Long-term Ozone Exposure Research Articles

Ambient ozone exposure and depression among middle-aged and older adults: Nationwide longitudinal evidence in China.

Epidemiological studies have linked long-term ozone (O3) exposure with depression in developed countries. However, available literature is sparse and exists great heterogeneities. We aimed to investigate the association of long-term O3 exposure with depression among Chinese middle-aged and older adults. We designed a repeated measurement study based on longitudinal data from four waves (2011, 2013, 2015, and 2018) of the China Health and Retirement Longitudinal Study (CHARLS). Annual mean O3 concentrations assessed through machine learning-based spatiotemporal models were assigned to each participant at city level. Depression score was measured using the 10-item Center for Epidemiologic Studies Depression scale (CES-D-10), with scores above the cut-off point of ten defined as depressive symptom. Mixed-effects models were used to evaluate the impact of O3 on depression score and depressive symptom, and quantify the concentration-response (C-R) relationships. Subgroup analyses were performed to examine the potential effect modifications. A total of 19,582 participants with 60,125 visits were included in our analysis, with mean depression score of 8.1 (standard deviation: 6.3). Multivariable-adjusted mixed-effects model estimated a 6.34% (95% confidence interval [CI]: 3.34%, 9.43%) increase in depression score and an odds ratio (OR) of 1.29 (95% CI: 1.16, 1.45) for depressive symptom associated with per 10-μg/m3 rise in annual mean O3 exposure. Significantly elevated risks were identified only at high concentrations (approximately ≥90μg/m3). Participants who suffered from chronic diseases had a significant increased risk of depression (% Change in depression score: 8.42% [95% CI: 4.79%, 12.17%], and OR: 1.42 [95% CI: 1.24, 1.62]), and an evident effect modification was identified for depressive symptom (P=0.01). Our study provided novel evidence that long-term O3 exposure could be a risk factor for depression among Chinese middle-aged and older adults. Our findings may have significant implications for formulating policies in reducing disease burden of depression by controlling air pollution.

Comparison of using plant growth promoting bacteria and exogenous indole acetic acid on rice under ozone stress

Plant growth promoting bacteria (PGPB) could mitigate plants under abiotic stress by influencing plant physiology and adaptation tolerance to stress. In this study, the aims are compared three strains of PGPB (Bacillus thuringensis, Lysinibacillus sp. N5 and Bacillus sp. N7) inoculation and both exogenous 5 μM and 10 μM IAA and compare the application of seed inoculation of PGPB and IAA and soil inoculation of PGPB/foliar spraying IAA on improving rice productivity under ozone stress. Ozone affected on rice productivity by decreasing AsA due to increasing malondialdehyde (MDA). Rice inoculated with PGPB and foliar spraying 5 μM IAA could lower MDA via enhancing IAA, AsA, and chlorophyll content. Nevertheless, improving rice productivity (grain yield and 100-grain weight) were found in both seed and soil inoculation of PGPB and applying seed inoculation of IAA5 and 10 μM. Therefore, both seed and soil inoculation of PGPB and seed inoculation of IAA were the best way for applying in rice under long-term ozone exposure.

Excess mortality associated with high ozone exposure: A national cohort study in China

Emerging epidemiological studies suggest that long-term ozone (O3) exposure may increase the risk of mortality, while pre-existing evidence is mixed and has been generated predominantly in North America and Europe. In this study, we investigated the impact of long-term O3 exposure on all-cause mortality in a national cohort in China. A dynamic cohort of 20882 participants aged ≥40 years was recruited between 2011 and 2018 from four waves of the China Health and Retirement Longitudinal Study. A Cox proportional hazard regression model with time-varying exposures on an annual scale was used to estimate the mortality risk associated with warm-season (April–September) O3 exposure. The annual average level of participant exposure to warm-season O3 concentrations was 100 μg m−3 (range: 61–142 μg m−3). An increase of 10 μg m−3 in O3 was associated with a hazard ratio (HR) of 1.18 (95% confidence interval [CI]: 1.13–1.23) for all-cause mortality. Compared with the first exposure quartile of O3, HRs of mortality associated with the second, third, and highest exposure quartiles were 1.09 (95% CI: 0.95–1.25), 1.02 (95% CI: 0.88–1.19), and 1.56 (95% CI: 1.34–1.82), respectively. A J-shaped concentration–response association was observed, revealing a non-significant increase in risk below a concentration of approximately 110 μg m−3. Low-temperature-exposure residents had a higher risk of mortality associated with long-term O3 exposure. This study expands current epidemiological evidence from China and reveals that high-concentration O3 exposure curtails the long-term survival of middle-aged and older adults.

