Association between neighbourhood air pollution concentrations and dispensed medication for psychiatric disorders in a large longitudinal cohort of Swedish children and adolescents

Air and Noise Pollution Exposure in Early Life and Mental Health From Adolescence to Young Adulthood

Importance

Growing evidence associates air pollution exposure with various psychiatric disorders. However, the importance of early-life (eg, prenatal) air pollution exposure to mental health during youth is poorly understood, and few longitudinal studies have investigated the association of noise pollution with youth mental health.

Objectives

To examine the longitudinal associations of air and noise pollution exposure in pregnancy, childhood, and adolescence with psychotic experiences, depression, and anxiety in youths from ages 13 to 24 years.

Design, Setting, and Participants

This cohort study used data from the Avon Longitudinal Study of Parents and Children, an ongoing longitudinal birth cohort founded in 1991 through 1993 in Southwest England, United Kingdom. The cohort includes over 14 000 infants with due dates between April 1, 1991, and December 31, 1992, who were subsequently followed up into adulthood. Data were analyzed October 29, 2021, to March 11, 2024.

Exposures

A novel linkage (completed in 2020) was performed to link high-resolution (100 m2) estimates of nitrogen dioxide (NO2), fine particulate matter under 2.5 μm (PM2.5), and noise pollution to home addresses from pregnancy to 12 years of age.

Main outcomes and measures

Psychotic experiences, depression, and anxiety were measured at ages 13, 18, and 24 years. Logistic regression models controlled for key individual-, family-, and area-level confounders.

Results

This cohort study included 9065 participants who had any mental health data, of whom (with sample size varying by parameter) 51.4% (4657 of 9051) were female, 19.5% (1544 of 7910) reported psychotic experiences, 11.4% (947 of 8344) reported depression, and 9.7% (811 of 8398) reported anxiety. Mean (SD) age at follow-up was 24.5 (0.8) years. After covariate adjustment, IQR increases (0.72 μg/m3) in PM2.5 levels during pregnancy (adjusted odds ratio [AOR], 1.11 [95% CI, 1.04-1.19]; P = .002) and during childhood (AOR, 1.09 [95% CI, 1.00-1.10]; P = .04) were associated with elevated odds for psychotic experiences. Pregnancy PM2.5 exposure was also associated with depression (AOR, 1.10 [95% CI, 1.02-1.18]; P = .01). Higher noise pollution exposure in childhood (AOR, 1.19 [95% CI, 1.03-1.38]; P = .02) and adolescence (AOR, 1.22 [95% CI, 1.02-1.45]; P = .03) was associated with elevated odds for anxiety.

Conclusions and Relevance

In this longitudinal cohort study, early-life air and noise pollution exposure were prospectively associated with 3 common mental health problems from adolescence to young adulthood. There was a degree of specificity in terms of pollutant-timing-outcome associations. Interventions to reduce air and noise pollution exposure (eg, clean air zones) could potentially improve population mental health. Replication using quasi-experimental designs is now needed to shed further light on the underlying causes of these associations.

Association between prenatal and childhood PM2.5 exposure and preadolescent anxiety and depressive symptoms

Background

Fine particulate matter (PM2.5) exposure has been linked to anxiety and depression in adults; however, there is limited research in the younger populations, in which symptoms often first arise.

Methods

We examined the association between early-life PM2.5 exposure and symptoms of anxiety and depression in a cohort of 8-11-year-olds in Mexico City. Anxiety and depressive symptoms were assessed using the Spanish versions of the Revised Children's Manifest Anxiety Scale and Children's Depression Inventory. Daily PM2.5 was estimated using a satellite-based exposure model and averaged over several early and recent exposure windows. Linear and logistic regression models were used to estimate the change in symptoms with each 5-µg/m3 increase in PM2.5. Models were adjusted for child's age, child's sex, maternal age, maternal socioeconomic status, season of conception, and temperature.

Results

Average anxiety and depressive symptom T-scores were 51.0 (range 33-73) and 53.4 (range 44-90), respectively. We observed consistent findings for exposures around the fourth year of life, as this was present for both continuous and dichotomized anxiety symptoms, in both independent exposure models and distributed lag modeling approaches. This window was also observed for elevated depressive symptoms. An additional consistent finding was for PM2.5 exposure during early pregnancy in relation to both clinically elevated anxiety and depressive symptoms, this was seen in both traditional and distributed lag modeling approaches.

Conclusion

Both early life and recent PM2.5 exposure were associated with higher mental health symptoms in the child highlighting the role of PM2.5 in the etiology of these conditions.

Particulate Matter in Human Elderly: Higher Susceptibility to Cognitive Decline and Age-Related Diseases

This review highlights the significant impact of air quality, specifically particulate matter (PM), on cognitive decline and age-related diseases in the elderly. Despite established links to other pathologies, such as respiratory and cardiovascular illnesses, there is a pressing need for increased attention to the association between air pollution and cognitive aging, given the rising prevalence of neurocognitive disorders. PM sources are from diverse origins, including industrial activities and combustion engines, categorized into PM10, PM2.5, and ultrafine PM (UFPM), and emphasized health risks from both outdoor and indoor exposure. Long-term PM exposure, notably PM2.5, has correlated with declines in cognitive function, with a specific vulnerability observed in women. Recently, extracellular vesicles (EVs) have been explored due to the interplay between them, PM exposure, and human aging, highlighting the crucial role of EVs, especially exosomes, in mediating the complex relationship between PM exposure and chronic diseases, particularly neurological disorders. To sum up, we have compiled the pieces of evidence that show the potential contribution of PM exposure to cognitive aging and the role of EVs in mediating PM-induced cognitive impairment, which presents a promising avenue for future research and development of therapeutic strategies. Finally, this review emphasizes the need for policy changes and increased public awareness to mitigate air pollution, especially among vulnerable populations such as the elderly.

Long-term exposure to air pollution and incidence of mental disorders. A large longitudinal cohort study of adults within an urban area

BACKGROUND

Recent epidemiological evidence suggests associations between air pollution exposure and major depressive disorders, but the literature is inconsistent for other mental illnesses. We investigated the associations of several air pollutants and road traffic noise with the incidence of different categories of mental disorders in a large population-based cohort.

METHODS

We enrolled 1,739,277 individuals 30 + years from the 2011 census in Rome, Italy, and followed them up until 2019. In detail, we analyzed 1,733,331 participants (mean age 56.43 +/- 15.85 years; 54.96 % female) with complete information on covariates of interest. We excluded subjects with prevalent mental disorders at baseline to evaluate the incidence (first hospitalization or co-pay exemption) of schizophrenia spectrum disorders, bipolar, anxiety, personality, or substance use disorders. In addition, we studied subjects with first prescriptions of antipsychotics, antidepressants, and mood stabilizers. Annual average concentrations of fine particulate matter (PM2.5), nitrogen dioxide (NO₂), Black Carbon (BC), ultrafine particles (UFP), and road traffic noise were assigned to baseline residential addresses. We applied Cox regression models adjusted for individual and area-level covariates.

RESULTS

Each interquartile range (1.13 µg/m3) increase in PM2.5 was associated with a hazard ratio (HR) of 1.070 (95 % confidence interval [CI]: 1.017, 1.127) for schizophrenia spectrum disorder, 1.135 (CI: 1.086, 1.186) for depression, 1.097 (CI: 1.030, 1.168) for anxiety disorders. Positive associations were also detected for BC and UFP, and with the three categories of drug prescriptions. Bipolar, personality, and substance use disorders did not show clear associations. The effects were highest in the age group 30-64 years, except for depression.

CONCLUSIONS

Long-term exposure to ambient air pollution, especially fine and ultrafine particles, was associated with increased risks of schizophrenia spectrum disorder, depression, and anxiety disorders. The association of the pollutants with the prescriptions of specific drugs increases the credibility of the results.

Multiple Chemical Sensitivity: It's time to catch up to the science

Multiple chemical sensitivity (MCS) is a complex medical condition associated with low dose chemical exposures. MCS is characterized by diverse features and common comorbidities, including fibromyalgia, cough hypersensitivity, asthma, and migraine, and stress/anxiety, with which the syndrome shares numerous neurobiological processes and altered functioning within diverse brain regions. Predictive factors linked to MCS comprise genetic influences, gene-environment interactions, oxidative stress, systemic inflammation, cell dysfunction, and psychosocial influences. The development of MCS may be attributed to the sensitization of transient receptor potential (TRP) receptors, notably TRPV1 and TRPA1. Capsaicin inhalation challenge studies demonstrated that TRPV1 sensitization is manifested in MCS, and functional brain imaging studies revealed that TRPV1 and TRPA1 agonists promote brain-region specific neuronal variations. Unfortunately, MCS has often been inappropriately viewed as stemming exclusively from psychological disturbances, which has fostered patients being stigmatized and ostracized, and often being denied accommodation for their disability. Evidence-based education is essential to provide appropriate support and advocacy. Greater recognition of receptor-mediated biological mechanisms should be incorporated in laws, and regulation of environmental exposures.

The wellbeing of adolescents and the role of greenness: A cross-sectional study among Italian students

Introduction

Adolescence is a critical period of life, and the level of wellbeing acquired during this stage might have an influence on health status in adulthood. The wellbeing of adolescents is associated with both biological and environmental determinants. To date, few studies have evaluated the effect of exposure to urban green spaces (i.e., greenness) on adolescents' wellbeing. Therefore, the aim of this study is to assess the association between exposure to greenness and the wellbeing of adolescents, accounting for the level of urbanization surrounding schools.

