Air pollution and hospital visits for acute upper and lower respiratory infections among children in Ningbo, China: A time-series analysis

Causal relationship between air pollution and infections: a two-sample Mendelian randomization study

Background

Traditional observational studies exploring the association between air pollution and infections have been limited by small sample sizes and potential confounding factors. To address these limitations, we applied Mendelian randomization (MR) to investigate the potential causal relationships between particulate matter (PM2.5, PM2.5-10, and PM10), nitrogen dioxide, and nitrogen oxide and the risks of infections.

Methods

Single nucleotide polymorphisms (SNPs) related to air pollution were selected from the genome-wide association study (GWAS) of the UK Biobank. Publicly available summary data for infections were obtained from the FinnGen Biobank and the COVID-19 Host Genetics Initiative. The inverse variance weighted (IVW) meta-analysis was used as the primary method for obtaining the Mendelian randomization (MR) estimates. Complementary analyses were performed using the weighted median method, MR-Egger method, and MR Pleiotropy Residual Sum and Outlier (MR-PRESSO) test.

Results

The fixed-effect IVW estimate showed that PM2.5, PM2.5-10 and Nitrogen oxides were suggestively associated with COVID-19 [for PM2.5: IVW (fe): OR 3.573(1.218,5.288), PIVW(fe) = 0.021; for PM2.5-10: IVW (fe): OR 2.940(1.385,6.239), PIVW(fe) = 0.005; for Nitrogen oxides, IVW (fe): OR 1.898(1.318,2.472), PIVW(fe) = 0.010]. PM2.5, PM2.5-10, PM10, and Nitrogen oxides were suggestively associated with bacterial pneumonia [for PM2.5: IVW(fe): OR 1.720 (1.007, 2.937), PIVW(fe) = 0.047; for PM2.5-10: IVW(fe): OR 1.752 (1.111, 2.767), P IVW(fe) = 0.016; for PM10: IVW(fe): OR 2.097 (1.045, 4.208), PIVW(fe) = 0.037; for Nitrogen oxides, IVW(fe): OR 3.907 (1.209, 5.987), PIVW(fe) = 0.023]. Furthermore, Nitrogen dioxide was suggestively associated with the risk of acute upper respiratory infections, while all air pollution were not associated with intestinal infections.

Conclusions

Our results support a role of related air pollution in the Corona Virus Disease 2019, bacterial pneumonia and acute upper respiratory infections. More work is need for policy formulation to reduce the air pollution and the emission of toxic and of harmful gas.

Association between short-term exposure to ambient air pollutants and the risk of hospital visits for acute upper respiratory tract infections among adults: a time-series study in Ningbo, China

OBJECTIVES

Acute upper respiratory tract infections (AURTIs) are prevalent in the general population. However, studies on the association of short-term exposure to air pollution with the risk of hospital visits for AURTIs in adults are limited. This study aimed to explore the short-term exposure to air pollutants among Chinese adults living in Ningbo.

METHODS

Quasi-Poisson time serious regressions with distributed lag non-linear models (DLNM) were applied to explore the association between ambient air pollution and AURTIs cases. Patients ≥ 18 years who visit three hospitals, being representative for urban, urban-rural junction and rural were included in this retrospective study.

RESULTS

In total, 104,441 cases with AURTIs were enrolled in hospital during 2015-2019. The main results showed that particulate matter with an aerodynamic diameter less than 2.5 μm (PM2.5), nitrogen dioxide (NO2) and nitrogen dioxide (SO2), were positively associated to hospital visits for AURTIs, except for nitrogen dioxide (O3), which was not statistically significant. The largest single-lag effect for PM2.5 at lag 8 days (RR = 1.02, 95%CI: 1.08-1.40), for NO2 at lag 13 days (RR = 1.03, 95%CI: 1.00-1.06) and for SO2 at lag 5 days (RR = 1.27, 95%CI: 1.08-1.48), respectively. In the stratified analysis, females, and young adults (18-60 years) were more vulnerable to PM2.5 and SO2 and the effect was greater in rural areas and urban-rural junction.

CONCLUSIONS

Exposure to ambient air pollution was significantly associated with hospital visits for AURTIs. This study provides epidemiological evidence for policymakers to control better air quality and establish an enhanced system of air pollution alerts.

Differentiated impacts of short-term exposure to fine particulate constituents on infectious diseases in 507 cities of Chinese children and adolescents: A nationwide time-stratified case-crossover study from 2008 to 2021

This study assesses the association of short-term exposure to PM2.5 (particles ≤2.5 μm) on infectious diseases among Chinese children and adolescents. Analyzing data from 507 cities (2008-2021) on 42 diseases, it focuses on PM2.5 components (black carbon (BC), ammonium (NH4+), inorganic nitrate (NO3-), organic matter (OM), and sulfate (SO42-)). PM2.5 constituents significantly associated with incidence. Sulfate showed the most substantial effect, increasing all-cause infectious disease risk by 2.72 % per interquartile range (IQR) increase. It was followed by BC (2.04 % increase), OM (1.70 %), NO3- (1.67 %), and NH4+ (0.79 %). Specifically, sulfate and BC had pronounced impacts on respiratory diseases, with sulfate linked to a 10.73 % increase in seasonal influenza risk and NO3- to a 16.39 % rise in tuberculosis. Exposure to PM2.5 also marginally increased risks for gastrointestinal, enterovirus, and vectorborne diseases like dengue (7.46 % increase with SO42-). Sexually transmitted and bloodborne diseases saw an approximate 6.26 % increase in incidence, with specific constituents linked to diseases like hepatitis C and syphilis. The study concludes that managing PM2.5 levels could substantially reduce infectious disease incidence, particularly in China's middle-northern regions. It highlights the necessity of stringent air quality standards and targeted disease prevention, aligning PM2.5 management with international guidelines for public health protection.

Association between short-term exposure to ambient air pollution and upper respiratory tract infection in Kunshan

The health effects of air pollution have become a major public health problem. Studies on the relationship between short-term exposure to air pollutants and upper respiratory tract infection (URTI) related clinic visits and expenditures were scarce. From January 1, 2019, to December 31, 2021, we included all the URTI cases that turned to 11 public hospitals in Kunshan, and summarized individual medical cost. Daily meteorological factors and 24-h mean concentrations of four common air pollutants, including particulate matter with an aerodynamic diameter less than 2.5 μm (PM2.5) and 10 μm (PM10), sulfur dioxide (SO2), and nitrogen dioxide (NO2), were consecutively recorded. Generalized additive regression model was adopted to quantify the associations between each air pollutant and the daily clinic visits of URTI cases. We further calculated attributable number (AN) and attributable fraction, and performed sensitivity analysis by gender, age, and season. A total of 934,180 cases were retrieved during the study period. PM2.5, PM10, SO2, and NO2 showed significant associations with hospital visits and expenditures due to URTI. Relative risks for them were 1.065 (95% confidence interval [CI] 1.055, 1.076), 1.045 (95% CI 1.037, 1.052), 1.098 (95% CI 1.038, 1.163), and 1.098 (95% CI 1.085, 1.111) on lag 0-5 days, respectively. Thirty-one thousand four hundred fifty-five (95% CI 27,457, 35,436) cases could be ascribed to increased NO2 and accounted for 3.37% (95% CI 2.94%, 3.79%) of all clinic visits. Sensitivity analyses indicated that the effects of air pollution were generally consistent for male and female. PM2.5, PM10, and NO2 had stronger associations among people aged ≤ 18 years, followed by those aged 19-64 years and ≥ 65 years. The association strengths of air pollution varied seasonally. Short-term exposure to ambient air pollutants had significant associations with clinic visits and expenditures owing to URTI. Children and adolescents appeared to be more susceptible to adverse health effects of air pollution. NO2 may be a priority when formulating pollution control measures.

Effect of ambient air pollution on hospital admission for respiratory diseases in Hanoi children during 2007-2019

Air pollution poses a threat to children's respiratory health. This study aims to quantify the association between short-term air pollution exposure and respiratory hospital admissions among children in Hanoi, Vietnam, and estimate the population-attributable burden using local data. A case-crossover analysis was conducted based on the individual records where each case is their own control. The health data was obtained from 13 hospitals in Hanoi and air pollution data was collected from four monitoring stations from 2007 to 2019. We used conditional logistic regression to estimate Percentage Change (PC) and 95% Confidence Interval (CI) in odd of hospital admissions per 10 μg/m3 increase in daily average particulate matter (e.g. PM1, PM2.5, PM10), Sulfur Dioxide (SO2), Nitrogen Dioxide (NO2), 8-h maximum Ozone and per 1000 μg/m3 increase in daily mean of Carbon Monoxide (CO). We also calculated the number and fraction of admissions attributed to air pollution in Hanoi by using the coefficient at lag 0. A 10 μg/m3 increase in the concentration of PM10, PM2.5, PM1, SO2, NO2, O3 8-h maximum and 1000 μg/m3 increase in CO concentration was associated with 0.6%, 1.2%, 1.4%, 0.8%, 1.6%, 0.3%, and 1.7% increase in odd of admission for all respiratory diseases among children under 16 years at lag 0-2. All PM metrics and NO2 are associated with childhood admission for pneumonia and bronchitis. Admissions due to asthma and upper respiratory diseases are related to increments in NO2 and CO. For attributable cases, PM2.5 concentrations in Hanoi exceeding the World Health Organization Air Quality Guidelines accounted for 1619 respiratory hospital admissions in Hanoi children in 2019. Our findings show that air pollution has a detrimental impact on the respiratory health of Hanoi children and there will be important health benefits from improved air quality management planning to reduce air pollution in Vietnam.

