Air pollution and children's health-a review of adverse effects associated with prenatal exposure from fine to ultrafine particulate matter

Life-course exposure to air pollution and the risk of dementia in the Lothian Birth Cohort 1936

Background

Air pollution in later life has been associated with dementia; however, limited research has investigated the association between air pollution across the life course, either at specific life periods or cumulatively. The project investigates the association of air pollution with dementia via a life-course epidemiological approach.

Methods

Participants of the Lothian Birth Cohort, born in 1936, provided lifetime residential history in 2014. Participant's air pollution exposure for time periods 1935, 1950, 1970, 1980, 1990, 2001, and 2007 was modeled using an atmospheric chemistry transport model. Lifetime cumulative exposures were calculated as time-weighted mean exposure. Of 572 participants, 67 developed all-cause dementia [35 with Alzheimer's dementia (AD)] by wave 5 (~82 years). Cox proportional hazards and competing risk models assessed the association between all-cause dementia and AD with particulate matter (diameter of ≤2.5 µm) PM2.5 and nitrogen dioxide (NO2) exposure at specific life periods and cumulatively. False discovery rate (FDR) correction was applied for multiple testing.

Results

The mean follow-up was 11.26 years. One standard deviation (SD) higher exposure to air pollution in 1935 (PM2.5 = 14.03 μg/m3, NO2 = 5.35 μg/m3) was positively linked but not statistically significant to all-cause dementia [PM2.5 hazard ratio (HR) = 1.16, 95% confidence interval (CI) = 0.90, 1.49; NO2 HR = 1.13, 95% CI = 0.88, 1.47] and AD (PM2.5 HR = 1.38, 95% CI = 1.00, 1.91; NO2 HR = 1.35, 95% CI = 0.92, 1.99). In the competing risk model, one SD elevated PM2.5 exposure (1.12 μg/m3) in 1990 was inversely associated with dementia (subdistribution HR = 0.82, 95% CI = 0.67, 0.99) at P = 0.034 but not after FDR correction (P FDR = 0.442). Higher cumulative PM2.5 per one SD was associated with an increased risk of all-cause dementia and AD for all accumulation models except for the early-life model.

Conclusion

The in-utero and early-life exposure to PM2.5 and NO2 was associated with higher AD and all-cause dementia risk, suggesting a sensitive/critical period. Cumulative exposure to PM2.5 across the life course was associated with higher dementia risk. Midlife PM2.5 exposure's negative association with all-cause dementia risk may stem from unaddressed confounders or bias.

Prenatal black carbon exposure and DNA methylation in umbilical cord blood

BACKGROUND/OBJECTIVES

Prenatal exposure to ambient air pollution is associated with adverse cardiometabolic outcomes in childhood. We previously observed that prenatal black carbon (BC) was inversely associated with adiponectin, a hormone secreted by adipocytes, in early childhood. Changes to DNA methylation have been proposed as a potential mediator linking in utero exposures to lasting health impacts.

METHODS

Among 532 mother-child pairs enrolled in the Colorado-based Healthy Start study, we performed an epigenome-wide association study of the relationship between prenatal exposure to a component of air pollution, BC, and DNA methylation in cord blood. Average pregnancy ambient BC was estimated at the mother's residence using a spatiotemporal prediction model. DNA methylation was measured using the Illumina 450K array. We used multiple linear regression to estimate associations between prenatal ambient BC and 429,246 cysteine-phosphate-guanine sites (CpGs), adjusting for potential confounders. We identified differentially methylated regions (DMRs) using DMRff and ENmix-combp. In a subset of participants (n = 243), we investigated DNA methylation as a potential mediator of the association between prenatal ambient BC and lower adiponectin in childhood.

RESULTS

We identified 44 CpGs associated with average prenatal ambient BC after correcting for multiple testing. Several genes annotated to the top CpGs had reported functions in the immune system. There were 24 DMRs identified by both DMRff and ENmix-combp. One CpG (cg01123250), located on chromosome 2 and annotated to the UNC80 gene, was found to mediate approximately 20% of the effect of prenatal BC on childhood adiponectin, though the confidence interval was wide (95% CI: 3, 84).

CONCLUSIONS

Prenatal BC was associated with DNA methylation in cord blood at several sites and regions in the genome. DNA methylation may partially mediate associations between prenatal BC and childhood cardiometabolic outcomes.

Ambient air pollution, urban green space and childhood overweight and obesity: A health impact assessment for Barcelona, Spain

BACKGROUND

The burden of childhood overweight and obesity attributable to ambient air pollution and a lack of urban green spaces (UGS) remains unknown. This study aimed to estimate the attributable cases of childhood overweight and obesity due to air pollution and insufficient UGS exposure in Barcelona, Spain.

METHODS

We applied a quantitative health impact assessment approach. We collected childhood overweight and obesity prevalence levels and exposure data from 69 spatial basic health zones in Barcelona. We estimated particulate matter (PM2.5) and nitrogen dioxide (NO2) levels using land use regression models, normalized difference vegetation index (NDVI) levels using remote sensing and percentage of green area (%GA) using land use. We estimated relative risks, population attributable fractions, and preventable overweight/obesity cases in children under following scenarios: Compliance of World Health Organization (WHO) air quality guidelines (AQGs) for (1) PM2.5 and (2) NO2; achieving (3) city-target NDVI levels and (4) 25% green area (%GA) recommendations. The analyses were stratified by socioeconomic deprivation index (in quintiles). Uncertainty was quantified using Monte Carlos simulations.

RESULTS

Compliance of WHO AQGs could prevent 0.4% [253 (95%CI, -604; 1086)] and 4.2% [3000 (95%CI, 1009; 4943)] of childhood overweight/obesity cases due to excess PM2.5 and NO2 levels in Barcelona, respectively. Compliance of NDVI and %GA targeted levels could prevent 6% [4094 (95%CI, 1698; 6379)] and 10% [6853 (95%CI, 1440; 12779)] of childhood overweight/obesity cases respectively. The preventable burdens of childhood overweight/obesity cases were slightly higher in middle-class socioeconomic areas due to the higher adverse exposure levels at baseline (high air pollution, less UGS).

DISCUSSION

Compliance with WHO AQGs and achieving UGS targets can reduce childhood overweight and obesity levels in Barcelona, and potentially in other locations as well. This underscores the need for policies that foster healthier urban environments of high environmental quality in order to protect child health.

The association of increased pre- and postnatal NO2 and PM2.5 exposure with the infant nasal microbiome composition and respiratory symptoms

BACKGROUND

Little is known about the mediating role of nasal microbiome on the association between pre- and postnatal air pollution exposure and subsequent respiratory morbidity in infancy. We aimed to examine the impact of air pollution on microbiome and respiratory symptoms, and whether microbiome mediates the association between air pollution and symptoms.

METHODS

Nasal swabs from 270 infants in the prospective Basel-Bern Infant Lung Development cohort were analyzed by 16S ribosomal RNA gene sequencing. We investigated the association of pre- and postnatal nitrogen dioxide (NO2) and particulate matter ≤2.5 μm (PM2.5) with microbiome at 4-6 weeks and with respiratory symptoms during the first year of life. Hierarchical clustering and generalized structural equation modeling were used.

RESULTS

Mean prenatal air pollution levels were 21.54 μg/m3 (NO2) and 13.84 μg/m3 (PM2.5) (WHO guideline limits: NO2: 40 μg/m3 (2005), 10 μg/m3 (2021); PM2.5: 10 μg/m3 (2005), 5 μg/m3 (2021)). We identified two distinct microbiome clusters, characterized by high Corynebacterium/Dolosigranulum and high Staphylococcus abundance. Higher pre- and postnatal air pollution exposure was associated with Staphylococcus cluster (e.g., per 10 μg/m3 increase of prenatal NO2: odds ratio 1.58, 95% confidence interval 1.08; 2.29, padj = 0.034). Pre- and postnatal PM2.5 was associated with increased risk of severe respiratory symptoms. This association was not mediated by nasal microbiome.

CONCLUSION

Pre- and postnatal air pollution was associated with microbiome and respiratory symptoms in infancy. The microbiome did not mediate the association of air pollution with respiratory symptoms, which may indicate that other mechanisms are more relevant at this age.

Associations of exposure to outdoor PM2.5 and NO2 during pregnancy with childhood asthma, rhinitis, and eczema in a predominantly rural French mother-child cohort

Uncertainty remains regarding the effects of outdoor air pollution in rural areas on childhood asthma, rhinitis, and eczema. Although these diseases often coexist, few studies have examined the effects of air pollution on their multimorbidity. The objective of this study was to investigate the associations of pregnancy exposure to outdoor fine particulate matter (PM2.5) and nitrogen dioxide (NO2) with childhood asthma, rhinitis, eczema, and their multimorbidity. We included children from the 6-year (n = 1322) and 12-year (n = 1118) follow-up of the Pélagie mother-child cohort in Brittany, France where 64% of the participants lived in rural areas. Asthma, rhinitis, eczema, and a multimorbidity phenotype (concomitant presence of ≥2 diseases) were defined by validated questionnaires. PM2.5 and NO2 concentrations during pregnancy were modeled at residential address using land use regression. We assessed associations using logistic regressions per interquartile range (PM2.5: 3 μg/m3; NO2: 10 μg/m3). We also performed stratification by type of area (urban and rural). Asthma, rhinitis, eczema, and the multimorbidity phenotype prevalence were 12%, 20%, 22% and 12% at 6-years, and 10%, 23%, 19% and 11% at 12-years of follow-up. At 6-years, for eczema, a tendency of an association was observed with NO2 (OR = 1.15, 95% CI = 0.97-1.36, p-value = 0.10), and stratification by type of area showed statistically significant associations for PM2.5 (1.49 (1.03-2.13), p = 0.03) and NO2 (1.40 (1.08-1.82), p = 0.01) in the urban stratum. At 12-years, main analyses showed a tendency of associations of PM2.5 (1.38 (0.98-1.93), p = 0.07) and NO2 (1.25 (0.98-1.59), p = 0.07) with asthma, and of NO2 with the multimorbidity phenotype (1.23 (0.97-1.56), p = 0.09). While overall results were not statistically significant, associations in urban settings were stronger than in rural ones at 6-years suggesting that possible differences between the effects in urban and rural areas should be further explored.