Methods

In the frame of the 2018 Italian Health Behaviour in School-aged Children (HBSC), we analyzed cross-sectional data from the Piedmont Region. Exposure to greenness was quantified by the Normalized Difference Vegetation Index (NDVI). Schools were geocoded, and a fixed buffer (radius 1,500 m) centered on each school was then built to enable average NDVI calculations. Adolescents' wellbeing was assessed by self-reported psychological, somatic, and psychosomatic health complaints as follows. Respondents were asked how often, in the last 6 months, they had experienced: (a) headache, (b) stomachache, (c) backache, (d) dizziness, (e) feeling low, (f) irritability or bad temper, (g) feeling nervous, and (h) difficulties getting to sleep using the HBSC Symptom Checklist (HBSC-SCL), an eight-item tool. Multivariable, multilevel logistic regression models tested the association between exposure to NDVI and psychosomatic, somatic, and psychological health complaints, one at a time, using schools as a random intercept.

Results

In total, 2065 subjects (47.6% girls) aged 11 (48.4%) and 13 (51.6%) years were involved. Greenness was found to be inversely associated with reported psychosomatic (OR 0.72, 95% CI: 0.53-0.98) and psychological health complaints (OR 0.67, 95% CI: 0.49-0.92) in boys only, adjusting for age, urbanization level, and socioeconomic status, and stratifying by gender.

Discussion

Our results support the implementation of future policies for urban environmental design supporting the increase of green spaces, as suggested by the United Nations Sustainable Development Goals. Further studies are needed to confirm our findings.

Oxidative stress response in pulmonary cells exposed to different fractions of PM2.5-0.3 from urban, traffic and industrial sites

The aim of this work was to study the relationship between oxidative stress damages and particulate matter (PM) chemical composition, sources, and PM fractions. PM_2.5-0.3 (PM with equivalent aerodynamic diameter between 2.5 and 0.3 μm) were collected at urban, road traffic and industrial sites in the North of France, and were characterized for major and minor chemical species. Four different fractions (whole PM_2.5-0.3, organic, water-soluble and non-extractable matter) were considered for each of the PM_2.5-0.3 samples from the three sites. After exposure of BEAS-2B cells to the four different fractions, oxidative stress was studied in cells by quantifying reactive oxygen species (ROS) accumulation, oxidative damage to proteins (carbonylated proteins), membrane alteration (8-isoprostane) and DNA damages (8-OHdG). Whole PM_2.5-0.3 was capable of inducing ROS overproduction and caused damage to proteins at higher levels than other fractions. Stronger cell membrane and DNA damages were found associated with PM and organic fractions from the urban site. ROS overproduction was correlated with level of expression of carbonylated proteins, DNA damages and membrane alteration markers. The PM_2.5-0.3 collected under industrial influence appears to be the less linked to cell damages and ROS production in comparison with the other influences.

Association of NO2 with daily hospital admissions for mental disorders: Investigation of the modification effects of green spaces and long-term NO2 exposure

Air pollution is a risk factor for increased hospital admissions due to mental disorders, while green spaces have been linked with better mental health. We linked daily hospital admission records from Wuhan's 74 municipal hospitals from 2017 to 2019 with modeled annual average NO₂ concentrations and added data on the residential surrounding green spaces with 250 m and 500 m buffers based on the normalized difference vegetation index (NDVI) using a land use regression model (LUR). The conditional logistic regression model was used to estimate the acute effect of short-term NO₂ exposure, and stratification analyses were applied to explore the modification effect of long-term NO₂ exposure and green spaces by estimating the odds ratios in the single- and dual-environmental factor groups. A total of 42,705 hospital admissions for mental disorders were identified. Short-term exposure to NO₂ was associated with an increased risk of hospital admission for mental disorders. A 10 μg/m³ increase in NO₂ (lag01 day) was associated with an increase in hospital admissions of 2.86% (95% CI, 2.05-3.68) for the total mental disorders. Compared with patients in the "low-NDVI/low-NO₂" group (ER = 2.27%, 95% CI, 0.27-4.31), patients in the "high-NDVI/low-NO₂" group (ER = 1.93%, -0.10-3.99) showed a lower and insignificant increase in hospitalizations for the total mental disorders, while greenness had a slight moderating effect in the high-level long-term NO₂ exposure areas. This study suggested that green spaces may moderate the acute effect of NO₂ exposure for mental disorder hospitalizations, especially in low-level long-term NO₂ exposure areas.

Long-term air pollution exposure, greenspace and health-related quality of life in the ECRHS study

BACKGROUND

Associations of long-term exposure to air pollution and greenspace with health-related quality of life (HRQOL) are poorly studied and few studies have accounted for asthma-rhinitis status.

OBJECTIVE

To assess the associations of air pollution and greenspace with HRQOL and whether asthma and/or rhinitis modify these associations.

METHODS

The study was based on the participants in the second (2000-2002, n = 6542) and third (2011-2013, n = 3686) waves of the European Community Respiratory Health Survey (ECRHS) including 19 centres. The mean follow-up time was 11.3 years. HRQOL was assessed by the SF-36 Physical and Mental Component Summary scores (PCS and MCS). NO₂, PM_2.5 and PM₁₀ annual concentrations were estimated at the residential address from existing land-use regression models. Greenspace around the residential address was estimated by the (i) mean of the Normalized Difference Vegetation Index (NDVI) and by the (ii) presence of green spaces within a 300 m buffer. Associations of each exposure variable with PCS and MCS were assessed by mixed linear regression models, accounting for the multicentre design and repeated data, and adjusting for potential confounders. Analyses were stratified by asthma-rhinitis status.

RESULTS

The mean (SD) age of the ECRHS-II and III participants was 43 (7.1) and 54 (7.2) years, respectively, and 48 % were men. Higher NO₂, PM_2.5 and PM₁₀ concentrations were associated with lower MCS (regression coefficients [95%CI] for one unit increase in the inter-quartile range of exposures were -0.69 [-1.23; -0.15], -1.79 [-2.88; -0.70], -1.80 [-2.98; -0.62] respectively). Higher NDVI and presence of forests were associated with higher MCS. No consistent associations were observed for PCS. Similar association patterns were observed regardless of asthma-rhinitis status.

CONCLUSION

European adults who resided at places with higher air pollution and lower greenspace were more likely to have lower mental component of HRQOL. Asthma or rhinitis status did not modify these associations.

Evaluating physical urban features in several mental illnesses using electronic health record data

Objectives

Understanding the potential impact of physical characteristics of the urban environment on clinical outcomes on several mental illnesses.

Materials and Methods

Physical features of the urban environment were examined as predictors for affective and non-affective several mental illnesses (SMI), the number and length of psychiatric hospital admissions, and the number of short and long-acting injectable antipsychotic prescriptions. In addition, the urban features with the greatest weight in the predicted model were determined. The data included 28 urban features and 6 clinical variables obtained from 30,210 people with SMI receiving care from the South London and Maudsley NHS Foundation Trust (SLaM) using the Clinical Record Interactive Search (CRIS) tool. Five machine learning regression models were evaluated for the highest prediction accuracy followed by the Self-Organising Map (SOM) to represent the results visually.

Results

The prevalence of SMI, number and duration of psychiatric hospital admission, and antipsychotic prescribing were greater in urban areas. However, machine learning analysis was unable to accurately predict clinical outcomes using urban environmental data.

Discussion

The urban environment is associated with an increased prevalence of SMI. However, urban features alone cannot explain the variation observed in psychotic disorder prevalence or clinical outcomes measured through psychiatric hospitalisation or exposure to antipsychotic treatments.

Conclusion

Urban areas are associated with a greater prevalence of SMI but clinical outcomes are likely to depend on a combination of urban and individual patient-level factors. Future mental healthcare service planning should focus on providing appropriate resources to people with SMI in urban environments.

Deposition-mediated phytoremediation of nitrogen oxide emissions

The growing global population and use of natural resources lead to significant air pollution. Nitrogen oxide emissions is a potential killer threatening human health requiring focus and remediation using vegetation being efficient and cheap. Here we review the mechanisms of removing nitrogen oxides by dry deposition of plants, discussing the principle of leaf absorption of pollutants and factors affecting the removal of nitrogen oxides providing a theoretical basis for the selection of urban greening vegetation.

Entitlement, Indeterminacy and Professional Discretion in Urban Planning: Problematising a Child’s Right to Clean Air for Play in London

The interaction between air quality and play space receives less focus in planning than it has in public health and environmental sciences research. In this paper, seven local planning authorities of inner London (UK) were sampled from the 10 boroughs with the worst air quality in parks. Greenwich, with significantly better air quality, was included for comparison. The selected authorities were validated against deprivation data, ensuring variance in socio-economic terms. Across this sample, 21 major residential planning applications were assessed, alongside a document analysis of planning policy documents for each authority. Lastly, five semi-structured interviews with different practitioners collectively provided multi-disciplinary perspectives on the planning processes across the sample. Despite the national government having conferred children a right to leisure space and a healthy environment via international conventions, the English planning system, as an institutional rights framework, is not consistently prioritising the delivery of children’s play space nor delivering play space where the air quality has been robustly assessed. In other words, such rights have been subjugated to other priorities in limited urban space in London. Therefore, a discretionary planning system does not preclude individual human rights from becoming disadvantaged under democratically controlled decision-making processes.