Estimation of Short-Term and Long-Term Ozone Exposure Levels in Beijing–Tianjin–Hebei Region Based on Geographically Weighted Regression Model

In recent years, ozone (O3) concentration has shown a decreasing trend in the Beijing–Tianjin–Hebei (BTH) region in China. However, O3 pollution remains a prominent problem. Accurate estimation of O3 exposure levels can provide support for epidemiological studies. A total of 13 variables were combined to estimate short- and long-term O3 exposure levels using the geographically weighted regression (GWR) model in the BTH region with a spatial resolution of 1 × 1 km from 2017 to 2020. Five variables were left in the GWR model. O3 concentration was positively correlated with temperature, wind speed, and SO2, whereas is was negatively correlated with precipitation and NO2. Results showed that the model performed well. Leave-one-out cross-validation (LOOCV) R2 for short- and long-term simulation results were 0.91 and 0.71, and the values for RMSE were 11.14 and 3.49 μg/m3, respectively. The annual maximum 8 h average O3 concentration was the highest in 2018 and the lowest in 2020. Decreasing concentrations of major precursors of O3 due to the regional joint prevention and control may be the reason. O3 concentration was high in the southeast of the BTH region, including in Hengshui, Handan, Xingtai and Cangzhou.

Long-term exposure to ambient ozone and mortality in a population-based cohort of South Korea: Considering for an alternative exposure time metric

Studies on the health effects of long-term ozone exposure remain limited with mixed results. One potential source of this inconsistency is the difference in exposure time metrics. This study aimed to investigate the association between long-term exposure to ambient ozone and mortality in South Korea, using different exposure metrics. We also examined whether heterogeneity between previous studies was due to the different exposure metrics. The study population comprised 179,806 participants from the National Health Insurance Service-National Sample Cohort (2002–2015) residing in seven major cities in South Korea. Several ozone exposure metrics (year-round 24-h, year-round 8-h, warm-season 24-h, and warm-season 8-h) were calculated. Time-varying Cox proportional hazards models were used to estimate the association between ozone and all-cause and cause-specific mortalities. Random-effect meta-analysis and meta-regression analysis were performed to pool the effect estimates of previous studies and examine whether the exposure metric can explain the between-study heterogeneity. The hazard ratios (HRs) per 10 ppb increment in year-round 24-h ozone for all-cause (HR, 1.18; 95% CI, 1.07–1.29) and circulatory (HR, 1.52; 95% CI, 1.25–1.84) mortality were higher than those of the other metrics. Year-round 8-h ozone exhibited the largest association with respiratory mortality (HR, 1.43; 95% CI, 1.04–1.96). A meta-analysis of 29 previous studies and the present study showed the largest HR for all-cause mortality from studies using year-round 8-h exposure (HR, 1.014; 95% CI, 0.994–1.033). The exposure metric was significantly associated with effect estimates in the multivariable meta-regression model. In conclusion, in the population-based cohort in South Korea, we found positive associations between several long-term ozone exposure metrics and mortality. The different ozone exposure metrics exhibited heterogeneous effect estimates. A year-round 24-h average ozone metric also could be considered an alternative long-term standard for ozone.

Aging of polyvinylidene fluoride (PVDF) ultrafiltration membrane due to ozone exposure in water treatment: Evolution of membrane properties and performance

