 492 patients with asthma were included in this study. Of these patients, 13.0% were current smokers, 9.6% were former smokers, and 77.4% were never smokers. Compared with never smokers, the current and former smokers had a longer duration of asthma; lower ACT scores, FEV1, FEV1%pred, and FEV1/FVC; and higher ACQ scores, IgE, FeNO, blood eosinophils, and ICS dose (p < .05). In addition, the patients exposed to biomass alone were older; had higher exacerbation in the past year; a longer duration of asthma; and lower FEV1, FEV1%pred, FEV1/FVC, IgE, and FeNO compared with smoking or occupational exposure alone. Compared with smoking exposure alone, patients with occupational exposure alone had a longer duration of asthma and lower FEV1, FEV1%pred, FVC, IgE, FeNO, and ICS dose (p < .05).

CONCLUSIONS

There are significant differences in the clinical characteristics of patients with asthma depending on the smoking status. In addition, significant differences also observed among smoking, biomass, and occupational exposure.

Are children with sickle cell disease at particular risk from the harmful effects of air pollution? Evidence from a large, urban/peri-urban cohort

INTRODUCTION

Pathophysiologic pathways of sickle cell disease (SCD) and air pollution involve inflammation, oxidative stress, and endothelial damage. It is therefore plausible that children with SCD are especially prone to air pollution's harmful effects.

METHODS

Patient data were collected from a single-center, urban/peri-urban cohort of children with confirmed SCD. Daily ambient concentrations of particulate matter (PM2.5 ) were collected via satellite-derived remote-sensing technology, and carbon monoxide (CO), nitrogen dioxide (NO2 ), and ozone from local monitoring stations. We used multivariable regression to quantify associations of pollutant levels and daily counts of emergency department (ED) visits, accounting for weather and time trends. For comparison, we quantified the associations of pollutant levels with daily all-patient (non-SCD) ED visits to our center.

RESULTS

From 2010 to 2018, there were 17,731 ED visits by 1740 children with SCD (64.8% HbSS/HbSβ0 ). Vaso-occlusive events (57.8%), respiratory illness (17.1%), and fever (16.1%) were the most common visit diagnoses. Higher 3-day (lags 0-2) rolling mean PM2.5 and CO levels were associated with daily ED visits among those with SCD (PM2.5 incident rate ratio [IRR] 1.051 [95% confidence interval: 1.010-1.094] per 9.4 μg/m3 increase; CO 1.088 [1.045-1.132] per 0.5 ppm). NO2 showed positive associations in secondary analyses; ozone levels were not associated with ED visits. The comparison, all-patient ED visit analyses showed lower IRR for all pollutants.

CONCLUSIONS

Our results suggest short-term air pollution levels as triggers for SCD events and that children with SCD may be more vulnerable to air pollution than those without SCD. Targeted pollution-avoidance strategies could have significant clinical benefits in this population.

Short-term associations of low-level fine particulate matter (PM2.5) with cardiorespiratory hospitalizations in 139 Japanese cities

There have been few studies in non-western countries on the relationship between low levels of daily fine particulate matter (PM_2.5) exposure and morbidity or mortality, and the impact of PM_2.5 concentrations below 15 μg/m³, which is the latest World Health Organization Air Quality Guideline (WHO AQG) value for the 24-h mean, is not yet clear. We assessed the associations between low-level PM_2.5 exposure and cardiorespiratory admissions in Japan. We collected the daily hospital admission count data, air pollutant data, and meteorological condition data recorded from April 2016 to March 2019 in 139 Japanese cities. City-specific estimates were obtained from conditional logistic regression models in a time-stratified case-crossover design and pooled by random-effect models. We estimated that every 10-μg/m³ increase in the concurrent-day PM_2.5 concentration was related to a 0.52% increase in cardiovascular admissions (95% CI: 0.13-0.92%) and a 1.74% increase in respiratory admissions (95% CI: 1.41-2.07%). These values were nearly the same when the datasets were filtered to contain only daily PM_2.5 concentrations <15 μg/m³. The exposure-response curves showed approximately sublinear-to-linear curves with no indication of thresholds. These associations with cardiovascular diseases weakened after adjusting for nitrogen dioxide or sulfur dioxide, but associations with respiratory diseases were almost unchanged when additionally adjusted for other pollutants. This study demonstrated that associations between daily PM_2.5 and daily cardiorespiratory hospitalizations might persist at low concentrations, including those below the latest WHO AQG value. Our findings suggest that the updated guideline value may still be insufficient from the perspective of public health.

Spatial distribution of hospital admissions for asthma in the central area of Asturias, Northern Spain

BACKGROUND

Asturias is one of the communities with the highest rates of hospital admission for asthma in Spain. The environmental pollution or people lifestyle are some of the factors that contribute to the appearance or aggravation of this illness. The aim of this study was to show the spatial distribution of asthma admissions risks in the central municipalities of Asturias and to analyze the observed spatial patterns.