Green space, air pollution, traffic noise and mental wellbeing throughout adolescence: Findings from the PIAMA study

BACKGROUND

Green space, air pollution and traffic noise exposure may be associated with mental health in adolescents. We assessed the associations of long-term exposure to residential green space, ambient air pollution and traffic noise with mental wellbeing from age 11 to 20 years.

METHODS

We included 3059 participants of the Dutch PIAMA birth cohort who completed the five-item Mental Health Inventory (MHI-5) at ages 11, 14, 17 and/or 20 years. We estimated exposure to green space (the average Normalized Difference Vegetation Index (NDVI) and percentages of green space in circular buffers of 300 m, 1000 m and 3000 m), ambient air pollution (particulate matter (PM₁₀ and PM_2.5), nitrogen dioxide, PM_2.5 absorbance and the oxidative potential of PM_2.5) and road traffic and railway noise (L_den) at the adolescents' home addresses at the times of completing the MHI-5. Associations with poor mental wellbeing (MHI-5 score ≤ 60) were assessed by generalized linear mixed models with a logit link, adjusting for covariates.

RESULTS

The odds of poor mental wellbeing at age 11 to 20 years decreased with increasing exposure to green space in a 3000 m buffer (adjusted odds ratio (OR) 0.78 [95% CI 0.68-0.88] per IQR increase in the average NDVI; adjusted OR 0.77 [95% CI 0.67-0.88] per IQR increase in the total percentage of green space). These associations persisted after adjustment for air pollution and road traffic noise. Relationships between mental wellbeing and green space in buffers of 300 m and 1000 m were less consistent. Higher air pollution exposure was associated with higher odds of poor mental wellbeing, but these associations were strongly attenuated after adjustment for green space in a buffer of 3000 m, traffic noise and degree of urbanization. Traffic noise was not related to mental wellbeing throughout adolescence.

CONCLUSIONS

Residential exposure to green space may be associated with a better mental wellbeing in adolescents.

Neurotoxicants, the developing brain, and mental health

While life in urban environments may confer a number of benefits, it may also result in a variety of exposures, with toxic consequences for neurodevelopment and neuropsychological health. Neurotoxicants are any of a large number of chemicals or substances that interfere with normal function and/or compromise adaptation in the central and/or peripheral nervous system. Evidence suggests that neurotoxicant effects have a greater effect when occurring in utero and during early childhood. Recent findings exploring neural-level mechanisms provide a crucial opportunity to explore the ways in which environmental conditions may get “under the skin” to impact a number of psychological behaviors and cognitive processes, ultimately allowing for greater synergy between macro- and microlevel efforts to improve mental health in the presence of neurotoxicant exposures. In this review, we provide an overview of 3 types of neurotoxicants related to the built environment and relevant to brain development during childhood and adolescence: lead exposure, outdoor particulate matter pollution, and endocrine-disrupting chemicals. We also discuss mechanisms through which these neurotoxicants affect central nervous system function, including recent evidence from neuroimaging literature. Furthermore, we discuss neurotoxicants and mental health during development in the context of social determinants and how differences in the spatial distribution of neurotoxicant exposures result in health disparities that disproportionately affect low-income and minority populations. Multifaceted approaches incorporating social systems and their effect on neurotoxicant exposures and downstream mental health will be key to reduce societal costs and improve quality of life for children, adolescents, and adults.

Report of the intergovernmental panel on climate change: implications for the mental health policy of children and adolescents in Europe-a scoping review

Climate change is a worldwide challenge. Its consequences do encompass severe threats not only for the existence and somatic health, but also for the mental health of children and adolescents. Mental health can be impaired by three types of consequences. Direct consequences of climate change, such as natural disasters and indirect consequences, such as loss of land, flight and migration, exposure to violence, change of social, ecological, economic or cultural environment. Moreover, the increasing awareness of the existential dimension of climate change in children and adolescents can influence their well-being or challenge their mental health. Consequences of climate change for somatic health may interact with mental health or have psychological sequelae in children and adolescents. Based on the estimates by the United Nations Intergovernmental Panel on Climate Change, we have summarized current data on these differential pathways as to how climate change affects the mental health of children worldwide through selective literature research on Pubmed. Mental health sequelae of direct and indirect consequences of climate change, increased awareness and physical health problems caused by climate change are presented. We give insights into special vulnerabilities of children and adolescents and identify high-risk groups. As the "Fridays for Future" movement has been initiated in northern Europe, we will discuss these results with a focus on children and adolescents in Europe. The results indicate that climate change is a serious threat to children and adolescent mental health. Children´s rights, mental health and climate change should not continue to be seen as separate points; instead, they need to be brought together to address this major challenge determining the future of our children and their descendants.

Exposure to ambient air pollution during childhood and subsequent risk of self-harm: A national cohort study

A growing body of evidence indicates that exposure to air pollution not only impacts on physical health but is also linked with a deterioration in mental health. We conducted the first study to investigate exposure to ambient particulate matter with an aerodynamic diameter of less than 2.5 μm (PM_2.5) and nitrogen dioxide (NO₂) during childhood and subsequent self-harm risk. The study cohort included persons born in Denmark between January 1, 1979 and December 31, 2006 (N = 1,424,670), with information on daily exposures to PM_2.5 and NO₂ at residence from birth to 10th birthday. Follow-up began from 10th birthday until first hospital-presenting self-harm episode, death, or December 31, 2016, whichever came first. Incidence rate ratios estimated by Poisson regression models revealed a dose relationship between increasing PM_2.5 exposure and rising self-harm risk. Exposure to 17-19 μg/m³ of PM_2.5 on average per day from birth to 10th birthday was associated with a 1.45 fold (95% CI 1.37-1.53) subsequently elevated self-harm risk compared with a mean daily exposure of <13 μg/m³, whilst those exposed to 19 μg/m³ or above on average per day had a 1.59 times (1.45-1.75) elevated risk. Higher mean daily exposure to NO₂ during childhood was also linked with increased self-harm risk, but the dose-response relationship observed was less evident than for PM_2.5. Covariate adjustment attenuated the associations, but risk remained independently elevated. Although causality cannot be assumed, these novel findings indicate a potential etiological involvement of ambient air pollution in the development of mental ill health.

A life course approach to understanding associations between natural environments and mental well-being for the Danish blood donor cohort

Natural environments have been associated with mental health benefits, but globally access to these benefits is threatened by urban development and densification. However, it remains unclear how natural environments relate to mental health and how consistent the association is across populations. Here we use a life-course approach with a population consisting of 66 194 individuals from the Danish Blood Donor Study (DBDS) to investigate the association between green and blue space (e.g. parks and lakes) and self-evaluated mental well-being. Green and blue space was identified from remotely-sensed images from the Landsat program, while mental well-being was based on the mental component score (MCS) calculated using the 12-item short form health survey. We use multivariate linear regression models and logistic regression models to quantify the associations. We adjust for additional environmental (urbanization, and air pollution) and lifestyle factors (smoking, body mass index, socioeconomic status, and physical activity) and specifically evaluate the role of physical activity and air pollution as possible mediating factors. We found a positive association between the MCS and current and childhood green space, and a non-significant association for current and childhood blue space. Adjusting for environmental and the other factors attenuated the effect sizes indicating that a broad range of factors determine mental well-being. Physical activity and air pollution were both associated with the MCS as possible mediators of green space associations. In addition, the odds for successfully completing tasks', seeing others, and feeling less downhearted increased with higher levels of green space, and the odds of feeling calm increased with higher levels of blue space. In conclusion, we found support for an association between green and, to less degree, blue space and mental well-being throughout different life stages. In addition, we found a positive association with individual indicators of mental well-being such as being productive, feeling less downhearted and calmer, and being social. The healthy blood donor effect and the bias towards urban residency may explain why we found smaller effect sizes between green and blue space and mental well-being for this generally healthy and resourceful cohort compared to previous studies.

Mental health consequences of urban air pollution: prospective population-based longitudinal survey

PURPOSE

The World Health Organisation (WHO) recently ranked air pollution as the major environmental cause of premature death. However, the significant potential health and societal costs of poor mental health in relation to air quality are not represented in the WHO report due to limited evidence. We aimed to test the hypothesis that long-term exposure to air pollution is associated with poor mental health.

METHODS

A prospective longitudinal population-based mental health survey was conducted of 1698 adults living in 1075 households in South East London, from 2008 to 2013. High-resolution quarterly average air pollution concentrations of nitrogen dioxide (NO2) and oxides (NOx), ozone (O3), particulate matter with an aerodynamic diameter < 10 μm (PM10) and < 2.5 μm (PM2.5) were linked to the home addresses of the study participants. Associations with mental health were analysed with the use of multilevel generalised linear models, after adjusting for large number of confounders, including the individuals' socioeconomic position and exposure to road-traffic noise.

RESULTS

We found robust evidence for interquartile range increases in PM2.5, NOx and NO2 to be associated with 18-39% increased odds of common mental disorders, 19-30% increased odds of poor physical symptoms and 33% of psychotic experiences only for PM10. These longitudinal associations were more pronounced in the subset of non-movers for NO2 and NOx.

CONCLUSIONS

The findings suggest that traffic-related air pollution is adversely affecting mental health. Whilst causation cannot be proved, this work suggests substantial morbidity from mental disorders could be avoided with improved air quality.