Short-term effects of air pollution on hospitalization of children with acute upper respiratory infections: A time series analysis in Lanzhou, China

OBJECTIVE

Short-term air pollution exposure is correlated with childhood acute upper respiratory infections (AURI) hospitalizations. We surveyed the relationship between AURI hospitalizations and air pollutant concentrations in children aged 0-14 years from 1 January 2014 to 31 December 2019 in Lanzhou City.

METHODS

We collected both data on air pollutant concentrations and children's AURI hospitalizations during the study period. Distributional lagged nonlinear models were adopted to assess the short-term effects of air pollutants on children's AURI hospitalizations. We also performed subgroup analysis and sensitivity analysis.

RESULTS

A total of 15,881 children were hospitalized for AURI during the study period. The results showed that for each 10 µg/m3 increase in PM2.5 , SO2 , and NO2 concentrations at lag0-6, the relative risk (RR) values for children hospitalized for AURI were RR = 1.0247 (95% CI: 1.0092,1.0405), RR = 1.0928 (95% CI: 1.0562, 1.1308), and RR = 1.0715 (95% CI: 1.0495, 1.0940), respectively. PM10 was significantly associated with AURI hospitalization in children only at lag0, RR = 1.0028 (95% CI: 1.0000, 1.0056).

CONCLUSION

Short-term exposures to PM2.5 , PM10 , SO2 , and NO2 all increase the risk of AURI hospitalization in children variously.

Association of Air Pollution with the Number of Common Respiratory Visits in Children in a Heavily Polluted Central City, China

Children's respiratory health is vulnerable to air pollution. Based on data collected from June 2019 to June 2022 at a children's hospital in Zhengzhou, China, this study utilized Spearman correlation analysis and a generalized additive model (GAM) to examine the relationship between daily visits for common respiratory issues in children and air pollutant concentrations. Results show that the number of upper respiratory tract infection (URTI), pneumonia (PNMN), bronchitis (BCT), and bronchiolitis (BCLT) visits in children showed a positive correlation with PM2.5, PM10, NO2, SO2, and CO while exhibiting a negative correlation with temperature and relative humidity. The highest increases in PNMN visits in children were observed at lag 07 for NO2, SO2, and CO. A rise of 10 μg/m3 in NO2, 1 μg/m3 in SO2, and 0.1 mg/m3 in CO corresponded to an increase of 9.7%, 2.91%, and 5.16% in PNMN visits, respectively. The effects of air pollutants on the number of BCT and BCLT visits were more pronounced in boys compared to girls, whereas no significant differences were observed in the number of URTI and PNMN visits based on sex. Overall, air pollutants significantly affect the prevalence of respiratory diseases in children, and it is crucial to improve air quality to protect the children's respiratory health.

Short-term effects of air pollution on hospitalization for acute lower respiratory infections in children: a time-series analysis study from Lanzhou, China

BACKGROUND

Short-term exposure to air pollution is associated with acute lower respiratory infections (ALRI) in children. We investigated the relationship between hospitalization for ALRI in children and air pollutant concentrations from January 1, 2014 to December 31, 2020 in Lanzhou City.

METHODS

We collected data on air pollutant concentrations and children's hospitalization data during the study period. A time series regression analysis was used to assess the short-term effects of air pollutants on ALRI in children, and subgroup analyses and sensitivity analyses were performed.

RESULTS

A total of 51,206 children with ALRI were studied, including 40,126 cases of pneumonia and 11,080 cases of bronchiolitis. The results of the study revealed that PM2.5, PM10, SO2 and NO2 were significantly associated with hospitalization for ALRI in children aged 0-14 years. For each 10 µg/m3 increase in air pollutant concentration in lag0-7, the relative risk of ALRI hospitalization in children due to PM2.5, PM10, SO2 and NO2 increased by 1.089 (95%CI:1.075, 1.103), 1.018 (95%CI:1.014, 1.021), 1.186 (95%CI:1.154. 1.219) and 1.149 (95%CI:1.130, 1.168), respectively.

CONCLUSIONS

PM2.5, PM10, SO2 and NO2 short-term exposures were positively associated with ALRI, pneumonia and bronchiolitis hospitalizations in Lanzhou, China. Local governments should make efforts to improve urban ambient air quality conditions to reduce hospitalization rates for childhood respiratory diseases.

Short-term effects and economic burden of air pollutants on acute lower respiratory tract infections in children in Southwest China: a time-series study

BACKGROUND

There are few studies on the effects of air pollutants on acute lower respiratory tract infections (ALRI) in children. Here, we investigated the relationship of fine particulate matter (PM_2.5), inhalable particulate matter (PM₁₀), sulfur dioxide (SO₂), and nitrogen dioxide (NO₂) with the daily number of hospitalizations for ALRI in children in Sichuan Province, China, and to estimate the economic burden of disease due to exposure to air pollutants.

METHODS

We collected records of 192,079 cases of childhood ALRI hospitalization between January 1, 2017 and December 31, 2018 from nine municipal/prefecture medical institutions as well as the simultaneous meteorological and air pollution data from 183 monitoring sites in Sichuan Province. A time series-generalized additive model was used to analyze exposure responses and lagged effects while assessing the economic burden caused by air pollutant exposure after controlling for long-term trends, seasonality, day of the week, and meteorological factors.

RESULTS

Our single-pollutant model shows that for each 10 μg/m³ increase in air pollutant concentration (1 μg/m³ for SO₂), the effect estimates of PM_2.5, PM₁₀, SO₂, and NO₂ for pneumonia reached their maximum at lag4, lag010, lag010, and lag07, respectively, with relative risk (RR) values of 1.0064 (95% CI, 1.0004-1.0124), 1.0168(95% CI 1.0089-1.0248), 1.0278 (95% CI 1.0157-1.0400), and 1.0378 (95% CI, 1.0072-1.0692). By contrast, the effect estimates of PM_2.5, PM₁₀, SO₂, and NO₂ for bronchitis all reached their maximum at lag010, with RRs of 1.0133 (95% CI 1.0025-1.0242), 1.0161(95% CI 1.0085-1.0238), 1.0135 (95% CI 1.0025-1.0247), and 1.1133(95% CI 1.0739-1.1541). In addition, children aged 5-14 years were more vulnerable to air pollutants than those aged 0-4 years (p < 0.05). According to the World Health Organization's air quality guidelines, the number of ALRI hospitalizations attributed to PM_2.5, PM₁₀, and NO₂ pollution during the study period was 7551, 10,151, and 7575, respectively, while the incurring economic burden was CNY 2847.06, 3827.27, and 2855.91 million.

CONCLUSION

This study shows that in Sichuan Province, elevated daily average concentrations of four air pollutants lead to increases in numbers of childhood ALRI hospitalizations and cause a serious economic burden.

Impacts of climate change and environmental degradation on children in Malaysia

The impacts of climate change and degradation are increasingly felt in Malaysia. While everyone is vulnerable to these impacts, the health and wellbeing of children are disproportionately affected. We carried out a study composed of two major components. The first component is an environmental epidemiology study comprised of three sub-studies: (i) a global climate model (GCM) simulating specific health-sector climate indices; (ii) a time-series study to estimate the risk of childhood respiratory disease attributable to ambient air pollution; and (iii) a case-crossover study to identify the association between haze and under-five mortality in Malaysia. The GCM found that Malaysia has been experiencing increasing rainfall intensity over the years, leading to increased incidences of other weather-related events. The time-series study revealed that air quality has worsened, while air pollution and haze have been linked to an increased risk of hospitalization for respiratory diseases among children. Although no clear association between haze and under-five mortality was found in the case-crossover study, the lag patterns suggested that health effects could be more acute if haze occurred over a longer duration and at a higher intensity. The second component consists of three community surveys on marginalized children conducted (i) among the island community of Pulau Gaya, Sabah; (ii) among the indigenous Temiar tribe in Pos Kuala Mu, Perak; and (iii) among an urban poor community (B40) in PPR Sg. Bonus, Kuala Lumpur. The community surveys are cross-sectional studies employing a socio-ecological approach using a standardized questionnaire. The community surveys revealed how children adapt to climate change and environmental degradation. An integrated model was established that consolidates our overall research processes and demonstrates the crucial interconnections between environmental challenges exacerbated by climate change. It is recommended that Malaysian schools adopt a climate-smart approach to education to instill awareness of the impending climate change and its cascading impact on children's health from early school age.