Adverse neurodevelopment in children associated with prenatal exposure to fine particulate matter (PM2.5) - Possible roles of polycyclic aromatic hydrocarbons (PAHs) and mechanisms involved

Prenatal exposure to ambient fine particles (PM2.5) and polycyclic aromatic hydrocarbons (PAHs) has been associated with adverse birth outcomes including neurodevelopmental effects with cognitive and/or behavioral implications in early childhood. As a background we first briefly summarize human studies on PM2.5 and PAHs associated with adverse birth outcomes and modified neurodevelopment. Next, we add more specific information from animal studies and in vitro studies and elucidate possible biological mechanisms. More specifically we focus on the potential role of PAHs attached to PM2.5 and explore whether effects of these compounds may arise from disturbance of placental function or more directly by interfering with neurodevelopmental processes in the fetal brain. Possible molecular initiating events (MIEs) include interactions with cellular receptors such as the aryl hydrocarbon receptor (AhR), beta-adrenergic receptors (βAR) and transient receptor potential (TRP)-channels resulting in altered gene expression. MIE linked to the binding of PAHs to cytochrome P450 (CYP) enzymes and formation of reactive electrophilic metabolites are likely less important. The experimental animal and in vitro studies support the epidemiological findings and suggest steps involved in mechanistic pathways explaining the associations. An overall evaluation of the doses/concentrations used in experimental studies combined with the mechanistic understanding further supports the hypothesis that prenatal PAHs exposure may cause adverse outcomes (AOs) linked to human neurodevelopment. Several MIEs will likely occur simultaneously in various cells/tissues involving several key events (KEs) which relative importance will depend on dose, time, tissue, genetics, other environmental factors, and neurodevelopmental endpoint in study.

Constructing an adverse outcome pathway framework for the impact of maternal exposure to PM2.5 on liver development and injury in offspring

Ambient fine particulate matter (PM2.5) is a significant contributor to air pollution. PM2.5 exposure poses a substantial hazard to public health. In recent years, the adverse effects of maternal PM2.5 exposure on fetal health have gradually gained public attention. As the largest organ in the body, the liver has many metabolic and secretory functions. Liver development, as well as factors that interfere with its growth and function, are of concern. This review utilized the adverse outcome pathway (AOP) framework as the analytical approach to demonstrate the link between maternal PM2.5 exposure and potential neonatal liver injury from the molecular to the population level. The excessive generation of reactive oxygen species (ROS), subsequent endoplasmic reticulum (ER) stress, and oxidative stress were regarded as the essential components in this framework, as they could trigger adverse developmental outcomes in the offspring through DNA damage, autophagy dysfunction, mitochondrial injury, and other pathways. To the best of our knowledge, this is the first article based on an AOP framework that elaborates on the influence of maternal exposure to PM2.5 on liver injury occurrence and adverse effects on liver development in offspring. Therefore, this review offered mechanistic insights into the developmental toxicity of PM2.5 in the liver, which provided a valuable basis for future studies and prevention strategies.

Prenatal exposure to ambient fine particulate matter and child lung function in the CANDLE cohort

BACKGROUND

Ambient fine particulate matter (PM2.5) exposure adversely impacts child airway health; however, research on prenatal PM2.5 exposure, and child lung function is limited. We investigated these associations in the ECHO-PATHWAYS Consortium, focusing on the role of exposure timing during different phases of fetal lung development.

METHODS

We included 675 children in the CANDLE cohort born between 2007 and 2011 in Memphis, TN, USA. Prenatal exposure to ambient PM2.5 was estimated using a spatiotemporal model based on maternal residential history and averaged over established prenatal periods of lung development. Forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) were measured by spirometry at age 8-9 years. We used linear regression and Bayesian Distributed Lag Interaction Models (BDLIM) to estimate associations between exposure and lung function z-scores, adjusting for maternal/child characteristics, prenatal/postnatal tobacco exposure, and birth year/season, and evaluating effect modification by child sex and allergic sensitization.

RESULTS

The average ambient concentration of PM2.5 during pregnancy was 11.1 µg/m3 (standard deviation:1.0 µg/m3). In the adjusted linear regression and BDLIM models, adverse, but not statistically significant, associations were observed between exposure during the pseudoglandular (5-16 weeks of gestation) and saccular (24-36 weeks) phases of lung development and FEV1 and FVC. The strongest association was between a 2 μg/m3 higher concentration of PM2.5 during the saccular phase and FEV1 z-score (-0.176, 95% Confidence Interval [CI]: -0.361, 0.010). The FEV1/FVC ratio was not associated with PM2.5 in any exposure window. No effect modification by child sex or allergic sensitization was observed.

CONCLUSIONS

We did not find strong evidence of associations between prenatal ambient PM2.5 exposure and child lung function in a large, well-characterized study sample. However, there was a suggested adverse association between FEV1 and exposure during late pregnancy. The saccular phase of lung development might be an important window for exposure to PM2.5.

The individual and combined effects of polycyclic aromatic hydrocarbons on asthma among US children: evidence from the NHANES study

Polycyclic Aromatic Hydrocarbons (PAHs) exposure has been linked to asthma, but their individual and combined effects in children remain unclear. Using data from the 2003-2012 National Health and Nutrition Examination Survey (NHANES), we investigated the associations between PAHs and asthma through logistic regression, Weighted Quantile Sum (WQS) regression, Quantile g Computation (qg computation), and Bayesian Kernel Machine Regression (BKMR). Subgroup analyses revealed a significant impact of PAHs on asthma, particularly in males. The WQS model showed a marginally significant combined effect of 9 PAHs on asthma (Odds Ratio = 1.37, 95% Confidence Interval: 1.06-1.75). BKMR also indicated a positive association between combined PAH exposure and asthma. 2-Hydroxyfluorene and 1-Hydroxypyrene were identified as the most significant contributors. These findings suggest that mixed PAH exposure is associated with asthma risk in children.

Maternal diesel particle exposure alters gut microbiota and induces lung injury in rat offspring

Maternal air pollutant exposure inhibits fetal lung development. Diesel exhaust particles (DEP) are one of the most substantial contributors to particulate matter pollution. The effects of maternal DEP exposure on gut microbiota in mothers and offspring and fetal lung development remain unclear. In this study, time-dated pregnant Sprague Dawley rats received intranasal administration of 100 μL phosphate-buffered saline (PBS) or DEP (250 μg) in 100 μL PBS from gestational days 16-21. The dams were permitted to deliver vaginally at term. On postnatal days 0 and 7, gut microbiota was sampled from the lower gastrointestinal tract. The right lung and terminal ileum were harvested for histological, cytokine, and 8-hydroxy-2'-deoxyguanosine (8-OHdG) analyses. On postnatal day 0, the dams exposed to DEP and rat offspring with maternal DEP exposure exhibited macrophages that phagocytized diesel particles and increased numbers of macrophages in the alveolar parenchyma. On postnatal days 0 and 7, the offspring of DEP-exposed dams exhibited significantly lower intestinal tight junction protein expression, higher lung 8-OHdG and cytokine levels, and substantial lung injury compared with the offspring of the control dams. No significant differences were observed in the microbiota composition and diversity between the control and DEP-exposed dams. Maternal DEP exposure altered the gut microbiota composition and diversity on postnatal days 0 and 7, with more significant effects observed in the offspring on postnatal day 7. Regarding the mechanism, lung injury in offspring may have been linked to altered gut microbiota communities and dysregulated metabolic pathways caused by maternal DEP exposure.

Spatial associations of daily PM2.5 concentration with cardiovascular and pulmonary morbidity in Korea

Air pollution, particularly fine particulate matter less than 2.5 μm in diameter (PM2.5), contributes to respiratory and cardiovascular diseases and poses significant public health risks worldwide. This study evaluated the short-term effects of PM2.5 on hospital admissions for cardiovascular and respiratory diseases, with additional analyses to identify vulnerable populations based on regional characteristics. The present study analyzed data from 249 Korean communities between 2006 and 2021. Data on daily hospital admissions for cardiovascular and respiratory diseases were obtained from the National Health Insurance Service. Data on PM2.5 concentrations were sourced from air quality modeling. Additional data on regional characteristics, including the regional deprivation index, proportion of elderly residents, education levels, and greenness levels, were also collected. We used case time series analysis to assess the associations between PM2.5 concentrations and hospital admissions for cardiovascular and respiratory diseases and explored effect modification by regional characteristics with stratified analyses. The mean numbers of daily cardiovascular admissions and respiratory admissions were 5.68 ± 5.46 and 6.46 ± 8.03, respectively. The mean PM2.5 concentrations were 23.58 ± 13.66 μg/m3. A10 μg/m³ increment in daily PM2.5 concentration was associated with increase of cardiovascular and respiratory hospitalization by 0.94% (95% CI: 0.84%, 1.04%) and 1.43% (95% CI: 1.34%, 1.52%), respectively. Regional characteristics analysis showed significant disparities, with higher risks for hospital admissions in areas with lower deprivation and low greenness. This study highlights the significant short-term health impacts of PM2.5 on respiratory and cardiovascular hospital admissions in Korean communities. The findings underscore the critical role of regional and demographic factors in modulating these effects, identifying socio-economic areas, age structure of the population, lower education levels, and low greenness as key vulnerability factors.