METHODS

Urgent hospital admissions for asthma and status asthmaticus occurred between 2016 to 2018 on the public hospitals of the central area of Asturias were used. Population data were assigned in 5 age groups. Standardised admission ratio (SAR), smoothed relative risk (SRR) and posterior risk probability (PP) were calculated for each census tract (CT). A spatial trend analysis was run, a spatial autocorrelation index (Morans I) was calculated and a cluster and outlier analysis (Anselin Local Morans I) was finally performed in order to analyze spatial clusters.

RESULTS

The total number of hospital urgent asthma admissions during the study period was 2324, 1475 (63.46%) men and 849 (36.56%) women. The municipalities with the highest values of SRR and PP were located on the northwest area: Avilés, Gozón, Carreño, Corvera de Asturias, Castrillón and Illas. A high risk cluster was found for the municipalities of Avilés, Gozón y Corvera de Asturias.

CONCLUSIONS

The spatial analysis showed high risk of hospitalization for asthma on the municipalities of the northwest area of the study, which highlight the existence of spatial inequalities on the distribution of urgent hospital admissions.

MitoQ ameliorates PM2.5-induced pulmonary fibrosis through regulating the mitochondria DNA homeostasis

Pulmonary fibrosis is a severe pulmonary disease, and may related to PM_2.5 exposure. Our study aims to explore the pathogenesis of PM_2.5-induced pulmonary fibrosis, and MitoQ protective effect in this process. Our results find that inflammatory cells aggregation and pulmonary fibrosis in mice lung after PM_2.5 exposure. Moreover, Collagen I/III overproduction, EMT and TGF-β1/Smad2 pathway activation in mice lung and BEAS-2B after PM_2.5 exposure. Fortunately, these changes were partially ameliorated after MitoQ treatment. Meanwhile, severe oxidative stress, mitochondrial homeostasis imbalance, overproduction of 8-oxoG (7,8-dihydro-8-oxoguanine), as well as the inhibition of SIRT3/OGG1 pathway have founded in mice lung or BEAS-2B after PM_2.5 exposure, which were alleviated by MitoQ treatment. Collectively, our study found that oxidative stress, especially mitochondrial oxidative stress participates in the PM_2.5-induced pulmonary fibrosis, and MitoQ intervention had a protective effect on this progress. Moreover, mitochondrial DNA homeostasis might participate in the pulmonary fibrosis caused by PM_2.5 exposure. Our study provides a novel pathogenesis of PM_2.5-caused pulmonary fibrosis and a possible targeted therapy for the pulmonary diseases triggered by PM_2.5.

Establishment of an artificial particulate matter-induced lung disease model through analyzing pathological changes and transcriptomic profiles in mice

Particulate matter (PM), an environmental risk factor, is linked with health risks such as respiratory diseases. This study aimed to establish an animal model of PM-induced lung injury with artificial PM (APM) and identify the potential of APM for toxicological research. APM was generated from graphite at 600 °C and combined with ethylene. We analyzed diesel exhaust particulate (DEP) and APM compositions and compared toxicity and transcriptomic profiling in lungs according to the exposure. For the animal study, C57BL/6 male mice were intratracheally administered vehicle, DEP, or APM. DEP or APM increased relative lung weight, inflammatory cell numbers, and inflammatory protein levels compared with the vehicle control. Histological assessments showed an increase in particle-pigment alveolar macrophages and slight inflammation in the lungs of DEP and APM mice. In the only APM group, granulomatous inflammation, pulmonary fibrosis, and mucous hyperplasia were observed in the lungs of some individuals. This is the first study to compare pulmonary toxicity between DEP and APM in an animal model. Our results suggest that the APM-treated animal model may contribute to understanding the harmful effects of PM in toxicological studies showing that APM can induce various lung diseases according to different doses of APM.

Social determinants of health and asthma

PURPOSE OF REVIEW

Social determinants of health play a major role in healthcare utilization and outcomes in patients with asthma. Continuing to understand how these complex and interwoven relationships interact to impact patient care will be crucial to creating innovative programmes that address these disparities.

RECENT FINDINGS

The current literature continues to support the association of substandard housing, urban and rural neighbourhoods, and race/ethnicity with poor asthma outcomes. Targeted interventions with community health workers (CHWs), telemedicine and local environmental rectifications can help improve outcomes.

SUMMARY

The link between social determinants and poor asthma outcomes continues to be supported by recent literature. These factors are both nonmodifiable and consequences of institutionalized racist policies that require innovative ideas, technologic equity and funding for groups most at risk for poorer outcomes.

Acute Effects of Ambient Air Pollution on Asthma Emergency Department Visits in Ten U.S. States

BACKGROUND

Previous studies of short-term ambient air pollution exposure and asthma morbidity in the United States have been limited to a small number of cities and/or pollutants and with limited consideration of effects across ages.

