Interaction effects of temperature and ozone on lung function and markers of systemic inflammation, coagulation, and fibrinolysis: a crossover study of healthy young volunteers

Temperature modification of air pollutants and their synergistic effects on respiratory diseases in a semi-arid city in Northwest China

Air pollutants and temperature are significant threats to public health, and the complex linkages between the environmental factors and their interactions harm respiratory diseases. This study is aimed to analyze the impact of air pollutants and meteorological factors on respiratory diseases and their synergistic effects in Dingxi, a city in northwestern China, from 2018 to 2020 using a generalized additive model (GAM). Relative risk (RR) was employed to quantitatively evaluate the temperature modification on the short-term effects of PM2.5 and O3 and the synergistic effects of air pollutants (PM2.5 and O3) and meteorological elements (temperature and relative humidity) on respiratory diseases. The results indicated that the RRs per inter-quatile range (IQR) rise in PM2.5 and O3 concentrations were (1.066, 95% CI: 1.009-1.127, lag2) and (1.037, 95% CI: 0.975-1.102, lag4) for respiratory diseases, respectively. Temperature stratification suggests that the influence of PM2.5 on respiratory diseases was significantly enhanced at low and moderate temperatures, and the risk of respiratory diseases caused by O3 was significantly increased at high temperatures. The synergy analysis demonstrated significant a synergistic effect of PM2.5 with low temperature and high relative humidity and an antagonistic effect of high relative humidity and O3 on respiratory diseases. The findings would provide a scientific basis for the impact of pollutants on respiratory diseases in Northwest China.

Accelerated aging and altered subclinical response to ozone exposure in young, healthy adults

Ozone exposure induces a myriad of adverse cardiopulmonary outcomes in humans. Although advanced age and chronic disease are factors that may exacerbate a person's negative response to ozone exposure, there are no molecular biomarkers of susceptibility. Here, we examine whether epigenetic age acceleration (EAA) is associated with responsiveness to short-term ozone exposure. Using data from a crossover-controlled exposure study (n = 17), we examined whether EAA, as measured in lung epithelial cells collected 24 h after clean air exposure, modifies the observed effect of ozone on autonomic function, cardiac electrophysiology, hemostasis, pulmonary function, and inflammation. EAA was assessed in lung epithelial cells extracted from bronchoalveolar lavage fluids, using the pan-tissue aging clock. We used two analytic approaches: (i) median regression to estimate the association between EAA and the estimated risk difference for subclinical responses to ozone and (ii) a block randomization approach to estimate EAA's effect modification of subclinical responses. For both approaches, we calculated Fisher-exact P-values, allowing us to bypass large sample size assumptions. In median regression analyses, accelerated epigenetic age modified associations between ozone and heart rate-corrected QT interval (QTc) ([Formula: see text]= 0.12, P-value = 0.007) and between ozone and C-reactive protein ([Formula: see text] = -0.18, P = 0.069). During block randomization, the directions of association remained consistent for QTc and C-reactive protein; however, the P-values weakened. Block randomization also revealed that responsiveness of plasminogen activator inhibitor-1 (PAI-1) to ozone exposure was modified by accelerated epigenetic aging (PAI-1 difference between accelerated aging-defined block groups = -0.54, P-value = 0.039). In conclusion, EAA is a potential biomarker for individuals with increased susceptibility to ozone exposure even among young, healthy adults.

An expert review of environmental heat exposure and stillbirth in the face of climate change: Clinical implications and priority issues

Exposure to extreme heat in pregnancy increases the risk of stillbirth. Progress in reducing stillbirth rates has stalled, and populations are increasingly exposed to high temperatures and climate events that may further undermine health strategies. This narrative review summarises the current clinical and epidemiological evidence of the impact of maternal heat exposure on stillbirth risk. Out of 20 studies, 19 found an association between heat and stillbirth risk. Recent studies based in low- to middle-income countries and tropical settings add to the existing literature to demonstrate that all populations are at risk. Additionally, both short-term heat exposure and whole-pregnancy heat exposure increase the risk of stillbirth. A definitive threshold of effect has not been identified, as most studies define exposure as above the 90th centile of the usual temperature for that population. Therefore, the association between heat and stillbirth has been found with exposures from as low as >12.64°C up to >46.4°C. The pathophysiological pathways by which maternal heat exposure may lead to stillbirth, based on human and animal studies, include both placental and embryonic or fetal impacts. Although evidence gaps remain and further research is needed to characterise these mechanistic pathways in more detail, preliminary evidence suggests epigenetic changes, alteration in imprinted genes, congenital abnormalities, reduction in placental blood flow, size and function all play a part. Finally, we explore this topic from a public health perspective; we discuss and evaluate the current public health guidance on minimising the risk of extreme heat in the community. There is limited pregnancy-specific guidance within heatwave planning, and no evidence-based interventions have been established to prevent poor pregnancy outcomes. We highlight priority research questions to move forward in the field and specifically note the urgent need for evidence-based interventions that are sustainable.

Effects of extreme temperature events on deaths and its interaction with air pollution

BACKGROUND

Both extreme temperature events (ETEs) and air pollution affected human health, and their effects were often not independent. Previous studies have provided limited information on the interactions between ETEs and air pollution.

METHODS

We collected data on deaths (non-accidental, cardiovascular, and respiratory) in Zibo City along with daily air pollution and meteorological data from January 2015 to December 2019. Distributed lag non-linear model was used to explore the health effects of ETEs on deaths. Non-parametric binary response model, hierarchical model and joint effect model were used to further explore the interaction between ETEs and air pollution in different seasons. Meanwhile, subgroup analysis by gender and age (≥ 65 years old and < 65 years old) was conducted to identify the vulnerable population.

RESULTS

ETEs increased death risk, especially for cardiovascular and respiratory deaths. Heat waves had a stronger impact than cold spells. Cold spells had a longer lag and fluctuating trend. Heat waves had a short-term impact, followed by a decrease. Females and those aged ≥ 65 were more affected, but subgroup differences were not significant. During ETEs and non-ETEs, there were different effects on deaths with per IQR increase in air pollutant concentrations. Joint effect models revealed that there was a significant interaction between ETEs and air pollution on non-accidental deaths. The interaction between PM2.5 and cold spells was antagonistic in the cold season. In the warm season, the health effects of heat waves and high O3 concentration were enhanced. The relative excess risk due to interaction (RERI) of cold spells and PM2.5 in total population was -0.09 (95 % CI: -0.17, -0.01), and 9 % (95 % CI: 1 %, 17 %) of the total effect was attributable to interaction. Subgroup analysis confirmed the interactions in females and those aged ≥ 65.

CONCLUSIONS

Significant association observed between ETEs and deaths. Females and ≥ 65 age groups were vulnerable. There were interactions between ETEs and air pollution. The effect of PM2.5 on deaths decreased during cold spells, while the effect of O3 increased during heat waves. In addition to improving air quality, it is necessary to further strengthen the prevention and control of ETEs.

Association between long-term exposure to ambient air pollution and lesion ischemia in patients with atherosclerosis

BACKGROUND AND AIMS

Air pollution has been associated with coronary artery disease. The underlying mechanisms were understudied, especially in relation to coronary stenosis leading to myocardial ischemia. Advances in computed tomography (CT) allow for novel quantification of lesion ischemia. We aim to investigate associations between air pollution exposures and fractional flow reserve on CT (CT-FFR), a measure of coronary artery blood flow.

METHODS

CT-FFR, which defines a ratio of maximal myocardial blood flow compared to its normal value (range: 0-100%), was characterized in 2017 patients with atherosclerosis between 2015 and 2017. Exposures to ozone (O3), nitrogen dioxide (NO2), and fine particulate matter (PM2.5) were estimated using high-resolution exposure models. Linear and logistic regression models were used to assess the association of each air pollutant with CT-FFR and with the prevalence of clinically relevant myocardial ischemia (CT-FFR <75%).

RESULTS

Participants were on average 60.1 years old. Annual mean O3, NO2, PM2.5 were 61, 47 and 60 μg/m3, respectively. Mean CT-FFR value was 76.9%. In the main analysis, a higher level of O3 was associated with a lower CT-FFR value (-1.74%, 95% CI: -2.85, -0.63 per 8 μg/m3) and a higher prevalence of myocardial ischemia (odds ratio: 1.32, 95% CI: 1.05-1.65), adjusting for potential confounders such as risk factors and plaque phenotypes, independent of the effects of exposure to NO2 and PM2.5. No associations were observed for PM2.5 or NO2 with CT-FFR.

CONCLUSIONS

Long-term exposure to O3 is associated with lower CT-FFR value in atherosclerotic patients, indicating higher risk of lesion ischemia.

Concurrent Heat and Air Pollution Exposures among People Experiencing Homelessness

BACKGROUND

Extreme heat and air pollution are important human health concerns; exposure can affect mental and physical well-being, particularly during periods of co-occurrence. Yet, the impacts on people are largely determined by underlying health conditions, coupled with the length and intensity of exposure. Preexisting adverse health conditions and prolonged exposure times are more common for people experiencing homelessness, particularly those with intersectional identity characteristics (e.g., disease, ability, age, etc.). Partially due to methodological limitations, such as data scarcity, there is a lack of research at the intersection of this at-risk population within the climate-health domain.

OBJECTIVES

We have three distinct objectives throughout this article: a) to advance critical discussions around the state of concurrent high heat and air pollution exposure research as it relates to people experiencing homelessness; b) to assert the importance of heat and air pollution exposure research among a highly vulnerable, too-often homogenized population-people experiencing homelessness; and c) to underline challenges in this area of study while presenting potential ways to address such shortcomings.