ACPM Position Statement: Air Pollution and Environmental Justice

The American Lung Association's "State of the Air" 2023 report reveals almost 36% of Americans live with unhealthy levels of air pollution. Studies link air pollution with acute respiratory symptoms and exacerbation of respiratory and cardiovascular diseases. Differential air pollution exposures between white and nonwhite communities are significant components of environmental injustices. Even during the coronavirus disease 2019 (COVID-19) lockdown, when the United States experienced significant decreases in polluting activities, these differences persisted. The American College of Preventive Medicine's Science and Translation Committee conducted a nonsystematic literature review to explore initiatives addressing air pollution as a key component of environmental justice, the state of the science regarding health impacts, and evidence supporting mitigations to reduce those impacts. We recommend advocacy for cleaner energy sources and increasing green space; and increasing research, surveillance, and education and training on linkages between air pollutants and health. We recommend preventive medicine physicians raise awareness about increased risks of cardiovascular disease, cancer, asthma, and reduced lung function with air pollution exposure. Preventive medicine physicians may also educate patients and other practitioners about exposures, and how "conventional" disease prevention strategies may have unintended consequences; and influence healthcare leaders to improve efficiency and reduce emissions. We also recommend physicians utilize social determinants of health Z-Codes to capture environmental factors. Private payers should incorporate pollution exposure data into social determinants of health risk adjustments for Medicare Advantage programs. Medicaid agencies should develop provider recommendations for pediatric populations, and states should finance in-home interventions for asthma.

Air pollution exposure during pregnancy and preterm birth in Brazil

Ambient air pollution is a significant environmental risk factor for adverse pregnancy outcomes, including preterm birth. However, the impact of different pollutants across various regions and trimesters of pregnancy has not been fully investigated in Brazil. This study aimed to examine the associations between exposure to PM2.5, NO2, and O3 during different trimesters of pregnancy and the risk of preterm birth across five regions of Brazil. We used logistic regression models to estimate the odds ratios (OR) of preterm birth associated with PM2.5, NO2, and O3 adjusting for potential confounders such as maternal age, education, and socioeconomic status. Our study included over 9.9 million live births from 2001 to 2018, with data obtained from the Ministry of Health in Brazil. On average, for each 1-μg/m3 increase in PM2.5, we estimated a 0.26 % (95 % CI: 0.08-0.44 %) increase in the risk of preterm birth nationally in the first trimester. For NO2, each 1ppb increase was associated with a percentage increase in preterm birth risk of 7.26 % (95 % CI: 4.77-9.74 %) in the first trimester, 8.05 % (95 % CI: 5.73-10.38 %) in the second trimester, and 7.48 % (95 % CI: 5.25-9.72 %) in the third trimester. For O3, each 1ppb increase was associated with a percentage increase in preterm birth risk of 1.24 % (95 % CI: 0.29-2.18 %) in the first trimester, 1.51 % (95 % CI: 0.60-2.41 %) in the second trimester, and 0.72 % (95 % CI: -0.18-1.62 %) in the third trimester. This study highlights the significant impact of ambient air pollution on preterm birth risk in Brazil, with significant regional variations. Our findings underscore the need for targeted public health interventions to mitigate the effects of air pollution on pregnancy outcomes, particularly in the most affected regions.

EV-miRNA associated with environmental air pollution exposures in the MADRES cohort

Air pollution is a hazardous contaminant, exposure to which has substantial consequences for health during critical periods, such as pregnancy. MicroRNA (miRNA) is an epigenetic mechanism that modulates transcriptome responses to the environment and has been found to change in reaction to air pollution exposure. The data are limited regarding extracellular-vesicle (EV) miRNA variation associated with air pollution exposure during pregnancy and in susceptible populations who may be disproportionately exposed. This study aimed to identify EV-miRNA expression associated with ambient, residential exposure to PM2.5, PM10, NO2, O3 and with traffic-related NOx in 461 participants of the MADRES cohort, a low income, predominantly Hispanic pregnancy cohort based in Los Angeles, CA. This study used residence-based modeled air pollution data as well as Nanostring panels for EVmiRNA extracted with Qiagen exoRNeasy kits to evaluate 483 miRNA in plasma in early and late pregnancy. Average air pollution exposures were considered separately for 1-day, 1-week, and 8-week windows before blood collection in both early and late pregnancy. This study identified 63 and 66 EV-miRNA significantly associated with PM2.5 and PM10, respectively, and 2 miRNA associated with traffic-related NOX (False Discovery Rate-adjusted P-value < .05). Of 103 unique EV-miRNA associated with PM, 92% were associated with lung conditions according to HMDD (Human miRNA Disease Database) evidence. In particular, EV-miRNA previously identified with air pollution exposure also associated with PM2.5 and PM10 in this study were: miR-126, miR-16-5p, miR-187-3p, miR200b-3p, miR486-3p, and miR-582-3p. There were no significant differences in average exposures in early vs late pregnancy. Significant EV-miRNAs were only identified in late pregnancy with an 8-week exposure window, suggesting a vulnerable timeframe of exposure, rather than an acute response. These results describe a wide array of EV-miRNA for which expression is affected by PM exposure and may be in part mediating the biological response to ambient air pollution, with potential for health implications in pregnant women and their children.

Examining the Link between Air Quality (PM, SO2, NO2, PAHs) and Childhood Obesity: A Systematic Review

Background/Objectives: Childhood obesity has emerged as a global health concern with profound implications for long-term health outcomes. In recent years, there has been increasing interest in the potential role of environmental factors in the development of childhood obesity. This comprehensive review aims to elucidate the intricate relationship between various components of air pollution and childhood obesity. Methods: We systematically analyze the existing literature from the past 5 years to explore the mechanistic pathways linking air pollution, including particulate matter (PM), nitrogen oxides (NOx), sulfur dioxide (SO2), and polycyclic aromatic hydrocarbons (PAHs), to childhood obesity. This systematic review examines 33 epidemiological studies on the link between air pollution and childhood obesity, published from 1 January 2018, to 31 January 2024. Results: Studies from counties with low overall air pollution noticed only low to no impact of the exposure to childhood obesity, unlike studies from countries with higher levels of pollution, suggesting that the mitigation of air pollutants can reduce the chance of it being a negative factor for the development of obesity. This relationship was noticed for PM2.5, PM1, PM10, NOx, and SO2 but not for PAHs, which showed a negative effect on children's health across 10 out of 11 studies. Conclusions: This review underscores the need for interdisciplinary approaches to address both environmental and socio-economic determinants of childhood obesity. Efforts aimed at reducing air pollution levels and promoting healthy lifestyle behaviors are essential for safeguarding the health and well-being of children worldwide.

Childhood PM2.5 exposure and upward mobility in the United States

Although it is well documented that exposure to fine particulate matter (PM2.5) increases the risk of several adverse health outcomes, less is known about its relationship with economic opportunity. Previous studies have relied on regression modeling, which implied strict assumptions regarding confounding adjustments and did not explore geographical heterogeneity. We obtained data for 63,165 US census tracts (86% of all census tracts in the United States) on absolute upward mobility (AUM) defined as the mean income rank in adulthood of children born to families in the 25th percentile of the national income distribution. We applied and compared several state-of-the-art confounding adjustment methods to estimate the overall and county-specific associations of childhood exposure to PM2.5 and AUM controlling for many census tract-level confounders. We estimate that census tracts with a 1 μg/m3 higher PM2.5 concentrations in 1982 are associated with a statistically significant 1.146% (95% CI: 0.834, 1.458) lower AUM in 2015, on average. We also showed evidence that this relationship varies spatially between counties, exhibiting a more pronounced negative relationship in the Midwest and the South.

An epigenome-wide study of a needs-based family intervention for offspring of trauma-exposed mothers in Kosovo

INTRODUCTION

Maternal stress and trauma during pregnancy have been shown to influence cortisol levels and epigenetic patterns, including DNA methylation, in the offspring. This study aimed to determine whether a tailor-made family intervention could help reduce cortisol levels in children born to traumatized mothers, and to determine whether it effected offspring DNA methylation. The secondary aim was to determine whether the family intervention influenced DNA methylation aging, a marker of biological aging.

METHODS

A needs-based family intervention was designed to help address relational difficulties and family functioning, and included a focus on family strengths and problem-solving patterns. Women survivors of sexual violence during the Kosovar war in 1998-1999, and their families (children with or without partners) were randomly assigned to 10 sessions of a family therapy over a 3-5-month period, or to a waitlist control group. Both mothers and children completed assessments prior to and after the intervention phase. Children's blood samples collected at these two time points were used to measure cortisol and epigenome-wide DNA methylation patterns (Illumina EPIC array). Cortisol levels, and genome-wide DNA methylation changes pre-/postintervention were compared between children in the intervention and the waitlist groups. DNA methylation age and accelerated biological aging were calculated.

RESULTS

Sixty-two women-child dyads completed the study, 30 were assigned first to the intervention group, and 32 to the waitlist control group. In adjusted linear regression, the family intervention was associated with a significant decline in cortisol levels compared to the waitlist control (β = -124.72, 95% confidence interval [CI]: -197.4 to -52.1, p = .001). Children in the intervention group, compared to the waitlist control group, showed >1% differential methylation degree at 5819 CpG (5'-C-phosphate-G-3') sites across the genome (p < .01), with the largest methylation difference being 21%. However, none of these differences reached genome-wide significant levels. There was no significant difference in DNA methylation aging between the two groups.

CONCLUSION

We find evidence that a tailored family-based intervention reduced stress levels in the children (based on cortisol levels), and modified DNA methylation levels at a number of sites across the genome. This study provides some preliminary evidence to suggest the potential for tailored interventions to help break the intergenerational transmission of trauma, however, large studies powered to detect associations at genome-wide significant levels are needed.