OBJECTIVES

To estimate acute age group-specific effects of fine and coarse particulate matter (PM), major PM components, and gaseous pollutants on emergency department (ED) visits for asthma during 2005-2014 across the United States.

METHODS

We acquired ED visit and air quality data in regions surrounding 53 speciation sites in 10 states. We used quasi-Poisson log-linear time-series models with unconstrained distributed exposure lags to estimate site-specific acute effects of air pollution on asthma ED visits overall and by age group (1-4, 5-17, 18-49, 50-64, and 65+ y), controlling for meteorology, time trends, and influenza activity. We then used a Bayesian hierarchical model to estimate pooled associations from site-specific associations.

RESULTS

Our analysis included 3.19 million asthma ED visits. We observed positive associations for multiday cumulative exposure to all air pollutants examined [e.g., 8-d exposure to PM2.5: rate ratio of 1.016 with 95% credible interval (CI) of (1.008, 1.025) per 6.3-μg/m3 increase, PM10-2.5: 1.014 (95% CI: 1.007, 1.020) per 9.6-μg/m3 increase, organic carbon: 1.016 (95% CI: 1.009, 1.024) per 2.8-μg/m3 increase, and ozone: 1.008 (95% CI: 0.995, 1.022) per 0.02-ppm increase]. PM2.5 and ozone showed stronger effects at shorter lags, whereas associations of traffic-related pollutants (e.g., elemental carbon and oxides of nitrogen) were generally stronger at longer lags. Most pollutants had more pronounced effects on children (<18 y old) than adults; PM2.5 had strong effects on both children and the elderly (>64 y old); and ozone had stronger effects on adults than children.

CONCLUSIONS

We reported positive associations between short-term air pollution exposure and increased rates of asthma ED visits. We found that air pollution exposure posed a higher risk for children and older populations. https://doi.org/10.1289/EHP11661.

Trends in seasonal pollen and asthma-related morbidity among adults and children in a U.S. high-density urban center, 2001-2020

OBJECTIVE

To analyze the long-term trends in pollen counts and asthma-related emergency department visits (AREDV) in adult and pediatric populations in the Bronx.

METHODS

Daily values of adult and pediatric AREDV were retrospectively obtained from three major Bronx hospitals using ICD-10 codes and pollen counts were obtained from the Armonk station from 2001-2020. Wilcoxon Ranked Sum was applied to compare median values, while Spearman correlation was employed to examine the association between these variables, for both decades and each season.

RESULTS

The median value of pediatric AREDV increased by 200% from the 1st to 2nd decade (p < 0.001) and AREDV peak shifted from predominantly the spring season in the 1st decade to the fall and winter seasons in the 2nd decade. Seasonal patterns were consistent over 20 years with summer AREDV lower than all other seasons (9 vs. 17 per day) (p < 0.001). Spring tree pollen peaks were correlated with AREDV peaks (rho = 0.34) (p < 0.001). Tree pollen exceeding 100 grains/m³ corresponded to a median of 19.0 AREDVs while all other tree pollen (0 - 99 grains/m³) corresponded to a median of 15.0 AREDVs (p < 0.001). AREDVs sharply declined in 2020, coinciding with the emergence of COVID-19.

CONCLUSIONS

Pollen and AREDVs peak earlier in the spring and are more strongly interconnected, while asthma rates among children are rapidly rising, particularly in the fall and winter. These findings can advise targeted awareness campaigns for better management of asthma related morbidity.

Short-Term Association between Sulfur Dioxide and Mortality: A Multicountry Analysis in 399 Cities

BACKGROUND

Epidemiological evidence on the health risks of sulfur dioxide (SO 2 ) is more limited compared with other pollutants, and doubts remain on several aspects, such as the form of the exposure-response relationship, the potential role of copollutants, as well as the actual risk at low concentrations and possible temporal variation in risks.

OBJECTIVES

Our aim was to assess the short-term association between exposure to SO 2 and daily mortality in a large multilocation data set, using advanced study designs and statistical techniques.

METHODS

The analysis included 43,729,018 deaths that occurred in 399 cities within 23 countries between 1980 and 2018. A two-stage design was applied to assess the association between the daily concentration of SO 2 and mortality counts, including first-stage time-series regressions and second-stage multilevel random-effect meta-analyses. Secondary analyses assessed the exposure-response shape and the lag structure using spline terms and distributed lag models, respectively, and temporal variations in risk using a longitudinal meta-regression. Bi-pollutant models were applied to examine confounding effects of particulate matter with an aerodynamic diameter of ≤ 10 μ m (PM 10 ) and 2.5 μ m (PM 2.5 ), ozone, nitrogen dioxide, and carbon monoxide. Associations were reported as relative risks (RRs) and fractions of excess deaths.