DISCUSSION

The health insights from concurrent air pollution and heat exposure studies are consequential when studying unhoused communities who are already overexposed to harmful environmental conditions. Without holistic data sets and more advanced methods to study concurrent exposures, appropriate and targeted prevention and intervention strategies cannot be developed to protect this at-risk population. We highlight that a) concurrent high heat and air pollution exposure research among people experiencing homelessness is significantly underdeveloped considering the pressing human health implications; b) the severity of physiological responses elicited by high heat and air pollution are predicated on exposure intensity and time, and thus people without means of seeking climate-controlled shelter are most at risk; and c) collaboration among transdisciplinary teams is needed to resolve data resolution issues and enable targeted prevention and intervention strategies. https://doi.org/10.1289/EHP13402.

Associations between PM2.5 and O3 exposures and new onset type 2 diabetes in regional and national samples in the United States

BACKGROUND

Exposure to particulate matter ≤2.5 μm in diameter (PM2.5) and ozone (O3) has been linked to numerous harmful health outcomes. While epidemiologic evidence has suggested a positive association with type 2 diabetes (T2D), there is heterogeneity in findings. We evaluated exposures to PM2.5 and O3 across three large samples in the US using a harmonized approach for exposure assignment and covariate adjustment.

METHODS

Data were obtained from the Veterans Administration Diabetes Risk (VADR) cohort (electronic health records [EHRs]), the Reasons for Geographic and Racial Disparities in Stroke (REGARDS) cohort (primary data collection), and the Geisinger health system (EHRs), and reflect the years 2003-2016 (REGARDS) and 2008-2016 (VADR and Geisinger). New onset T2D was ascertained using EHR information on medication orders, laboratory results, and T2D diagnoses (VADR and Geisinger) or report of T2D medication or diagnosis and/or elevated blood glucose levels (REGARDS). Exposure was assigned using pollutant annual averages from the Downscaler model. Models stratified by community type (higher density urban, lower density urban, suburban/small town, or rural census tracts) evaluated likelihood of new onset T2D in each study sample in single- and two-pollutant models of PM2.5 and O3.

RESULTS

In two pollutant models, associations of PM2.5, and new onset T2D were null in the REGARDS cohort except for in suburban/small town community types in models that also adjusted for NSEE, with an odds ratio (95% CI) of 1.51 (1.01, 2.25) per 5 μg/m3 of PM2.5. Results in the Geisinger sample were null. VADR sample results evidenced nonlinear associations for both pollutants; the shape of the association was dependent on community type.

CONCLUSIONS

Associations between PM2.5, O3 and new onset T2D differed across three large study samples in the US. None of the results from any of the three study populations found strong and clear positive associations.

High temperature exacerbates ozone-induced airway inflammation: Implication of airway microbiota and metabolites

Short-term exposure to ozone (O3) has been associated with airway inflammation. Given that high temperature (HT) accelerates O3 production, it is of significance to determine whether co-exposure to HT exacerbates O3-induced airway inflammation. The aim of this study was to examine the possible promotive effect of HT on O3-induced airway inflammation and underlying mechanisms. Forty-eight C57BL/6 N male mice were randomly divided into four groups: filtered air (control), O3, HT, and HT + O3 (co-exposure) groups. Mice in control and O3 groups were exposed to filtered air or 1 ppm O3 at 24 °C, respectively, while mice in HT and co-exposure groups were exposed to filtered air or 1 ppm O3 at 36 °C, respectively. The exposure scenario for four groups was 4 h/d for 5 consecutive days. Bronchoalveolar lavage fluids (BALF) were collected 24 h after the last exposure and subjected to examinations of oxidative stress and inflammation biomarkers, 16S rRNA sequencing, and metabolic profiling. Lung tissues were processed for H&E histological staining. The results showed that O3 inhalation triggered oxidative stress and inflammation in the airways, which was worsen by co-exposure to HT. Further studies revealed that co-exposure to HT strengthened O3-induced decline in Firmicutes and Allobaculum in airways. Moreover, co-exposure to HT promoted O3-induced airway metabolic disorder. Spearman correlation analysis revealed correlations among microbiota dysbiosis, metabolic disorder, oxidative stress and inflammation induced by co-exposure to HT and O3. Taken together, HT exposure aggravates O3-induced airway oxidative stress and inflammation, possibly through modulation of microbiota and metabolism of the airways.

Developing Climate Change and Health Impact Monitoring with eHealth at the South East Asia Community Observatory and Health and Demographic Surveillance Site, Malaysia (CHIMES)

Background

Malaysia is projected to experience an increase in heat, rainfall, rainfall variability, dry spells, thunderstorms, and high winds due to climate change. This may lead to a rise in heat-related mortality, reduced nutritional security, and potential migration due to uninhabitable land. Currently, there is limited data regarding the health implications of climate change on the Malaysian populace, which hinders informed decision-making and interventions.

Objective

This study aims to assess the feasibility and reliability of using sensor-based devices to enhance climate change and health research within the SEACO health and demographic surveillance site (HDSS) in Malaysia. We will particularly focus on the effects of climate-sensitive diseases, emphasizing lung conditions like chronic obstructive pulmonary disease (COPD) and asthma.

Methods

In our mixed-methods approach, 120 participants (>18 years) from the SEACO HDSS in Segamat, Malaysia, will be engaged over three cycles, each lasting 3 weeks. Participants will use wearables to monitor heart rate, activity, and sleep. Indoor sensors will measure temperature in indoor living spaces, while 3D-printed weather stations will track indoor temperature and humidity. In each cycle, a minimum of 10 participants at high risk for COPD or asthma will be identified. Through interviews and questionnaires, we will evaluate the devices' reliability, the prevalence of climate-sensitive lung diseases, and their correlation with environmental factors, like heat and humidity.

Results

We anticipate that the sensor-based measurements will offer a comprehensive understanding of the interplay between climate-sensitive diseases and weather variables. The data is expected to reveal correlations between health impacts and weather exposures like heat. Participant feedback will offer perspectives on the usability and feasibility of these digital tools.

Conclusion

Our study within the SEACO HDSS in Malaysia will evaluate the potential of sensor-based digital technologies in monitoring the interplay between climate change and health, particularly for climate-sensitive diseases like COPD and asthma. The data generated will likely provide details on health profiles in relation to weather exposures. Feedback will indicate the acceptability of these tools for broader health surveillance. As climate change continues to impact global health, evaluating the potential of such digital technologies is crucial to understand its potential to inform policy and intervention strategies in vulnerable regions.

The mediation of the placenta on the association between maternal ambient temperature exposure and birth weight

Studies have indicated that exposure to low and high temperatures during pregnancy negatively affects fetal development. The placenta plays vital functions in fetal development and could also be impacted by suboptimal temperatures. However, whether the placenta mediates the association between suboptimal temperature and birth weight is unknown. Our study aims to evaluate the association between ambient temperature and birth weight as well as the mediation effect of the placenta. A prospective birth cohort study was conducted during 2017-2020 in Guangzhou, China (n = 3349 participants). We defined extreme temperature exposure during the whole pregnancy by using different thresholds, including low temperatures (< 25th, < 15th, < 10th, < 5th percentiles), and high temperatures (> 75th, > 85th, > 90th, > 95th percentiles). Three different approaches (generalized linear model, inverse probability weighting, and doubly robust model) were applied to estimate the effects of low/high temperatures on birth weight and placental indicators, including placental weight, placental volume, and placental-to-birth weight ratio (PFR), respectively. We observed that both low and high ambient temperatures during the whole pregnancy were associated with lower birth weight and negative changes in placental indicators. The estimated lower mean birth weight ranged from -158 g (95 % CI: -192 g, -123 g) to -363 g (95 % CI: -424 g, -301 g) for low temperatures and from -97 g (95 % CI: -135 g, -59 g) to -664 g (95 % CI: -742 g, -585 g) for high temperatures. In mediation analyses, placental weight mediated 28.79 % to 40.47 % and 48.22 % to 54.38 % of the association of low and high temperatures with birth weight, respectively. The findings suggest that placental weight may mediate the association between ambient temperature exposure and birth weight.

Ambient temperature exposure causes lung function impairment: The evidence from Controlled Temperature Study in Healthy Subjects (CTSHS)

BACKGROUND

The effect of non-optimal ambient temperatures (low and high temperatures) on lung function and the underlying mechanisms remains unclear.

METHODS

Forty-three (20 males, 23 females) healthy non-obese volunteers with an average of 23.9 years participated in the controlled temperature study. All volunteers underwent three temperature exposures in a sequence (moderate [18 °C], low [6 °C], and high [30 °C] temperatures) lasting 12 h with air pollutants controlled. lung function parameters (forced vital capacity [FVC], forced expiratory volume in 1 s [FEV₁], and peak expiratory flow [PEF]) were determined in each exposure. Blood and urine samples were collected after each exposure and assayed for inflammatory markers [C-reactive protein (CRP), procalcitonin (PCT), platelet-lymphocyte ratio (PLR), and neutrophil-lymphocyte ratio (NLR)] and oxidative damage markers [protein carbonylation (PCO), 4-hydroxy-2-nominal-mercapturic acid (HNE-MA), 8-iso-prostaglandin-F_2α (8-isoPGF_2α), and 8-hydroxy-2-deoxyguanosine (8-OHdG)]. Mixed-effects models were constructed to assess the changes of the above indexes under low or high temperatures relative to moderate temperature, and then the repeated measures correlation analyses were performed.