Chronic maternal exposure to low-dose PM2.5 impacts cognitive outcomes in a sex-dependent manner

There is no safe level of air pollution for human health. Traffic-related particulate matter (PM2.5) is a major in-utero toxin, mechanisms of action of which are not fully understood. BALB/c dams were exposed to an Australian level of traffic PM2.5 (5 µg/mouse/day, intranasal, 6 weeks before mating, during gestation and lactation). Male offspring had reduced memory in adulthood, whereas memory was normal in female littermates, similar to human responses. Maternal PM2.5 exposure resulted in oxidative stress and abnormal mitochondria in male, but not female, brains. RNA-sequencing analysis showed unique sex-related changes in newborn brains. Two X-chromosome-linked histone lysine demethylases, Kdm6a and Kdm5c, demonstrated higher expression in female compared to male littermates, in addition to upregulated genes with known functions to support mitochondrial function, synapse growth and maturation, cognitive function, and neuroprotection. No significant changes in Kdm6a and Kdm5c were found in male littermates, nor other genes, albeit significantly impaired memory function after birth. In primary foetal cortical neurons, PM2.5 exposure suppressed neuron and synaptic numbers and induced oxidative stress, which was prevented by upregulation of Kdm6a or Kdm5c. Therefore, timely epigenetic adaptation by histone demethylation to open DNA for translation before birth may be the key to protecting females against prenatal PM2.5 exposure-induced neurological disorders, which fail to occur in males associated with their poor cognitive outcomes.

Association Between Long-Term Exposure to Environmental Fine Particulate Matter and the Prevalence of Thyroid Disorders: A National Cross-Sectional Study in China

Background: Exposure to particles with an aerodynamic diameter of ≤2.5 μm (PM2.5) is associated with the occurrence of thyroid dysfunction among pregnant women and neonates, but it is not known if this association occurs in the general population. We aimed to determine the association of prolonged exposure to PM2.5 with the prevalence of thyroid disorders among adults in China. Methods: A nationally representative cross-sectional study of thyroid disorders, iodine status, and diabetes status was carried out in all 31 provinces across China from 2015 to 2017. In total, 73,900 adults aged 18 years and older were included. Serum concentrations of thyroid hormones, thyrotropin, and thyroid antibodies and the urine iodine concentration were measured. The environmental concentration of PM2.5 for each participant's residential address at a spatial resolution of 1 × 1 km was estimated. Results: The average long-term exposure to PM2.5 at residential addresses was 66.41 μg/m3, ranging from 17.58 μg/m3 to 120.40 μg/m3. Compared with that of individuals with lower exposure levels, the prevalence of thyroid diseases such as autoimmune thyroiditis and subclinical hypothyroidism was greater in those with PM2.5 concentrations within the third quartile range (60.18 to 73.78 μg/m3). Compared with those in the first quartile (17.58 to 46.38 μg/m3), participants in the highest PM2.5 quartile (73.78 to 120.40 μg/m3) presented an increased risk of overt hypothyroidism (OR 1.23 [CI 0.94-1.61]), subclinical hypothyroidism (1.10 [1.01-1.21]), autoimmune thyroiditis (1.09 [1.00-1.18]), and thyroglobulin antibody positivity (1.17 [1.07-1.29]). However, there was no association between PM2.5 exposure and overt hyperthyroidism, subclinical hyperthyroidism, Graves' disease, or thyroid peroxidase antibody positivity (p > 0.05). Each 10 μg/m³ increase in the PM2.5 concentration was associated with an increased risk of overt hypothyroidism (OR 1.05 [1.00-1.11]), subclinical hypothyroidism (1.02 [1.00-1.03]), and thyroglobulin antibody positivity (1.02 [1.00-1.04]). Furthermore, a nearly linear exposure-response relationship was observed between long-term PM2.5 exposure and thyroglobulin antibody positivity. Conclusions: PM2.5 exposure was associated with thyroid disorders among Chinese adults. A dose-response relationship between PM2.5 exposure and autoimmune thyroiditis, as well as thyroglobulin antibody positivity, was also observed.

Association of antenatal and early childhood air pollution and greenspace exposures with respiratory pathogen upper airway acquisitions and respiratory health outcomes

The association of air pollution and greenspace with respiratory pathogen acquisition and respiratory health was investigated in a community-based birth-cohort of 158 Australian children. Weekly nasal swabs and daily symptom-diaries were collected for 2-years, with annual reviews from ages 3-7-years. Annual exposure to fine-particulate-matter (PM2.5), nitrogen-dioxide (NO2), and normalised-difference-vegetation-index (NDVI) was estimated for pregnancy and the first 2-years-of-life. We examined rhinovirus, any respiratory virus, Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae detections in the first 3-months-of-life, age at initial pathogen detection, wheezing in the first 2-years, and asthma at ages 5-7-years. Our findings suggest that higher NDVI was associated with fewer viral and M. catarrhalis detections in the first 3-months, while increased PM2.5 and NO2 were linked to earlier symptomatic rhinovirus and H. influenzae detections, respectively. However, no associations were observed with wheezing or asthma. Early-life exposure to air pollution and greenspace may influence early-life respiratory pathogen acquisition and illness.  .

Protective effects of docosahexaenoic acid supplementation on cognitive dysfunction and hippocampal synaptic plasticity impairment induced by early postnatal PM2.5 exposure in young rats

PM2.5 exposure is a challenging environmental issue that is closely related to cognitive development impairment; however, currently, relevant means for prevention and treatment remain lacking. Herein, we determined the preventive effect of docosahexaenoic acid (DHA) supplementation on the neurodevelopmental toxicity induced by PM2.5 exposure. Neonatal rats were divided randomly into three groups: control, PM2.5, and DHA + PM2.5 groups. DHA could ameliorate PM2.5-induced learning and memory dysfunction, as well as reverse the impairment of hippocampal synaptic plasticity, evidenced by enhanced long-term potentiation, recovered synaptic ultrastructure, and increased expression of synaptic proteins. Moreover, DHA increased CREB phosphorylation and BDNF levels and attenuated neuroinflammation and oxidative stress, reflected by lower levels of IBA-1, IL-1β, and IL-6 and increased levels of SOD1 and Nrf2. In summary, our findings demonstrated that supplementation of DHA effectively mitigated the cognitive dysfunction and synaptic plasticity impairment induced by early postnatal exposure to PM2.5. These beneficial effects may be attributed to the upregulation of the CREB/BDNF signaling pathway, as well as the reduction of neuroinflammation and oxidative stress.

Contribution of ethnicity, area level deprivation and air pollution to paediatric intensive care unit admissions in the United Kingdom 2008-2021

Background

There is emerging evidence on the impact of social and environmental determinants of health on paediatric intensive care unit (PICU) admissions and outcomes. We analysed UK paediatric intensive care data to explore disparities in the incidence of admission according to a child's ethnicity and the degree of deprivation and pollution in the child's residential area.

Methods

Data were extracted on children <16 years admitted to UK PICUs between 1st January 2008 and 31st December 2021 from the Paediatric Intensive Care Audit Network (PICANet) database. Ethnicity was categorised as White, Asian, Black, Mixed or Other. Deprivation was quantified using the 'children in low-income families' measure and outdoor air pollution was characterised using mean annual PM2.5 level at local authority level, both divided into population-weighted quintiles. UK population estimates were used to calculate crude incidence of PICU admission. Incidence rate ratios were calculated using Poisson regression models.

Findings

There were 245,099 admissions, of which 60.7% were unplanned. After adjusting for age and sex, Asian and Black children had higher relative incidence of unplanned PICU admission compared to White (IRR 1.29 [95% CI: 1.25-1.33] and 1.50 [95% CI: 1.44-1.56] respectively), but there was no evidence of increased incidence of planned admission. Children living in the most deprived quintile had 1.50 times the incidence of admission in the least deprived quintile (95% CI: 1.46-1.54). There were higher crude admission levels of children living in the most polluted quintile compared to the least (157.8 vs 113.6 admissions per 100,000 child years), but after adjustment for ethnicity, deprivation, age and sex there was no association between pollution and PICU admission (IRR 1.00 [95% CI: 1.00-1.00] per 1 μg/m3 increase).

Interpretation

Ethnicity and deprivation impact the incidence of PICU admission. When restricting to unplanned respiratory admissions and ventilated patients only, increasing pollution level was associated with increased incidence of PICU admission. It is essential to act to reduce these observed disparities, further work is needed to understand mechanisms behind these findings and how they relate to outcomes.

Funding

There was no direct funding for this project. HM was funded by an NIHR Academic Clinical Fellowship (ACF-2022-18-017).

Outdoor air pollution and brain development in childhood and adolescence

Exposure to outdoor air pollution has been linked to adverse health effects, including potential widespread impacts on the CNS. Ongoing brain development may render children and adolescents especially vulnerable to neurotoxic effects of air pollution. While mechanisms remain unclear, promising advances in human neuroimaging can help elucidate both sensitive periods and neurobiological consequences of exposure to air pollution. Herein we review the potential influences of air pollution exposure on neurodevelopment, drawing from animal toxicology and human neuroimaging studies. Due to ongoing cellular and system-level changes during childhood and adolescence, the developing brain may be more sensitive to pollutants' neurotoxic effects, as a function of both timing and duration, with relevance to cognition and mental health. Building on these foundations, the emerging field of environmental neuroscience is poised to further decipher which air toxicants are most harmful and to whom.