Air pollution in Delhi, India: It’s status and association with respiratory diseases

The policymakers need research studies indicating the role of different pollutants with morbidity for polluted cities to install a strategic air quality management system. This study critically assessed the air pollution of Delhi for 2016–18 to found out the role of air pollutants in respiratory morbidity under the ICD-10, J00-J99. The critical assessment of Delhi air pollution was done using various approaches. The mean PM_2.5 and PM₁₀ concentrations during the measurement period exceeded both national and international standards by a wide margin. Time series charts indicated the interdependence of PM_2.5 and PM₁₀ and connection with hospital visits due to respiratory diseases. Violin plots showed that daily respiratory disease hospital visits increased during the winter and autumn seasons. The winter season was the worst from the city’s air pollution point of view, as revealed by frequency analyses. The single and multi-pollutant GAM models indicated that short-term exposure to PM₁₀ and SO₂ led to increased hospital visits due to respiratory diseases. Per 10 units increase in concentrations of PM₁₀ brought the highest increase in hospital visits of 0.21% (RR: 1.00, 95% CI: 1.001, 1.002) at lag0-6 days. This study found the robust effect of SO₂ persisted in Delhi from lag0 to lag4 days and lag01 to lag06 days for single and cumulative lag day effects, respectively. While every 10 μg m^-3 increase of SO₂ concentrations on the same day (lag0) led to 32.59% (RR: 1.33, 95% CI: 1.09, 1.61) rise of hospital visits, the cumulative concentration of lag0-1 led to 37.21% (RR: 1.37, 95% CI:1.11, 1.70) rise in hospital visits which further increased to even 83.33% (RR: 1.83, 95% CI:1.35, 2.49) rise at a lag0-6 cumulative concentration in Delhi. The role of SO₂ in inducing respiratory diseases is worrying as India is now the largest anthropogenic SO₂ emitter in the world.

Residential greenness, air pollution, and incident ischemic heart disease: A prospective cohort study in China

Greener residential surroundings are associated with beneficial health outcomes, whereas higher air pollution exposure is linked with elevated risks of chronic diseases. To date, limited studies have explored the interaction between residential greenness and air pollution on the risk of ischemic heart disease (IHD). We performed a prospective cohort study that included 29,141 adult participants recruited from Yinzhou District, Ningbo, China. Normalized Difference Vegetation Index (NDVI) around each participant's residence was calculated to measure residential greenness exposure. Land-use regression models were conducted to estimate long-term individual exposure to air pollutants, including nitrogen dioxide (NO₂) and particulate matter with aerodynamic diameters ≤ 2.5 μm (PM_2.5) and ≤10 μm (PM₁₀). Cox proportional hazard models were used to calculate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the associations of residential greenness and air pollutants with the risk of incident IHD. During 101,172.5 person-years of follow-up, 1392 incident IHD cases were reported in the study population. Residential greenness, expressed as an interquartile range (IQR) increase in NDVI within 250 m, was inversely associated with incident IHD (HR = 0.89, 95%CI: 0.81,0.98). However, long-term exposures to air pollution were associated with higher IHD incidence (HR = 1.21, 95%CI:1.10,1.33 per IQR increase for PM_2.5; HR = 1.12, 95%CI:1.03,1.22 per IQR increase for PM₁₀; HR = 1.09, 95%CI:1.02,1.16 per IQR increase for NO₂). Mediation analyses suggested that the beneficial effect of residential greenness on incident IHD could be partly mediated by reducing the exposure to PM_2.5. These findings suggested that higher greenness was associated with decreased risk of IHD, while air pollutants were positively associated with incident IHD. Meanwhile, residential greenness may decrease the risk of IHD by reducing exposure to PM_2.5.

Viral etiology among children hospitalized for acute respiratory tract infections and its association with meteorological factors and air pollutants: a time-series study (2014-2017) in Macao

Background

The associations between viral etiology of acute respiratory infections (ARI) with meteorological factors and air pollutants among children is not fully understood. This study aimed to explore the viral etiology among children hospitalized for ARI and the association of meteorological factors and air pollutants with children hospitalization due to viral ARI.

Methods

Electronic health record data about children (aged between 1 month and 14 years) admitted for ARI at Kiang Wu Hospital in Macao between 2014 and 2017 was analyzed retrospectively. xMAP multiplex assays were used to detect viruses in the nasopharyngeal swab and distributed-lag nonlinear model (DLNM) was used to evaluate associations.

Results

Among the 4880 cases of children hospitalization due to ARI, 3767 (77.2%) were tested positive for at least one virus and 676 (18%) exhibited multiple infections. Enterovirus (EV)/rhinovirus (HRV), adenovirus (ADV), respiratory syncytial virus (RSV) and influenza virus (IFV) were the most common viral pathogens associated with ARI and human bocavirus (hBOV) exhibited the highest multiple infection rates. Meteorological factors and air pollutants (PM₁₀, PM_2.5 and NO₂) were associated with the risk of viral ARI hospitalization. The relative risk of viral infection increased with daily mean temperature but plateaued when temperature exceeded 23 °C, and increased when the relative humidity was < 70% and peaked at 50%. The effect of solar radiation was insignificant. Air pollutants (including PM₁₀, PM_2.5, NO₂ and O₃) showed strong and immediate effect on the incidence of viral infection.

Conclusions

The effects of mean temperature, relative humidity and air pollutants should be taken into account when considering management of ARI among children.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07585-y.

Outdoor particulate matter exposure and upper respiratory tract infections in children and adolescents: A systematic review and meta-analysis

BACKGROUND

While the relationship between outdoor particulate matter (PM) and lower respiratory tract infections in children and adolescents is accepted, we know little about the impacts of outdoor PM on the risk of developing or aggravating upper respiratory tract infections (URTIs).

METHODS

We aimed to review the literature examining the relationship between outdoor PM exposure and URTIs in children and adolescents. A systematic search of EMBASE, MEDLINE, PubMed, Scopus, CINAHL and Web of Science databases was undertaken on April 3, 2020 and October 27, 2021. Comparable short-term studies of time-series or case-crossover designs were pooled in meta-analyses using random-effects models, while the remainder of studies were combined in a narrative analysis. Quality, risk of bias and level of evidence for health effects were appraised using a combination of emerging frameworks in environmental health.

RESULTS

Out of 1366 articles identified, 34 were included in the systematic review and 16 of these were included in meta-analyses. Both PM_2.5 and PM₁₀ levels were associated with hospital presentations for URTIs (PM_2.5: RR = 1.010, 95%CI = 1.007-1.014; PM₁₀: RR = 1.016, 95%CI = 1.011-1.021) in the meta-analyses. Narrative analysis found unequivocally that total suspended particulates were associated with URTIs, but mixed results were found for PM_2.5 and PM₁₀ in both younger and older children.

CONCLUSION

This study found some evidence of associations between PM and URTIs in children and adolescents, the relationship strength increased with PM₁₀. However, the number of studies was limited and heterogeneity was considerable, thus there is a need for further studies, especially studies assessing long-term exposure and comparing sources.

Association between Ambient Air Pollutants and Pneumonia in Wuhan, China, 2014–2017

Objectives: To assess associations between short-time air pollution exposure and outpatient visits for pneumonia by the distributed lag nonlinear model (DLNM). Methods: Daily outpatient visits for pneumonia and air pollutant data were collected from Wuhan Basic Medical Insurance Database in China and 10 national air quality monitoring stations in Wuhan from 2014 to 2017, respectively. Taking the first percentile of the concentration as the reference, DLNM was used to estimate the impact of moderate (50th) and high levels (99th) of pollutants on pneumonia. Results: A total of 133,882 outpatient visits were identified during the period of the study. Moderate-level (P50) fine particulate matter (PM2.5) or sulfur dioxide (SO2) and high-level nitrogen dioxide (NO2) (P99) can increase the risk of pneumonia. The maximum RR was 1.198 (95% CI: 1.094–1.311) at lag0-11, 1.304 (95% CI: 1.166–1.458) at lag0-13, and 1.286 (95% CI: 1.060–1.561) at lag0-14, respectively. Females and children had greater risks. Conclusions: Short-time PM2.5, SO2, and NO2 exposure were associated with outpatient visits for pneumonia in Wuhan, China.

Association between air pollution and emergency department visits for upper respiratory tract infection inLanzhou, China

There is limited evidence regarding the associations between air pollution and emergency hospital visits for upper respiratory tract infection (URTI) in the arid regions of northwest China. We collected daily emergency department (ED) visits for URTI from three hospitals in Lanzhou during January 2014 and December 2018, as well as daily air pollutants and meteorological factors. In the present study, generalized additive model with quasi-Poisson regression was used to evaluate the relationship between short-term exposure to ambient pollutants and daily emergency hospital visits for URTI in Lanzhou, China. Furthermore, subgroup analyses were conducted by gender (male and female), age (0-14, 15-64, and ≥ 65 years)), and season (cold season, warm season). The results of the single-pollutant model show that the associations of PM_2.5, PM₁₀, SO₂, NO₂, and CO with URTI ED visits were all statistically significant, whereas we observed insignificant associations of O₃8h. The highest association of each pollutant with hospital emergency visits was observed with PM_2.5 (5.302% (95% CI: 3.202, 7.445)), PM₁₀ (0.808% (95% CI: 0.291, 1.328)), SO₂ (10.607% (95% CI: 5.819, 15.611)), and NO₂ (5.325% (95% CI: 2.379, 8.357)) at lag 07 for an increase of 10 ug/m³ in concentrations of the pollutants. Percentage increase for each 1-mg/m³ increase in CO was 20.799% (95% CI: 11.834, 30.482) at lag 07. In the stratification analyses, females were more susceptible to PM_2.5 and PM₁₀, while males were more sensitive to the effects of SO₂, NO₂, and CO, and the higher association effect of four pollutants (PM_2.5, SO₂, NO₂, and CO) on hospital visits for URTI among children (0-14 years). The associations appeared to be stronger in the cool season than in the warm season. This study suggests that short-term exposure to air pollution, especially to SO₂ and CO, was associated with increased risk of hospital emergency visits for URTI in Lanzhou, China. Relevant strategies and health interventions should be strengthened to reduce the air pollution level in the future.