RESULTS

Compared with moderate temperature, a 2.20% and 2.59% net decrease in FVC, FEV₁, and a 5.68% net increase for PEF were observed under low-temperature exposure, while a 1.59% net decrease in FVC and a 7.29% net increase in PEF under high-temperature exposure were found (all P < 0.05). In addition, low temperature elevated inflammatory markers (PCT, PLR, and NLR) and oxidative damage markers (8-isoPGF_2α, 8-OHdG), and high temperature elevated HNE-MA. Repeated measures correlation analyses revealed that PCT (r = -0.33) and NLR (r = -0.31) were negatively correlated with FVC and HNE-MA (r = -0.35) and 8-OHdG (r = -0.31) were negatively correlated with the FEV₁ under low-temperature exposure (all P < 0.05).

CONCLUSION

Non-optimal ambient temperatures exposure alters lung function, inflammation, and oxidative damage. Inflammation and oxidative damage might be involved in low temperature-related lung function reduction.

Association between ambient air pollution and daily hospital visits for cardiovascular diseases in Wuhan, China: a time-series analysis based on medical insurance data

Although evidence showed the adverse effects of air pollution on cardiovascular disease (CVDs), few studies were based on medically insured populations. We applied a generalized additive Poisson model (GAM) to estimate the short-term effects of ambient air pollution on a group of medically insured population in Wuhan, China. We extracted daily air pollution data, meteorological data, and daily hospital visits for CVDs. We found that the ambient air pollutants sulfur dioxide (SO₂), nitrogen dioxide (NO₂), ground-level ozone (O₃) particulate matter (PM) with an aerodynamic diameter ≤10 μm (PM₁₀), and those ≤2.5 μm (PM_2.5) all increased the risk of daily hospital visits for CVDs. We also found that the effect of air pollution on daily hospital visits for CVDs is greater in the cold season than in the warm season. Our findings can be used as evidence that supports the formulation of policies for air pollution and CVDs.

Ambient PM2.5, ozone and mortality in Chinese older adults: A nationwide cohort analysis (2005-2018)

BACKGROUND

Cohort evidence linking long-term survival with exposure to multiple air pollutants (e.g., fine particulate matter [PM_2.5] and ozone) was extensively sparse in low- and middle-income countries, especially among older adults. This study aimed to investigate potential associations of long-term exposures to PM_2.5 and ozone with all-cause mortality in Chinese older adults.

METHODS

A dynamic nationwide prospective cohort comprising 20,352 adults aged ≥65 years were enrolled from the Chinese Longitudinal Healthy Longevity Study and followed up through 2005-2018. Participants' annual exposures to warm-season ozone and year-round PM_2.5 were assigned using satellite-derived spatiotemporal estimates. A directed acyclic graph (DAG) was developed to identify confounding variables. Associations of annual mean exposures to PM_2.5 and ozone with mortality were evaluated using single- and two-pollutant Cox proportional hazards models, adjusting for time-dependent individual risk factors and ambient temperature.

RESULTS

During 100 thousand person-years of follow-up (median: 3.6 years), a total of 14,313 death events occurred. The participants were averagely aged 87.1 years at baseline and exposed to a wide range of annual average concentrations of warm-season maximum 8-hour ozone (mean, 54.4 ppb; range, 23.3-81.6 ppb) and year-round PM_2.5 (mean, 65.5 μg/m³; range, 10.1-162.9 μg/m³). Approximately linear concentration-response relationship was identified for ozone, whereas significant increases in PM_2.5-associated mortality risks were observed only when concentrations were above 60 μg/m³. Rises of 10 ppb in ozone and 10 µg/m³ in PM_2.5 above 60 µg/m³ were associated with increases in all-cause mortality of 13.2% (95% confidence interval [CI]: 10.2-16.2%) and 6.2% (95% CI: 4.6-7.7%) in DAG-based single-pollutant model, and of 9.7% (95% CI: 6.6-13.0%) and 5.3% (95% CI: 3.7-6.9%) in DAG-based two-pollutant model, respectively. We detected significant effect modification by temperature in associations of mortality with ozone (P <0.001 for interaction), suggesting greater ozone-related risks among participants in warmer locations.

CONCLUSIONS

This study provided longitudinal evidence that long-term exposure to ambient PM_2.5 and ozone significantly and independently contributed to elevated risks of all-cause mortality among older adults in China.

Effect modification by temperature on the association between O3 and emergency ambulance dispatches in Japan: A multi-city study

Numerous epidemiological studies have reported that ozone (O₃) and temperature are independently associated with health outcomes, but modification of the effects of O₃ on health outcomes by temperature, and vice versa, has not been fully described. This study aimed to investigate effect modification by temperature on the association between O₃ and emergency ambulance dispatches (EADs) in Japan. Data on daily air pollutants, ambient temperature, and EADs were obtained from eight Japanese cities from 2007 to 2015. A distributed lag non-linear model combined with Poisson regression was performed with temperature as a confounding factor and effect modifier to estimate the effects of O₃ on EADs at low (<25th percentile), moderate (25th-75th percentile), and high (>75th percentile) temperature for each city. The estimates obtained from each city were pooled by random-effects meta-analysis. When temperature was entered as a confounder, the estimated effects of O₃ on EADs for all acute, cardiovascular, and respiratory illnesses were largest at lag 0 (current-day lag). Therefore, this lag was used to further estimate the effects of O₃ on EADs in each temperature category. The estimated effects of O₃ on EADs for all acute, cardiovascular, and respiratory illnesses in all eight Japanese cities increased with increasing temperature. Specifically, a 10 ppb increase in O₃ was associated with 0.80 % (95 % CI: 0.25 to 1.35), 0.19 % (95 % CI: -0.85 to 1.25), and 1.14 % (95 % CI: -0.01 to 2.31) increases in the risk of EADs for all acute, cardiovascular, and respiratory illnesses, respectively, when city-specific daily temperature exceeded the 75th percentile. Our findings suggest that the association between O₃ and EADs for all acute, cardiovascular, and respiratory illnesses is the highest during high temperature. Finding of this study can be used to develop potential mitigation measures against O₃ exposure in high temperature environment to reduce its associated adverse health effects.

Modification effects of ambient temperature on associations of ambient ozone exposure before and during pregnancy with adverse birth outcomes: A multicity study in China

BACKGROUND

Epidemiological studies suggest that both ambient ozone (O₃) and temperature were associated with increased risks of adverse birth outcomes. However, very few studies explored their interaction effects, especially for small for gestational age (SGA) and large for gestational age (LGA).

OBJECTIVES

To estimate the modification effects of ambient temperature on associations of ambient O₃ exposure before and during pregnancy with preterm birth (PTB), low birth weight (LBW), SGA and LGA based on multicity birth cohorts.

METHODS

A total of 56,905 singleton pregnant women from three birth cohorts conducted in Tianjin, Beijing and Maoming, China, were included in the study. Maximum daily 8-h average O₃ concentrations of each pregnant woman from the preconception period to delivery for every day were estimated by matching their home addresses with the Tracking Air Pollution in China (TAP) datasets. We first applied the Cox proportional-hazards regression model to evaluate the city-specific effects of O₃ exposure before and during pregnancy on adverse birth outcomes at different temperature levels with adjustment for potential confounders, and then a meta-analysis across three birth cohorts was conducted to calculate the pooled associations.

RESULTS

In pooled analysis, significant modification effects of ambient temperature on associations of ambient O₃ with PTB, LBW and LGA were observed (P_interaction < 0.05). For a 10 μg/m³ increase in ambient O₃ exposure at high temperature level (> 75^th percentile), the risk of LBW increased by 28 % (HR: 1.28, 95% CI: 1.13-1.46) during the second trimester and the risk of LGA increased by 116% (HR: 2.16, 95%CI: 1.16-4.00) during the entire pregnancy, while the null or weaker association was observed at corresponding low (≤ 25^th percentile) and medium (> 25^th and ≤ 75^th percentile) temperature levels.

CONCLUSION

This multicity study added new evidence that ambient high temperature may enhance the potential effects of ambient O₃ on adverse birth outcomes.

Modifiable contributing factors to COVID-19: A comprehensive review

The devastating complications of coronavirus disease 2019 (COVID-19) result from an individual's dysfunctional immune response following the initial severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Multiple toxic stressors and behaviors contribute to underlying immune system dysfunction. SARS-CoV-2 exploits the dysfunctional immune system to trigger a chain of events ultimately leading to COVID-19. The current study identifies eighty immune system dysfunction-enabling toxic stressors and behaviors (hereafter called modifiable contributing factors (CFs)) that also link directly to COVID-19. Each CF is assigned to one of the five categories in the CF taxonomy shown in Section 3.3.: Lifestyle (e.g., diet, substance abuse); Iatrogenic (e.g., drugs, surgery); Biotoxins (e.g., micro-organisms, mycotoxins); Occupational/Environmental (e.g., heavy metals, pesticides); Psychosocial/Socioeconomic (e.g., chronic stress, lower education). The current study shows how each modifiable factor contributes to decreased immune system capability, increased inflammation and coagulation, and increased neural damage and neurodegeneration. It is unclear how real progress can be made in combatting COVID-19 and other similar diseases caused by viral variants without addressing and eliminating these modifiable CFs.