Environmental Risk Factors for Schizophrenia and Bipolar Disorder and Their Relationship to Genetic Risk: Current Knowledge and Future Directions

Schizophrenia (SZ) and bipolar disorder (BD) are severe psychiatric disorders which result from complex interplay between genetic and environmental factors. It is well-established that they are highly heritable disorders, and considerable progress has been made identifying their shared and distinct genetic risk factors. However, the 15-40% of risk that is derived from environmental sources is less definitively known. Environmental factors that have been repeatedly investigated and often associated with SZ include: obstetric complications, infections, winter or spring birth, migration, urban living, childhood adversity, and cannabis use. There is evidence that childhood adversity and some types of infections are also associated with BD. Evidence for other risk factors in BD is weaker due to fewer studies and often smaller sample sizes. Relatively few environmental exposures have ever been examined for SZ or BD, and additional ones likely remain to be discovered. A complete picture of how genetic and environmental risk factors confer risk for these disorders requires an understanding of how they interact. Early gene-by-environment interaction studies for both SZ and BD often involved candidate genes and were underpowered. Larger samples with genome-wide data and polygenic risk scores now offer enhanced prospects to reveal genetic interactions with environmental exposures that contribute to risk for these disorders. Overall, although some environmental risk factors have been identified for SZ, few have been for BD, and the extent to which these account for the total risk from environmental sources remains unknown. For both disorders, interactions between genetic and environmental risk factors are also not well understood and merit further investigation. Questions remain regarding the mechanisms by which risk factors exert their effects, and the ways in which environmental factors differ by sex. Concurrent investigations of environmental and genetic risk factors in SZ and BD are needed as we work toward a more comprehensive understanding of the ways in which these disorders arise.

Childhood exposure to ambient air pollution and predicting individual risk of depression onset in UK adolescents

Knowledge about early risk factors for major depressive disorder (MDD) is critical to identify those who are at high risk. A multivariable model to predict adolescents' individual risk of future MDD has recently been developed however its performance in a UK sample was far from perfect. Given the potential role of air pollution in the aetiology of depression, we investigate whether including childhood exposure to air pollution as an additional predictor in the risk prediction model improves the identification of UK adolescents who are at greatest risk for developing MDD. We used data from the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally representative UK birth cohort of 2232 children followed to age 18 with 93% retention. Annual exposure to four pollutants - nitrogen dioxide (NO₂), nitrogen oxides (NO_X), particulate matter <2.5 μm (PM_2.5) and <10 μm (PM₁₀) - were estimated at address-level when children were aged 10. MDD was assessed via interviews at age 18. The risk of developing MDD was elevated most for participants with the highest (top quartile) level of annual exposure to NO_X (adjusted OR = 1.43, 95% CI = 0.96-2.13) and PM_2.5 (adjusted OR = 1.35, 95% CI = 0.95-1.92). The separate inclusion of these ambient pollution estimates into the risk prediction model improved model specificity but reduced model sensitivity - resulting in minimal net improvement in model performance. Findings indicate a potential role for childhood ambient air pollution exposure in the development of adolescent MDD but suggest that inclusion of risk factors other than this may be important for improving the performance of the risk prediction model.

Association of Air Pollution Exposure in Childhood and Adolescence With Psychopathology at the Transition to Adulthood

IMPORTANCE

Air pollution exposure damages the brain, but its associations with the development of psychopathology are not fully characterized.

OBJECTIVE

To assess whether air pollution exposure in childhood and adolescence is associated with greater psychopathology at 18 years of age.

DESIGN, SETTING, AND PARTICIPANTS

The Environmental-Risk Longitudinal Twin Study is a population-based cohort study of 2232 children born from January 1, 1994, to December 4, 1995, across England and Wales and followed up to 18 years of age. Pollution data generation was completed on April 22, 2020; data were analyzed from April 27 to July 31, 2020.

EXPOSURES

High-resolution annualized estimates of outdoor nitrogen oxides (NOx) and particulate matter with aerodynamic diameter less than 2.5 μm (PM2.5) linked to home addresses at the ages of 10 and 18 years and then averaged.

MAIN OUTCOMES AND MEASURES

Mental health disorder symptoms assessed through structured interview at 18 years of age and transformed through confirmatory factor analysis into continuous measures of general psychopathology (primary outcome) and internalizing, externalizing, and thought disorder symptoms (secondary outcomes) standardized to a mean (SD) of 100 (15). Hypotheses were formulated after data collection, and analyses were preregistered.

RESULTS

A total of 2039 participants (1070 [52.5%] female) had full data available. After adjustment for family and individual factors, each interquartile range increment increase in NOx exposure was associated with a 1.40-point increase (95% CI, 0.41-2.38; P = .005) in general psychopathology. There was no association between continuously measured PM2.5 and general psychopathology (b = 0.45; 95% CI, -0.26 to 1.11; P = .22); however, those in the highest quartile of PM2.5 exposure scored 2.04 points higher (95% CI, 0.36-3.72; P = .02) than those in the bottom 3 quartiles. Copollutant models, including both NOx and PM2.5, implicated NOx alone in these significant findings. NOx exposure was associated with all secondary outcomes, although associations were weakest for internalizing (adjusted b = 1.07; 95% CI, 0.10-2.04; P = .03), medium for externalizing (adjusted b = 1.42; 95% CI, 0.53-2.31; P = .002), and strongest for thought disorder symptoms (adjusted b = 1.54; 95% CI, 0.50-2.57; P = .004). Despite NOx concentrations being highest in neighborhoods with worse physical, social, and economic conditions, adjusting estimates for neighborhood characteristics did not change the results.

CONCLUSIONS AND RELEVANCE

Youths exposed to higher levels of outdoor NOx experienced greater psychopathology at the transition to adulthood. Air pollution may be a nonspecific risk factor for the development of psychopathology.

Particulate matter pollution and risk of outpatient visits for psychological diseases in Nanjing, China

Exposure to air pollution has been associated with increased risk for a range of adverse mental health conditions. Less is known about whether air pollution is also associated with increases in the utilization of mental health services, especially outpatient mental health service utilization. This study aimed to examine the association between the number of daily outpatient visits at the psychological disease departments of two major hospitals (PSYC) and daily average concentrations of PM_2.5 and PM₁₀ in a heavily polluted city in China, Nanjing, from 2013/7/1 to 2019/2/28, using generalized additive models with a quasi-Poisson regression. Results showed that each 10 μg/m³ increase in PM_2.5 concentration on lag0 day was associated with a 0.40% increase (95% CI: 0.07-0.72) in PSYC visits, and each 10 μg/m³ increase in PM₁₀ concentration on the same day a 0.31% increase (95% CI: 0.09-0.54) in PSYC visits. Exposure-response curves suggested linear relationships between PM concentration and daily PSYC outpatient visits, without evidence of a threshold. Associations remained positive, but were non-significant, with adjustment for co-pollutants, SO₂, NO₂ and CO. Significantly larger effects were found for older and male participants, vs. their counterparts. These findings add to the growing literature linking air pollution to mental health service utilization, demonstrating the critical need for both air pollution mitigation measures and increased capacity of the mental health system in China.

Elevated environmental PM2.5 increases risk of schizophrenia relapse: Mediation of inflammatory cytokines

BACKGROUND

Ecological epidemiology suggests that hospital admissions for schizophrenia are associated with an increased environmental PM_2.5, but no prospective study has verified this result, and the physiological mechanism is not clear.

METHODS

We used a repeated-measures design to prospectively assess the association of environmental PM_2.5 and the risk of relapse in schizophrenia, and used two linear mixed-effects models to explore possible mediating effects of immune cytokines on the premise of controlling confounders.

RESULTS

We import the data using EpiData software, and collate and analyze of the data using R software. The increase of PM_2.5 at lag0 had the greatest impact on the relapse of schizophrenia (for each 10 μg/m³ increase in PM_2.5, the relapse risk score increased by 1.504, that is to say, odds ratio (OR) = 4.500 (95% confidence interval (CI): 2.849-7.106，P < 0.001)), and cumulative effects lasted for four days with the maximum at the second day (for each 10 μg/m³ increase in PM_2.5, the relapse risk score increased by 1.301, OR = 3.673 (95%CI: 1.962-6.876，P < 0.001)). PM_2.5 exposure was statistically related to four symptom dimensions of early signs scale (ESS), and the symptoms most affected by the increased PM_2.5 were depression/withdrawal (ESSN) (OR = 1.990, 95%CI: 1.701-2.328), anxiety/agitation (ESS-A) (OR = 1.537, 95%CI: 1.340-1.763), initial psychosis (ESS-IP) (OR = 1.398, 95%CI: 1.151-1.697), and disinhibition (ESS-D) (OR = 1.235, 95%CI: 1.133-1.347). Furthermore, there are three statistically significant pathways in intermediary analysis: of PM_2.5 and relapse risk: "PM_2.5 → IL-17 → ESS", "PM_2.5 → IL-17 → ESS-A", and "PM_2.5 → IL-17 → ESS-N", and the intermediary ratio of IL-17 was 11.66%, 16.37% and 22.55%, respectively.

CONCLUSIONS

Increased environmental PM_2.5 is a risk factor for the relapse of schizophrenia. Early relapse identification and intervention based on clinical characteristics are of great significance for timely termination of relapse and slowing down of relapse.

Brain Disorders and Chemical Pollutants: A Gap Junction Link?