Prenatal exposure to air pollutants and the risk of congenital heart disease: a Korean national health insurance database-based study

Air pollution and heavy metal exposure are emerging public health concerns. Prenatal exposure to air pollutants and heavy metals has been implicated in the development of congenital heart disease (CHD). However, the relationship between exposure to airborne heavy metals and CHD has not yet been investigated. Therefore, in this large population-based study, we investigated the association between air pollutants, including airborne heavy metals, and the risk of CHD using national health insurance claims data from South Korea. Data regarding 1,129,442 newborns and their mothers were matched with air pollutant levels during the first 8 weeks of gestation. In the five-air pollutant model, we found significant positive correlations between prenatal exposure to sulfur dioxide (SO2; odds ratio [OR] 6.843, 95% confidence interval [CI] 5.746-8.149) and cadmium (Cd; OR 1.513, 95% CI 1.187-1.930) and the risk of ventricular septal defects in newborns. This study highlights the association between prenatal exposure to air pollutants, including airborne heavy metals, and an elevated CHD risk. Further research is essential to validate and expand these findings, with the ultimate goal of enhancing public health outcomes.

Impact of Respiratory Dust on Health: A Comparison Based on the Toxicity of PM2.5, Silica, and Nanosilica

Respiratory dust of different particle sizes in the environment causes diverse health effects when entering the human body and makes acute or chronic damage through multiple systems and organs. However, the precise toxic effects and potential mechanisms induced by dust of different particle sizes have not been systematically summarized. In this study, we described the sources and characteristics of three different particle sizes of dust: PM2.5 (<2.5 μm), silica (<5 μm), and nanosilica (<100 nm). Based on their respective characteristics, we further explored the main toxicity induced by silica, PM2.5, and nanosilica in vivo and in vitro. Furthermore, we evaluated the health implications of respiratory dust on the human body, and especially proposed potential synergistic effects, considering current studies. In summary, this review summarized the health hazards and toxic mechanisms associated with respiratory dust of different particle sizes. It could provide new insights for investigating the synergistic effects of co-exposure to respiratory dust of different particle sizes in mixed environments.

Prenatal air pollution exposure is associated with inflammatory, cardiovascular, and metabolic biomarkers in mothers and newborns

BACKGROUND

Prenatal air pollution exposure has been associated with individual inflammatory, cardiovascular, and metabolic biomarkers in mothers and neonates. However, studies of air pollution and a comprehensive panel of biomarkers across maternal and cord blood samples remain limited. Few studies used data-driven methods to identify biomarker groupings that converge biomarkers from multiple biological pathways. This study aims to investigate the impacts of prenatal air pollution on groups of biomarkers in maternal and cord blood samples.

METHODS

In the Maternal And Developmental Risks from Environmental and Social Stressors (MADRES) cohort, 87 biomarkers were quantified from 45 trimester 1 maternal blood and 55 cord blood samples. Pregnancy and trimester 1-averaged concentrations of particulate matter ≤2.5 μm and ≤10 μm in diameter (PM2.5 and PM10), nitrogen dioxide (NO2), and ozone (O3) were estimated, using inverse distance squared weighted spatial interpolation from regulatory air monitoring stations. Traffic-related NOx was assessed using California Line Source Dispersion Model: freeway/highway roads, non-freeway major roads, non-freeway minor roads, and their sum as total NOx. Elastic Net (EN) regression within the rexposome R package was used to group biomarkers and assess their associations with air pollution.

RESULTS

In maternal samples, trimester 1-averaged PM10 was associated with elevated inflammation biomarkers and lowered cardiovascular biomarkers. NO2 exhibited positive associations with cardiovascular and inflammation markers. O3 was inversely associated with inflammation, metabolic, and cardiovascular biomarkers. In cord blood, pregnancy-averaged PM2.5 was associated with higher cardiovascular biomarkers and lower metabolic biomarkers. PM10 was associated with lower inflammation and higher cardiovascular biomarkers. Total and major road NOx was associated with lower cardiovascular biomarkers.

CONCLUSION

Prenatal air pollution exposure was associated with changes in biomarkers related to inflammation, cardiovascular, metabolic, cancer, and neurological function in both mothers and neonates. This study shed light on mechanisms by which air pollution can influence biological function during pregnancy.

Long-term exposure to air pollution and precocious puberty in South Korea

BACKGROUND AND AIM

The increasing prevalence of precocious puberty (PP) has emerged as a significant medical and social problem worldwide. However, research on the relationship between long-term air pollution exposure and PP has been relatively limited. We thus investigated the association between long-term air pollution exposure and the onset of PP in South Korea.

METHODS

We investigated a retrospective cohort using the Korea National Health Insurance Database. Six-year-old children born from 2007 to 2009 were examined (2013-2015). We included boys ≤10 years and girls aged ≤9 years who visited hospitals for early pubertal development, were diagnosed with PP per the ICD-10 (E228, E301, and E309), and received gonadotropin-releasing hormone agonist treatment. We analyzed data for boys up until 10 years old (60-month follow-up) and for girls up to 9 years old (48-month follow-up). We assessed the association between long-term air pollution exposure and the onset of PP using a Cox proportional hazard model. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) per 1 μg/m3 increase in fine particulate matter (PM2.5) and particulate matter (PM10) and per 1 ppb increase in sulfur dioxide (SO2), nitrogen dioxide (NO2), and ozone (O3).

RESULTS

This study included 1,205,784 children aged six years old between 2013 and 2015. A positive association was found between the 48-month moving average PM2.5 (HR: 1.019; 95% CI: 1.012, 1.027), PM10 (HR: 1.009; 95% CI: 1.006, 1.013), SO2 (HR: 1.037; 95% CI: 1.018, 1.055), and O3 (HR: 1.006; 95% CI: 1.001, 1.010) exposure and PP in girls but not boys.

CONCLUSIONS

This study provides valuable insights into the harmful effects of air pollution during childhood and adolescence, emphasizing that air pollution is a risk factor that should be managed and reduced.

Joint effects of prenatal exposure to indoor air pollution and psychosocial factors on early life inflammation

It is hypothesized that air pollution and stress impact the central nervous system through neuroinflammatory pathways Despite this, the association between prenatal exposure to indoor air pollution and psychosocial factors on inflammatory markers in infancy has been underexplored in epidemiology studies. This study investigates the individual and joint effects of prenatal exposure to indoor air pollution and psychosocial factors on early life inflammation (interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α)). We analyzed data from the South African Drakenstein Child Health Study (N = 225). Indoor air pollution and psychosocial factor measurements were taken in the 2nd trimester of pregnancy. Circulating inflammatory markers (IL-1β, Il-6, and TNF-α) were measured in serum in the infants at 6 weeks postnatal. Linear regression models were used to investigate associations between individual exposures and inflammatory markers. To investigate joint effects of environmental and psychosocial factors, Self-Organizing Maps (SOM) were used to create exposure profile clusters. These clusters were added to linear regression models to investigate the associations between exposure profiles and inflammatory markers. All models were adjusted for maternal age, maternal HIV status, and ancestry to control for confounding. Most indoor air pollutants were positively associated with inflammatory markers, particularly benzene and TNF-α in single pollutant models. No consistent patterns were found for psychosocial factors in single-exposure linear regression models. In joint effects analyses, the SOM profile with high indoor air pollution, low SES, and high maternal depressive symptoms were associated with higher inflammation. Indoor air pollutants were consistently associated with increased inflammation in both individual and joint effects models, particularly in combination with low SES and maternal depressive symptoms. The trend for individual psychosocial factors was not as clear, with mainly null associations. As we have observed pro- and anti-inflammatory effects, future research should investigate joint effects of these exposures on inflammation and their health effects.

The effects of fine particulate matter on the blood-testis barrier and its potential mechanisms

With the rapid expansion of industrial scale, an increasing number of fine particulate matter (PM2.5) has bringing health concerns. Although exposure to PM2.5 has been clearly associated with male reproductive toxicity, the exact mechanisms are still unclear. Recent studies demonstrated that exposure to PM2.5 can disturb spermatogenesis through destroying the blood-testis barrier (BTB), consisting of different junction types, containing tight junctions (TJs), gap junctions (GJs), ectoplasmic specialization (ES) and desmosomes. The BTB is one of the tightest blood-tissue barriers among mammals, which isolating germ cells from hazardous substances and immune cell infiltration during spermatogenesis. Therefore, once the BTB is destroyed, hazardous substances and immune cells will enter seminiferous tubule and cause adversely reproductive effects. In addition, PM2.5 also has shown to cause cells and tissues injury via inducing autophagy, inflammation, sex hormones disorder, and oxidative stress. However, the exact mechanisms of the disruption of the BTB, induced by PM2.5, are still unclear. It is suggested that more research is required to identify the potential mechanisms. In this review, we aim to understand the adverse effects on the BTB after exposure to PM2.5 and explore its potential mechanisms, which provides novel insight into accounting for PM2.5-induced BTB injury.

The Impact of Fine Particulate Matter on Embryonic Development

Airborne fine particulate matter (PM2.5) in air pollution has become a significant global public health concern related to allergic diseases. Previous research indicates that PM2.5 not only affects the respiratory system but may also induce systemic inflammation in various tissues. Moreover, its impact may vary among different populations, with potential consequences during pregnancy and in newborns. However, the precise mechanisms through which PM2.5 induces inflammatory reactions remain unclear. This study aims to explore potential pathways of inflammatory responses induced by PM2.5 through animal models and zebrafish embryo experiments. In this study, zebrafish embryo experiments were conducted to analyze the effects of PM2.5 on embryo development and survival, and mouse experimental models were employed to assess the impact of PM2.5 stimulation on various aspects of mice. Wild-type zebrafish embryos were exposed to a PM2.5 environment of 25-400 μg/mL starting at 6 h after fertilization (6 hpf). At 6 days post-fertilization, the survival rates of the 25, 50, 100, and 200 µg/mL groups were 100%, 80, 40%, and 40%, respectively. Zebrafish embryos stimulated with 25 μg/mL of PM2.5 still exhibited successful development and hatching. Additionally, zebrafish subjected to doses of 25-200 μg/mL displayed abnormalities such as spinal curvature and internal swelling after hatching, indicating a significant impact of PM2.5 stimulation on embryo development. In the mouse model, mice exposed to PM2.5 exhibited apparent respiratory overreaction, infiltration of inflammatory cells into the lungs, elevated levels of inflammatory response-related cytokines, and inflammation in various organs, including the liver, lungs, and uterus. Blood tests on experimental mice revealed increased expression of inflammatory and chemotactic cytokines, and GSEA indicated the induction of various inflammatory responses and an upregulation of the TNF-α/NFκB pathway by PM2.5. Our results provide insights into the harmful effects of PM2.5 on embryos and organs. The induced inflammatory responses by PM2.5 may be mediated through the TNF-α/NFκB pathway, leading to systemic organ inflammation. However, whether PM2.5-induced inflammatory responses in various organs and abnormal embryo development are generated through different pathways requires further study to comprehensively clarify and identify potential treatment and prevention methods.