Pre-ozonation is an effective pretreatment tactic for mitigating fouling of ultrafiltration (UF) membrane in water and wastewater treatment, but the compatibility of polymeric UF membranes with residual ozone remains unclear. In this study, effects of long-term ozone exposure on properties and performance of polyvinylidene fluoride (PVDF) UF membrane reinforced by polyethylene terephthalate (PET) layer were systematically investigated. The exposure intensities were designed to simulate ozone exposure at 0.1 mg/L for 0.5–5 years. Chemical composition analysis suggested that the hydrophilic additives, such as possibly polyvinyl pyrrolidone (PVP), was gradually degraded and released from the membrane, whereas the PVDF matrix exhibited fairly good ozone resistance. Ozonation resulted in increase of pore size and decrease of surface hydrophilicity, which can be attributed to oxidation and dislodgement of hydrophilic additives. Accordingly, long-term ozonation led to moderate changes in performance factors, including increase of membrane permeability by 34%, decrease of retention ability by 21.8%, increase of organic fouling propensity. It is worth noting that membrane tensile strength suffered substantial decrease after ozonation, probably due to ozonation of the PET support layer. Overall, it seems that the PVDF functional layer exhibited good ozone resistance, but the PET support layer was the Achilles' heel of the reinforced PVDF membrane for integrating with pre-ozonation.

Long-term Exposure to Ambient Ozone and Mortality in a population-based cohort of South Korea

Background and aim: Compared to robust evidence from studies on short-term exposure, the health effects of long-term ozone exposure have been less studied, and the results are mixed. One of the potential sources of inconsistency is the difference in exposure metrics. This study aimed to investigate the association between long-term exposure to ambient ozone and mortality in South Korea, using different exposure metrics. We also examined sources of heterogeneity between previous studies. Methods: The study population comprised 179,806 subjects from the National Health Insurance Service-National Sample Cohort (2002-2015) residing in 7 major cities in South Korea. Several ozone exposure metrics (year-round 24-h, year-round 8-h, warm-season 24-h, and warm-season 8-h) were calculated for each district. Time‐varying Cox proportional hazards models were adopted to estimate the association between ozone and all-cause and cause-specific mortality. Random-effects meta-analysis and meta-regression analysis were performed to pool the effect estimates of previous studies and examined whether selected study characteristics can explain between-study heterogeneity. Results: The HRs per 10 ppb increment in year-round 24-h ozone for all-cause (HR, 1.18; 95% CI, 1.07-1.29) and circulatory (HR, 1.52; 95% CI, 1.25-1.84) mortality were higher than that of other exposure metrics. For respiratory mortality, year-round 8-h ozone showed the largest associations (HR per 10 ppb, 4.13; 95% CI, 1.04-1.96). The meta-analysis of 26 previous studies and the present study showed a positive association between long-term ozone exposure and all-cause mortality, with the largest HR from warm-season 8-h ozone (HR, 1.042; 95% CI, 1.015-1.071). The exposure metric was significantly associated with the effect estimates in the multivariable meta-regression model. Conclusions: In the population-based cohort of South Korea, we found positive associations between several long-term ozone exposure metrics and mortality. Different ozone exposure metrics could be an important source of heterogeneity between studies. Keywords: ozone, mortality, long-term exposure, cohort study, meta-analysis

Long-term Ozone Exposure and Incident Frailty in Older Adults: Findings from a Prospective Cohort Study in Chinese Elderly

Long-term Ozone Exposure and Incident Frailty in Older Adults: Findings from a Prospective Cohort Study in Chinese Elderly

Long-term exposure to ozone and cardiovascular mortality in China: a nationwide cohort study

The evidence for a causal relationship between long-term ozone exposure and cardiovascular mortality is inconclusive, and most published data are from high-income countries. We aimed to investigate the association between long-term exposure to ozone and cardiovascular mortality in China, the most populous middle-income country. We did a nationwide cohort study comprising Chinese adults aged 18 years and older from the 2010-11 China Chronic Disease and Risk Factors Surveillance project; participants were followed up until Dec 31, 2018, or the date of death. Data on participants' deaths were obtained through linkage to the Disease Surveillance Point system, a national death registration database. Residential ozone exposure was estimated with a previously developed random forest model. We applied stratified Cox proportional hazards models to estimate the associations of ozone with mortality due to overall cardiovascular diseases, ischaemic heart disease, and stroke. The models were stratified by age and sex and adjusted for a set of individual-level and regional covariates. Warm-season average ozone concentration for the previous 1-3 years was added as a time-varying variable. We also did subgroup analyses by age, sex, level of education, smoking status, urban or rural residence, and geographical region. Data were analysed for 96 955 participants. The warm-season average ozone concentration during the follow-up period was 89·7 μg/m3 (SD 14·4). In the fully adjusted models, we observed significant and positive associations between ozone and mortality from overall cardiovascular diseases (hazard ratio [HR] 1·093 [95% CI 1·046-1·142] per 10 μg/m3 increase in warm-season ozone concentrations), ischaemic heart disease (1·184 [1·099-1·276] per 10 μg/m3 increase in warm-season ozone concentrations), and stroke (1·063 [1·002- 1·128] per 10 μg/m3 increase in warm-season ozone concentrations). After adjusting for fine particulate matter, the associations with overall cardiovascular disease and ischaemic heart disease mortality were almost unchanged, whereas the association with stroke mortality lost statistical significance. The association of long-term ozone exposure with cardiovascular mortality was more prominent in people aged 65 years and older than in those younger than 65 years. We did not find any effect modification of sex, level of education, smoking status, urban or rural residence, and geographical region. We observed an almost linear exposure-response relationship between ozone and cardiovascular mortality. This study is, to the best of our knowledge, the first nationwide cohort study to show that long-term ozone exposure contributes to elevated risks of cardiovascular mortality, particularly from ischaemic heart disease, in a middle-income setting. The exposure-response function generated from this study could potentially inform future air quality standard revisions and environmental health impact assessments. National Natural Science Foundation of China.