The incidence of brain pathologies has increased during last decades. Better diagnosis (autism spectrum disorders) and longer life expectancy (Parkinson's disease, Alzheimer's disease) partly explain this increase, while emerging data suggest pollutant exposures as a possible but still underestimated cause of major brain disorders. Taking into account that the brain parenchyma is rich in gap junctions and that most pollutants inhibit their function; brain disorders might be the consequence of gap-junctional alterations due to long-term exposures to pollutants. In this article, this hypothesis is addressed through three complementary aspects: (1) the gap-junctional organization and connexin expression in brain parenchyma and their function; (2) the effect of major pollutants (pesticides, bisphenol A, phthalates, heavy metals, airborne particles, etc.) on gap-junctional and connexin functions; (3) a description of the major brain disorders categorized as neurodevelopmental (autism spectrum disorders, attention deficit hyperactivity disorders, epilepsy), neurobehavioral (migraines, major depressive disorders), neurodegenerative (Parkinson's and Alzheimer's diseases) and cancers (glioma), in which both connexin dysfunction and pollutant involvement have been described. Based on these different aspects, the possible involvement of pollutant-inhibited gap junctions in brain disorders is discussed for prenatal and postnatal exposures.

Long-term PM2.5 exposure and depressive symptoms in China: A quasi-experimental study

Background

Air pollutants, particularly fine particulate matters (PM_2.5) have been associated with mental disorder such as depression. Clean air policy (CAP, i.e., a series of emission-control actions) has been shown to reduce the public health burden of air pollutions. There were few studies on the health effects of CAP on mental health, particularly, in low-income and middle-income countries (LMICs). We investigated the association between a stringent CAP and depressive symptoms among general adults in China.

Methods

We used three waves (2011, 2013 and 2015) of the China Health and Retirement Longitudinal Study (CHARLS), a prospective nationwide cohort of the middle-aged and older population in China. We assessed exposure to PM_2.5 through a satellite-retrieved dataset. We implemented a difference-in-differences (DID) approach, under the quasi-experimental framework of the temporal contrast between 2011 (before the CAP) and 2015 (after the CAP), to evaluate the effect of CAP on depressive symptoms. The association was further explored using a mixed-effects model of the three waves. To increase the interpretability, the estimated impact of PM_2.5 was compared to that of aging, an established risk factor for depression.

Findings

Our analysis included 15,954 participants. In the DID model, we found a 10-µg/m³ reduction of PM_2.5 concentration was associated with a 4.14% (95% CI: 0.41–8.00%) decrement in the depressive score. The estimate was similar to that from the mixed-effects model (3.63% [95% CI, 2.00–5.27%]). We also found improved air quality during 2011–2015 offset the negative impact from 5-years’ aging.

Interpretation

The findings suggest that implementing CAP may improve mental wellbeing of adults in China and other LMICs.

Short-term effects of air pollution on cause-specific mental disorders in three subtropical Chinese cities

BACKGROUND

The effects of ambient air pollution on specific mental disorders are rarely studied, and the reported results are inconsistent.

OBJECTIVE

To assess the short-term effect of ambient air pollution on the morbidity of mental disorders in three subtropical Chinese cities.

METHODS

Daily concentrations of air pollution were averaged from 19 fixed monitoring stations across each city, and data on patients were collected from three psychiatric specialty hospitals. A time-series study combined with a generalized additive Poisson model was conducted to investigate the association between air pollution and mental disorders. The exposure-response relationships were explored and stratified analyses by age and sex were conducted.

RESULTS

A total of 1,133,220 outpatient visits were recorded in three subtropical cities (Huizhou, Shenzhen, and Zhaoqing). The number of daily outpatient visits for mental disorders increased with higher air pollutant (PM_2.5, PM₁₀, SO₂ and NO₂) concentrations, and the effect of NO₂ appeared to be consistently significant across the three cities, with excess risk (ER) of 4.45% (95% CI: 2.90%, 6.04%) in Huizhou, 7.94% (95% CI: 6.28%, 9.62%) in Shenzhen, and 2.19% (95% CI: 0.51%, 3.89%) in Zhaoqing, respectively, at lag03. We also observed significant effect of PM_2.5 at lag0 (ER = 1.20%, 95% CI: 0.28%, 2.13%), PM₁₀ at lag0 (ER = 0.99%, 95% CI: 0.36%, 1.62%), and SO₂ at lag0 (ER = 10.74%, 95% CI: 3.20%, 18.84%) in Shenzhen. For specific mental disorders, significant associations were found in all the air pollutants except between SO₂ and affective disorder and between PM_2.5 and schizophrenia. In addition, we found that air pollution exhibited stronger effects for males and adults (≥18 years).

CONCLUSION

Acute exposure to air pollution, especially NO₂, might be an important trigger of mental disorders.

The Relationship Between Air Pollution and Cognitive Functions in Children and Adolescents: A Systematic Review

Air pollution has a negative impact on one's health and on the central nervous system. We decided to assess studies that evaluated the relationship between air pollution and cognitive functions in children and adolescents by reviewing studies that had been published between January 2009 and May 2019. We searched three major databases for original works (26 studies) and for studies using brain imaging methods based on MRI (six studies). Adverse effects of air pollutants on selected cognitive or psychomotor functions were found in all of the studies. Exposure to nitrogen dioxide, for example, was linked to impaired working memory, general cognitive functions, and psychomotor functions; particulate matter 2.5 was linked to difficulties in working memory, short-term memory, attention, processing speed, and fine motor function; black carbon was linked to poor verbal intelligence, nonverbal intelligence, and working memory; airborne copper was linked to impaired attentiveness and fine motor skills; isophorone was linked to lower mathematical skills; and polycyclic aromatic hydrocarbons in fetal life were linked to lower intelligence scores. The studies using MRI showed that high concentrations of air pollutants were linked to changes in the brain's white matter or lower functional integration and segregation in children's brain networks. In view of the global increase in air pollution, there is a need for further research to elucidate the relationship between air pollution and cognitive and motor development in children. According to some studies, neuroinflammation, the e4 allele of the apolipoprotein E gene, and gutathione-S-transferase gene polymorphism processes may play a role.

In vitro exposure to ambient fine and ultrafine particles alters dopamine uptake and release, and D2 receptor affinity and signaling

The exposure to environmental pollutants, such as fine and ultrafine particles (FP and UFP), has been associated with increased risk for Parkinson's disease, depression and schizophrenia, disorders related to altered dopaminergic transmission. The striatum, a neuronal nucleus with extensive dopaminergic afferents, is a target site for particle toxicity, which results in oxidative stress, inflammation, astrocyte activation and modifications in dopamine content and D₂ receptor (D₂R) density. In this study we assessed the in vitro effect of the exposure to FP and UFP on dopaminergic transmission, by evaluating [³H]-dopamine uptake and release by rat striatal isolated nerve terminals (synaptosomes), as well as modifications in the affinity and signaling of native and cloned D₂Rs. FP and UFP collected from the air of Mexico City inhibited [³H]-dopamine uptake and increased depolarization-evoked [³H]-dopamine release in striatal synaptosomes. FP and UFP also enhanced D₂R affinity for dopamine in membranes from either rat striatum or CHO-K1 cells transfected with the long isoform of the human D₂R (hD_2LR)2LR). In CHO-K1-hD2L In CHO-K1-hD_2LR cells or striatal slices, FP and UFP increased the potency of dopamine or the D₂R agonist quinpirole, respectively, to inhibit forskolin-induced cAMP formation. The effects were concentration-dependent, with UFP being more potent than FP. These results indicate that FP and UFP directly affect dopaminergic transmission.

Attributable risks associated with hospital outpatient visits for mental disorders due to air pollution: A multi-city study in China

AIM

To determine the associations between outdoor air pollution and hospital outpatient visits for mental disorders in China.

METHODS

We obtained data of 111,842 hospital outpatient visits for mental disorders from the largest hospitals of 13 cities, China, between January 01, 2013 and December 31, 2015. We collected air pollutant data including particulate matter ≤2.5 µm in diameter (PM_2.5), particulate matter ≤10 µm in diameter (PM₁₀), nitrogen dioxide (NO₂), ozone (O₃) and sulphur dioxide (SO₂) from China National Environmental Monitoring Centre during the same period. We conducted a time-stratified case-crossover design with conditional logistic regression models to determine the associations.

RESULTS

A 10 µg/m³ increase in PM_2.5, PM₁₀, NO₂ and SO₂ was associated with a significant increase in hospital outpatient visits for mental disorders on the current day. When stratified by age, sex and season, the effects of PM_2.5 and NO₂ were robust among different subgroups at lag05 days. PM₁₀ showed positive associations in males, in cold season, and in depression patients. SO₂ showed positive associations in males, in cold season, and in anxiety patients. O₃ showed positive associations in females, in warm season, and in depression patients. Nearly one sixth hospital outpatient visits for mental disorders can be attributable to NO₂.

CONCLUSIONS

Short-term increase in PM_2.5, PM₁₀, NO₂, SO₂ and O₃ concentrations was significantly associated with exacerbation of mental disorders in China as indicated by increases in hospital outpatient visits. NO₂ had more serious health threat than other pollutants in terms of mental disorders. Our findings strongly suggest a need for more strict emission control regulations to protect mental health from air pollution.