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

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

Increased vascular stiffness in children exposed in utero but not children exposed postnatally to emissions from a coal mine fire

Background

Chronic, low-intensity air pollution exposure has been consistently associated with increased atherosclerosis in adults. However, there was limited research regarding the implications of acute, high-intensity air pollution exposure during childhood. We aimed to determine whether there were any associations between early-life exposure to such an episode and early-life vascular function changes.

Methods

We conducted a prospective cohort study of children (<9 years old) who lived in the vicinity of the Hazelwood coal mine fire (n = 206). Vascular function was measured using noninvasive diagnostic methods including carotid intima-media thickness and pulse wave velocity (PWV). Exposure estimates were calculated from prognostic models and location diaries during the exposure period completed by each participant's parent. Linear mixed-effects models were used to determine whether there were any associations between exposure and changes in vascular outcomes at the 3- and 7-year follow-ups and over time.

Results

At the 7-year follow-up, each 10 μg/m3 increase in daily PM2.5 in utero was associated with increased PWV (β = 0.13 m/s; 95% confidence interval [CI] = 0.02, 0.24; P = 0.02). The association between in utero exposure to daily PM2.5 was not altered by adjustment for covariates, body mass index, and maternal fire stress. Each 1 µg/m3 increase in background PM2.5 was associated with increased PWV (β = 0.68 m/s; 95% CI = 0.10, 1.26; P = 0.025), in children from the in utero exposure group. There was a trend toward smaller PWV (β = -0.17 m/s; 95% CI = -0.366, 0.02) from the 3- to 7-year follow-up clinic suggesting that the deficits observed previously in children exposed postnatally did not persist.

Conclusion

There was a moderate improvement in vascular stiffness of children exposed to PM2.5 from a local coal mine fire in infancy. There was a mild increase in vascular stiffness in children exposed to PM2.5 from a local coal mine fire while their mothers were pregnant.

Particulate matter 2.5 exposure during pregnancy and birth outcomes: Evidence from Colombia

Particulate matter is a type of air pollution that consists of fine particles with a diameter <2.5 μm (PM2.5), which can easily penetrate the respiratory system and enter the bloodstream, increasing health risks for pregnant women and their unborn babies. Recent reports have suggested that there is a positive association between PM2.5 exposure and adverse pregnancy outcomes. However, most evidence of this relationship comes from Western countries. Thus, the objective of this study was to evaluate the association between PM2.5 exposure during pregnancy and birth outcomes among pregnant women in Colombia. This study included 542,800 singletons born in 2019 to Colombian women, aged 15+ years, residing in 981 municipalities. Data on parental, child and birth characteristics were extracted from anonymized live birth records. Satellite-based estimates of monthly PM2.5 concentrations at the surface level were extracted for each municipality from the Atmospheric Composition Analysis Group (ACAG). PM2.5 exposure during pregnancy was indicated by the monthly average of PM2.5 concentrations across the pregnancy duration for the municipality where the child was born. The associations of municipality-level PM2.5 concentration during pregnancy with pre-term birth (PTB) and low birth weight (LBW) were tested in separate two-level logistic regression models, with babies nested within municipalities. The prevalence of PTB and LBW were 8.6 % and 8.3 %, respectively. The mean PM2.5 concentration across the 981 municipalities was 18.26 ± 3.30 μg/m3, ranging from 9.11 to 31.44 μg/m3. Greater PM2.5 concentration at municipality level was associated with greater odds of PTB (1.05; 95%CI: 1.04-1.06) and LBW (1.04; 95%CI: 1.03-1.05), after adjustment for confounders. Our findings provide new evidence on the association between PM2.5 on adverse pregnancy outcomes from a middle-income country.

Environmental Interventions for Preventing Atopic Diseases

PURPOSE OF REVIEW

In this review, we detail the exposome (consisting of environmental factors such as diet, microbial colonization, allergens, pollutants, and stressors), mechanistic and clinical research supporting its influence on atopic disease, and potentiation from climate change. We highlight contemporary environmental interventions and available evidence substantiating their roles in atopic disease prevention, from observational cohorts to randomized controlled trials, when available.

RECENT FINDINGS

Early introduction to allergenic foods is an effective primary prevention strategy to reduce food allergy. Diverse dietary intake also appears to be a promising strategy for allergic disease prevention, but additional study is necessary. Air pollution and tobacco smoke are highly associated with allergic disease, among other medical comorbidities, paving the way for campaigns and legislation to reduce these exposures. There is no clear evidence that oral vitamin D supplementation, prebiotic or probiotic supplementation, daily emollient application, and antiviral prophylaxis are effective in preventing atopic disease, but these interventions require further study. While some environmental interventions have a well-defined role in the prevention of atopic disease, additional study of many remaining interventions is necessary to enhance our understanding of their role in disease prevention. Alignment of research findings from randomized controlled trials with public policy is essential to develop meaningful public health outcomes and prevent allergic disease on the population level.

Longitudinal assessment of oxidative stress markers and their relationship with exposure to PM2.5 and its bound metals in healthy participants

OBJECTIVE

Exposure to ambient PM2.5 and its bound metals poses a risk to health and disease, via, in part, oxidative stress response. A variety of oxidative stress markers have been used as markers of response, but their relevance to environmental exposure remains to be established. We evaluated, longitudinally, a battery of oxidative stress markers and their relationship with the exposure of PM2.5 and its bound metals in a panel of healthy participants.

MATERIAL AND METHODS

Levels of residence- and personal-based ambient air PM2.5 and its bound metals, as well as of lung function parameters, were assessed in a total of 58 questionnaire-administered healthy never smoker participants (male, 39.7%). Levels of urinary oxidative stress markers, including Nε-(hexanoyl)-lysine (HEL; an early lipid peroxidation product), 4-hydroxynonenal (4-HNE), N7-methylguanine (N7-meG), and 8-hydroxy-2-deoxyguanosine (8-OHdG), plasma antioxidants [superoxide dismutase (SOD) and glutathione peroxidase (GPx), and urinary metals were measured by ELISA, LC-MS, and ICP-MS, respectively. The results of three repeated measurements at two-month intervals were analyzed using the Generalized Estimating Equation (GEE).

RESULTS

After adjusting for confounders, residence- and personal-based PM2.5 levels were positively associated with HEL (β = 0.22 and 0.18) and N7-meG (β = 0.39 and 0.13). Significant correlations were observed between personal air PM2.5-Pb and urinary Pb with HEL (β = 0.08 and 0.26). While FVC, FEV1, FEV1/FVC, MMF, and PEFR predicted% were normal, a negative interaction (pollutant*time, P < 0.05) was noted for PM2.5-V, Mn, Co, Ni, Zn, As, and Pb. Additionally, a negative interaction was found for N7-meG (β = -21.35, -18.77, -23.86) and SOD (β = -26.56, -26.18, -16.48) with FEV1, FVC, and PEFR predicted%, respectively.

CONCLUSION

These findings emphasize potential links between environmental exposure, internal dose, and health effects, thereby offering valuable markers for future research on metal exposure, oxidative stress, and health outcomes.

Prenatal and early life exposure to air pollution and the risk of severe lower respiratory tract infections during early childhood: the Espoo Cohort Study

BACKGROUND

There is inconsistent evidence of the effects of exposure to ambient air pollution on the occurrence of lower respiratory tract infections (LRTIs) in early childhood. We assessed the effects of individual-level prenatal and early life exposure to air pollutants on the risk of LRTIs in early life.

METHODS

We studied 2568 members of the population-based Espoo Cohort Study born between 1984 and 1990 and living in 1991 in the City of Espoo, Finland. Exposure assessment was based on dispersion modelling and land-use regression for lifetime residential addresses. The outcome was a LRTI based on data from hospital registers. We applied Poisson regression to estimate the incidence rate ratio (IRR) of LTRIs, contrasting incidence rates in the exposure quartiles to the incidence rates in the first quartile. We used weighted quantile sum (WQS) regression to estimate the joint effect of the studied air pollutants.

RESULTS

The risk of LRTIs during the first 2 years of life was significantly related to exposure to individual and multiple air pollutants, measured with the Multipollutant Index (MPI), including primarily sulphur dioxide (SO2), particulate matter with a dry diameter of up to 2.5 µm (PM2.5) and nitrogen dioxide (NO2) exposures in the first year of life, with an adjusted IRR of 1.72 per unit increase in MPI (95% CI 1.20 to 2.47). LRTIs were not related to prenatal exposure.

CONCLUSIONS

We provide evidence that ambient air pollution exposure during the first year of life increases the risk of LRTIs during the first 2 years of life. SO2, PM2.5 and NO2 were found to contribute the highest weights on health effects.