Variation in leaf transcriptome responses to elevated ozone corresponds with physiological sensitivity to ozone across maize inbred lines.

We examine the impact of sustained elevated ozone concentration on the leaf transcriptome of 5 diverse maize inbred genotypes, which vary in physiological sensitivity to ozone (B73, Mo17, Hp301, C123, and NC338), using long reads to assemble transcripts and short reads to quantify expression of these transcripts. More than 99% of the long reads, 99% of the assembled transcripts, and 97% of the short reads map to both B73 and Mo17 reference genomes. Approximately 95% of the genes with assembled transcripts belong to known B73-Mo17 syntenic loci and 94% of genes with assembled transcripts are present in all temperate lines in the nested association mapping pan-genome. While there is limited evidence for alternative splicing in response to ozone stress, there is a difference in the magnitude of differential expression among the 5 genotypes. The transcriptional response to sustained ozone stress in the ozone resistant B73 genotype (151 genes) was modest, while more than 3,300 genes were significantly differentially expressed in the more sensitive NC338 genotype. There is the potential for tandem duplication in 30% of genes with assembled transcripts, but there is no obvious association between potential tandem duplication and differential expression. Genes with a common response across the 5 genotypes (83 genes) were associated with photosynthesis, in particular photosystem I. The functional annotation of genes not differentially expressed in B73 but responsive in the other 4 genotypes (789) identifies reactive oxygen species. This suggests that B73 has a different response to long-term ozone exposure than the other 4 genotypes. The relative magnitude of the genotypic response to ozone, and the enrichment analyses are consistent regardless of whether aligning short reads to: long read assembled transcripts; the B73 reference; the Mo17 reference. We find that prolonged ozone exposure directly impacts the photosynthetic machinery of the leaf.

Antioxidants and Phytohormones Act in Coordination to Regulate Sage Response to Long Term Ozone Exposure.

Antioxidants and phytohormones are hallmarks of abiotic stress responses in plants. Although it is known that they can offer cell protection or accelerate programmed cell death (PCD) depending on the level of stress, the involvement of these metabolites in stress acclimation is still not fully elucidated. Here, we showed the role of antioxidants and phytohormones in Salvia officinalis tolerance to long-term ozone (O3) exposure (120 ppb for 36 days, 5 h day−1). Salicylic acid (SA) content was increased under O3 throughout the whole experiment (+150%, as average compared with control), being required to maintain the cellular redox state and potentiate defense responses. This accumulation was induced before the production of ethylene (ET), suggesting that ET was controlled by SA during O3 exposure to modulate the magnitude of chlorosis formation and the cell redox balance (by regulating ascorbate and glutathione levels). The synthesis and/or regeneration of these antioxidants did not protect membranes from lipid peroxidation, as demonstrated by the accumulation of malondialdehyde (+23% as average). However, these processes of lipid oxidation did not include the synthesis of the membrane breakdown products, as confirmed by the unchanged values of jasmonic acid, thus indicating that this compound was not involved in the regulation of PCD strategies.

Long-term ozone exposure and cognitive impairment among Chinese older adults: A cohort study.