Association between short-term exposure to ambient air pollution and biomarkers of coagulation: A systematic review and meta-analysis

Ambient air pollution is one of the major global risk factors for cardiovascular health, and coagulation changes have been proposed to mediate this risk. Plasminogen activator inhibitor-1 (PAI-1), von Willebrand factor (vWF), soluble P-selectin (sP-selectin) and tissue plasminogen activator (t-PA) are major coagulation biomarkers. However, there has been no systematic meta-analysis to summarize associations of ambient air pollution with these coagulation biomarkers. To assess the overall associations between ambient particulate matter (PM_2.5, PM₁₀), ozone (O₃), nitrogen dioxide (NO₂), carbon monoxide (CO) and major coagulation biomarkers including PAI-1, vWF, sP-selectin and t-PA based on the existing epidemiological research. We performed a systematic literature search of publications reporting the associations of ambient air pollutants (PM_2.5, PM₁₀, O₃, NO_2, and CO) with coagulation biomarkers (PAI-1, vWF, sP-selectin and t-PA) in PubMed, Web of Science, EMBASE, and Scopus databases as of April 5, 2022. Then, we performed a random-effect meta-analysis, which included 27 articles, and then identified the potential sources of heterogeneity. The pooled percent changes of coagulation biomarkers per 10 μg/m³ increase in short-term exposure to ambient PM_2.5 were 2.43% (95% CI: 0.59%, 4.29%) in PAI-1, 1.08% (95% CI: 0.21%, 1.96%) in vWF and 1.14% (95% CI: 0.59%, 1.68%) in sP-selectin, respectively. We also found significant associations of short-term exposure to ambient O₃ with PAI-1 (1.62%, 95% CI: 0.01%, 3.25%), sP-selectin (9.59%, 95% CI:2.78%, 16.86%) and t-PA (0.45%, 95% CI: 0.02%, 0.88%), respectively. Short-term exposures to ambient PM₁₀, NO₂ and CO were not significantly associated with changes in coagulation biomarkers. In conclusion, short-term exposures to PM_2.5 and O₃ are associated with significant increases in coagulation biomarkers, suggesting an activated coagulation state upon air pollution exposure.

Efficacy of ozone adjuvant therapy in COVID-19 patients: A meta-analysis study

Introduction

Using ozone therapy to manage COVID-19 patients has been accompanied by conflicting results in prior studies. Therefore, we aimed to widely assess the effects of ozone as adjuvant therapy in COVID-19 patients.

Methods

PubMed, Scopus, Web of Science, Cochrane, ProQuest, Springer, and Sage journals were searched systematically until April 2022. Mortality rate, ICU admission, hospital-length stay, negative PCR, pulmonary, renal, and hepatic functions, as well as inflammatory and blood systems were pooled to compare the efficacy of ozone as adjacent therapy (OZ) and standard treatment (ST). Analyses were run with the random/fixed models, sub-group analysis, funnel plot, and sensitivity analysis using comprehensive meta-analysis (CMA) software version 2.0.

Results

The results of four randomized clinical trials (RCTs) and four case-control studies with a total of 371 COVID-19 positive patients were analyzed. The OZ group patients had a shorter length of hospital stay (P > 0.05), lower ICU admissions (P > 0.05), and lower mortality rates (P < 0.05) than the ST group cases. After treatment, 41% more COVID-19 patients had negative PCR tests than the ST group (P < 0.05). Serum creatinine and urea levels were not modified in either group (P > 0.05). Moreover, except for albumin serum levels, which decreased significantly in the OZ group, serum bilirubin, ALT, and AST were not modified in either group (P > 0.05). Both arms did not show a decrease in C-reactive protein blood levels (P > 0.05), but the OZ group showed a significant modification in LDH serum levels (P < 0.05). Unlike the d-dimer and WBC serum levels (P > 0.05), platelet levels were increased in the OZ group (P < 0.05). No negative side effects were demonstrated in either group.

Conclusion

Ozone therapy was effective significantly on PCR test and LDH serum levels, as well as mortality based on overall estimation. Concerning the length of hospital stay and ICU admissions, although the results were insignificant, their effect sizes were notable clinically. More RCT studies are needed to show the efficacy of ozone therapy on other studied variables.

Short-term field research on air pollution within the boundaries of the large city in the Baltic region

Air quality in urban and suburban areas is strongly affected by the level of local urbanization, climatic conditions and industrial activity. Monitoring the main air pollutants such as nitrogen oxides, carbon monoxide and particulate matter may help control the most polluted areas of the site and take measures to reduce pollution. Uncontrolled emissions from other chemical pollutants, including volatile organic compounds and odorous contamination sources like ammonia, may cause both a chronic human disease and damage to flora and fauna. The conducted field research is aimed at determining air pollution within the areas of the large city (residential territory, recreation territory and the areas close to intense transport streets) polluted with the gaseous pollutants of varying nature (CO, NO₂, ozone, sulfur dioxide, VOC and NH₃) as well as particulate matter in different seasons of the year. Studies on Vilnius district air quality were carried out in 17 urban locations (sites) and based on two-phase measurements. The first phase was initiated in 2016-2017 and the second one took place in 2019-2020. It was observed that in the areas close to intense transport streets, the concentration of pollutants can increase more than 3 times, thus reaching up to 36.0 µg/m³ of PM10 (particulate matter) and up to 48.0 µg/m³ of nitrogen dioxide. During the summer period, ammonia concentrations can increase up to 3 times, reaching up to 11.0 µg/m³ from farming and/or industrial activities.

Associations Between Ambient Extreme Heat Exposure and Emergency Department Visits Related to Kidney Disease

RATIONALE & OBJECTIVE

Extreme heat exposure is associated with multiple diseases. However, our current understanding of the specific impact of extreme heat exposure on kidney disease is limited.

STUDY DESIGN

Case-crossover study.

SETTING & PARTICIPANTS

1,114,322 emergency department (ED) visits with a principal diagnosis of kidney disease were identified in New York state, 2005-2013.

EXPOSURE

Extreme heat exposure was defined as when the daily temperature exceeded the 90th percentile temperature of that month during the study period in the county.

OUTCOME

ED visits with a principal diagnosis of kidney disease and its subtypes (ICD-9 [International Classification of Diseases, Ninth Revision] codes 580-599, 788).

ANALYTICAL APPROACH

Extreme heat exposure on the ED visit days was compared with extreme heat exposure on control days using a conditional logistic regression model, controlling for humidity, air pollutants, and holidays. The excess risk of kidney disease was calculated for a week (lag days 0-6) after extreme heat exposure during the warm season (May through September). We also stratified our estimates by sociodemographic characteristics.

RESULTS

Extreme heat exposure was associated with a 1.7% (lag day 0) to 3.1% (lag day 2) higher risk of ED visits related to kidney disease; this association was stronger with a greater number of extreme heat exposure days in the previous week. The association with extreme heat exposure lasted for an entire week and was stronger in the transitional months (ie, May and September; excess rates ranged from 1.8% to 5.1%) rather than the summer months (June through August; excess rates ranged from 1.5% to 2.7%). The strength of association was greater among those with ED visits related to acute kidney injury, kidney stones, and urinary tract infections. Age and sex may modify the association between extreme heat exposure and ED visits.

LIMITATIONS

Individual exposure to heat-how long people were outside or whether they had access to air conditioning-was unknown.

CONCLUSIONS

Extreme heat exposure was significantly associated with a dose-dependent greater risk of ED visits for kidney disease.

Ambient temperature and term birthweight in Latin American cities

BACKGROUND

Extreme temperatures may lead to adverse pregnancy and birth outcomes, including low birthweight. Studies on the impact of temperature on birthweight have been inconclusive due to methodological challenges related to operationalizing temperature exposure, the definitions of exposure windows, accounting for gestational age, and a limited geographic scope.

METHODS

We combined data on individual-level term live births (N≈15 million births) from urban areas in Brazil, Chile, and Mexico from 2010 to 2015 from the SALURBAL study (Urban Health in Latin America) with high-resolution daily air temperature data and computed average ambient temperature for every month of gestation for each newborn. Associations between full-term birthweight and average temperature during gestation were analyzed using multi-level distributed lag non-linear models that adjusted for newborn's sex, season of conception, and calendar year of child's birth; controlled for maternal age, education, partnership status, presence of previous births, and climate zone; and included a random term for the sub-city of mother's residence.

FINDINGS

Higher temperatures during the entire gestation are associated with lower birthweight, particularly in Mexico and Brazil. The cumulative effect of temperature on birthweight is mostly driven by exposure to higher temperatures during months 7-9 of gestation. Higher maternal education can attenuate the temperature-birthweight associations.

INTERPRETATION

Our work shows that climate-health impacts are likely to be context- and place-specific and warrants research on temperature and birthweight in diverse climates to adequately anticipate global climate change. Given the high societal cost of suboptimal birthweight, public health efforts should be aimed at diminishing the detrimental effect of higher temperatures on birthweight.

FUNDING

The Wellcome Trust.

Long-Term Exposure to Ozone and Fine Particulate Matter and Risk of Premature Coronary Artery Disease: Results from Genetics of Atherosclerotic Disease Mexican Study

(1) Background: Epidemiological studies have identified associations between fine particulate matter (PM2.5) and ozone exposure with cardiovascular disease; however, studies linking ambient air pollution and premature coronary artery disease (pCAD) in Latin America are non-existing. (2) Methods: Our study was a case−control analysis nested in the Genetics of Atherosclerotic Disease (GEA) Mexican study. We included 1615 participants (869 controls and 746 patients with pCAD), recruited at the Instituto Nacional de Cardiología Ignacio Chávez from June 2008 to January 2013. We defined pCAD as history of myocardial infarction, angioplasty, revascularization surgery or coronary stenosis > 50% diagnosed before age 55 in men and age 65 in women. Controls were healthy individuals without personal or family history of pCAD and with coronary artery calcification equal to zero. Hourly measurements of ozone and PM2.5 from the Atmospheric Monitoring System in Mexico City (SIMAT in Spanish; Sistema de Monitero Atmosférico de la Ciudad de México) were used to calculate annual exposure to ozone and PM2.5 in the study participants. (3) Results: Each ppb increase in ozone at 1-year, 2-year, 3-year and 5-year averages was significantly associated with increased odds (OR = 1.10; 95% CI: 1.03−1.18; OR = 1.17; 95% CI: 1.05−1.30; OR = 1.18; 95% CI: 1.05−1.33, and OR = 1.13; 95% CI: 1.04−1.23, respectively) of pCAD. We observed higher risk of pCAD for each 5 µg/m3 increase only for the 5-year average of PM2.5 exposure (OR = 2.75; 95% CI: 1.47−5.16), compared to controls. (4) Conclusions: Ozone exposure at different time points and PM2.5 exposure at 5 years were associated with increased odds of pCAD. Our results highlight the importance of reducing long-term exposure to ambient air pollution levels to reduce the burden of cardiovascular disease in Mexico City and other metropolitan areas.