Association of children wheezing diseases with meteorological and environmental factors in Suzhou, China

Wheezing diseases are one of the major chronic respiratory diseases in children. To explore the effects of meteorological and environmental factors on the prevalence of children wheezing diseases, clinical data of children hospitalized with wheezing diseases in Suzhou, China from 2013 to 2017 were collected. Meteorological and environmental factors from 2013 to 2017 were obtained from the local Meteorological Bureau and Environmental Protection Bureau. Relationships between wheezing diseases and meteorological and environmental factors were evaluated using Pearson's correlation and multivariate regression analysis. An autoregressive integrated moving average (ARIMA) model was used to estimate the effects of meteorological and environmental variables on children wheezing diseases. Children wheezing diseases were frequently presented in infants less than 12 months old (1897/2655, 58.28%), and the hospitalization rate was highest in winter (1024/3255, 31.46%). In pathogen-positive specimens, the top three pathogens were respiratory syncytial virus (21.35%), human rhinovirus (16.28%) and mycoplasma pneumoniae (10.47%). The seasonality of wheezing children number showed a distinctive winter peak. Children wheezing diseases were negatively correlated with average temperature (P < 0.001, r =  - 0.598). The ARIMA (1,0,0)(0,0,0)₁₂ model could be used to predict temperature changes associated wheezing diseases. Meteorological and environmental factors were associated with the number of hospitalized children with wheezing diseases and can be used as early warning indicators for the occurrence of wheezing diseases and prevalence of virus.

GPR61 methylation in cord blood: a potential target of prenatal exposure to air pollutants

To explore the impact of air pollutants exposure during pregnancy on infant DNA methylation, we identified correlated methylated genes in maternal and cord blood samples using the Illumina Human Methylation 27 k BeadChip. Quantitative methylation-specific PCR (QMS-PCR) was performed to validate the target gene methylation pattern in 568 participants. Then the association between air pollutants exposure and DNA methylation level in the target gene was investigated. The GPR61 gene with a higher methylation level both in mothers and newborns was identified as the target gene, and we found a positive mother-infant DNA methylation correlation in the promoter region of GPR61. Air pollutants exposure during entire pregnancy was associated with maternal and infant GPR61 DNA methylation. After adjusting confounding variables, maternal air pollutants exposure was still associated with infant GPR61 DNA methylation. In summary, GPR61 methylation in cord blood may be a potential target of prenatal exposure to air pollutants.

Ambient NO2 is associated with Streptococcus pneumoniae-induced pneumonia in children and increases the minimum inhibitory concentration of penicillin

The present study aimed to assess the correlation between ambient air pollutants and Streptococcus pneumoniae (S. pneumoniae)-induced pneumonia in children and retrospectively reviewed the daily data regarding S. pneumoniae from children with pneumonia in a tertiary hospital of Hangzhou City, between January 1st, 2018, and December 31st, 2018. The excess risk (ER) of NO₂ with regard to the daily number of S. pneumoniae isolates obtained from the respiratory tract specimens of children with pneumonia was 13.31% (95% confidence interval [CI]: 3.12-24.51%, P = 0.010) in the single-pollutant model. An increase of 10 μg/m³ in NO₂ exposure was associated with a 23.30% increased risk for the acquisition of S. pneumoniae-induced pneumonia in children (95% CI: 2.02-49.02%; P = 0.031) according to the multi-pollutant model. The ER of NO₂ with regard to the daily number of S. pneumoniae isolates (1 μg/ml ≤ minimum inhibitory concentration (MIC) to penicillin ≤ 2 μg/ml) obtained from the respiratory tract specimens of children with pneumonia was 15.80% (95% CI: 2.02-31.45%; P = 0.024) in the single-pollutant model. According to the multi-pollutant model, the ER of NO₂ with regard to the daily number of S. pneumoniae isolates (1 μg/ml ≤ MIC to penicillin ≤ 2 μg/ml) obtained from the respiratory tract specimens of children with pneumonia was 37.09% (95% CI: 5.70-77.81%; P = 0.018). In conclusion, ambient NO₂ is associated with S. pneumoniae-induced pneumonia in children. More importantly, NO₂ exposure is associated with the increased MICs of penicillin against S. pneumoniae from children with pneumonia.

Analysis of multimorbidity networks associated with different factors in Northeast China: a cross-sectional analysis

OBJECTIVES

This study aimed to identify and study the associations and co-occurrence of multimorbidity, and assessed the associations of diseases with sex, age and hospitalisation duration.

DESIGN

Cross-sectional.

SETTING

15 general hospitals in Jilin Province, China.

PARTICIPANTS

A total of 431 295 inpatients were enrolled through a cross-sectional study in Jilin Province, China.

PRIMARY OUTCOME MEASURES

The complex relationships of multimorbidity were presented as weighted networks.

RESULTS

The distributions of the numbers of diseases differed significantly by sex, age and hospitalisation duration (p<0.001). Cerebrovascular diseases (CD), hypertensive diseases (HyD), ischaemic heart diseases (IHD) and other forms of heart disease (OFHD) showed the highest weights in the multimorbidity networks. The connections between different sexes or hospitalisation duration and diseases were similar, while those between different age groups and diseases were different.

CONCLUSIONS

CD, HyD, IHD and OFHD were the central points of disease clusters and directly or indirectly related to other diseases or factors. Thus, effective interventions for these diseases should be adopted. Furthermore, different intervention strategies should be developed according to multimorbidity patterns in different age groups.

Long-term exposure to air pollution and the risk of developing sudden sensorineural hearing loss

Background

The association between exposure to air pollution and sudden sensorineural hearing loss (SSNHL) has not been extensively discussed in the literature. Therefore, we conducted this nationwide study to evaluate the risk of SSNHL in Taiwanese residents with exposure to air pollution.

Methods

We enrolled subjects aged older than 20 years with no history of SSNHL from 1998 to 2010, and followed up until developing SSNHL, withdrawn from the National Health Insurance program, and the end of the database (2011/12/31). The air quality data are managed by Taiwan Environmental Protection Administration. The annual concentrations of PM_2.5, SO₂, CO, NO, and NO₂ from 1998 to 2010 were classified into the three levels according to tertiles. We calculated the annual average of pollutants from baseline until the end of the study, and classified into tertiles. The adjusted hazard ratio (aHR) was estimated by using the multivariate Cox proportional hazard model.

Results

When considered continuous air pollutants concentration, subjects who exposed with higher concentration of CO (aHR = 2.16, 95% CI 1.50–3.11), NO (aHR = 1.02, 95% CI 1.01–1.03), and NO₂ (aHR = 1.02, 95% CI 1.01–1.04) developing significant higher risk of SSNHL. When classified air pollutants concentration into low, moderate and high level by tertiles, and selected low level as reference, patients exposed with moderate (aHR = 1.56, 95% CI 1.20–2.04) or high level (aHR = 1.33, 95% CI 1.01–1.75) of PM_2.5 showed significant higher risk of developing SSNHL.

Conclusion

This study indicated an increased risk of SSNHL in residents with long-term exposure to air pollution. Nevertheless, further experimental, and clinical studies are needed to validate the study findings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03095-8.

An association between PM2.5 and pediatric respiratory outpatient visits in four Chinese cities

BACKGROUND

The effects of exposure to particulate matter with aerodynamic diameter less than 2.5 μm (PM_2.5) on children's respiratory system were investigated in numerous epidemiological literatures. However, studies on the association between PM_2.5 and pediatric outpatient visits for respiratory diseases, especially considering the multicenter studies were limited in China.

OBJECTIVES

To study the association between the short-term exposure to PM_2.5 and the number of children's outpatient visits for respiratory diseases in four Chinese cities as well as the pooled health effects.

METHODS

Data of pediatric outpatient visits for respiratory diseases (RD, ICD: J00-J99) from representative hospitals in Shijiazhuang (SJZ), Xi'an (XA), Nanjing (NJ) and Guangzhou (GZ) in China from 2015 to 2018 were collected and the air quality data for the same period were collected from environmental protection departments. Generalized additive model (GAM) with quasi-Poisson regression was conducted to analyze the effects of PM_2.5 on the number of pediatric outpatient visits in each city. Single-day lag model (lag0 to lag7) and moving average lag model (lag01 and lag07) were used to examine the lag effects and cumulative effects. Random-effects meta-analysis was used to pool the estimated risks of four cities. The interactions between PM_2.5 and temperature were also explored.