Different adverse effects of air pollutants on dry eye disease: Ozone, PM2.5, and PM10

To date, there have been no well-organized clinical studies evaluating which air pollutants affect dry eye disease (DED). In this study, we investigated changes in the clinical parameters of DED according to exposure to outdoor air pollutants, including PM_2.5 (particulate matter with an aerodynamic diameter of less than 2.5 μm), PM₁₀ (less than 10 μm), and ozone. A prospective observational study was conducted on 43 DED patients who had used the same topical eye drop treatment between 2016 and 2018 in South Korea. Ocular surface discomfort index (OSDI) score, tear film break-up time (TBUT), corneal fluorescein staining score (CFSS), and tear secretion were measured during each visit. Air pollution data of ambient PM₁₀, PM_2.5, and ozone, based on the patients' address, were obtained, and mean concentrations were computed for one day, one week, and one month before the examination. The relationships between air pollutants and DED were analyzed in single- and multi-pollutant models adjusted for demographic and clinical factors. In the multi-pollutant model, the OSDI score was positively correlated with ozone and PM_2.5 exposure [ozone: β(exposure for 1 day/1 week) = 0.328 (95% CI: 0.161-0.494)/0.494 (0.286-0.702), p < 0.001/<0.001, per 1 ppb increase; PM_2.5: β(1 day/1 week) = 0.378 (0.055-0.699)/0.397 (0.092-0.703), p = 0.022/ = 0.011, per 1 μg/m³ increase], and tear secretion decreased with increased ozone exposure [ozone: β(1 week/1 month) = -0.144 (-0.238 to -0.049)/-0.164 (-0.298 to -0.029), p = 0.003/ = 0.017, per 1 ppb increase]. Interestingly, increased PM₁₀ exposure was only associated with decreased TBUT [β(1 day/1 week/1 month) = -0.028(-0.045 to -0.011)/-0.029(-0.046 to -0.012)/-0.023(-0.034 to -0.006), p = 0.001/ = 0.001/ = 0.018, per 1 μg/m³ increase]. Tear secretion and CFSS were not associated with PM₁₀ exposure. Increased ozone and PM_2.5 exposure led to aggravated ocular discomfort, and increased PM₁₀ concentration aggravated tear film stability in patients with DED. Thus, each air pollutant may aggravate DED via different mechanisms of action.

Associations between growing up in natural environments and subsequent psychiatric disorders in Denmark

Natural environments have been associated with mental health benefits worldwide. However, how different elements and types of natural environments associate with mental health is still largely unknown. In this study, we perform a detailed analysis on a large, nation-wide data set of mental health records (908 553 individuals) for Denmark combined with remotely-sensed land cover and vegetation density data. We explore associations between growing up surrounded by different environments and rates of a spectrum of 18 psychiatric disorders. Childhood land cover exposure for urban, agricultural, near-natural green space, and blue space was determined around the residence of each individual. Vegetation density and air pollution were evaluated as potential pathways. Cox proportional hazards models were used to estimate rates as hazard ratios and then adjusted for potential confounding from other known risk factors. For 12 of 18 disorders, rates were lower for children growing up in environments with more natural elements (near-natural green space, blue space, and agriculture) compared to children growing up in urban environments. High vegetation density was associated with lower rates for most disorders within all the examined environments, whereas mitigation of air pollution by natural environments seemed a less important potential pathway. Rates were not notably changed by adjustment for urbanization, parental and municipal socioeconomic status, family history of mental illness, and parents' age. In conclusion, we found that growing up surrounded by a range of natural environments such as near-natural green space, blue space, and agriculture may lower rates of psychiatric disorders. Our results show the importance of ensuring access to natural environments from as nature-based solutions for improved public health and sustainable, livable cities.

Associations between perceived environmental pollution and health-related quality of life in a Chinese adult population

BACKGROUND

Health-related quality of life (HRQoL) measures are being used in increasingly diverse populations. However, there have no known studies to date to examine the associations between perceived environmental pollution and HRQoL in a Chinese population. This study aimed to report the associations between air, water, noise pollution and HRQoL among Chinese adult population.

METHODS

A cross-sectional survey data was used from East Asian Social Survey 2010 with a sample of 3866 Chinese populations regarding environmental pollution. HRQoL was computed by SF-12 and reflected by physical and mental component summary score (PCS & MCS). Ordinary least regression analyses were used to examine associations between perceived environmental pollution and PCS and MCS scores. Models in SPSS PROCESS were selected to demonstrate the moderating and mediating effects.

RESULTS

Only considering one pollutant, perceived air pollution and perceived water pollution had significant associations with PCS and MCS scores. Perceived noise pollution had significant associations with PCS scores. Perceived air×noise, air×water, noise×water, and air×noise×water pollution had significant associations with PCS and MCS scores. Conditional (moderated) mediation showed that there were no moderating effects and mediating effects of perceived one pollutant on another pollutant.

CONCLUSIONS

Co-occurring perceived environmental pollution were mainly associated with progressive increase in PCS and MCS scores among the Chinese adult population. These results suggested that some effective policies should be carried out to improve environmental quality in Chinese adult population.

Air Pollution and Emergency Department Visits for Mental Disorders among Youth

Although exposure to ambient air pollution has been linked to mental health problems, little is known about its potential effects on youth. This study investigates the association between short-term exposure to air pollutants and emergency department (ED) visits for mental health disorders. The National Ambulatory Care Reporting System database was used to retrieve ED visits for young individuals aged 8–24 years in Toronto, Canada. Daily average concentrations of nitrogen dioxide (NO₂), fine particulate matter (PM_2.5), and daily maximum 8 h ozone (O₃) were calculated using measurement data from seven fixed stations. A case-crossover (CC) design was implemented to estimate the associations between ED visits and air pollution concentrations. Mental health ED visits were identified using International Classification of Diseases 10th Revision (ICD-10) codes, with seven categories considered. Models incorporating air pollutants and ambient temperature (with lags of 0–5 days) using a time-stratified CC technique were applied. Multivariable regression was performed by sex, three age groups, and seven types of mental health disorders to calculate relative risk (RR). The RRs were reported for one interquartile range (IQR) change in the air pollutant concentrations. Between April 2004 and December 2015 (4292 days), there were 83,985 ED visits for mental-health related problems in the target population. Several exposures to air pollutants were shown to have associations with ED visits for mental health including same day exposure to fine particulate matter (IQR = 6.03 μg/m³, RR = 1.01 (95% confidence interval: 1.00–1.02), RR = 1.02 (1.00–1.03)) for all and female-only patients, respectively. One-day lagged exposure was also associated with ED visits for PM_2.5 (RR = 1.02 (1.01–1.03)), for nitrogen dioxide (IQR = 9.1 ppb, RR = 1.02 (1.00–1.04)), and ozone (IQR = 16.0 ppb, RR = 1.06 (1.01–1.10)) for males. In this study, urban air pollution concentration—mainly fine particulate matter and nitrogen dioxide—is associated with an increased risk for ED visits for adolescents and young adults with diagnosed mental health disorders.

Multiple risk factors affecting childhood psychosocial dysfunction in primary school Egyptian children

Background

Childhood psychosocial dysfunction (CPD) is an important cause of morbidity among children, and its frequency in primary care is growing. The information about its prevalence and risk factors is weak in many developing countries. The study aims to determine the prevalence of psychosocial problems among primary school children and identify the risk factors associated with childhood psychosocial dysfunction.

Results

A cross-sectional study was conducted on 368 primary school children aged 6–12 years. About (19.0%) of the studied sample had probable CPD according to Strengths and Difficulties Questionnaire (SDQ). CPD was statistically associated with older age group, male sex, and low social class.

The association between biological and medical risk factors of the studied group and CPD showed statistical significant relations between CPD and low body weight (n = 35, 50.7%), maternal history of problems with pregnancy (n = 26, 66.47%), history of receiving medications during pregnancy (n = 13, 86.7%), abnormal general condition of baby at birth (n = 57, 16.2%), family history of mental disorders (n = 2, 100%), medical history of congenital diseases (n = 9, 90%), acute medical disorders (n = 29, 90.6%), chronic diseases, receiving medications (n = 22, 91.7%), and exposure to trauma (n = 27, 84.4%).

Also, The association between psychosocial risk factors and CPD revealed high statistical significant relation between CPD among the studied children and presence of family problems (n = 33, 62.3%), living with single parent (n = 15, 71.4%), parent(s) death (n = 12, 63.2%), major changes in the family (n = 39, 79.6%), parent(s) smoking status (n = 22, 51.2%), and parent(s) addiction (n = 4, 100%).

Moreover, there was statistical significant relation between CPD among the studied children and poor academic achievement (n = 19, 27.5%), problems with teachers (n = 25, 33.3%), problems with peers (n = 22, 51.2%), and exposure to violence (n = 56, 22.4%).

Conclusions

Psychosocial dysfunction is common among Egyptian school children. It is associated with many risk factors. Hence, mental health services should be incorporated into primary health care facilities and school health program. Also, training of family physicians and primary health care providers is crucial.

Exposure to air pollution during childhood and risk of developing schizophrenia: a national cohort study

BACKGROUND

Ambient air pollution affects neurological function, but its association with schizophrenia risk is unclear. We investigated exposure to nitrogen oxides (NO_X) as a whole and nitrogen dioxide (NO₂) specifically, as well as PM₁₀, and PM_2·5, during childhood and subsequent schizophrenia risk.

METHODS

People born in Denmark from 1980 to 1984 (N=230 844), who were residing in the country on their tenth birthday, and who had two Danish-born parents were followed-up from their tenth birthday until schizophrenia diagnosis or Dec 31, 2016. Mean daily exposure to each pollutant (NO₂, NO_X, PM₁₀, and PM_2·5) at all of an individual's residential addresses from birth to their tenth birthday was modelled. Incidence rate ratios, cumulative incidence, and population attributable risks were calculated using survival analysis techniques.