Ozone exposure and prothrombosis: Mechanistic insights from a randomized controlled exposure trial

Epidemiological studies have associated ozone exposure with cardiovascular diseases, but the molecular mechanisms were not elucidated. We performed an untargeted serum proteomic analysis in a randomized, crossover, controlled exposure trial. We recruited 32 healthy young adults and asked them to receive filtered air and 200-ppb ozone exposures for 2 h in a random order before serum collection. Linear mixed-effect models were used to identify differentially expressed proteins (DEPs) between the two exposures and Gene Ontology enrichment and ingenuity pathway analysis were performed to determine their biological function. A total of 56 DEPs were identified. For example, acute ozone exposure increased coagulation factor X and factor VII-activating protease by 20.96% and 28.35%, respectively. Whereas, protein Z, protein Z-dependent protease inhibitor, and plasminogen decreased by 13.62%, 33.54%, and 10.47%, respectively. We also observed a 42.32% decrease in paraoxonase 3 and evident changes in four apolipoproteins. Additionally, we found 18.21% and 95.82% increases in L-selectin and β2-microglobulin, respectively, and significant changes in three complements. DEPs and enriched pathways suggest that short-term ozone exposure may promote coagulation, suppress fibrinolysis, disrupt lipoprotein metabolism, activate immune responses, and affect the complement system. These findings provide additional insights into the mechanisms linking acute ozone exposure to thrombosis.

Short-term ozone exposure and metabolic status in metabolically healthy obese and normal-weight young adults: A viewpoint of inflammatory pathways

Unhealthy metabolic status increases risks of cardiovascular and other diseases. This study aims to explore whether there is a link between O₃ and metabolic health indicators through a viewpoint of inflammatory pathways. 49 metabolically healthy normal-weight (MH-NW) and 39 metabolically healthy obese (MHO) young adults aged 18-26 years were recruited from a panel study with three visits. O₃ exposure were estimated based on fixed-site environmental monitoring data and time-activity diary for each participant. Compared to MH-NW people, MHO people were more susceptible to the adverse effects on metabolic status, including blood pressure, glucose, and lipid indicators when exposed to O₃. For instance, O₃ exposure was associated with significant decreases in high-density lipoprotein cholesterol (HDL-C), and increases in C-peptide and low-density lipoprotein cholesterol (LDL-C) among MHO people, while only weaker changes in HDL-C and LDL-C among MH-NW people. Mediation analyses indicated that leptin mediated the metabolic health effects in both groups, while eosinophils and MCP-1 were also important mediating factors for the MHO people. Although both with a metabolically healthy status, compared to normal-weight people, obese people might be more susceptible to the negative effects of O₃ on metabolic status, possibly through inflammatory indicators such as leptin, eosinophils, and MCP-1.

Association between ambient temperature and cognitive function in a community-dwelling elderly population: a repeated measurement study

OBJECTIVES

Evidence on the associations between short-term and long-term air temperature exposure and cognitive function in older adults, particularly those in Asia, is limited. We explored the relationships of short-term and long-term air temperature exposure with cognitive function in Taiwanese older adults through a repeated measures survey.

DESIGN AND SETTING

We used data the ongoing Taiwan Longitudinal Study on Aging, a multiple-wave nationwide survey.

PARTICIPANTS

We identified 1956, 1700, 1248 and 876 older adults in 1996, 1999, 2003 and 2007, respectively.

PRIMARY AND SECONDARY OUTCOME MEASURES

Participants' cognitive function assessment was based on the Short Portable Mental Status Questionnaire. We calculated the temperature moving average (TMA) for temperature exposure windows between 1993 and 2007 using data from air quality monitoring stations, depending on the administrative zone of each participant's residence. Generalised linear mixed models were used to examine the effects of short-term and long-term temperature changes on cognitive function.

RESULTS

Short-term and long-term temperature exposure was significantly and positively associated with moderate-to-severe cognitive impairment, with the greatest increase in ORs found for 3-year TMAs (OR 1.247; 95% CI 1.107 to 1.404). The higher the quintiles of temperature exposure were, the higher were the ORs. The strongest association found was in long-term TMA exposure (OR 3.674; 95% CI 2.103 to 6.417) after covariates were controlled for.

CONCLUSIONS

The risk of mild cognitive impairment increased with ambient temperature in community-dwelling older adults in Taiwan.

A self-controlled approach to survival analysis, with application to air pollution and mortality

BACKGROUND

Many studies have reported that long-term air pollution exposure is associated with increased mortality rates. These investigations have been criticized for failure to control for omitted, generally personal, confounders. Study designs that are robust to such confounders can address this issue.

METHODS

We used a self-controlled design for survival analysis. We stratified on each person in the Medicare cohort between 2000 and 2015 who died, and examined whether PM2.5, O3 and NO2 exposures predicted in which follow-up period the death occurred. We used conditional logistic regression stratified on person and controlled for nonlinear terms in calendar year and age. By design slowly varying covariates such as smoking history, BMI, diabetes and other pre-existing conditions, usual alcohol consumption, sex, race, socioeconomic status, and green space were controlled by matching each person to themselves.

RESULTS

There were 6,452,618 deaths in the study population in the study period. We observed a 5.37% increase in the mortality rate (95% CI 4.67%, 6.08%) for every 5 μg/m3 increase in PM2.5, a 1.98% (95% CI 1.61%, 2.36%) increase for 5 ppb increment in O3, and a 2.10% decrease (95% CI 1.88%, 2.33%) for a 5 ppb increase in NO2. When restricted to persons whose PM2.5 exposure never exceeded 12 μg/m3 in any year between 2000 and 2015, the effect size increased for PM2.5 (12.71% (11.30, 14.15)), and the signs of O3 and NO2 reversed (-0.26% (-0.88, 0.35) for O3 and 1.77% increase (1.40, 2.13) for NO2). Effect sizes were larger for Blacks (e.g. 7.71% (5.46, 10.02) for PM2.5).

CONCLUSION

There is strong evidence that the association between annual exposure to PM2.5 and mortality is not confounded by individual or neighborhood covariates, and continues below the standard. The effects of O3 and NO2 are difficult to disentangle.

Association of long-term exposure to air pollution with chronic sleep deprivation in adults from 141 urban communities in South Korea: a community-level longitudinal study, 2008‒2016

Aims

It has been well known that air pollution and sleep deprivation individually have impacts on human health; however, the association between the two has not been well researched. The aim of this study was to investigate this relationship at a community level.

Methods

We collected sleep outcomes from the Korean Community Health Survey between years of 2008 and 2016. The data contained 1 130 080 selected adults aged ⩾ 19 years, from 141 communities. As sleep outcomes, annual chronic sleep deprivation (% of people who sleep ⩽ 5 h per day on average) and average values of daily mean sleep duration were used. Community-specific annual averages of particulate matter with a diameter ⩽ 10 μm (PM₁₀), nitrogen dioxide (NO₂) and carbon monoxide (CO) were collected and then applied to a linear mixed effects model to estimate the association between air pollution over the past 4 years and sleep outcomes. Population density, green space, health behaviour, and gross regional domestic product per capita variables were considered as confounders in all mixed effect models.

Results

From the linear mixed effect models, we found that the chronic sleep deprivation % was positively associated with PM₁₀ (0.33% increase with 95% CI 0.05–0.60; per 10 μg/m³) and NO₂ (0.68% with 95% CI 0.44–0.92; per 10 ppm). Higher PM₁₀ and NO₂ were also associated with shorter sleep duration, with a reduction of 0.37 min (95% CI −0.33 to 1.07 min; per 10 μg/m³) and 2.09 min (95% CI 1.50–2.68 min; per 10 ppm), respectively. The associations between PM₁₀ and sleep outcomes were higher in females than males and in the older age groups (⩾ 60-years) than in younger age groups (19–39 and 40–59 years). However, the association between NO₂ and sleep outcomes were more higher in males than in females and in the younger age groups (19–39 years) than other age groups.

Conclusions

Our findings provide epidemiological evidence that long-term interventions to reduce air pollutions are anticipated to provide improvements in sleep deficiency.