RESULTS

The average daily/total outpatient visits for RD, in SJZ, XA, NJ and GZ from 2015 to 2018 were 854.2/1,245,384, 2353.9/3,439,025, 1267.2/1,851,438 and 1399.5/2,044,740 respectively. The percentages of acute upper respiratory infections (URD, ICD: J00-J06) and other acute lower respiratory infections (LRD, ICD: J20-J22) in RD were 33%, 13% (SJZ), 43%, 32% (XA), 26%, 21% (NJ) and 54%, 26% (GZ). The largest pooled estimates of single-day lag effects for RD, URD, and LRD were at lag0, lag0 and lag1. Every 10 μg/m³ increase in PM_2.5 concentration was associated with a 0.46% (95%CI: 0.21%-0.70%), 0.50% (95%CI: 0.19%-0.81%) and 0.42% (95%CI: 0.06%-0.79%) increased number of outpatient visits significantly. While max cumulative effects which were all at lag 07 were 1.10% (95%CI: 0.46%-1.74%), 0.96% (95%CI: 0.20%-1.73%) and 1.06% (95%CI: 0.12%-2.00%). Less polluted cities (GZ and NJ) showed greater city-specific excess risks, but the excess risks significantly decreased after adjusting for NO₂ in two-pollutant models. Generally, PM_2.5 showed larger health hazards on lower temperature days.

CONCLUSIONS

Our study showed that exposure to the ambient PM_2.5 was associated with the increase of the number of outpatient visits with pediatric respiratory diseases in four Chinese cities. The health effects of PM_2.5 may not be independent of other air pollutants and could be modified by temperature.

Associations of fine particulate matter and constituents with pediatric emergency room visits for respiratory diseases in Shanghai, China

BACKGROUND

Although ambient fine particulate matter (PM_2.5) has been associated with adverse respiratory outcomes in children, few studies have examined PM_2.5 constituents with respiratory diseases in children in China.

OBJECTIVES

To investigate the associations of short-term exposure to PM_2.5 and its constituents with pediatric emergency room visits (ERVs) for respiratory diseases in Shanghai, China.

METHODS

We collected daily concentrations of PM_2.5 and its constituents in urban Shanghai from January 1, 2016, to December 31, 2018. Daily pediatric ERVs for four major respiratory diseases, including upper respiratory tract infection, bronchitis, pneumonia, and asthma, were obtained from 66 hospitals in Shanghai during the same period. Associations of exposure to daily PM_2.5 and constituents with respiratory ERVs were estimated using the over-dispersed generalized additive models.

RESULT

Short-term exposure to PM_2.5 and its constituents were associated with increased pediatric ERVs for respiratory diseases. Specifically, an interquartile range increase in the 3-day average PM_2.5 level (31 μg/m³) was associated with 1.86% (95%CI: 0.52, 3.22), 1.53% (95%CI: 0.01, 3.08), 1.90% (95%CI: 0.30, 3.52), and 2.67% (95%CI: 0.70, 4.68) increase of upper respiratory tract infection, bronchitis, pneumonia, and asthma ERVs, respectively. As for PM_2.5 constituents, we found organic carbon, ammonium, nitrate, selenium, and zinc were associated with higher risk of respiratory ERVs in the single constituent and the constituent-PM_2.5 models.

CONCLUSION

Short-term exposure to PM_2.5 was associated with increased pediatric ERVs for respiratory diseases. Constituents related to anthropogenic combustion and traffic might be the dominant contributors of the observed associations.

Short-term nitrogen dioxide exposure is associated with the spread of S. pyogenes-induced vulvovaginitis in prepubertal girls in Hangzhou, China

As a cause of vulvovaginitis in prepubertal girls, Streptococcus pyogenes (S. pyogenes) is commonly isolated from vaginal introitus swabs. Studies have identified several risk factors, but have not focused on the correlation between ambient air pollutants and S. pyogenes-induced vulvovaginitis in prepubertal girls. This study was conducted to determine whether ambient air pollutants were associated with S. pyogenes-induced vulvovaginitis in prepubertal girls. Daily data about S. pyogenes-induced vulvovaginitis in prepubertal girls from the outpatient department of Children's Hospital at the Zhejiang University School of Medicine in Hangzhou City between January 1, 2015, and December 31, 2018, were retrospectively reviewed. Ambient air pollutants in Hangzhou were measured daily. A generalized additive model (GAM) was utilized to assess the associations between daily air pollutants and S. pyogenes isolates obtained from vaginal introitus swabs of prepubertal girls. The mean daily concentration of nitrogen dioxide (NO₂) in Hangzhou City during the study period was 44.6 μg/m³ (25th-75th percentiles, 32.0-56.0 μg/m³). The GAM showed that the largest estimate effects in S. pyogenes-induced vulvovaginitis in prepubertal girls were found in NO₂ with a moving (accumulative) average on day 3. The excess risk of NO₂ in terms of the daily number of S. pyogenes isolates obtained from the vaginal introitus swabs was 14.91% (95% confidence interval [CI]: 4.85-25.94%) in the single-pollutant model. The multipollutant model revealed that an increase of 10 μg/m³ in NO₂ exposure was associated with an 18.33% increased risk for acquiring S. pyogenes-induced vulvovaginitis in prepubertal girls (95% CI: 1.21-38.35%; P < 0.05). In conclusion, short-term NO₂ exposure was strongly associated with the spread of S. pyogenes-induced vulvovaginitis in prepubertal girls.

Disease burden and attributable risk factors of respiratory infections in China from 1990 to 2019

BACKGROUND

There was lack of data on the burdens and trends of upper and lower respiratory infections (URIs and LRIs) over the past three decades in China.

METHODS

We estimated the incidence, mortality, and disability-adjusted life years (DALYs) due to upper and lower respiratory infections (URIs and LRIs) and attributable risk factors in China by a systematic analysis of the Global Burden of Disease 2019 study. Incidence, mortality, and DALYs were stratified by sex, age, and province. Risk factors for respiratory infections were analyzed from exposure data.

FINDINGS

The age-standardized incidence rates of URIs and LRIs were 179,077 and 3926 per 100,000 persons in 2019, with a 7•52% and 35•07% decrease from 1990, respectively. Moreover, 2801 and 185,264 persons died of URIs and LRIs in 2019, respectively. DALYs for URIs and LRIs also decreased from 1,516,727 in 1990 to 928,617 in 2019 and from 38,278,504 in 1990 to 4,020,676 in 2019. The burden of URIs and LRIs were generally similar in males and females, but relatively higher in the new-borns and the elderly. Child malnutrition and low birth weight were the most important cause of age-standardized DALYs of LRIs and URIs, respectively.

INTERPRETATION

Future URI and LRI prevention strategies should focus on the maternal and child health, air pollution, and tobacco control, especially in young children and the elderly population.

FUNDING

National Key R&D Program of China (2018YFA0606200); National Natural Science Foundation of China (82041021); Fundamental Research Funds for the Central Universities (20ykpy86) and Guangdong Basic and Applied Basic Research Foundation (2019A1515110003); Bill & Melinda Gates Foundation (No.: INV-006371).

Ambient air pollution and hospital visits for peptic ulcer disease in China: A three-year analysis

BACKGROUND

Peptic ulcer disease (PUD) continued to be a source of significant morbidity and mortality worldwide. Recently, it has been reported that exposure to air pollution is a potential risk factor for PUD, but evidence on the association still remains inconsistent.

METHODS

We performed an ecological study to examine the association between short-term exposure to air pollution and daily hospital visits for PUD in Yinzhou, China from January 1st, 2017 to December 31st, 2019. Distributed lag nonlinear models were used to estimate the nonlinear and lag-response effects of air pollutants. Subgroup analyses stratified by sex, age and season were conducted to examine the effect modifications.

RESULTS

Overall, we found that short-term exposure to air pollution including SO₂, NO₂, CO, O₃ and PM_2.5 was significantly associated with hospital visits for PUD among all subjects. The lag-response effects of SO₂, NO₂ and O₃ varied at different concentrations and lag days. The cumulative risk ratios of CO and PM_2.5 showed nearly linear adverse effects and increased to maxima of 2.68 (95% CI: 1.49-4.78) and 2.40 (95% CI: 1.36-4.24) with their ranges from the references to the maximum concentrations, respectively. Moreover, the cumulative risks of particulate matters on hospital visits for PUD increased significantly in cold seasons, but not in warm seasons.

CONCLUSIONS

Our findings could provide growing evidence regarding the adverse health effects of air pollution on PUD, thereby strengthening the hypothesis that air pollutants have harmful impacts on digestive system.

Air pollution exposure-the (in)visible risk factor for respiratory diseases

There is increasing interest in understanding the role of air pollution as one of the greatest threats to human health worldwide. Nine of 10 individuals breathe air with polluted compounds that have a great impact on lung tissue. The nature of the relationship is complex, and new or updated data are constantly being reported in the literature. The goal of our review was to summarize the most important air pollutants and their impact on the main respiratory diseases (chronic obstructive pulmonary disease, asthma, lung cancer, idiopathic pulmonary fibrosis, respiratory infections, bronchiectasis, tuberculosis) to reduce both short- and the long-term exposure consequences. We considered the most important air pollutants, including sulfur dioxide, nitrogen dioxide, carbon monoxide, volatile organic compounds, ozone, particulate matter and biomass smoke, and observed their impact on pulmonary pathologies. We focused on respiratory pathologies, because air pollution potentiates the increase in respiratory diseases, and the evidence that air pollutants have a detrimental effect is growing. It is imperative to constantly improve policy initiatives on air quality in both high- and low-income countries.