Ambient particulate matter pollution has been linked to impaired cognitive performance, but the effect of ambient ozone exposure on cognitive function remains largely unknown. We examined the association of long-term ozone exposure with the risk of cognitive impairment among a national representative cohort of 9,544 Chinese older adults (aged 65years and over) with baseline normal cognition from the Chinese Longitudinal Healthy Longevity Survey (2005-2018). The ozone exposure of each participant was measured by annual mean ozone concentrations for the county of residence. Cognitive function was assessed by the Chinese version of the Mini-Mental State Examination (MMSE). We defined cognitive impairment as an MMSE score below 18 points accompanied by an MMSE score that declined≥4 points from baseline. Cox proportional hazards models were applied to explore the association of ozone exposure with cognitive impairment. During the mean follow-up time of 6.5years, 2,601 older adults developed cognitive impairment. Each 10-μg/m3 increase in annual mean ozone exposure was associated with a 10.4% increased risk of cognitive impairment. The exposure-response relationship between ozone exposure and risk of cognitive impairment showed a linear trend. Sensitivity analyses revealed the association to be robust. We found that older adults from Eastern, Central, and Southern China were particularly susceptible. Our results show that ozone is a risk factor for late-life cognitive decline. Reducing ambient ozone pollution may help delay the onset of cognitive impairment among older adults.

Long-Term Ozone Exposure and Mortality in Patients With Chronic Kidney Disease: A Large Cohort Study

Long-Term Ozone Exposure and Mortality in Patients With Chronic Kidney Disease: A Large Cohort Study

Long-term ozone exposure and mortality from neurological diseases in Canada.

There is increasing interest in the health effects of air pollution. However, the relationships between ozone exposure and mortality attributable to neurological diseases remain unclear. To assess associations of long-term exposure to ozone with death from Parkinson's disease, dementia, stroke, and multiple sclerosis. Our analyses were based on the 2001 Canadian Census Health and Environment Cohort. Census participants were linked with vital statistics records through 2016, resulting in a cohort of 3.5 million adults/51,045,700 person-years, with 8,500/51,300/43,300/1,300 deaths from Parkinson's/dementia/stroke/multiple sclerosis, respectively. Ten-year average ozone concentrations estimated by chemical transport models and adjusted by ground measurements were assigned to subjects based on postal codes. Cox proportional hazards models were used to calculate hazard ratios (HRs) for deaths from the four neurological diseases, adjusting for eight common demographic and socioeconomic factors, seven environmental indexes, and six contextual covariates. The fully adjusted HRs for Parkinson's, dementia, stroke, and multiple sclerosis mortalities related to one interquartile range increase in ozone (10.1ppb), were 1.09 (95% confidence interval 1.04-1.14), 1.08 (1.06-1.10), 1.06 (1.04-1.09), and 1.35 (1.20-1.51), respectively. The covariates did not influence significance of the ozone-mortality associations, except airshed (i.e., broad region of Canada). During the period of 2001-2016, 5.66%/5.01%/ 3.77%/19.11% of deaths from Parkinson's/dementia/stroke/multiple sclerosis, respectively, were attributable to ozone exposure. We found positive associations between ozone exposure and mortality due to Parkinson's, dementia, stroke, and multiple sclerosis.

Long-Term Ozone Exposure and Small Airway Dysfunction: The China Pulmonary Health (CPH) Study.

Rationale: It remains unknown whether long-term ozone exposure can impair lung function. Objectives: To investigate the associations between long-term ozone exposure and adult lung function in China. Methods: Lung function results and diagnosis of small airway dysfunction (SAD) were collected from a cross-sectional study, the China Pulmonary Health Study (N = 50,991). We used multivariable linear and logistic regression models to examine the associations of long-term ozone exposure with lung function parameters and SAD, respectively, adjusting for demographic characteristics, individual risk factors, and longitudinal trends. We then performed a stratification analysis by chronic obstructive pulmonary disease (COPD). Measurements and Main Results: We observed that each 1 SD (4.9 ppb) increase in warm-season ozone concentrations was associated with a 14.2 ml/s (95% confidence interval [CI], 8.8-19.6 ml/s] decrease in forced expiratory flow at the 75th percentile of vital capacity and a 29.5 ml/s (95% CI, 19.6-39.5 ml/s) decrease in mean forced expiratory flow between the 25th and 75th percentile of vital capacity. The odds ratio of SAD was 1.09 (95% CI, 1.06-1.11) for a 1 SD increase in warm-season ozone concentrations. Meanwhile, we observed a significant association with decreased FEV1/FVC but not with FEV1 or FVC. The association estimates were greater in the COPD group than in the non-COPD group. Conclusions: We found independent associations of long-term ozone exposure with impaired small airway function and higher SAD risks, while the associations with airflow obstruction were weak. Patients with COPD appear to be more vulnerable.