Ambient extreme heat exposure in summer and transitional months and emergency department visits and hospital admissions due to pregnancy complications

Although extreme heat exposure (EHE) was reported to be associated with increased risks of multiple diseases, little is known about the effects of EHE on pregnancy complications. We examined the EHE-pregnancy complications associations by lag days, subtypes, sociodemographic characteristics, and areas in New York State (NYS). We conducted a case-crossover analysis to assess the EHE-pregnancy complications associations in summer (June-August) and transitional months (May and September). All emergency department (ED) visits and hospital admissions due to pregnancy complications (ICD 9 codes: 630-649) from 2005 to 2013 in NYS were included. Daily mean temperature > 90th percentile of the monthly mean temperature in each county was defined as an EHE. We used conditional logistic regression while controlling for other weather factors, air pollutants and holidays to assess the EHE-pregnancy complications associations. EHE was significantly associated with increased ED visits for pregnancy complications in summer (ORs ranged: 1.01-1.04 from lag days 0-5). There was also a significant and stronger association in transitional months (ORs ranged: 1.02-1.06, Lag 0). Furthermore, we found EHE affected multiple subtypes of pregnancy complications, including threatened/spontaneous abortion, renal diseases, infectious diseases, diabetes, and hypertension (ORs range: 1.13-1.90) during transitional months. A significant concentration response effect between the number of consecutive days of EHE and ED visits in summer (P for trend <0.001), ED visits in September (P for trend =0.03), and hospital admission in May (P for trend<0.001) due to pregnancy complications was observed, respectively. African Americans and residents in lower socioeconomic position (SEP) counties were more susceptible to the effects of EHE. In conclusion, we found an immediate and prolonged effect of EHE on pregnancy complications in summer and a stronger, immediate effect in transitional months. These effects were stronger in African Americans and counties with lower SEP. Earlier warnings regarding extreme heat are recommended to decrease pregnancy complications.

A Direct Estimate of the Impact of PM2.5, NO2, and O3 Exposure on Life Expectancy Using Propensity Scores

Supplemental Digital Content is available in the text.

Many studies have reported associations of air pollutants and death, but fewer examined multiple pollutants, or used causal methods. We present a method for directly estimating changes in the distribution of age at death using propensity scores.

Association between Physiological Equivalent Temperature (PET) with adverse pregnancy outcomes in Ahvaz, southwest of Iran

Background

There are few epidemiological studies on the relation between temperature changes and adverse pregnancy outcomes. The purpose of this study was to determine the relation between Physiological Equivalent Temperature (PET) with adverse pregnancy outcomes including stillbirth, low birth weight (LBW), preterm labor (PTL), spontaneous abortion (SA), preeclampsia and hypertension in Ahvaz, Iran.

Methods

Distributed Lag Non-linear Models (DLNM) combined with quasi-Poisson regression were used to investigate the effect of PET on adverse pregnancy outcomes. In this study the effect of time trend, air pollutants (NO₂, SO₂ and PM₁₀), and weekdays were adjusted.

Results

High PET (45.4 C°, lag = 0) caused a significant increase in risk of stillbirth. Also, high levels of PET (45.4, 43.6, 42.5 C°, lag = 0–6) and low levels of PET (9.9, 16.9 C°, lags = 0, 0–13, 0–21) significantly increased the risk of LBW. But, low levels of PET (6.4, 9.9, 16.9 C°, lags = 0–6, 0–13) reduced the risk of gestational hypertension.

Conclusion

The results of this study showed that hot and cold thermal stress may be associated with increased risk of stillbirth, and LBW in Ahvaz.

Recent case studies on the use of ozone to combat coronavirus: Problems and perspectives

Coronavirus pandemic has created havoc in the world. COVID-19 is now officially labeled as Severe Acute Respiratory Syndrome-related Coronavirus-SARS-CoV-2. Therefore, it is equally important to combat the virus both inside the human body as well as in the environment. These viruses, being RNA viruses, are found to be susceptible to ozone. Ozone being an unstable molecule can breakup into its split products namely reactive oxygen species and ozonides creating a toxic environment for these viruses. Ozone mainly prevents the membrane fusion with the host cell, thus interfering with their replication. With vast applications of the gas, it has created a new spark in the field of medicine in combating these viruses and many other organisms. In this context, this article provides insights from recent clinical and research studies on the problems and possibilities in employing the ozone to combat the coronaviruses.

Oxygen-ozone (O2-O3) immunoceutical therapy for patients with COVID-19. Preliminary evidence reported

Objective

This study evaluated the potential efficacy of a novel approach to treat COVID-19 patients, using an oxygen-ozone (O₂-O₃) mixture, via a process called Oxygen-Ozone- Immunoceutical Therapy. The methodology met the criteria of a novel, promising approach to treat successfully elderly COVID-19 patients, particularly when hospitalized in intensive care units (ICUs) Experimental design: We investigated the therapeutic effect of 4 cycles of O₂-O₃ in 50 hospitalized COVID-19 subjects suffering from acute respiratory disease syndrome (ARDS), aged more than 60 years, all males and undergoing non invasive mechanical ventilation in ICUs.

Results

Following O₂-O₃ treatment a significant improvement in inflammation and oxygenation indexes occurred rapidly and within the first 9 days after the treatment, despite the expected 14–20 days. A significant reduction of inflammatory and thromboembolic markers (CRP, IL-6, D-dimer) was observed. Furthermore, amelioration in the major respiratory indexes, such as respiratory and gas exchange markers (SatO₂%, PaO₂/FiO₂ ratio), was reported.

Conclusion

Our results show that O₂-O₃ treatment would be a promising therapy for COVID-19 patients. It leads patients to a fast recovery from ARDS via the improvement of major respiratory indexes and blood gas parameters, following a relatively short time of dispensed forced ventilation (about one to two weeks). This study may encourage the scientific community to further investigate and evaluate the proposed method for the treatment of COVID-19 patients.

Air pollutants disrupt iron homeostasis to impact oxidant generation, biological effects, and tissue injury

Air pollutants cause changes in iron homeostasis through: 1) a capacity of the pollutant, or a metabolite(s), to complex/chelate iron from pivotal sites in the cell or 2) an ability of the pollutant to displace iron from pivotal sites in the cell. Through either pathway of disruption in iron homeostasis, metal previously employed in essential cell processes is sequestered after air pollutant exposure. An absolute or functional cell iron deficiency results. If enough iron is lost or is otherwise not available within the cell, cell death ensues. However, prior to death, exposed cells will attempt to reverse the loss of requisite metal. This response of the cell includes increased expression of metal importers (e.g. divalent metal transporter 1). Oxidant generation after exposure to air pollutants includes superoxide production which functions in ferrireduction necessary for cell iron import. Activation of kinases and phosphatases and transcription factors and increased release of pro-inflammatory mediators also result from a cell iron deficiency, absolute or functional, after exposure to air pollutants. Finally, air pollutant exposure culminates in the development of inflammation and fibrosis which is a tissue response to the iron deficiency challenging cell survival. Following the response of increased expression of importers and ferrireduction, activation of kinases and phosphatases and transcription factors, release of pro-inflammatory mediators, and inflammation and fibrosis, cell iron is altered, and a new metal homeostasis is established. This new metal homeostasis includes increased total iron concentrations in cells with metal now at levels sufficient to meet requirements for continued function.

Synergic effect between high temperature and air pollution on mortality in Northeast Asia

High temperature and air pollutants have been reported as potential risk factors of mortality. Previous studies investigated interaction between the two variables; however, the excess death risk due to the synergic effect (i.e. interaction on the additive scale) between the two variables has not been investigated adequately on a multi-country scale. This study aimed to assess the excess death risk due to the synergism between high temperature and air pollution on mortality using a multicity time-series analysis. We collected time-series data on mortality, weather variables, and four air pollutants (PM₁₀, O₃, NO₂, and CO) for 16 metropolitan cities of three countries (Japan, Korea, and Taiwan) in Northeast Asia (1979-2015). Quasi-Poisson time-series regression and meta-analysis were used to estimate the additive interaction between high temperature and air pollution. The additive interaction was measured by relative excess risk due to interaction (RERI) index. We calculated RERI with relative risks (RR) of the 99th/10th, 90th/90th, and 99th/90th percentiles of temperature/air pollution metrics, where risk at the 90th/10th percentiles of temperature/air pollution metrics was the reference category. This study showed that there may exist positive and significant excess death risks due to the synergism between high temperature and air pollution in the total population for all pollutants (95% lower confidence intervals of all RERIs>0 or near 0). In final, we measured quantitatively the excess death risks due to synergic effect between high temperature and air pollution, and the synergism should be considered in public health interventions and a composite warning system.

Long-Term Exposure to Ozone and Cause-Specific Mortality Risk in the United States

Rationale: Many studies have linked short-term exposure to ozone (O3) with morbidity and mortality, but epidemiologic evidence of associations between long-term O3 exposure and mortality is more limited.Objectives: To investigate associations of long-term (annual or warm season average of daily 8-h maximum concentrations) O3 exposure with all-cause and cause-specific mortality in the NIH-AARP Diet and Health Study, a large prospective cohort of U.S. adults with 17 years of follow-up from 1995 to 2011.Methods: The cohort (n = 548,780) was linked to census tract-level estimates for O3. Associations between long-term O3 exposure (averaged values from 2002 to 2010) and multiple causes of death were evaluated using multivariate Cox proportional hazards models, adjusted for individual- and census tract-level covariates, and potentially confounding copollutants and temperature.Measurements and Main Results: Long-term annual average exposure to O3 was significantly associated with deaths caused by cardiovascular disease (per 10 ppb; hazard ratio [HR], 1.03; 95% confidence interval [CI], 1.01-1.06), ischemic heart disease (HR, 1.06; 95% CI, 1.02-1.09), respiratory disease (HR, 1.04; 95% CI, 1.00-1.09), and chronic obstructive pulmonary disease (HR, 1.09; 95% CI, 1.03-1.15) in single-pollutant models. The results were robust to alternative models and adjustment for copollutants (fine particulate matter and nitrogen dioxide), although some evidence of confounding by temperature was observed. Significantly elevated respiratory disease mortality risk associated with long-term O3 exposure was found among those living in locations with high temperature (Pinteraction < 0.05).Conclusions: This study found that long-term exposure to O3 is associated with increased risk for multiple causes of mortality, suggesting that establishment of annual and/or seasonal federal O3 standards is needed to more adequately protect public health from ambient O3 exposures.