Spatial patterns of lower respiratory tract infections and their association with fine particulate matter

This study aimed to identify the spatial patterns of lower respiratory tract infections (LRIs) and their association with fine particulate matter (PM_2.5). The disability-adjusted life year (DALY) database was used to represent the burden each country experiences as a result of LRIs. PM_2.5 data obtained from the Atmosphere Composition Analysis Group was assessed as the source for main exposure. Global Moran's I and Getis-Ord Gi* were applied to identify the spatial patterns and for hotspots analysis of LRIs. A generalized linear mixed model was coupled with a sensitivity test after controlling for covariates to estimate the association between LRIs and PM_2.5. Subgroup analyses were performed to determine whether LRIs and PM_2.5 are correlated for various ages and geographic regions. A significant spatial auto-correlated pattern was identified for global LRIs with Moran's Index 0.79, and the hotspots of LRIs were clustered in 35 African and 4 Eastern Mediterranean countries. A consistent significant positive association between LRIs and PM_2.5 with a coefficient of 0.21 (95% CI 0.06-0.36) was identified. Furthermore, subgroup analysis revealed a significant effect of PM_2.5 on LRI for children (0-14 years) and the elderly (≥ 70 years), and this effect was confirmed to be significant in all regions except for those comprised of Eastern Mediterranean countries.

Intraday effects of outdoor air pollution on acute upper and lower respiratory infections in Australian children

Children's respiratory health are particularly vulnerable to outdoor air pollution, but evidence is lacking on the very acute effects of air pollution on the risk of acute upper respiratory infections (AURI) and acute lower respiratory infections (ALRI) in children. This study aimed to evaluate the risk of cause-specific AURI and ALRI, in children within 24 h of exposure to air pollution. We obtained data on emergency cases, including 11,091 AURI cases (acute pharyngitis, acute tonsillitis, acute obstructive laryngitis and epiglottitis, and unspecified acute upper respiratory infections) and 11,401 ALRI cases (pneumonia, acute bronchitis, acute bronchiolitis, unspecified acute lower respiratory infection) in Brisbane, Australia, 2013-2015. A time-stratified case-crossover analysis was used to examine the hourly association of AURI and ALRI with high concentration (95th percentile) of four air pollutants (particulate matters with aerodynamic diameter <10 μm (PM₁₀) and <2.5 μm (PM_2.5), ozone (O₃), nitrogen dioxide (NO₂)). We observed increased risk of acute tonsillitis associated with PM_2.5 within 13-24 h (odds ratio (OR), 1.45; 95% confidence interval [CI], 1.02-2.06) and increased risk of unspecified acute upper respiratory infections related to O₃ within 2-6 h (OR, 1.38, 95%CI, 1.12-1.70), NO₂ within 1 h (OR, 1.19; 95%CI, 1.01-1.40), and PM_2.5 within 7-12 h (OR, 1.21; 95%CI, 1.02-1.43). Cold season and nigh-time air pollution has greater effects on AURI, whereas greater risk of ALRI was seen in warm season and daytime. Our findings suggest exposures to particulate and gaseous air pollution may transiently increase risk of AURI and ALRI in children within 24 h. Prevention measures aimed at protecting children's respiratory health should consider the very acute effects of air pollution.

Short-term exposure to ambient particulate matter and outpatient visits for respiratory diseases among children: A time-series study in five Chinese cities

There was limited evidence regarding the association between short-term exposure to ambient particulate matter (PM) and respiratory outpatient visits among children at a multicity level. In this study, a time-series study was conducted among children aged 0-14 years in five Chinese cities from 2013 to 2018. City-specific effects of fine particles (PM_2.5), inhalable particles (PM₁₀) and coarse particles (PM_10-2.5) were estimated for time lags of zero up to seven previous days using the overdispersed generalized additive models after adjusting for time trends, meteorological variables, day of the week and holidays. Meta-analyses were applied to pool the overall effects, while the exposure-response (E-R) curves were evaluated using a cubic regression spline. The overall effects of PM were significantly associated with total and cause-specific respiratory outpatients among children, even at PM_2.5 and PM₁₀ levels below the current Chinese Ambient Air Quality Standards (CAAQS) Grade II. Each 10 μg/m³ increment in PM_2.5, PM₁₀ and PM_10-2.5 at lag 07 was associated with a 1.39% (95% CI: 0.38%, 2.40%), 1.10% (95% CI: 0.38%, 1.83%) and 2.93% (95% CI: 1.05%, 4.84%) increase in total respiratory outpatients, respectively. An E-R relationship was observed except for PM_2.5 in Beijing and PM₁₀ and PM_10-2.5 in Shanghai. The effects of PM were stronger in cold season in 3 southern cities, while it was stronger in transition season in 2 northern cities. In conclusion, short-term PM exposures were dose-responsive associated with increased respiratory outpatient visits among children, even for PM_2.5 and PM₁₀ levels below current CAAQS II in certain cities.

Short-Term Exposure to Fine Particulate Matter and Hospitalizations for Acute Lower Respiratory Infection in Korean Children: A Time-Series Study in Seven Metropolitan Cities

Although several studies have evaluated the association between fine particulate matter (PM_2.5) and acute lower respiratory infection (ALRI) in children, their results were inconsistent Therefore, we aimed to evaluate the association between short-term exposure to PM_2.5 and ALRI hospitalizations in children (0–5 years) living in seven metropolitan cities of Korea. The ALRI hospitalization data of children living in seven metropolitan cities of Korea from 2008 to 2016 was acquired from a customized database constructed based on National Health Insurance data. The time-series data in a generalized additive model were used to evaluate the relationship between ALRI hospitalization and 7-day moving average PM_2.5 exposure after adjusting for apparent temperature, day of the week, and time trends. We performed a meta-analysis using a two-stage design method. The estimates for each city were pooled to generate an average estimate of the associations. The average PM_2.5 concentration in 7 metropolitan cities was 29.0 μg/m³ and a total of 713,588 ALRI hospitalizations were observed during the 9-year study period. A strong linear association was observed between PM_2.5 and ALRI hospitalization. A 10 μg/m³ increase in the 7-day moving average of PM_2.5 was associated with a 1.20% (95% CI: 0.71, 1.71) increase in ALRI hospitalization. While we found similar estimates in a stratified analysis by sex, we observed stronger estimates of the association in the warm season (1.71%, 95% CI: 0.94, 2.48) compared to the cold season (0.31%, 95% CI: −0.51, 1.13). In the two-pollutant models, the PM_2.5 effect adjusted by SO₂ was attenuated more than in the single pollutant model. Our results suggest a positive association between PM_2.5 exposure and ALRI hospitalizations in Korean children, particularly in the warm season. The children need to refrain from going out on days when PM_2.5 is high.

Short term effects of air pollutants on hospital admissions for respiratory diseases among children: A multi-city time-series study in China

Evidence concerning short-term acute association between air pollutants and hospital admissions for respiratory diseases among children in a multi-city setting was quite limited. We conducted a time-series analysis to evaluate the association of six common air pollutants with hospital admissions for respiratory diseases among children aged 0-14 years in 4 cities (Guangzhou, Shanghai, Wuhan and Xining), China during 2013-2018. We used generalized additive models incorporating penalized smoothing splines and random-effect meta-analysis to calculate city-specific and pooled estimates, respectively. The exposure-response relationship curves were fitted using the cubic spline regression. Subgroup analyses by gender, age, season and disease subtype were also performed. A total of 183,036 respiratory diseases hospitalizations were recorded during the study period, and 94.1% of the cases were acute respiratory infections. Overall, we observed that increased levels of air pollutants except O₃, were significantly associated with increased hospital admissions for respiratory disease. Each 10 μg/m³ increase in PM_2.5, SO₂ and NO₂ at lag 07, PM₁₀ at lag 03 and per 1 mg/m³ increase in CO at lag 01 corresponded to increments of 1.19%, 3.58%, 2.23%, 0.51% and 6.10% in total hospitalizations, respectively. Generally, exposure-response relationships of PM_2.5 and SO₂ in Guangzhou, SO₂, NO₂ and CO in Wuhan, as well as SO₂ and NO₂ in Xining with respiratory disease hospitalizations were also found. Moreover, the adverse effects of these pollutants apart from PM_2.5 in certain cities remained significant even at exposure levels below the current Chinese Ambient Air Quality Standards (CAAQS) Grade II. Children aged 4-14 years appeared to be more vulnerable to the adverse effects of PM_2.5, SO₂ and NO₂. Furthermore, with the exception of O₃, the associations were stronger in cold season than in warm season. Short-term exposure to PM_2.5, SO₂, NO₂ and CO were associated, in dose-responsive manners, with increased risks of hospitalizations for childhood respiratory diseases, and adverse effects of air pollutants except PM_2.5 held even at exposure levels below the current CAAQS Grade II in certain cities.