FINDINGS

We analysed data between Aug 1, 2018, and Nov 15, 2019. Of 230 844 individuals included, 2189 cohort members were diagnosed with schizophrenia during follow-up. Higher concentrations of residential NO₂ and NO_X exposure during childhood were associated with subsequent elevated schizophrenia risk. People exposed to daily mean concentrations of more than 26·5 μg/m³ NO₂ had a 1·62 (95% CI 1·41-1·87) times increased risk compared with people exposed to a mean daily concentration of less than 14·5 μg/m³. The absolute risks of developing schizophrenia by the age of 37 years when exposed to daily mean concentrations of more than 26·5 μg/m³ NO₂ between birth and 10 years were 1·45% (95% CI 1·30-1·62%) for men and 1·03% (0·90-1·17) for women, whereas when exposed to a mean daily concentration of less than 14·5 μg/m³, the risk was 0·80% (95% CI 0·69-0·92%) for men and 0·67% (0·57-0·79) for women. Associations between exposure to PM_2·5 or PM₁₀ and schizophrenia risk were less consistent.

INTERPRETATION

If the association between air pollution and schizophrenia is causal, reducing ambient air pollution including NO₂ and NO_X could have a potentially considerable effect on lowering schizophrenia incidence at the population level. Further investigations are necessary to establish a causal relationship.

FUNDING

Lundbeck Foundation, Stanley Medical Research Institute, European Research Council, NordForsk, Novo Nordisk Foundation, National Health and Medical Research Council, Danish National Research Foundation.

Neurobehavioral Consequences of Traffic-Related Air Pollution

Traffic-related air pollution (TRAP) is a major contributor to global air pollution. The World Health Organization (WHO) has reported that air pollution due to gasoline and diesel emissions from internal combustion engines of automobiles, trucks, locomotives, and ships leads to 800,000 premature deaths annually due to pulmonary, cardiovascular, and neurological complications. It has been observed that individuals living and working in areas of heavy vehicle traffic have high susceptibility to anxiety, depression, and cognitive deficits. Information regarding the mechanisms that potentially lead to detrimental mental health effects of TRAP is gradually increasing. Several studies have suggested that TRAP is associated with adverse effects in the central nervous system (CNS), primarily due to increase in oxidative stress and neuroinflammation. Animal studies have provided further useful insights on the deleterious effects of vehicle exhaust emissions (VEEs). The mechanistic basis for these effects is unclear, although gasoline and diesel exhaust-induced neurotoxicity seems the most plausible cause. Several important points emerge from these studies. First, TRAP leads to neurotoxicity. Second, TRAP alters neurobehavioral function. Exactly how that happens remains unclear. This review article will discuss current state of the literature on this subject and potential leads that have surfaced from the preclinical work.

Air pollutants and daily number of admissions to psychiatric emergency services: evidence for detrimental mental health effects of ozone

AIMS

Aim of the current study is to investigate the associations between daily levels of air pollutants (particulate matter, ozone, carbon monoxide, nitrogen dioxide) and daily admissions for mental disorders to the emergency department of two general hospitals in Umbria region (Italy).

METHODS

We collected data about daily admissions to psychiatric emergency services of two general hospitals, air pollutants' levels and meteorological data for the time period 1 January 2015 until 31 December 2016. We assessed the impact of an increase in air pollutants on the number of daily admissions using a time-series econometric framework.

RESULTS

A total of 1860 emergency department admissions for mental disorders were identified. We observed a statistically significant impact of ozone levels on daily admissions. The estimated coefficient of O3 is statistically significant at the 1% level. All other pollutants were not significantly associated with the number of daily admissions.

CONCLUSIONS

Short-term exposure to ozone may be associated with increased psychiatric emergency services admissions. Findings add to previous literature on existing evidence for air pollution to have an impact on mental health. Ozone may be considered a potential environmental risk factor for impaired mental health.

Ambient fine particulate matter is associated with increased emergency ambulance dispatches for psychiatric emergencies

AIMS

As a top ambient pollutant in urban area, fine particulate matter (PM_2.5) has been associated with the occurrence and deterioration of many medical conditions, while limited studies have observed the association with psychiatric conditions. This study aimed to investigate the association between short-term PM_2.5 exposure and psychiatric emergency events, and further explored the variation by age, sex and seasonal patterns, which have been suggested to be associated with both psychiatric risk and pollutant toxicity.

METHODS

We used time-series analysis to investigate the association between short-term exposure of PM_2.5 and emergency ambulance dispatches for psychiatric emergencies (EPE) (n = 158634) in Beijing, one of the top polluted cities in China during the study period between 2008 and 2014. Stratified analyses were conducted to examine the effects of age, sex and seasonal pattern.

RESULTS

Every 10 μg/m³ increase of the PM_2.5 concentration was associated with a 0.12% increase of the same-day overall EPE (95% CI: 0.03-0.22%, p = 0.013) and a 0.12% increase of the suicide-related EPE at lag 2 (95%CI: 0.01-0.24%, p = 0.041). The associations remained when adjusted for sunlight duration. An age effect was observed where children (age <18) showed a higher risk of suicide-related EPE after PM_2.5 exposure compared to adults (18 ≤ age≤64). We did not observe evidence of effect modification by sex and season based on the results of stratified analysis.

CONCLUSIONS

We found a positive association between acute PM_2.5 exposure and increased psychiatric emergency presentations indicated by emergency ambulance dispatches data. Children were more vulnerable and might develop psychiatric problems including those leading to suicide. Public awareness of the health risks of PM_2.5 is important to strengthen current efforts to reduce emissions.

lifetime exposure to traffic-related air pollution and symptoms of depression and anxiety at age 12 years

BACKGROUND

While air pollution has been associated with depression and anxiety in adults, its impact on childhood mental health is understudied.

OBJECTIVE

We examined lifetime exposure to traffic-related air pollution (TRAP) and symptoms of depression and anxiety at age 12 years in the Cincinnati Childhood Allergy and Air Pollution Study cohort.

METHODS

We estimated exposure to elemental carbon attributable to traffic (ECAT), a surrogate of diesel exhaust, at birth, age 12 years, and average exposure throughout childhood, using a validated land use regression model. We assessed depression and anxiety at age 12 years by parent report with the Behavior Assessment System for Children-2, and by child report with the Child Depression Inventory-2 (CDI-2) and the Spence Children's Anxiety Scale (SCAS). Associations between TRAP at birth, age 12 years, and childhood average and mental health outcomes were estimated using linear regression models adjusting for covariates including parent depression, secondhand smoke exposure, race, household income, and others.

RESULTS

Exposure to ECAT was not significantly associated with parent-reported depression or anxiety. However, exposure to ECAT at birth was associated with increased child-reported depression and anxiety. Each 0.25 µg/m3 increase in ECAT was associated with a 3.5 point increase (95% CI 1.6-5.5) in CDI-2 scores and 2.3 point increase (95% CI 0.8-3.9) in SCAS total anxiety scores. We observed similar associations between average childhood ECAT exposures but not for concurrent exposures at age 12.

CONCLUSIONS

TRAP exposure during early life and across childhood was significantly associated with self-reported depression and anxiety symptoms in children. The negative impact of air pollution on mental health previously reported among adults may also be present during childhood.

Ambient air pollution exposure and risk of depression: A systematic review and meta-analysis of observational studies

Recent studies have reported an association between air pollution exposure and depression, with inconsistent results. To address this controversy, we conducted a systematic review and meta-analysis of published observational studies that investigated outdoor air pollution and depression. Five electronic databases were searched, and fifteen articles were finally identified. Pooled odds risks were calculated separately based on pollutant type, exposure duration and outcome. Subgroup analyses were conducted based on design, population, important potential confounders, and pollutants levels. We found a significantly increased risk of depression with long-term exposure to PM_2.5 and short-term exposure to PM₁₀, NO₂, SO₂, CO. No evidence was found in the association between exposure to O₃ and depression. Besides, exposure to high levels of pollutants indicates a higher risk of depression. Our results highlight the necessity of air pollution control for depression. However, further studies with standardized methods are still required to support the results due to the inconsistent results in stratified analyses and methodological limitations of the included studies.

The quality of air outside and inside the home: associations with emotional and behavioural problem scores in early childhood

Background

This study explored the role of outdoor air pollution [nitrogen dioxide (NO₂) and sulphur dioxide (SO₂)] and indoor air quality (measured with damp or condensation and secondhand smoke exposures) at age 9 months in emotional, conduct and hyperactivity problems at age 3 years.

Method

Data from 11,625 Millennium Cohort Study children living in England and Wales were modelled using multilevel regression.

Results

After adjusting for a host of confounders, having a damp or condensation problem at home was related to both emotional and conduct problems. Secondhand smoke exposure was associated with all three problem types. Associations with outdoor air pollution were less consistent.

Conclusions

Exposures to damp or condensation and secondhand smoke in the home are likely to be risk factors for child emotional and behavioural problems. Parents should continue to be educated about the dangers of exposing their children to poor air quality at home.