Associations between community green view index and fine particulate matter from Airboxes

Urban greenery can help to improve air quality, reduce health risks and create healthy livable urban communities. This study aimed to explore the role of urban greenery in reducing air pollution at the community level in Tainan City, Taiwan, using air quality sensors and street-view imagery. We also collected the number of road trees around each air quality sensor site and identified the species that were best at absorbing PM2.5. Three greenness metrics were used to assess community greenery in this study: two Normalized Difference Vegetation Indices (NDVI) from different satellites and the Green View Index (GVI) from Google Street View (GSV) images. Land-use Regression (LUR) was used for statistical analysis. The results showed that a higher GVI within a 500 m buffer was significantly associated with decreased PM2.5. Neither NDVI metrics within a 500 m circular buffer were significantly associated with decreased PM2.5. Evergreen trees were significantly associated with lower ambient PM2.5, compared with deciduous and semi-deciduous trees. Because localized changes in air quality profoundly affect public health and environmental equity, our findings provide evidence for future urban community greenspace planning and its beneficial impacts on reducing air pollution.

Intrauterine and early postnatal exposures to submicron particulate matter and childhood allergic rhinitis: A multicity cross-sectional study in China

BACKGROUND

Airborne particulate matter pollution has been linked to occurrence of childhood allergic rhinitis (AR). However, the relationships between exposure to particulate matter with an aerodynamic diameter ≤1 μm (PM1) during early life (in utero and first year of life) and the onset of childhood AR remain largely unknown. This study aims to investigate potential associations of in utero and first-year exposures to size-segregated PMs, including PM1, PM1-2.5, PM2.5, PM2.5-10, and PM10, with childhood AR.

METHODS

We investigated 29286 preschool children aged 3-6 years in 7 Chinese major cities during 2019-2020 as the Phase II of the China Children, Families, Health Study. Machine learning-based space-time models were utilized to estimate early-life residential exposure to PM1, PM2.5, and PM10 at 1 × 1-km resolutions. The concentrations of PM1-2.5 and PM2.5-10 were calculated by subtracting PM1 from PM2.5 and PM2.5 from PM10, respectively. Multiple mixed-effects logistic models were used to assess the odds ratios (ORs) and 95% confidence intervals (CIs) of childhood AR associated with per 10-μg/m3 increase in exposure to particulate air pollution during in utero period and the first year of life.

RESULTS

Among the 29286 children surveyed (mean ± standard deviation, 4.9 ± 0.9 years), 3652 (12.5%) were reported to be diagnosed with AR. Average PM1 concentrations during in utero period and the first year since birth were 36.3 ± 8.6 μg/m3 and 33.1 ± 6.9 μg/m3, respectively. Exposure to PM1 and PM2.5 during pregnancy and the first year of life was associated with an increased risk of AR in children, and the OR estimates were higher for each 10-μg/m3 increase in PM1 than for PM2.5 (e.g., 1.132 [95% CI: 1.022-1.254] vs. 1.079 [95% CI: 1.014-1.149] in pregnancy; 1.151 [95% CI: 1.014-1.306] vs. 1.095 [95% CI: 1.008-1.189] in the first year of life). No associations were observed between AR and both pre- and post-natal exposure to PM1-2.5, indicating that PM1 rather than PM1-2.5 contributed to the association between PM2.5 and childhood AR. In trimester-stratified analysis, childhood AR was only found to be associated with exposure to PM1 (OR = 1.077, 95% CI: 1.027-1.128), PM2.5 (OR = 1.048, 95% CI: 1.018-1.078), and PM10 (OR = 1.032, 95% CI: 1.007-1.058) during the third trimester of pregnancy. Subgroup analysis suggested stronger PM-AR associations among younger (<5 years old) and winter-born children.

CONCLUSIONS

Prenatal and postnatal exposures to ambient PM1 and PM2.5 were associated with an increased risk of childhood AR, and PM2.5-related hazards could be predominantly attributed to PM1. These findings highlighted public health significance of formulating air quality guideline for ambient PM1 in mitigating children's AR burden caused by particulate air pollution.

Developmental Toxicity of Fine Particulate Matter: Multifaceted Exploration from Epidemiological and Laboratory Perspectives

Particulate matter of size ≤ 2.5 μm (PM2.5) is a critical environmental threat that considerably contributes to the global disease burden. However, accompanied by the rapid research progress in this field, the existing research on developmental toxicity is still constrained by limited data sources, varying quality, and insufficient in-depth mechanistic analysis. This review includes the currently available epidemiological and laboratory evidence and comprehensively characterizes the adverse effects of PM2.5 on developing individuals in different regions and various pollution sources. In addition, this review explores the effect of PM2.5 exposure to individuals of different ethnicities, genders, and socioeconomic levels on adverse birth outcomes and cardiopulmonary and neurological development. Furthermore, the molecular mechanisms involved in the adverse health effects of PM2.5 primarily encompass transcriptional and translational regulation, oxidative stress, inflammatory response, and epigenetic modulation. The primary findings and novel perspectives regarding the association between public health and PM2.5 were examined, highlighting the need for future studies to explore its sources, composition, and sex-specific effects. Additionally, further research is required to delve deeper into the more intricate underlying mechanisms to effectively prevent or mitigate the harmful effects of air pollution on human health.

Lung function changes in children exposed to mine fire smoke in infancy

BACKGROUND AND OBJECTIVE

Chronic, low-intensity air pollution exposure has been consistently associated with reduced lung function throughout childhood. However, there is limited research regarding the implications of acute, high-intensity air pollution exposure. We aimed to determine whether there were any associations between early life exposure to such an episode and lung growth trajectories.

METHODS

We conducted a prospective cohort study of children who lived in the vicinity of the Hazelwood coalmine fire. Lung function was measured using respiratory oscillometry. Z-scores were calculated for resistance (R5 ) and reactance at 5 Hz (X5 ) and area under the reactance curve (AX). Two sets of analyses were conducted: (i) linear regression to assess the cross-sectional relationship between post-natal exposure to mine fire-related particulate matter with an aerodynamic diameter of less than 2.5 micrometres (PM2.5 ) and lung function at the 7-year follow-up and (ii) linear mixed-effects models to determine whether there was any association between exposure and changes in lung function between the 3- and 7-year follow-ups.

RESULTS

There were no associations between mine fire-related PM2.5 and any of the lung function measures, 7-years later. There were moderate improvements in X5 (β: -0.37 [-0.64, -0.10] p = 0.009) and AX (β: -0.40 [-0.72, -0.08] p = 0.014), between the 3- and 7-year follow-ups that were associated with mean PM2.5 , in the unadjusted and covariance-adjusted models. Similar trends were observed with maximum PM2.5 .

CONCLUSION

There was a moderate improvement in lung stiffness of children exposed to PM2.5 from a local coalmine fire in infancy, consistent with an early deficit in lung function at 3-years after the fire that had resolved by 7-years.

Health effects of exposure to urban ambient particulate matter: A spatial-statistical study on 3rd-trimester pregnant women

Pregnant women are highly vulnerable to environmental stressors such as ambient particulate matter (PM). Particularly during their 3rd trimester, their bodies undergo significant oxidative stresses. To further consolidate this dialogue into practice, the current study evaluated healthy pregnant women (n = 150 housewives; 18-40 years old; gestation age >36 weeks) from the highly polluted city of Yazd, Iran, from September to November 2021. The aerosol optical depth (AOD) data retrieved from the Moderate Resolution Imaging Spectroradiometer (MODIS) were employed as influencing variables and validated using field-collected PM10 data (r = 0.62, p-value <0.01). The links between blood platelet count, enzymes (SGOT, SGPT, LDH, bilirubin), metabolic products (urea and acid uric) and different combinations of AOD data were assessed using the Generalized Additive Model. The results showed a high temporal variability in AOD (0.94 ± 0.51) but a spatially stable distribution pattern. The mean AOD during the 3rd trimester, followed by that of the three-month peak, were identified as the most significant non-linear predictors, while the mean AOD during the 1st trimester and throughout the entire pregnancy showed no significant associations with any of the biomarkers. Considering the associations found between AOD variables and maternal oxidative stresses, urgent planning is required to improve the urban air quality for sensitive subpopulations.

Association of Fetal Lung Development Disorders with Adult Diseases: A Comprehensive Review

Fetal lung development is a crucial and complex process that lays the groundwork for postnatal respiratory health. However, disruptions in this delicate developmental journey can lead to fetal lung development disorders, impacting neonatal outcomes and potentially influencing health outcomes well into adulthood. Recent research has shed light on the intriguing association between fetal lung development disorders and the development of adult diseases. Understanding these links can provide valuable insights into the developmental origins of health and disease, paving the way for targeted preventive measures and clinical interventions. This review article aims to comprehensively explore the association of fetal lung development disorders with adult diseases. We delve into the stages of fetal lung development, examining key factors influencing fetal lung maturation. Subsequently, we investigate specific fetal lung development disorders, such as respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), congenital diaphragmatic hernia (CDH), and other abnormalities. Furthermore, we explore the potential mechanisms underlying these associations, considering the role of epigenetic modifications, transgenerational effects, and intrauterine environmental factors. Additionally, we examine the epidemiological evidence and clinical findings linking fetal lung development disorders to adult respiratory diseases, including asthma, chronic obstructive pulmonary disease (COPD), and other respiratory ailments. This review provides valuable insights for healthcare professionals and researchers, guiding future investigations and shaping strategies for preventive interventions and long-term care.