Effects of short-term ambient air pollution exposure on HPV infections: A five-year hospital-based study

Human papillomavirus (HPV) infections are common sexually-transmitted diseases among reproductive-aged women with increasing concern. Until now, there are no prior study about the association between HPV infections and ambient air pollution. This study aimed to explore the relationship between short-term exposure to ambient pollutants and daily outpatient visits for HPV infections in China. Data of daily outpatient visits for HPV infections were obtained from January 1, 2014 to December 31, 2018 (1826 days). Over-dispersed Poisson generalized additive models were applied by adjusting weather conditions and day of the week. We identified a total of 39,746 cases for HPV infections. A 10 μg/m³ increase of PM₁₀, PM_2.5, SO₂, and NO₂ or a 0.1 mg/m³ rise of CO in concurrent day (lag 0) concentrations was related to an elevation of 0.822% (95% Cl: 0.282%, 1.36%), 1.05% (95% Cl: 0.280%, 1.81%), 5.72% (95% Cl: 1.79%, 9.65%), 5.02% (95% Cl: 3.45%, 6.60%), and 2.40% (95% Cl: 1.43%, 3.37%) in daily outpatient-visits for HPV infections, respectively. The association was more significant in those women aged 41 or over. As for 10 μg/m³ increase of O₃, a -1.33% (95% Cl: -2.13%, -0.530%) change was observed on the lag 03 and such effects appeared to be more obvious in the aged 18-40 group. Our results provided the first evidence that short-term exposure to ambient pollutants was related to, which may be indirectly, the increased risk of HPV infections while O₃ may act as a "protective" factor.

Association between short-term exposure to ambient air pollution and hospital visits for depression in China

Depression is one of the leading causes of disability, but the etiology remains unclear. Recently, it has been suggested that air pollution is a potential risk factor for depression. However, the results remained inconsistent. So we conducted this study to assess the association between short-term exposure to ambient air pollution and hospital visits for depression in China. Daily hospital visits for depression from January 18, 2013 to June 10, 2018 were extracted from a regional health information system (HIS) covered 1.34 million population in Ningbo, China. We collected daily air pollutant concentrations and meteorological data from environmental air quality monitoring sites and meteorological stations in the study area. Quasi-Poisson regression models with generalized additive models (GAM) were applied to explore the associations between air pollution and hospital visits for depression. Stratified analyses were also conducted by gender, age, and season to examine the effects modification. The results disclosed that air pollutants including PM_2.5, PM₁₀, SO₂, CO, and NO₂ were positively correlated with hospital visits for depression. The strongest effects all occurred on lag0 (the same) day, and the corresponding excess risks (ERs) were 2.59 (95%CI: 0.72, 4.49) for PM_2.5, 3.08 (95%CI: 1.05, 5.16) for PM₁₀, 3.22 (95%CI: 1.16, 5.32) for SO₂, 4.38 (95%CI: 1.83, 6.99) for CO, and 4.94 (95%CI: 2.03, 7.92) for NO₂ per IQR increase, respectively. The associations were found to be stronger in the elderly (≥65 years) and cold season. Furthermore, the effects of CO and NO₂ remained significant in most two-pollutant models, suggesting that traffic-related air pollutants might be more important triggers of depression.

Effects of short-term fine particulate matter exposure on acute respiratory infection in children

BACKGROUND

Previous studies on the association between fine particulate matter (PM_2.5) exposure and acute respiratory infection in children are scarce and present inconsistent results. We estimated the association between short-term PM_2.5 exposure and acute respiratory infection among children aged 0-4 years using a difference-in-differences approach.

METHODS

We used data on the daily PM_2.5 concentrations, hospital admissions for acute respiratory infection, and meteorological factors of the 15 regions in the Republic of Korea (2013-2015). To estimate the cumulative effects, we used a difference-in-differences approach generalized to multiple spatial units (regions) and time periods (day) with distributed lag non-linear models.

RESULTS

With PM_2.5 levels of 20.0 μg/m³ as a reference, PM_2.5 levels of 30.0 μg/m³ were positively associated with the risk of acute upper respiratory infection (relative risk (RR) = 1.048, 95% confidence interval (CI): 1.028, 1.069) and bronchitis or bronchiolitis (RR = 1.060, 95% CI: 1.038, 1.082) but not with the risk of acute lower respiratory infection and pneumonia. PM_2.5 levels of 40.0 μg/m³ were also positively associated with the risk of acute upper respiratory infection (RR = 1.083, 95% CI: 1.046, 1.122) and bronchitis or bronchiolitis (RR = 1.094, 95% CI: 1.054, 1.136).

CONCLUSIONS

We found the associations of short-term PM_2.5 exposure with acute upper respiratory infection and bronchitis or bronchiolitis among children aged 0-4 years. As causal inference methods can provide more convincing evidence of the effects of PM_2.5 levels on respiratory infections, public health policies and guidelines regarding PM_2.5 need to be strengthened accordingly.

Association of air pollution with outpatient visits for respiratory diseases of children in an ex-heavily polluted Northwestern city, China

BACKGROUND

A great number of studies have confirmed that children are a particularly vulnerable population to air pollution.

METHODS

In the present study, 332,337 outpatient visits of 15 hospitals for respiratory diseases among children (0-13 years), as well as the simultaneous meteorological and air pollution data, were obtained from 2014 to 2016 in Lanzhou, China. The generalized additive model was used to examine the effects of air pollutants on children's respiratory outpatient visits, including the stratified analysis of age, gender and season.

RESULTS

We found that PM_2.5, NO₂ and SO₂ were significantly associated with the increased total respiratory outpatient visits. The increments of total respiratory outpatient visits were the highest in lag 05 for NO₂ and SO₂, a 10 μg/m³ increase in NO₂ and SO₂ was associated with a 2.50% (95% CI: 1.54, 3.48%) and 3.50% (95% CI: 1.51, 5.53%) increase in total respiratory outpatient visits, respectively. Those associations remained stable in two-pollutant models. Through stratification analysis, all air pollutants other than PM₁₀ were significantly positive associated with the outpatients of bronchitis and upper respiratory tract infection. Besides, both NO₂ and SO₂ were positively related to the pneumonia outpatient visits. PM_2.5 and SO₂ were significantly related to the outpatient visits of other respiratory diseases, while only NO₂ was positively associated with the asthma outpatients. We found these associations were stronger in girls than in boys, particularly in younger (0-3 years) children. Interestingly, season stratification analysis indicated that these associations were stronger in the cold season than in the transition or the hot season for PM₁₀, PM_2.5 and SO₂.

CONCLUSIONS

Our results indicate that the air pollution exposure may account for the increased risk of outpatient visits for respiratory diseases among children in Lanzhou, particularly for younger children and in the cold season.

Short-term exposure to ZnO/MCB persistent free radical particles causes mouse lung lesions via inflammatory reactions and apoptosis pathways

Environmentally persistent free radicals (EPFRs) are easily generated in the combustion processes of municipal solid waste (MSW) and can cause adverse effects on human health. This study focuses on understanding the toxicity of EPFR particles (ZnO/MCB containing EPFRs) to human bronchial epithelial cell lines BEAS-2B and 16HBE, murine macrophages Raw264.7, and the lung of BALB/c mice after a short exposure (7 days). Exposure of BEAS-2B, 16HBE, and Raw264.7 cells to ZnO/MCB particles significantly increased the reactive oxygen species (ROS) production and perturbed levels of intracellular redox conditions (decreased the intracellular GSH level and the activity of cytosolic SOD, and stimulated oxidative stress related proteins such as HO-1 and Nrf2). EPFR particles decreased the mitochondrial membrane potential (MMP) and induced cell apoptosis, including the activation of Caspase-3, Bax, and Bcl-2 apoptotic signalling pathways. A signature inflammatory condition was observed in both cell models and the mouse model for lung lesions. Our data suggest that EPFRs in particles have greater toxicity to lung cells and tissues that are potential health hazards to human lung.

Effect modification of the short-term effects of air pollution on morbidity by season: A systematic review and meta-analysis

Studies of the health effects of air pollution have traditionally controlled for ambient temperature as a confounder, and vice versa. However, season might be an important factor contributing to adverse health effects of air pollution. Given the current inconsistencies in results of previous studies on the effect modification of air pollution on morbidity by season, a systematic review and meta-analysis was conducted to synthesize the current evidence on effects of season on air pollution and morbidity. The electronic databases including PubMed, Web of Science, Embase, CNKI, and Wanfang were used to identify papers published up to the 30st of November in 2019. We identified 4284 articles, after screening, eighty papers met the inclusion criteria. Significant effect modification of CO, O₃, SO₂ and NO₂ on morbidity by season was observed, with corresponding ratio of relative risk of 1.0009 (95% CI: 1.0001-1.0018), 1.0080 (95% CI: 1.0021-1.0138), 0.9828 (95% CI: 0.9697-0.9962) and 0.9896 (95% CI: 0.9824-0.9968), respectively. Season significantly modified the effect of CO on pneumonia, the effect of SO₂ on cardiovascular disease, the effect of PM₁₀ on stroke, and the effect of O₃ on stroke, asthma and pneumonia. The effect modifications of air pollution by season were similar among males and females, while the effect estimates seem to be higher among children under 18 years old and the elderly aged 75 or over. Further research is needed to better understand the mechanisms underlying the seasonal variance of the effect of air pollutants on morbidity.