Relationships between Long-Term Ozone Exposure and Allergic Rhinitis and Bronchitic Symptoms in Chinese Children.

Numerous studies have demonstrated that exposure to ambient ozone (O3) could have adverse effects on children’s respiratory health. However, previous studies mainly focused on asthma and wheezing. Evidence for allergic rhinitis and bronchitic symptoms (e.g., persistent cough and phlegm) associated with O3 is limited, and results from existing studies are inconsistent. This study included a total of 59,754 children from the seven northeastern cities study (SNEC), who were aged 2 to 17 years and from 94 kindergarten, elementary and middle schools. Information on doctor-diagnosed allergic rhinitis (AR), persistent cough, and persistent phlegm was collected during 2012–2013 using a standardized questionnaire developed by the American Thoracic Society (ATS). Information for potential confounders was also collected via questionnaire. Individuals’ exposure to ambient ozone (O3) during the four years before the investigation was estimated using a satellite-based random forest model. A higher level of O3 was significantly associated with increased risk of AR and bronchitic symptoms. After controlling for potential confounders, the OR (95% CI) were 1.13 (1.07–1.18), 1.10 (1.06–1.16), and 1.12 (1.05–1.20) for AR, persistent cough, and persistent phlegm, respectively, associated with each interquartile range (IQR) rise in O3 concentration. Interaction analyses showed stronger adverse effects of O3 on AR in children aged 7–17 years than those aged 2–6 years, while the adverse association of O3 with cough was more prominent in females and children aged 7–12 years than in males and children aged 2–6 and 13–17 years. This study showed that long-term exposure to ambient O3 was significantly associated with higher risk of AR and bronchitic symptoms in children, and the association varies across age and gender. Our findings contribute additional evidence for the importance of controlling O3 pollution and protecting children from O3 exposure.

Long-term Ozone Exposure and Cognitive Impairment among Chinese Older Adults: Analysis of the Chinese Longitudinal Healthy Longevity Survey

BACKGROUND AND AIM: Increasing evidence points to an association between PM₂.₅ exposure and late-life cognitive health, but little is known about whether ambient ozone exposure affects cognitive functioning. This study aimed to examine the association of long-term ozone exposure with risk of cognitive impairment among older adults in China. METHODS: We used longitudinal data from five waves (2005, 2008-2009, 2011-2012, 2014, and 2017-2018) of the Chinese Longitudinal Healthy Longevity Survey. In total, 9,544 participants (aged 81.4 ± 10.8 years at baseline, 48.3% male) with normal cognitive function at the baseline surveys from March 2005 to November 2014 were included in this analysis. The ozone exposure of each participant was estimated by the cumulative annual average ozone concentration for the county of residence. Cognitive function was assessed by the Chinese version of the Mini-Mental State Examination (MMSE). We used a cutoff MMSE score below 18 points with an additional restriction of MMSE decline ≥ 4 points from baseline to define cognitive impairment. A Cox proportional hazard model was utilized to explore the association of ozone exposure with cognitive decline. RESULTS:During an average observation time of 6.5 years (62,133 person-years), 2,601 participants developed cognitive impairment. Preliminary results show that each 10-μg/m³ increase in ozone was associated with a 13.1% increased risk of cognitive impairment [95% confidence interval (CI): 6.8%, 19.8%]. No evidence was found for a threshold down to 70 μg/m³. The association between ozone exposure and risk of cognitive impairment was stronger for men than women (p-value for interaction: 0.03). CONCLUSIONS:Long-term exposure to ozone was associated with an increased risk of cognitive impairment among Chinese older adults. Reducing ambient ozone pollution may delay cognitive decline among older adults in China. KEYWORDS: Ozone, Long-term exposure, Neurodegenerative outcomes