Association of Ambient Air Pollution with Increased Liver Enzymes in Korean Adults

An association between exposure to air pollution and liver enzymes in certain areas or older people has been reported in the literature; however, it cannot be generalized to the general population. We investigated the association between air pollution, liver enzyme levels, and alcohol consumption using nationwide data of South Korean adults. Air pollutants included particulate matter with an aerodynamic diameter ≤10 µm (PM₁₀), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and carbon monoxide (CO). Liver enzymes included alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Exposure to air pollutants were significantly associated with elevation of log ALT and log AST, especially increases from 0.0073 IU/L (95% confidence interval (CI) = 0.0042, 0.0104) to 0.0251 IU/L (95% CI = 0.0132, 0.0371) per interquartile range (IQR) increase of each pollutant (all pollutants: p < 0.001). Association of the liver enzymes with PM₁₀ (β (95% CI) = 0.0285 IU/L (0.0201, 0.0368) for log ALT; β (95% CI) = 0.0139 IU/L (0.0079, 0.0198) for log AST) and CO (β (95% CI) = 0.0247 IU/L (0.0182, 0.0311) for log ALT; β (95% CI) = 0.0164 IU/L (0.0118, 0.0210) for log AST) were only significant among drinkers. Our findings suggest that chronic exposure to PM₁₀ and CO is a risk factor for liver enzymes increases among the general adult population who admitted to drinking alcohol.

Residential green space in childhood is associated with lower risk of psychiatric disorders from adolescence into adulthood

Growing up in urban environments is associated with risk of developing psychiatric disorders, but the underlying mechanisms are unknown. Green space can provide mental health benefits and possibly lower risk of psychiatric disorders. This nation-wide study covering >900,000 people shows that children who grew up with the lowest levels of green space had up to 55% higher risk of developing a psychiatric disorder independent from effects of other known risk factors. Stronger association between cumulated green space and risk during childhood constitutes evidence that prolonged presence of green space is important. Our findings affirm that integrating natural environments into urban planning is a promising approach to improve mental health and reduce the rising global burden of psychiatric disorders.

Urban residence is associated with a higher risk of some psychiatric disorders, but the underlying drivers remain unknown. There is increasing evidence that the level of exposure to natural environments impacts mental health, but few large-scale epidemiological studies have assessed the general existence and importance of such associations. Here, we investigate the prospective association between green space and mental health in the Danish population. Green space presence was assessed at the individual level using high-resolution satellite data to calculate the normalized difference vegetation index within a 210 × 210 m square around each person’s place of residence (∼1 million people) from birth to the age of 10. We show that high levels of green space presence during childhood are associated with lower risk of a wide spectrum of psychiatric disorders later in life. Risk for subsequent mental illness for those who lived with the lowest level of green space during childhood was up to 55% higher across various disorders compared with those who lived with the highest level of green space. The association remained even after adjusting for urbanization, socioeconomic factors, parental history of mental illness, and parental age. Stronger association of cumulative green space presence during childhood compared with single-year green space presence suggests that presence throughout childhood is important. Our results show that green space during childhood is associated with better mental health, supporting efforts to better integrate natural environments into urban planning and childhood life.

Exploration of NO2 and PM2.5 air pollution and mental health problems using high-resolution data in London-based children from a UK longitudinal cohort study

Air pollution is a worldwide environmental health issue. Increasingly, reports suggest that poor air quality may be associated with mental health problems, but these studies often use global measures and rarely focus on early development when psychopathology commonly emerges. To address this, we combined high-resolution air pollution exposure estimates and prospectively-collected phenotypic data to explore concurrent and longitudinal associations between air pollutants of major concern in urban areas and mental health problems in childhood and adolescence. Exploratory analyses were conducted on 284 London-based children from the Environmental Risk (E-Risk) Longitudinal Twin Study. Exposure to annualized PM_2.5 and NO₂ concentrations was estimated at address-level when children were aged 12. Symptoms of anxiety, depression, conduct disorder, and attention-deficit hyperactivity disorder were assessed at ages 12 and 18. Psychiatric diagnoses were ascertained from interviews with the participants at age 18. We found no associations between age-12 pollution exposure and concurrent mental health problems. However, age-12 pollution estimates were significantly associated with increased odds of major depressive disorder at age 18, even after controlling for common risk factors. This study demonstrates the potential utility of incorporating high-resolution pollution estimates into large epidemiological cohorts to robustly investigate associations between air pollution and youth mental health.

The association between short-term ambient air pollution and daily outpatient visits for schizophrenia: A hospital-based study

Schizophrenia is a devastating neuropsychiatric disorder with increasing concern. Limited studies have been conducted to assess the relationship between short-term exposure to ambient air pollution and schizophrenia attacks. This study aimed to investigate the associations between short-term air pollution exposure and schizophrenia outpatient visits based on a time-series study performed in China. Daily data of schizophrenia outpatient admissions and air pollution from 1 October 2010 to 31 December 2013 were collected in Xi'an, a heavily-polluted city in China. We utilized a time-series Poisson regression model to examine the associations between short-term air pollution and schizophrenia outpatient visits with different lag days. A total of 34,865 outpatient-visits for schizophrenia were identified. A 10 μg/m³ increase of PM₁₀, SO₂, and NO₂ concentrations corresponded to 0.289% (95% Cl: 0.118%, 0.460%), 1.374% (95% Cl: 0.723%, 2.025%), and 1.881% (95% Cl: 0.957%, 2.805%) elevation in outpatient-visits for schizophrenia at lag 0, and the associations appeared to be stronger, although not statistically significantly, in females and in middle and older age adults (40 and over). The most significant associations were observed on the concurrent day in different lag models. In conclusion, short-term exposure to ambient air pollution (PM₁₀, SO₂, and NO₂) can be associated with increased risk of daily outpatient visits for schizophrenia, which may contribute to the further understanding of the potential adverse effects of air pollution in schizophrenia and other neuropsychiatric disorders.

Childhood exposure to green space - A novel risk-decreasing mechanism for schizophrenia?

Schizophrenia risk has been linked to urbanization, but the underlying mechanism remains unknown. Green space is hypothesized to positively influence mental health and might mediate risk of schizophrenia by mitigating noise and particle pollution exposure, stress relief, or other unknown mechanisms. The objectives for this study were to determine if green space are associated with schizophrenia risk, and if different measures of green space associate differently with risk. We used satellite data from the Landsat program to quantify green space in a new data set for Denmark at 30×30m resolution for the years 1985-2013. The effect of green space at different ages and within different distances from each person's place of residence on schizophrenia risk was estimated using Cox regression on a very large longitudinal population-based sample of the Danish population (943,027 persons). Living at the lowest amount of green space was associated with a 1.52-fold increased risk of developing schizophrenia compared to persons living at the highest level of green space. This association remained after adjusting for known risk factors for schizophrenia: urbanization, age, sex, and socioeconomic status. The strongest protective association was observed during the earliest childhood years and closest to place of residence. This is the first nationwide population-based study to demonstrate a protective association between green space during childhood and schizophrenia risk; suggesting limited green space as a novel environmental risk factor for schizophrenia. This study supports findings from other studies highlighting positive effects of exposure to natural environments for human health.

Is there a link between air pollution and mental disorders?

Several studies have demonstrated the association between air pollution and different medical conditions including respiratory and cardiovascular diseases. Air pollutants might have a role also in the etiology of mental disorders in the light of their toxicity on central nervous system. Purpose of the present manuscript was to review and summarize available data about an association between psychiatric disorders and air pollution. A research in the main database sources has been conducted to identify relevant papers about the topic. Different air pollutants and in particular PM and nitric oxides have been associated with poor mental health; long exposition to PM_2.5 has been associated with an increased risk of new onset of depressive symptoms (Cohen's effect size d: 0.05-0.81), while increased concentration of nitric dioxide in summer with worsening of existing depressive conditions (Cohen's effect size d: 0.05-1.77). However, the interpretation of these finding should take into account the retrospective design of most of studies, different periods of observations, confounding factors such as advanced age or medical comorbidity. Further studies with rigorous methodology are needed to confirm the results of available literature about this topic.

Long-term exposure to air pollution and the risk of suicide death: A population-based cohort study

Suicide is a major public health problem. Previous studies have reported a significant association between acute exposure to air pollution and suicide; little attention has been paid to the long-term effects of air pollution on risk of suicide. We investigated whether long-term exposure to particulate matter of ≤10μm in diameter (PM₁₀), nitrogen dioxide (NO₂), and sulfur dioxide (SO₂) would be associated with a greater risk of death by suicide. The study sample comprised 265,749 adults enrolled in the National Health Insurance Service-National Sample Cohort (2002-2013) in South Korea. Suicide death was defined as per ICD-10 code. Data on air pollution exposure used nationwide monitoring data, and individual exposure levels were assigned using geographic information systems. Air pollution exposure was categorized as the interquartile range (IQR) and quartiles. Hazards ratios (HRs) were calculated for the occurrence of suicide death after adjusting for potential covariates. During the study period, 564 (0.2%) subjects died from suicide. Increases in IQR pollutants (7.5μg/m³ for PM₁₀, 11.8ppb for NO₂, and 0.8ppb for SO₂) significantly increased HR for suicide death [PM₁₀: HR=3.09 (95% CI: 2.63-3.63); NO₂: HR=1.33 (95% CI: 1.09-1.64); and SO₂: HR=1.15 (95% CI: 1.07-1.24)]. Compared with the lowest level of air pollutants (Quartile 1), the risk of suicide significantly increased in the highest quartile level (Quartile 4) for PM₁₀ (HR=4.03; 95% CI: 2.97-5.47) and SO₂ (HR=1.65; 95% CI: 1.29-2.11) and in the third quartile for NO₂ (HR=1.52; 95% CI: 1.17-1.96). HRs for subjects with a physical or mental disorder were higher than that those for subjects without the disorder. Subjects living in metropolitan areas were more vulnerable to long-term PM₁₀ exposure than those living in non-metropolitan areas. Long-term exposure to air pollution was associated with a significantly increased risk of suicide death. People having underlying diseases or living in metropolitan areas may be more susceptible to high air pollution exposure.