The association of short-term effects of air pollution and sleep disorders among elderly residents in China

Sleep disorders, oftentimes co-occurring with other mental and neurological disorders in the elderly, have been previously linked to short-term exposures to air pollution. Here we assessed such associations among 395,651 elderly Chinese in Ningbo, China where air pollution exposures are high and the proportion of elderly in the population is growing. We utilized a regional health information database in China (2008-2017) that collected information on hospital visits for sleep disorders among the elderly (age 60+). Measures of daily air pollution concentrations including nitrogen dioxide (NO₂), sulfur dioxide (SO₂), ozone (O₃), inhalable particles (PM₁₀), and ambient fine particulate matter (PM_2.5) were generated from seven environmental air quality monitoring sites in the study area. We used a generalized additive model to evaluate the associations between hospital visits for sleep disorders and short-term air pollution exposures for up to 7 days prior to a hospital visit. Short-term exposure to multiple air pollutants was associated with hospital visits for sleep disorders in an elderly population; with the strongest associations during 2-3 days prior to a clinic visits for traffic-related pollutants including air quality index (AQI), PM_2.5, PM₁₀, and NO₂ and for SO₂ and O₃ for 5 days prior to the visits. Our study based on large health care record system suggested that short-term air pollution exposures are associated with sleep disorders in the elderly. Considering the individual covariates that could not be adjusted in time-series analyses, future studies with individual level data and an ability to evaluate the severity of sleep disorders and their relation to mental and physical health in general and air pollution are needed. An aging population with increasing health problems and the frequency of high and very high air pollution events in China make our findings very health policy relevant.

Disease spectrum analysis of hospitalized children in China: A study of 18 tertiary children's hospitals

IMPORTANCE

Morbidity and mortality of children are important indicators of the performance of the public health system in any country. In China, the children's disease spectrum has gradually changed in recent years. However, the gender- and age-specific disease spectrum for hospitalized children under 15 years old is still unclear.

OBJECTIVE

To explore the gender- and age-based distribution of diseases in hospitalized children under 15 years in China.

METHODS

Medical records home page data for 2016 to 2018 were collected from 18 tertiary children's hospitals in China. The gender- and age-specific disease spectrum was analyzed, using the tenth revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10).

RESULTS

The most common diseases were those of the respiratory system (25.7% of all 2 232 142 hospitalized children). The top three diseases for boys were diseases of the respiratory system (25.6%), diseases of the digestive system (11.4%) and certain conditions originating in the perinatal period (8.6%). The top three diseases for girls were diseases of the respiratory system (25.9%), certain conditions originating in the perinatal period (10.1%), and factors influencing health status and contact with health services (9.4%). The most common diseases for children under 1 year old were certain conditions originating in the perinatal period (38.1%). For all other age groups, the most common conditions were respiratory diseases (33.8% for those aged 1-3 years, 25.2% for those aged 4-6 years, and 12.2% for those aged 7-14 years).

INTERPRETATION

This study analyzed the medical records home pages of 18 children's hospitals to provide the first overview of the disease spectrum and its gender- and age-specific distribution among children in China.

[Flu-like disease in summer - what do we know about it?]

Durchsucht man die deutschsprachige medizinische Literatur nach dem Begriff „Sommergrippe“, scheitert man kläglich. Jeder glaubt zu wissen, was damit gemeint ist, doch keiner schreibt darüber. Ist das überhaupt ein seriöses Thema?

Association of Visit-to-Visit Variability of Blood Pressure with Cardiovascular Disease among Type 2 Diabetes Mellitus Patients: A Cohort Study

BACKGROUND

Increasing evidence has shown that visit-to-visit variability (VVV) of blood pressure (BP) is associated with an increased risk of cardiovascular disease (CVD). The objective of this study was to evaluate the impact of VVV of systolic blood pressure (SBP) and diastolic blood pressure (DBP) on the risk of CVD among patients with type 2 diabetes mellitus (T2DM) in China.

METHODS

We conducted a retrospective cohort study of 10,163 T2DM patients who were not previously diagnosed with CVD from January 2008 to December 2012 in Ningbo, China. The VVV of BP was calculated using five metrics, including standard deviation (SD), coefficient of variation (CV), variation independent of mean, average real variability, and successive variability (SV) of measurements, obtained over a 24-month measurement period. Hazard ratios and 95% confidence intervals (CIs) were estimated by Cox proportional hazards regression models for the associations of variability in BP with risk of CVD.

RESULTS

A total of 894 CVD events were observed during a median follow-up of 49.5 months. The hazard ratio in the highest quintile of SD of SBP was 1.24 (95% CI, 1.01 to 1.52) compared with patients in the lowest quintile. The association between higher VVV of DBP and risk of CVD was not consistent across different metrics and sensitivity analyses.

CONCLUSION

Higher VVV of SBP was associated with an increased risk of CVD, irrespective of the mean SBP level. Future studies are needed to confirm these findings.

Association between ambient air pollutants and preterm birth in Ningbo, China: a time-series study

BACKGROUND

Exposure to air pollutants has been related to preterm birth, but little evidence can be available for PM2.5, O3 and CO in China. This study aimed to investigate the short-term effect of exposure to air pollutants on risk preterm birth during 2014-2016 in Ningbo, China.

METHODS

We conducted a time-series study to evaluate the associations between daily preterm birth and major air pollutants (including PM2.5, PM10, SO2, NO2, O3 and CO) in Ningbo during 2014-2016. A General Additive Model extend Poisson regression was used to evaluate the relationship between preterm birth and air pollution with adjustment for time-trend, meteorological factors and day of the week (DOW). We also conducted a subgroup analysis by season and age.

RESULTS

In this study, a total of 37,389 birth occurred between 2014 and 2016 from the Electronic Medical Records System of Ningbo Women and Children's Hospital, of which 5428 were verified as preterm birth. The single pollutant model suggested that lag effect of PM2.5, PM10, NO2 reached a peak at day 3 before delivery and day 6 for SO2, and no relationships were observed for O3 and preterm birth. Excess risks (95% confidence intervals) for an increase of IQR of air pollutant concentrations were 4.84 (95% CI: 1.77, 8.00) for PM2.5, 3.56 (95% CI: 0.07, 7.17) for PM10, 3.65 (95% CI: 0.86, 6.51) for SO2, 6.49 (95% CI: 1.86, 11.34) for NO2, - 0.90 (95% CI: -4.76, 3.11) for O3, and 3.36 (95% CI: 0.50, 6.30) for CO. Sensitivity analyses by exclusion of maternal age < 18 or > 35 years did not materially alter our results.

CONCLUSIONS

This study indicates that short-term exposure to air pollutants (including PM2.5, PM10, SO2, NO2) are positively associated with risk of preterm birth in Ningbo, China.

Acute effects of ambient air pollution on outpatient children with respiratory diseases in Shijiazhuang, China

Background

Associations between ambient air pollution and child health outcomes have been well documented in developed countries such as the United States; however, only a limited number of studies have been conducted in developing countries. This study aimed to explore the acute effects of five ambient air pollutants (inhalable particles [PM₁₀], fine particles [PM_2.5], sulfur dioxide [SO₂], nitrogen dioxide [NO₂] and 0zone [O₃]) on children hospital outpatients with respiratory diseases in Shijiazhuang, China.

Methods

Three years (2013–2015) of daily data, including cause-specific respiratory outpatient records and the concentrations of five air pollutants, were collected to examine the short-term association between air pollution and children’s respiratory diseases; using a quasi-Poisson regression generalized additive model. Stratified analyses by season and age were also performed.

Results

From 2013 to 2015, a total of 551,678 hospital outpatient records for children with respiratory diseases were collected in Shijiazhuang, China. A 10 μg/m³ increase in a two-day average concentration (lag01) of NO₂, PM_2.5, and SO₂ corresponded to an increase of 0.66% (95% confidence interval [CI]: 0.30–1.03%), 0.13% (95% CI: 0.02–0.24%), and 0.33% (95% CI: 0.10–0.56%) in daily hospital outpatient visits for children with respiratory diseases, respectively. The effects were stronger in the transition season (April, May, September and October) than in other seasons (the hot season [June to August] and the cool season [November to March]). Furthermore, results indicated a generally stronger association in older (7–14 years of age) than younger children (< 7 years of age).

Conclusions

This research found a significant association between ambient NO₂, PM_2.5, and SO₂ levels and hospital outpatient visits in child with respiratory diseases in Shijiazhuang, China.

Exposure to traffic-related air pollution and acute bronchitis in children: season and age as modifiers

Background

Acute bronchitis (AB) is one of the principal causes of childhood morbidity. Increasing number of studies has shown that air pollution is an important environmental contributor of respiratory disease. However, evidence so far is scarce regarding the effects of air pollution on childhood AB, and it also remains unclear how the risk of AB will change by season and age.

Methods

Data on hospital visits for AB in children, air pollution and meteorological factors from 1 January 2015 to 31 December 2016 were collected in Hefei, China. Time-series analysis was applied to assess the short-term effects of traffic-related air pollution on childhood AB outpatient visits. A Poisson generalised linear regression model combined with a distributed lag non-linear model was used to estimate the relationships, controlling for long-term trends, seasonal patterns, meteorological factors and other possible confounders.

Results

We found that an IQR increase in concentrations of nitrogen dioxide, particulate matter <2.5 µm and carbon monoxide significantly increased the daily hospital visits for childhood AB with 4-day cumulative effect estimates (relative risks: 1.03, 95% CI 1.01 to 1.05; 1.09, 95% CI 1.07 to 1.11; 1.07, 95% CI 1.05 to 1.09). Notably, the risk estimates during the cold season are pronounced; however, no significant association was observed during the warm season. Interestingly, children aged 6–14 years were more vulnerable to air pollutants than children aged less than 1 year and within 1–5 years. However, no gender difference was observed.

Conclusion

A significant association of traffic-related air pollution and increased department visits for childhood AB was observed, notably in school-age children and during the cold season.