RESULTS

The average daily concentration of SO 2 across the 399 cities was 11 . 7  μ g / m 3 , with 4.7% of days above the World Health Organization (WHO) guideline limit (40   μ g / m 3 , 24-h average), although the exceedances occurred predominantly in specific locations. Exposure levels decreased considerably during the study period, from an average concentration of 19.0   μ g / m 3 in 1980-1989 to 6.3   μ g / m 3 in 2010-2018. For all locations combined, a 10 - μ g / m 3 increase in daily SO 2 was associated with an RR of mortality of 1.0045 [95% confidence interval (CI): 1.0019, 1.0070], with the risk being stable over time but with substantial between-country heterogeneity. Short-term exposure to SO 2 was associated with an excess mortality fraction of 0.50% [95% empirical CI (eCI): 0.42%, 0.57%] in the 399 cities, although decreasing from 0.74% (0.61%, 0.85%) in 1980-1989 to 0.37% (0.27%, 0.47%) in 2010-2018. There was some evidence of nonlinearity, with a steep exposure-response relationship at low concentrations and the risk attenuating at higher levels. The relevant lag window was 0-3 d. Significant positive associations remained after controlling for other pollutants.

DISCUSSION

The analysis revealed independent mortality risks associated with short-term exposure to SO 2 , with no evidence of a threshold. Levels below the current WHO guidelines for 24-h averages were still associated with substantial excess mortality, indicating the potential benefits of stricter air quality standards. https://doi.org/10.1289/EHP11112.

Environmental risks and sphingolipid signatures in adult asthma and its phenotypic clusters: a multicentre study

BACKGROUND

Adult asthma is phenotypically heterogeneous with unclear aetiology. We aimed to evaluate the potential contribution of environmental exposure and its ensuing response to asthma and its heterogeneity.

METHODS

Environmental risk was evaluated by assessing the records of National Health Insurance Research Database (NHIRD) and residence-based air pollution (particulate matter with diameter less than 2.5 micrometers (PM_2.5) and PM_2.5-bound polycyclic aromatic hydrocarbons (PAHs)), integrating biomonitoring analysis of environmental pollutants, inflammatory markers and sphingolipid metabolites in case-control populations with mass spectrometry and ELISA. Phenotypic clustering was evaluated by t-distributed stochastic neighbor embedding (t-SNE) integrating 18 clinical and demographic variables.

FINDINGS

In the NHIRD dataset, modest increase in the relative risk with time-lag effect for emergency (N=209 837) and outpatient visits (N=638 538) was observed with increasing levels of PM_2.5 and PAHs. Biomonitoring analysis revealed a panel of metals and organic pollutants, particularly metal Ni and PAH, posing a significant risk for current asthma (ORs=1.28-3.48) and its severity, correlating with the level of oxidative stress markers, notably Nε-(hexanoyl)-lysine (r=0.108-0.311, p<0.05), but not with the accumulated levels of PM_2.5 exposure. Further, levels of circulating sphingosine-1-phosphate and ceramide-1-phosphate were found to discriminate asthma (p<0.001 and p<0.05, respectively), correlating with the levels of PAH (r=0.196, p<0.01) and metal exposure (r=0.202-0.323, p<0.05), respectively, and both correlating with circulating inflammatory markers (r=0.186-0.427, p<0.01). Analysis of six phenotypic clusters and those cases with comorbid type 2 diabetes mellitus (T2DM) revealed cluster-selective environmental risks and biosignatures.

INTERPRETATION

These results suggest the potential contribution of environmental factors from multiple sources, their ensuing oxidative stress and sphingolipid remodeling to adult asthma and its phenotypic heterogeneity.

Environmental justice and allergic disease: A Work Group Report of the AAAAI Environmental Exposure and Respiratory Health Committee and the Diversity, Equity and Inclusion Committee

Environmental justice is the concept that all people have the right to live in a healthy environment, to be protected against environmental hazards, and to participate in decisions affecting their communities. Communities of color and low-income populations live, work, and play in environments with disproportionate exposure to hazards associated with allergic disease. This unequal distribution of hazards has contributed to health disparities and is largely the result of systemic racism that promotes segregation of neighborhoods, disinvestment in predominantly racial/ethnic minority neighborhoods, and discriminatory housing, employment, and lending practices. The AAAAI Environmental Exposure and Respiratory Health Committee and Diversity, Equity and Inclusion Committee jointly developed this report to improve allergy/immunology specialists' awareness of environmental injustice, its roots in systemic racism, and its impact on health disparities in allergic disease. We present evidence supporting the relationship between exposure to environmental hazards, particularly at the neighborhood level, and the disproportionately high incidence and poor outcomes from allergic diseases in marginalized populations. Achieving environmental justice requires investment in at-risk communities to increase access to safe housing, clean air and water, employment opportunities, education, nutrition, and health care. Through policies that promote environmental justice, we can achieve greater health equity in allergic disease.