Cardiorespiratory responses to low-level ozone exposure: The inDoor Ozone Study in childrEn (DOSE)

BACKGROUND

Indoor air pollution has emerged as a significant environmental and public health concern in recent years. However, evidence regarding the cardiorespiratory effects of indoor ozone is limited, and the underlying biological mechanisms are unclear, especially in children. Our study aimed to assess the cardiorespiratory responses to indoor ozone exposure in children.

METHODS

A repeated-measure study was conducted in 46 middle-school children in Beijing, China. Real-time concentrations of ozone, along with co-pollutants including particulate matter (PM) and black carbon (BC), were monitored in classrooms from Monday to Friday. Three repeated health measurements of cardiorespiratory functions, including ambulatory electrocardiogram (ECG), blood pressure, fractional exhaled nitric oxide (FeNO) and lung function, were performed on each participant. Mixed-effect models were used to evaluate the effects of indoor ozone exposure.

RESULTS

The mean (SD) indoor ozone concentration was 8.7 (6.6) ppb during the study period, which was largely below the current guideline and standards. However, even this low-level ozone exposure was associated with reduced cardiac autonomic function and increased heart rate (HR) in children. For instance, per interquartile range (IQR) increase in ozone at 2-hour moving average was associated with -7.8% (95% CI: -9.9%, -5.6%) reduction in standard deviation of all normal-to-normal intervals (SDNN), and 2.6% (95% CI: 1.6%, 3.6%) increment in HR. In addition, the associations were stronger at high BC levels (BC ≥ 3.7 μg/m³). No significant associations were found for airway inflammation and pulmonary function.

CONCLUSIONS

Exposure to low-level indoor ozone that is not associated with respiratory effects was significantly related to disturbed cardiac autonomic function and increased HR in children, which suggested a possible mechanism through which ozone may affect cardiovascular health in children, and indicated more protective measures should be taken to alleviate the acute adverse effects of indoor ozone in this susceptible population.

Ozone effects on blood biomarkers of systemic inflammation, oxidative stress, endothelial function, and thrombosis: The Multicenter Ozone Study in oldEr Subjects (MOSES)

The evidence that exposure to ozone air pollution causes acute cardiovascular effects is mixed. We postulated that exposure to ambient levels of ozone would increase blood markers of systemic inflammation, prothrombotic state, oxidative stress, and vascular dysfunction in healthy older subjects, and that absence of the glutathione S-transferase Mu 1 (GSTM1) gene would confer increased susceptibility. This double-blind, randomized, crossover study of 87 healthy volunteers 55-70 years of age was conducted at three sites using a common protocol. Subjects were exposed for 3 h in random order to 0 parts per billion (ppb) (filtered air), 70 ppb, and 120 ppb ozone, alternating 15 min of moderate exercise and rest. Blood was obtained the day before, approximately 4 h after, and approximately 22 h after each exposure. Linear mixed effect and logistic regression models evaluated the impact of exposure to ozone on pre-specified primary and secondary outcomes. The definition of statistical significance was p<0.01. There were no effects of ozone on the three primary markers of systemic inflammation and a prothrombotic state: C-reactive protein, monocyte-platelet conjugates, and microparticle-associated tissue factor activity. However, among the secondary endpoints, endothelin-1, a potent vasoconstrictor, increased from pre- to post-exposure with ozone concentration (120 vs 0 ppb: 0.07 pg/mL, 95% confidence interval [CI] 0.01, 0.14; 70 vs 0 ppb: -0.03 pg/mL, CI -0.09, 0.04; p = 0.008). Nitrotyrosine, a marker of oxidative and nitrosative stress, decreased with increasing ozone concentrations, with marginal significance (120 vs 0 ppb: -41.5, CI -70.1, -12.8; 70 vs 0 ppb: -14.2, CI -42.7, 14.2; p = 0.017). GSTM1 status did not modify the effect of ozone exposure on any of the outcomes. These findings from healthy older adults fail to identify any mechanistic basis for the epidemiologically described cardiovascular effects of exposure to ozone. The findings, however, may not be applicable to adults with cardiovascular disease.

Innate Lymphoid Cell-Dependent Airway Epithelial and Inflammatory Responses to Inhaled Ozone: A New Paradigm in Pathogenesis

Epidemiological associations have been made between the new onset of childhood rhinitis/asthma and exposures to elevated ambient levels of ozone, a commonly encountered gaseous air pollutant. Our laboratory was the first to find that mice repeatedly exposed to ozone develop nasal type 2 immunity and eosinophilic rhinitis with mucous cell metaplasia. More recently, we have found that these ozone-induced upper airway alterations are mediated by group 2 innate lymphoid cells (ILC2s) and not by T and B cells that are important in adaptive immune responses typically associated with allergic rhinitis and asthma. Furthermore, repeated exposures of mice to ozone cause ILC2-mediated type 2 immunity and airway pathology in the lungs, like those found in the nasal airways. Our recent findings in ozone-exposed mice complement and extend previous reports of nonallergic nasal airway disease in ozone-exposed rats and nonhuman primates. Overall, these experimental results in laboratory animals suggest a plausible ILC2-dependent paradigm for the toxicologic pathobiology that underlies the development of nonallergic rhinitis/asthma in children who live in environments with repeated occurrences of high ambient concentrations of ozone.

Ambient Temperature and Markers of Fetal Growth: A Retrospective Observational Study of 29 Million U.S. Singleton Births

BACKGROUND

Emerging studies suggest that ambient temperature during pregnancy may be associated with fetal growth, but the existing evidence is limited and inconsistent.

OBJECTIVES

We aimed to evaluate the association of trimester-specific temperature with risk of being born small for gestational age (SGA) and birth weight-markers of fetal growth-among term births in the contiguous United States.

METHODS

We included data on 29,597,735 live singleton births between 1989 and 2002 across 403 U.S. counties. We estimated daily county-level population-weighted mean temperature using a spatially refined gridded climate data set. We used logistic regression to estimate the association between trimester-specific temperature and risk of SGA and linear regression to evaluate the association between trimester-specific temperature and term birth weight z-score, adjusting for parity, maternal demographics, smoking or drinking during pregnancy, chronic hypertension, and year and month of conception. We then pooled results overall and by geographic regions and climate zones.

RESULTS

High ambient temperatures ([Formula: see text] percentile) during the entire pregnancy were associated with higher risk of term SGA {odds ratio [OR] [Formula: see text] 1.041 [95% confidence interval (CI): 1.029, 1.054]} and lower term birth weight [standardized to [Formula: see text] (95% CI: [Formula: see text], [Formula: see text]) reduction in birth weight for infants born at 40 weeks of gestation]. Low temperatures ([Formula: see text] percentile) during the entire pregnancy were not associated with SGA [OR [Formula: see text] 1.003 (95% CI: 0.991, 1.015)] but were associated with a small decrement in term birth weight [standardized to [Formula: see text] (95% CI: [Formula: see text], [Formula: see text])]. Risks of term SGA and birth weight were more strongly associated with temperature averaged across the second and third trimesters, in areas the Northeast, and in areas with cold or very cold climates.

CONCLUSIONS

Above-average temperatures during pregnancy were associated with lower fetal growth. Our findings provide evidence that temperature may be a novel risk factor for reduced fetal growth. https://doi.org/10.1289/EHP4648.

Bayesian modeling of air pollution extremes using nested multivariate max-stable processes

Capturing the potentially strong dependence among the peak concentrations of multiple air pollutants across a spatial region is crucial for assessing the related public health risks. In order to investigate the multivariate spatial dependence properties of air pollution extremes, we introduce a new class of multivariate max-stable processes. Our proposed model admits a hierarchical tree-based formulation, in which the data are conditionally independent given some latent nested positive stable random factors. The hierarchical structure facilitates Bayesian inference and offers a convenient and interpretable characterization. We fit this nested multivariate max-stable model to the maxima of air pollution concentrations and temperatures recorded at a number of sites in the Los Angeles area, showing that the proposed model succeeds in capturing their complex tail dependence structure.

A national case-crossover study on ambient ozone pollution and first-ever stroke among Chinese adults: Interpreting a weak association via differential susceptibility

Evidence suggesting an association between ozone exposure and stroke risk remains inconsistent; variations in the distributions of susceptibilities of the study populations may explain some of it. We examined the hypothesis in a general Chinese population. During 2013-2015, 1356 first-ever stroke events were selected from a large representative sample, the China National Stroke Screening Survey (CNSSS) database; daily maximal 8-hour ozone concentrations were obtained from spatiotemporally interpolated estimates of in-situ observations over China. We conducted a time-stratified case-crossover design to assess associations between stroke risk and ambient ozone exposure. Next, potential effect modifiers were identified using interaction analyses. Final, a well-established approach was applied to estimate individual-level susceptibility (i.e., the individual-specific effect given a certain combination of multiple effect-modifiers) and its probability distribution among all the CNSSS participants (n = 1,292,010). With adjustments for temperature, relative humidity and ambient fine particulate matter exposure, a 10-μg/m³ increment in mean ozone levels 2-3 day prior to symptom onset was associated with a 3.0% change in stroke risk (95% confidence interval: -1.2%, 7.3%). This association was statistically significantly enhanced by male gender, rural residence and low vegetable and fruit consumption. The subgroup results suggested that a fraction of the population might be considerably affected by ozone, regardless of the insignificant association in average level. The analysis of susceptibility distribution further indicated that the ozone-stroke association was statistically significantly positive in 14% of the general population. Susceptibility to ozone-related stroke significantly varied among Chinese adults. Characterizing individual-level susceptibility reveals the complexity underlying the weak average effect of ozone, and supports to plan subpopulation-specific interventions to mitigate the stroke risk.