A study of the relationship between rear-of-wheel particle emissions and close-proximity tire/road noise of a passenger car

Non-exhaust particulate emissions and road traffic noise will continue to constitute significant threats to the environment and human health during the 21st century. In the EU alone, >60 million adults are subjected to unhealthy levels of vehicle noise, while over 200,000 premature deaths are caused by chronic exposure to excessive concentrations of fine particles, with road traffic being a key source. Although these pollutants share common sources and can affect the same targets, studies have often treated their emissions separately. This study establishes both the phenomenological and mathematical relationships between tire/road noise (TRN) and rear-of-wheel particle (RoWP) emissions. Information from test track measurements, coupled with correlation-based models, enables linking TRN with RoWP emissions through variables such as vehicle speed and pavement properties, including macro-texture scales. A careful examination of the data reveals that pavement macro-texture acts as a crucible in which TRN and RoWP emissions are generated in an interrelated manner. However, at speeds over 70-80 km/h, the depletion of readily mobilizable RoWP fractions, followed by the emergence of refractory (hard-to-mobilize) circum-/super-micron RoWP fractions from resuspension (which accompanies the intensification of air-pumping TRN generation mechanisms), marks a loss of this interdependence. These results, supplemented by valuable insights into the particulate emission performance of pavements, serve to outline future air quality challenges and provide a basis for the simplified monitoring and control (e.g. through acoustic measurements) of RoWP emissions.

Nationwide estimation of daily ambient PM2.5 from 2008 to 2020 at 1 km2 in India using an ensemble approach

High-resolution assessment of historical levels is essential for assessing the health effects of ambient air pollution in the large Indian population. The diversity of geography, weather patterns, and progressive urbanization, combined with a sparse ground monitoring network makes it challenging to accurately capture the spatiotemporal patterns of ambient fine particulate matter (PM2.5) pollution in India. We developed a model for daily average ambient PM2.5 between 2008 and 2020 based on monitoring data, meteorology, land use, satellite observations, and emissions inventories. Daily average predictions at each 1 km × 1 km grid from each learner were ensembled using a Gaussian process regression with anisotropic smoothing over spatial coordinates, and regression calibration was used to account for exposure error. Cross-validating by leaving monitors out, the ensemble model had an R2 of 0.86 at the daily level in the validation data and outperformed each component learner (by 5-18%). Annual average levels in different zones ranged between 39.7 μg/m3 (interquartile range: 29.8-46.8) in 2008 and 30.4 μg/m3 (interquartile range: 22.7-37.2) in 2020, with a cross-validated (CV)-R2 of 0.94 at the annual level. Overall mean absolute daily errors (MAE) across the 13 years were between 14.4 and 25.4 μg/m3. We obtained high spatial accuracy with spatial R2 greater than 90% and spatial MAE ranging between 7.3-16.5 μg/m3 with relatively better performance in urban areas at low and moderate elevation. We have developed an important validated resource for studying PM2.5 at a very fine spatiotemporal resolution, which allows us to study the health effects of PM2.5 across India and to identify areas with exceedingly high levels.

Higher air pollution exposure in early life is associated with worse health among older adults: A 72-year follow-up study from Scotland

Air pollution increases the risk of mortality and morbidity. However, limited evidence exists on the very long-term associations between early life air pollution exposure and health, as well as on potential pathways. This study explored the relationship between fine particle (PM2.5) exposure at age 3 and limiting long-term illness (LLTI) at ages 55, 65 and 75 using data from the Scottish Longitudinal Study Birth Cohort 1936, a representative administrative cohort study. We found that early life PM2.5 exposure was associated with higher odds of LLTI in mid-to-late adulthood (OR = 1.10, 95% CI: 1.06, 1.14 per 10 μg m-3 increment) among the 2085 participants, with stronger associations among those growing up in disadvantaged families. Path analyses suggested that 15-21% of the association between early life PM2.5 concentrations and LLTI at age 65 (n = 1406) was mediated through childhood cognitive ability, educational qualifications, and adult social position. Future research should capitalise on linked administrative and health data, and explore causal mechanisms between environment and specific health conditions across the life course.

Particulate Matter Induces Oxidative Stress and Ferroptosis in Human Lung Epithelial Cells

Numerous toxicological studies have highlighted the association between urban particulate matter (PM) and increased respiratory infections and lung diseases. The adverse impact on the lungs is directly linked to the complex composition of particulate matter, initiating reactive oxygen species (ROS) production and consequent lipid peroxidation. Excessive ROS, particularly within mitochondria, can destroy subcellular organelles through various pathways. In this study, we confirmed the induction of ferroptosis, an iron-dependent cell death, upon exposure to an urban PM using RT-qPCR and signaling pathway analysis. We used KRISS CRM 109-02-004, the certified reference material for the analysis of particulate matter, produced by the Korea Research Institute of Standards and Science (KRISS). To validate that ferroptosis causes lung endothelial toxicity, we assessed intracellular mitochondrial potential, ROS overproduction, lipid peroxidation, and specific ferroptosis biomarkers. Following exposure to the urban PM, a significant increase in ROS generation and a decrease in mitochondrial potential were observed. Furthermore, it induced hallmarks of ferroptosis, including the accumulation of lipid peroxidation, the loss of antioxidant defenses, and cellular iron accumulation. In addition, the occurrence of oxidative stress as a key feature of ferroptosis was confirmed by increased expression levels of specific oxidative stress markers such as NQO1, CYP1B1, FTH1, SOD2, and NRF. Finally, a significant increase in key ferroptosis markers was observed, including xCT/SLC7A11, NQO1, TRIM16, HMOX-1, FTL, FTH1, CYP1B1, CHAC1, and GPX4. This provides evidence that elevated ROS levels induce oxidative stress, which ultimately triggers ferroptosis. In conclusion, our results show that the urban PM, KRISS CRM, induces cellular and mitochondrial ROS production, leading to oxidative stress and subsequent ferroptosis. These results suggest that it may induce ferroptosis through ROS generation and may offer potential strategies for the treatment of lung diseases.

WITHDRAWN: Exposure to Ambient Particulate Matter during Pregnancy: Implications for Infant Telomere Length

This manuscript has been withdrawn by the authors as it was submitted and made public without the full consent of all the authors. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author. The authors have an approved version for citation that is peer reviewed. Ahlers, N.E.; Lin, J.; Weiss, S.J. Exposure to Ambient Particulate Matter during Pregnancy: Implications for Infant Telomere Length. Air 2024, 2, 24-37. https://doi.org/10.3390/air2010002.

Updates in Air Pollution: Current Research and Future Challenges

Background

The United Nations has declared that humans have a right to clean air. Despite this, many deaths and disability-adjusted life years are attributed to air pollution exposure each year. We face both challenges to air quality and opportunities to improve, but several areas need to be addressed with urgency.

Objective

This paper summarises the recent research presented at the Pacific Basin Consortium for Environment and Health Symposium and focuses on three key areas of air pollution that are important to human health and require more research.

Findings and conclusion

Indoor spaces are commonly places of exposure to poor air quality and are difficult to monitor and regulate. Global climate change risks worsening air quality in a bi-directional fashion. The rising use of electric vehicles may offer opportunities to improve air quality, but it also presents new challenges. Government policies and initiatives could lead to improved air and environmental justice. Several populations, such as older people and children, face increased harm from air pollution and should become priority groups for action.

The impact of air pollutants on spontaneous abortion: a case-control study in Tongchuan City

OBJECTIVES

Studies related to air pollutants and spontaneous abortion in urban northwestern China are scarce, and the main exposure windows of pollutants acting on pregnant women are unclear.

STUDY DESIGN

Case-control study.

METHODS

Data were collected from pregnant women in Tongchuan City from 2018 to 2019. A total of 289 cases of spontaneous abortion and 1156 cases of full-term labor were included and analyzed using a case-control study. Logistic regression models were developed to explore the relationship between air pollutants and spontaneous abortion after Chi square analysis and Air pollutant description.

RESULTS

O3 (odds ratio [OR] = 1.028) is a risk factor for spontaneous abortion throughout pregnancy. PM2.5 (OR = 1.015), PM10 (OR = 1.010), SO2 (OR = 1.026), and NO2 (OR = 1.028) are risk factors for spontaneous abortion in the 30 days before the last menstrual period. PM2.5 (OR = 1.015), PM10 (OR = 1.013), SO2 (OR = 1.036), and NO2 (OR = 1.033) are risk factors for spontaneous abortion in the 30-60 days before the last menstrual period. PM2.5 (OR = 1.028), PM10 (OR = 1.013), SO2 (OR = 1.035), and NO2 (OR = 1.059) are risk factors for spontaneous abortion in the 60-90 days before the last menstrual period.

CONCLUSION

Exposure to high levels of air pollutants may be a cause of increased risk of spontaneous abortion, especially in the first trimester of the last menstrual period.

Prenatal Urban Environment and Blood Pressure Trajectories From Childhood to Early Adulthood

Background

Prenatal urban environmental exposures have been associated with blood pressure in children. The dynamic of these associations across childhood and later ages is unknown.

Objectives

The purpose of this study was to assess associations of prenatal urban environmental exposures with blood pressure trajectories from childhood to early adulthood.

Methods

Repeated measures of systolic blood pressure (SBP) and diastolic blood pressure (DBP) were collected in up to 7,454 participants from a UK birth cohort. Prenatal urban exposures (n = 43) covered measures of noise, air pollution, built environment, natural spaces, traffic, meteorology, and food environment. An exposome-wide association study approach was used. Linear spline mixed-effects models were used to model associations of each exposure with trajectories of blood pressure. Replication was sought in 4 independent European cohorts (up to 9,261).

Results

In discovery analyses, higher humidity was associated with a faster increase (mean yearly change in SBP for an interquartile range increase in humidity: 0.29 mm Hg/y, 95% CI: 0.20-0.39) and higher temperature with a slower increase (mean yearly change in SBP per interquartile range increase in temperature: -0.17 mm Hg/y, 95% CI: -0.28 to -0.07) in SBP in childhood. Higher levels of humidity and air pollution were associated with faster increase in DBP in childhood and slower increase in adolescence. There was little evidence of an association of other exposures with change in SBP or DBP. Results for humidity and temperature, but not for air pollution, were replicated in other cohorts.

Conclusions

Replicated findings suggest that higher prenatal humidity and temperature could modulate blood pressure changes across childhood.