Impacts of pollution heterogeneity on population exposure in dense urban areas using ultra-fine resolution air quality data

Traditional air quality data have a spatial resolution of 1 km or above, making it challenging to resolve detailed air pollution exposure in complex urban areas. Combining urban morphology, dynamic traffic emission, regional and local meteorology, physicochemical transformations in air quality models using big data fusion technology, an ultra-fine resolution modeling system was developed to provide air quality data down to street level. Based on one-year ultra-fine resolution data, this study investigated the effects of pollution heterogeneity on the individual and population exposure to particulate matter (PM_2.5 and PM₁₀), nitrogen dioxide (NO₂), and ozone (O₃) in Hong Kong, one of the most densely populated and urbanized cities. Sharp fine-scale variabilities in air pollution were revealed within individual city blocks. Using traditional 1 km average to represent individual exposure resulted in a positively skewed deviation of up to 200% for high-end exposure individuals. Citizens were disproportionally affected by air pollution, with annual pollutant concentrations varied by factors of 2 to 5 among 452 District Council Constituency Areas (DCCAs) in Hong Kong, indicating great environmental inequities among the population. Unfavorable city planning resulted in a positive spatial coincidence between pollution and population, which increased public exposure to air pollutants by as large as 46% among districts in Hong Kong. Our results highlight the importance of ultra-fine pollutant data in quantifying the heterogeneity in pollution exposure in the dense urban area and the critical role of smart urban planning in reducing exposure inequities.

Air pollution and its effects on emergency room visits in tertiary respiratory care centers in Delhi, India

Environmental pollution has harmful effects on human health, particularly the respiratory system. We aimed to study the impact of daily ambient air pollution on daily emergency room visits for acute respiratory symptoms. This study was conducted in two tertiary respiratory care centres in Delhi, India. Daily counts of emergency room visits were collected. All patients attending the emergency room were screened for acute onset (less than 2 weeks) of respiratory symptoms and were recruited if they were staying in Delhi continuously for at least 4 weeks and having onset (≤2 weeks) of respiratory symptoms. Daily average air pollution data for the study period was obtained from four continuous ambient air quality monitoring stations. A total of 61,285 patients were screened and 11,424 were enrolled from June 2017 to February 2019. Cough and difficulty in breathing were most common respiratory symptoms. Poor air quality was observed during the months of October to December. Emergency room visits with acute respiratory symptoms significantly increased per standard deviation increase in PM10 from lag days 2-7. Increase in wheezing was primarily seen with increase in NO2. Pollutant levels have effect on acute respiratory symptoms and thus influence emergency room visits. *************************************************************** *Appendix Authors list Kamal Singhal,1 Kana Ram Jat,2 Karan Madan,3 Mohan P. George,4 Kalaivani Mani,5 Randeep Guleria,3 Ravindra Mohan Pandey,5 Rupinder Singh Dhaliwal,6 Rakesh Lodha,2 Varinder Singh1 1Department of Paediatrics, Lady Hardinge Medical College and associated Kalawati Saran Children's Hospital, New Delhi, India 2Department of Paediatrics, All India Institute of Medical Sciences, New Delhi, India 3Department of Pulmonary Medicine, Critical Care and Sleep Disorders, All India Institute of Medical Sciences, New Delhi, India 4Department of Environment, Delhi Pollution Control Committee, Kashmere Gate, New Delhi, India 5Department of Biostatistics, All India Institute of Medical Sciences, New Delhi, India 6Department of Non-communicable Diseases, Indian Council of Medical Research, New Delhi, India.

Association of ambient carbon monoxide exposure with hospitalization risk for respiratory diseases: A time series study in Ganzhou, China

Background

Ambient carbon monoxide (CO) exposure is associated with increased mortality and hospitalization risk for total respiratory diseases. However, evidence on the risk of hospitalization for specific respiratory diseases from ambient CO exposure is limited.

Methods

Data on daily hospitalizations for respiratory diseases, air pollutants, and meteorological factors from January 2016 to December 2020 were collected in Ganzhou, China. A generalized additive model with the quasi-Poisson link and lag structures was used to estimate the associations between ambient CO concentration and hospitalizations of total respiratory diseases, asthma, chronic obstructive pulmonary disease (COPD), upper respiratory tract infection (URTI), lower respiratory tract infection (LRTI), and influenza-pneumonia. Possible confounding co-pollutants and effect modification by gender, age, and season were considered.