MiR-1246 is upregulated and regulates lung cell apoptosis during heat stress in feedlot cattle

Globally, heat stress seriously threatens productivity of cattle. The objective of this study was to identify novel miRNAs that regulated heat stress in feedlot cattle. Experiment was conducted under heat stress and normal conditions. With profiling miRNAs of each feedlot cattle, our results showed the level of miR-1246 was significantly increased in these heat-stressed cattle (P < 0.05). Furthermore, by using bioinformatics analysis and luciferase reporter assays combined with qPCR and western blot, we found miR-1246 negatively regulated poly (C) binding protein 2 (PCBP2) and cAMP response element binding protein-like 2 (CREBL2) mRNA and protein levels through binding to the 3'-UTR region (P < 0.05); further, it inhibited heat-induced apoptosis in lung cells. Finally, our results suggested that miR-1246 plays an important role in heat stress and it has the potential to be a novel modulation factor for heat stress in feedlot cattle.

Age modification of ozone associations with cardiovascular disease risk in adults: a potential role for soluble P-selectin and blood pressure

Background

Studies have suggested that age increases susceptibility to ozone-associated mortality, but the underlying mechanisms are unclear. In a previous study, personal exposure to ozone was significantly associated with a platelet activation biomarker, plasma soluble P-selectin (sCD62P), and blood pressure in 89 healthy adults, aged 22-52 years. The present study examines whether age modifies these associations in the same adults and in additional adults.

Methods

Interaction terms of age and exposure were analyzed using hierarchical Bayesian mixed effects ridge regressions. Data from a similar additional study involving 71 healthy participants, aged 19-26 years, were pooled with the data from the first study to evaluate age effect modification when more young adults were added to the analysis.

Results

In the 89 adults, significant age interactions were observed for past 24-hour and 2-week ozone exposures and sCD62P. Based on the pooled data (89 plus 71 adults), a 10 ppb increase in 24-hour ozone exposure was associated with increases in sCD62P and systolic blood pressure (SBP) by 22.3% (95% CI: 14.3%, 31.2%) and 1.35 (-0.18, 2.84) mmHg, respectively, at age 25; these values increased to 48.6% (32.7%, 65.1%) and 4.98 (2.56, 7.35) mmHg, respectively, at age 40.

Conclusions

These results mechanistically suggest that increasing age enhances cardiovascular effects of ozone.

Two-way effect modifications of air pollution and air temperature on total natural and cardiovascular mortality in eight European urban areas

BACKGROUND

Although epidemiological studies have reported associations between mortality and both ambient air pollution and air temperature, it remains uncertain whether the mortality effects of air pollution are modified by temperature and vice versa. Moreover, little is known on the interactions between ultrafine particles (diameter ≤ 100 nm, UFP) and temperature.

OBJECTIVE

We investigated whether the short-term associations of particle number concentration (PNC in the ultrafine range (≤100 nm) or total PNC ≤ 3000 nm, as a proxy for UFP), particulate matter ≤ 2.5 μm (PM_2.5) and ≤ 10 μm (PM₁₀), and ozone with daily total natural and cardiovascular mortality were modified by air temperature and whether air pollution levels affected the temperature-mortality associations in eight European urban areas during 1999-2013.

METHODS

We first analyzed air temperature-stratified associations between air pollution and total natural (nonaccidental) and cardiovascular mortality as well as air pollution-stratified temperature-mortality associations using city-specific over-dispersed Poisson additive models with a distributed lag nonlinear temperature term in each city. All models were adjusted for long-term and seasonal trend, day of the week, influenza epidemics, and population dynamics due to summer vacation and holidays. City-specific effect estimates were then pooled using random-effects meta-analysis.

RESULTS

Pooled associations between air pollutants and total and cardiovascular mortality were overall positive and generally stronger at high relatively compared to low air temperatures. For example, on days with high air temperatures (>75th percentile), an increase of 10,000 particles/cm³ in PNC corresponded to a 2.51% (95% CI: 0.39%, 4.67%) increase in cardiovascular mortality, which was significantly higher than that on days with low air temperatures (<25th percentile) [-0.18% (95% CI: -0.97%, 0.62%)]. On days with high air pollution (>50th percentile), both heat- and cold-related mortality risks increased.

CONCLUSION

Our findings showed that high temperature could modify the effects of air pollution on daily mortality and high air pollution might enhance the air temperature effects.

Synergistic Environmental Exposures and the Airways Capturing Complexity in Humans: An Underappreciated World of Complex Exposures

Paradoxically, the vast majority of research models intended to understand the relationship between exogenous exposures and lung disease are reduced to a single inhalant. This approach is understandable given the practical challenges of investigation, but it is problematic in terms of translation to the real-world human condition. Furthermore, use of data from such models can lead to underestimation of effect, which may adversely influence regulatory imperatives to protect public health based on the most robust information. Efforts to incrementally introduce layers of complexity to observational and experimental systems have revealed pathophysiology previously "hidden" within simplified models. Capturing the effects of co-exposure to traffic-related air pollution and allergens is a paradigmatic example and illustrates the influence of co-exposures across a plethora of clinical and subclinical end points within the respiratory tract. From DNA methylation in the epithelium, to inflammatory mediators and allergen-specific antibodies in the airway, to airflow limitation and symptoms, the addition of a common second exposure induces profound changes. In addition, genetic variation significantly alters the product of these relationships, and capturing multidimensional interactions may reveal susceptible populations who are particularly affected by these exposures and may merit focused measures for protection. Collectively, better modeling, and ultimately deeper knowledge, of these complex relationships has important implications for personalized health and prevention, development and refinement of pharmacologic agents, and public health responses to climate change and the staggering burden of pollution-driven disease worldwide.

Ozone exposure is associated with acute changes in inflammation, fibrinolysis, and endothelial cell function in coronary artery disease patients

BACKGROUND

Air pollution is a major risk factor for cardiovascular disease, of which ozone is a major contributor. Several studies have found associations between ozone and cardiovascular morbidity, but the results have been inconclusive. We investigated associations between ozone and changes across biological pathways associated with cardiovascular disease.

METHODS

Using a panel study design, 13 participants with coronary artery disease were assessed for markers of systemic inflammation, heart rate variability and repolarization, lipids, blood pressure, and endothelial function. Daily measurements of ozone and particulate matter (PM2.5) were obtained from central monitoring stations. Single (ozone) and two-pollutant (ozone and PM2.5) models were used to assess percent changes in measurements per interquartile ranges of pollutants.

RESULTS

Per interquartile increase in ozone, changes in tissue plasminogen factor (6.6%, 95% confidence intervals (CI) = 0.4, 13.2), plasminogen activator inhibitor-1 (40.5%, 95% CI = 8.7, 81.6), neutrophils (8.7% 95% CI = 1.5, 16.4), monocytes (10.2%, 95% CI = 1.0, 20.1), interleukin-6 (15.9%, 95% CI = 3.6, 29.6), large-artery elasticity index (-19.5%, 95% CI = -34.0, -1.7), and the baseline diameter of the brachial artery (-2.5%, 95% CI = -5.0, 0.1) were observed. These associations were robust in the two-pollutant model.

CONCLUSIONS

We observed alterations across several pathways associated with cardiovascular disease in 13 coronary artery disease patients following ozone exposures, independent of PM2.5. The results support the biological plausibility of ozone-induced cardiovascular effects. The effects were found at concentrations below the EPA National Ambient Air Quality Standards for both ozone and PM2.5.

Meteorological factors, air pollutants, and emergency department visits for otitis media: a time series study

AbstractOtitis media (OM) is a very common disease in children, which results in a significant economic burden to the healthcare system for hospital-based outpatient departments, emergency departments (EDs), unscheduled medical examinations, and antibiotic prescriptions. The aim of this retrospective observational study is to investigate the association between climate variables, air pollutants, and OM visits observed in the 2007-2010 period at the ED of Cuneo, Italy. Measures of meteorological parameters (temperature, humidity, atmospheric pressure, wind) and outdoor air pollutants (particulate matter, ozone, nitrous dioxide) were analyzed at two statistical stages and in several specific steps (crude and adjusted models) according to Poisson's regression. Response variables included daily examinations for age groups 0-3, 0-6, and 0-18. Control variables included upper respiratory infections (URI), flu (FLU), and several calendar factors. A statistical procedure was implemented to capture any delayed effects. Results show a moderate association for temperature (T), age 0-3, and 0-6 with P < 0.05, as well as nitrous dioxide (NO₂) with P < 0.005 at age 0-18. Results of subsequent models point out to URI as an important control variable. No statistical association was observed for other pollutants and meteorological variables. The dose-response models (DLNM-final stage) implemented separately on a daily and hourly basis point out to an association between temperature (daily model) and RR 1.44 at age 0-3, CI 1.11-1.88 (lag time 0-1 days) and RR 1.43, CI 1.05-1.94 (lag time 0-3 days). The hourly model confirms a specific dose-response effect for T with RR 1.20, CI 1.04-1.38 (lag time range from 0 to 11 to 0-15 h) and for NO₂ with RR 1.03, CI 1.01-1.05 (lag time range from 0 to 8 to 0-15 h). These results support the hypothesis that the clinical context of URI may be an important risk factor in the onset of OM diagnosed at ED level. The study highlights the relevance of URI as a control variable to be included in the statistical analysis in association with meteorological factors and air pollutants. The study also points out to a moderate association of OM with low temperatures and NO₂, with specific risk factors for this variable early in life. Further studies are needed to confirm these findings, particularly with respect to air pollutants in larger urban environments.