Systematic Review of Ozone Effects on Human Lung Function, 2013 Through 2020

BackgroundOzone effects on lung function are particularly important to understand in the context of the air pollution-health outcomes epidemiologic literature, given the complex relationships between ozone and other air pollutants with known lung function effects.Research QuestionWhat has been learned about the association between ozone exposures and lung function from epidemiology studies published from 2013 through 2020?Study Design and MethodsOn March 18, 2018, and September 8, 2020, PubMed was searched using the terms health AND ozone, filtering to articles in English and about humans, from 2013 or later. An additional focused review searching for ozone AND (lung function OR FEV1OR FVC) was performed June 26, 2021. Articles were selected for this review if they reported a specific relationship between a lung function outcome and ozone exposure.ResultsOf 3,271 articles screened, 53 ultimately met criteria for inclusion. A systematic review with assessment of potential for bias was conducted, but a meta-analysis was not carried out because of differences in exposure duration and outcome quantification. Consistent evidence exists of small decreases in children’s lung function, even associated with very low levels of short-term ozone exposure. The effects on adult lung function from exposure to low-level, short-term ozone are less clear, although ozone-associated decrements may occur in the elderly. Finally, long-term ozone exposure decreases both lung function and lung function growth in children, although few new studies have examined long-term ozone and lung function in adults.InterpretationMuch of this literature involves concentrations below the current US Environmental Protection Agency’s National Ambient Air Quality Standard of 70 parts per billion over an 8-h averaging time, suggesting that this current standard may not protect children adequately from ozone-related decrements in lung function.

Evaluating spatial patterns of seasonal ozone exposure and incidence of respiratory emergency room visits in Dallas-Fort Worth.

BackgroundIn urban environments, environmental air pollution poses significant risks to respiratory health. Moreover, the seasonal spatial variability of the air pollutant ozone, and respiratory illness within Dallas-Fort Worth (DFW) is not well understood. We examine the relationships between spatial patterns of long-term ozone exposure and respiratory illness to better understand impacts on health outcomes. We propose that this study will establish an enhanced understanding of the spatio-temporal characteristics of ozone concentrations and respiratory emergency room visits (ERV) incidence.MethodsAir pollution data (ozone) and ERV incidence data from DFW was used to evaluate the relationships between exposures and outcomes using three steps: (1) develop a geostatistical model to produce quarterly maps of ozone exposure for the DFW area; (2) use spatial analysis techniques to identify clusters of zip codes with high or low values of ozone exposure and respiratory ERV incidence; and (3) use concentration-response curves to evaluate the relationships between respiratory ERV incidence and ozone exposure.ResultsRespiratory ERV incidence was highest in quarters 1 and 4, while ozone exposure was highest in quarters 2 and 3. Extensive statistically significant spatial clusters of ozone regions were identified. Although the maps revealed that there was no regional association between the spatial patterns of high respiratory ERV incidence and ozone exposure, the concentration-response analysis suggests that lower levels of ozone exposure may still contribute to adverse respiratory outcomes.

Health impacts of long-term ozone exposure in China over 2013–2017

Increasing ozone concentrations are becoming a severe problem for air pollution in China and have an adverse impact on human health. Here we evaluate premature deaths attributable to long-term exposure to ambient ozone in China between 2013 and 2017 with an air quality model at 5 km resolution and the latest estimates of the relative risk to health. We use a modified inverse distance weighting method to bias-correct the key model-simulated ozone metrics. We find that on a 5-year average basis there are 186,000 (95% Confidence Interval: 129,000–237,000) respiratory deaths and 125,000 (42,000–204,000) cardiovascular deaths attributable to ozone exposure. Sichuan exhibits the largest per capita respiratory mortality (0.31‰) among all provinces. We find that there are 73,000 (51,000–93,000) premature respiratory deaths in urban areas, accounting for 39% of total deaths. Between 2013 and 2017 the population-weighted annual average maximum daily 8-h average ozone (AMDA8) and premature respiratory deaths increased by 14% and 31%, respectively, at a national level. Changes in precursor emissions explain most of these increases, with differences in meteorology accounting for 21% and 16% respectively. Interannual variations in population-weighted ozone and premature respiratory deaths at a provincial level are much larger than those at a national level, particularly in northern, central and eastern China. These findings emphasize that ozone should be an important focus of future air quality policies in China, and tighter controls of precursor emissions are urgently needed.