Results

A total of 72,430 hospitalized cases of respiratory diseases were recorded. Significant positive exposure-response relationships were observed between ambient CO exposure and hospitalization risk from respiratory diseases. For each 1 mg/m³ increase in CO concentration (lag0-2), hospitalizations for total respiratory diseases, asthma, COPD, LRTI, and influenza-pneumonia increased by 13.56 (95% CI: 6.76%, 20.79%), 17.74 (95% CI: 1.34%, 36.8%), 12.45 (95% CI: 2.91%, 22.87%), 41.25 (95% CI: 18.19%, 68.81%), and 13.5% (95% CI: 3.41%, 24.56%), respectively. In addition, the associations of ambient CO with hospitalizations for total respiratory diseases and influenza-pneumonia were stronger during the warm season, while women were more susceptible to ambient CO exposure-associated hospitalizations for asthma and LRTI (all P < 0.05).

Conclusion

In brief, significant positive exposure-response relationships were found between ambient CO exposure and hospitalization risk for total respiratory diseases, asthma, COPD, LRTI, and influenza-pneumonia. Effect modification by season and gender was found in ambient CO exposure-associated respiratory hospitalizations.

Effect of ambient PM2.5 on healthcare utilisation for acute respiratory illness, Melbourne, Victoria, Australia, 2014-2019

Ambient particulate matter (PM_2.5) is an important component of natural and human-generated air pollution and a major contributor to the global burden of disease. Short-term effects of PM_2.5 exposure on respiratory illness have been described but most evidence arises from high pollution settings. We used case-crossover methods to estimate effects of outdoor PM_2.5 levels on emergency department (ED) presentations and hospital admissions for a range of acute respiratory illnesses and age groups in Melbourne, Australia from 2014-2019, with and without adjustment for other pollutants and weather conditions, using daily and one-week averaged lags. We estimated incidence rate ratios for a 10 μg/m³ increase in 7-day average ambient PM_2.5 of 1.043 (95% confidence interval (CI): 1.000-1.089) on ED presentation and 1.013 (95% CI: 0.971-1.056) on hospital admissions for acute respiratory illnesses for patients of any age. We observed distinct temporal patterns in daily lag effect by disease. The largest effects on acute lower respiratory tract infection and asthma were observed in children. Ambient PM_2.5 levels rarely exceeded standards in place at the time. Although uncertainty around most point estimates was relatively wide, these findings are most compatible with adverse health effects of ambient PM_2.5 at levels below currently established Australian national standards.Implications: Understanding the health impacts of air pollution is important for setting air quality targets, as well as for informing robust health system planning. Adverse effects of exposure to outdoor fine particulate matter on human respiratory health have been consistently described. However, most studies have been done in higher-pollution settings. Further, many studies have assessed health effects in broad categories such as all-cause respiratory mortality or hospitalization, and thus lack the granularity to inform detailed health service planning. Our study aimed to estimate effects of outdoor fine particulate matter on emergency department (ED) presentations and hospital admissions for a range of acute respiratory illnesses and age groups in Melbourne, Australia, a city with relatively good air quality by international comparison. Our study estimated consistent effects on both ED presentations and hospital admissions compatible with distinct patterns of adverse health effects at levels at or below established Australian national (and many international) standards. These results will help to inform both air quality policy and public health policy in similar settings.

Health impact assessments of shipping and port-sourced air pollution on a global scale: A scoping literature review

BACKGROUND

Globalisation has led to international trade expand rapidly. Seaborne transport moves 80% of traded goods across the globe, producing around 3% of greenhouse gases and other hazardous pollutants, such as PM, NO_x and SO_x, known to be harmful to health.

METHODS

A scoping literature review was conducted reviewing peer-reviewed studies on health impact assessments (HIA) of global shipping and port-sourced air pollution. For review inclusion, studies had to (1) use a HIA methodology; (2) quantify the air pollution concentration attributable to at least one shipping or port activity scenario; (3) assess at least one health outcome (i.e. epidemiological measure or monetization); (4) quantify the attributable health burden of the respective scenario.

RESULTS

Thirty-two studies were included, studying predominantly European Sea shipping/ port-sourced emissions with health impacts for global or respective European populations. Also, Global, Asian, North American and Australian Sea shipping/ port-sourced emissions were studied, with attributable health impacts for global or respective populations. The health outcome predominantly studied was mortality (all-cause, cause-specific, loss in life expectancy, years of life lost (YLLs)), but also morbidity (disease cases, hospital admissions, years lived with disability (YLDs)), disability-adjusted life-years (DALYs), restricted activity days and work loss days. The highest air pollution concentrations were identified along major shipping routes and ports, and the strongest health impacts occurred among respective riparian populations. Globally, ∼265,000 premature deaths were projected for 2020 (∼0.5% of global mortality) attributable to global shipping-sourced emissions. Emission control scenarios studied were predominantly sulphur fuel content caps and NO_x emission reduction scenarios, consisting of technological interventions, cleaner fuels or fuel switches, and were assessed as effective in reducing shipping-sourced emissions, and hence, health burdens.

CONCLUSIONS

Our review positions maritime transport an important source of air pollution and health risk factor, which needs more research and policy attention and rigorous emission control efforts, as shipping-sourced emissions are projected to increase with increases in global trade and shipping volumes.

Effect of Acute PM2.5 Exposure on Lung Function in Children: A Systematic Review and Meta-Analysis

Objective

The objective of this study was to conduct a systematic review and meta-analysis to identify the adverse effects of acute PM2.5 exposure on lung function in children.

Design

Systematic review and meta-analysis. Setting, participants and measures: Eligible studies analyzing PM2.5 level and lung function in children were screened out. Effect estimates of PM2.5 measurements were quantified using random effect models. Heterogeneity was investigated with Q-test and I² statistics. We also conducted meta-regression and sensitivity analysis to explore the sources of heterogeneity, such as different countries and asthmatic status. Subgroup analyses were conducted to determine the effects of acute PM2.5 exposure on children of different asthmatic status and in different countries.

Results

A total of 11 studies with 4314 participants from Brazil, China and Japan were included finally. A 10 μg/m³ increase of PM2.5 was associated with a 1.74L/min (95% CI: -2.68, -0.90) decrease in peak expiratory flow (PEF). Since the asthmatic status and country could partly explain the heterogeneity, we conducted the subgroup analysis. Children with severe asthma were more susceptible to PM2.5 exposure (-3.11 L/min per 10 μg/m³ increase, 95% CI -4.54, -1.67) than healthy children (-1.61 L/min per 10 μg/m³ increase, 95% CI -2.34, -0.91). In the children of China, PEF decreased by 1.54 L/min (95% CI -2.33, -0.75) with a 10 μg/m³ increase in PM2.5 exposure. In the children of Japan, PEF decreased by 2.65 L/min (95% CI -3.82, -1.48) with a 10 μg/m³ increase of PM2.5 exposure. In contrast, no statistic association was found between every 10 μg/m³ increase of PM2.5 and lung function in children of Brazil (-0.38 L/min, 95% CI -0.91, 0.15).

Conclusion

Our results demonstrated that the acute PM2.5 exposure exerted adverse impacts on children's lung function, and children with severe asthma were more susceptible to the increase of PM2.5 exposure. The impacts of acute PM2.5 exposure varied across different countries.

The Effect of Sustained Poor Air Quality on EMS Call Volume and Characteristics: A Time-Stratified Case-Crossover Study

OBJECTIVES

As wildfires and air pollution become more common across the United States, it is increasingly important to understand the burden they place on public health. Previous studies have noted relationships between air quality and use of Emergency Medical Services (EMS), but until now, these studies have focused on day-to-day air quality. The goal of this study is to investigate the effect of sustained periods of poor air quality on EMS call characteristics and volume.

METHODS

Using a time-stratified case-crossover design, the effect of exposure to periods of poor air quality on number and type of EMS calls in California, USA from 2014-2019 was observed. Poor air quality periods greater than three days were identified at the United States Environmental Protection Agency's (EPA's) Air Quality Index (AQI) levels of Unhealthy for Sensitive Groups (AQI 100) and Unhealthy (AQI 150). Periods less than three days apart were combined. Each poor air quality period was matched with two one-week controls, the first being the closest preceding week that did not intersect a different case. The second control was the closest week at least three days after the case and not intersecting with a different case. Due to seasonal variation in EMS usage, from the initial cases, cases were used only if it was possible to identify controls within 28 days of the case. A conditional Poisson regression calculated risk ratios for EMS call volume.

RESULTS

Comparing the case periods to the controls, significant increases were found at AQI >100 for total number of calls, and the primary impressions categories of emotional state or behavior, level of consciousness, no patient complaint, other, respiratory, and abdominal. At an AQI >150, significance was found for the primary impressions categories of other, pain, respiratory, and digestive.

CONCLUSION

These data demonstrate increased EMS calls during sustained poor air quality, and that several EMS primary impression categories are disproportionately affected. This study is limited by the imprecision of the primary impression's classification provided by the EMS clinician responding to the EMS call. More research is needed to understand the effects of periods of poor air quality on the EMS system for more efficient deployment of resources.

Study Protocol. Evaluating the life-course health impact of a city-wide system approach to improve air quality in Bradford, UK: A quasi-experimental study with implementation and process evaluation

BACKGROUND

Air quality is a major public health threat linked to poor birth outcomes, respiratory and cardiovascular disease, and premature mortality. Deprived groups and children are disproportionately affected. Bradford will implement a Clean Air Zone (CAZ) as part of the Bradford Clean Air Plan (B-CAP) in 2022 to reduce pollution, providing a natural experiment. The aim of the current study is to evaluate the impact of the B-CAP on health outcomes and air quality, inequalities and explore value for money. An embedded process and implementation evaluation will also explore barriers and facilitators to implementation, impact on attitudes and behaviours, and any adverse consequences.

METHODS

The study is split into 4 work packages (WP). WP1A: 20 interviews with decision makers, 20 interviews with key stakeholders; 10 public focus groups and documentary analysis of key reports will assess implementation barriers, acceptability and adverse or unanticipated consequences at 1 year post-implementation (defined as point at which charging CAZ goes 'live'). WP1B: A population survey (n = 2000) will assess travel behaviour and attitudes at baseline and change at 1 year post-implementation). WP2: Routine air quality measurements will be supplemented with data from mobile pollution sensors in 12 schools collected by N = 240 pupil citizen scientists (4 within, 4 bordering and 4 distal to CAZ boundary). Pupils will carry sensors over four monitoring periods over a 12 month period (two pre, and two post-implementation). We will explore whether reductions in pollution vary by CAZ proximity. WP3A: We will conduct a quasi-experimental interrupted time series analysis using a longitudinal routine health dataset of > 530,000 Bradford residents comparing trends (3 years prior vs 3 years post) in respiratory health (assessed via emergency/GP attendances. WP3B: We will use the richly-characterised Born in Bradford cohort (13,500 children) to explore health inequalities in respiratory health using detailed socio-economic data. WP4: will entail a multi-sectoral health economic evaluation to determine value for money of the B-CAP.

DISCUSSION

This will be first comprehensive quasi-experimental evaluation of a city-wide policy intervention to improve air quality. The findings will be of value for other areas implementing this type of approach.

TRIAL REGISTRATION

ISRCTN67530835 https://doi.org/10.1186/ISRCTN67530835.

Klimawandel und Kindergesundheit – Ein Aufruf zum Handeln

Der Klimawandel ist eine stille Krise und die größte Bedrohung unserer Zeit. Hitze, Extremwetterereignisse und Luftverschmutzung haben besondere Auswirkungen auf Frühgeburtlichkeit, akute und chronische Atemwegserkrankungen, Allergien und Asthma. Auch die Zunahme infektiöser Erkrankungen sowie eine erhöhte Exposition durch Karzinogene sowie deren Folgen werden beobachtet. Neben der Gefahr des Klimawandels für die somatische, hat die Krise auch Einfluss auf die mentale Gesundheit von Heranwachsenden und aggraviert das soziale Ungleichgewicht, wovon Kinder und Jugendliche in besonderer Weise betroffen sind.

Um die von Wissenschaftler:innen prognostizierten Szenarien abzuwenden, braucht es zum einen ein rasches und umfängliches Agieren der Politik, aber auch ein Neudenken unseres Selbstverständnisses als für Kinder- und Jugendgesundheit Verantwortliche sowie eine grundlegende Neuordnung von Prioritäten. Als Akteur:innen im Gesundheitswesen stehen wir besonders in der Verantwortung, uns für eine gesunde Erde einzusetzen. Dies kann und muss schon heute auf verschiedenen Ebenen, als Ärzt:innen, Wissenschaftler:innen, auf Ebenen der Patient:innenversorgung und der Fachgesellschaften erfolgen, um allen Kindern und Jugendlichen eine lebenswerte Zukunft zu ermöglichen.

Machine Learning-Based Analyses of the Effects of Various Types of Air Pollutants on Hospital Visits by Asthma Patients

Asthma is a chronic respiratory disorder defined by airway inflammation, chest pains, wheezing, coughing, and difficulty breathing that affects an estimated 300 million individuals globally. Although various studies have shown an association between air pollution and asthma, few studies have used statistical and machine learning algorithms to investigate the effect of each individual air pollutant on asthma. The purpose of this research was to assess the association between air pollutants and the frequency of hospital visits by asthma patients using three analysis methods: linear correlation analyses were performed by Pearson correlation coefficients, and least absolute shrinkage and selection operator (LASSO) and random forest (RF) models were used for machine learning-based analyses to investigate the effect of air pollutants. This research studied asthma patients using the hospital visit database in Seoul, South Korea, collected between 2013 and 2017. The data set included outpatient hospital visits (n = 17,787,982), hospital admissions (n = 215,696), and emergency department visits (n = 85,482). The daily atmospheric environmental information from 2013 to 2017 at 25 locations in Seoul was evaluated. The three analysis models revealed that NO₂ was the most significant pollutant on average in outpatient hospital visits by asthma patients. For example, NO₂ had the greatest impact on outpatient hospital visits, resulting in a positive association (r=0.331). In hospital admissions of asthma patients, CO was the most significant pollutant on average. It was observed that CO exhibited the most positive association with hospital admissions (I = 3.329). Additionally, a significant time lag was found between both NO₂ and CO and outpatient hospital visits and hospital admissions of asthma patients in the linear correlation analysis. In particular, NO₂ and CO were shown to increase hospital admissions at lag 4 in the linear correlation analysis. This study provides evidence that PM_2.5, PM₁₀, NO₂, CO, SO₂, and O₃ are associated with the frequency of hospital visits by asthma patients.