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In the United States (US), neonatal intensive care units (NICUs) monitor and treat newborns for a variety of adverse health concerns including preterm status, respiratory distress and restricted growth. As such, NICU admission is an integrated measure of neonatal risk. We linked 2018 US national birth registry NICU admission data among singleton births with satellite and modelled air pollution levels for the month prior to birth to examine whether late-pregnancy exposure to ambient air pollutants is associated with adverse neonatal health outcomes. Regardless of season, higher ambient levels of nitrogen dioxide (NO2) and fine particulate matter < 2.5 microns (PM2.5) increased the likelihood of NICU admission 30–35% for NO2 and 11–22% for PM2.5 even after adjustment for parental characteristics. Results for ozone exposure were inconsistent with largely null or reduced risk except for summer months. Despite the relatively low-moderate US exposure levels, traffic-related pollutants near the end of pregnancy appear to increase overall adverse health risks for newborns, underscoring the need to reduce prenatal exposure to ambient pollutants.

Published Jan 2, 2025

Phiri, Y. V. A., Canty, T., Nobles, C., Ring, A. M., Nie, J., & Mendola, P. (2025). Neonatal intensive care admissions and exposure to satellite-derived air pollutants in the United States, 2018. Scientific Reports 2024 15:1, 15(1), 420-. https://doi.org/10.1038/s41598-024-84755-9

Background
A growing body of epidemiologic and toxicologic literature indicates that fine airborne particulate matter (PM2.5) pollution is neurotoxic and threatens children’s neurobehavioral development, resulting in reduced cognitive function. Understanding the magnitude of this effect is critical for establishing public health policies that will protect children’s health, preserve human capital, and support societal progress.

Objective
To quantify the association between ambient PM2.5 air pollution and loss of cognitive function in children, as measured by Intelligence Quotient (IQ) scores, through a systematic literature review and meta-analysis.

Methods
Following PRISMA guidelines, we conducted a systematic literature search across seven databases: Agricultural and Environmental Science, BIOSIS Citation Index, Embase, GreenFILE, PubMed, Scopus, and Web of Science to identify original scientific studies that investigated the impact of PM2.5 exposure during pre-and postnatal periods on IQ loss during childhood. Using data from studies included for final review, we conducted a meta-analysis, using a random effects model to compute a beta coefficient that quantifies the overall effect of PM2.5 exposure on Full-Scale IQ (FSIQ), Performance IQ (PIQ), and Verbal IQ (VIQ).

Findings
Of the 1,107 unique publications identified, six studies met the inclusion criteria for final review, representing 4,860 children across three continents (North America, Europe, and Asia). The mean PM2.5 concentration across all studies was 30.4 ± 24.4 µg/m3. Exposure timing ranged from the prenatal period to mid-childhood. Children were an average of 8.9 years old at the time of cognitive testing. We found that each 1 µg/m3 increase in PM2.5 concentration is associated with a -0.27 point change in FSIQ (p < 0.001), 0.39 point change in PIQ (p = 0.003), and -0.24 point change in VIQ (p = 0.021). Conclusion Through a systematic review and meta-analysis, we identified a statistically significant relationship between increased exposure to PM2.5 air pollution and reduced cognitive function in children, with the most pronounced impact on PIQ. This analysis will enable estimation of the burden of adverse neurobehavioral development attributable to PM2.5 in pediatric populations and will inform local and global strategies for exposure prevention.

Published Dec 1, 2024

Alter, N. C., Whitman, E. M., Bellinger, D. C., & Landrigan, P. J. (2024). Quantifying the association between PM2.5 air pollution and IQ loss in children: a systematic review and meta-analysis. Environmental Health: A Global Access Science Source, 23(1), 1–17. https://doi.org/10.1186/S12940-024-01122-X/TABLES/8

Background:
Though observational studies have widely linked air pollution exposure to various chronic diseases, evidence comparing different exposures in the same people is limited. This study examined associations between changes in air pollution exposure due to relocation and the incidence and mortality of 14 major diseases.
Methods:
We included 50,522 participants enrolled in the UK Biobank from 2006 to 2010. Exposures to particulate matter with a diameter ≤2.5μ⁢m (PM2.5), particulate matter with a diameter ≤10μ⁢m (PM10), nitrogen oxides (NOx), nitrogen dioxide (NO2), and sulfur dioxide (SO2) were estimated for each participant based on their residential address and relocation experience during the follow-up. Nine exposure groups were classified based on changes in long-term exposures due to residential mobility. Incidence and mortality of 14 major diseases were identified through linkages to hospital inpatient records and death registries. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for incidence and mortality of the 14 diseases of interest.
Results:
During a median follow-up of 12.6 years, 29,869 participants were diagnosed with any disease of interest, and 3,144 died. Significantly increased risk of disease and all-cause mortality was observed among individuals who moved from a lower to higher air polluted area. Compared with constantly low exposure, moving from low to moderate PM2.5 exposure was associated with increased risk of all 14 diseases but not for all-cause mortality, with adjusted HRs (95% CIs) ranging from 1.18 (1.05, 1.33) to 1.48 (1.30, 1.69); moving from low to high PM2.5 areas increased risk of all 14 diseases: infections [1.37 (1.19, 1.58)], blood diseases [1.57 (1.34, 1.84)], endocrine diseases [1.77 (1.50, 2.09)], mental and behavioral disorders [1.93 (1.68, 2.21)], nervous system diseases [1.51 (1.32, 1.74)], ocular diseases [1.76 (1.56, 1.98)], ear disorders [1.58 (1.35, 1.86)], circulatory diseases [1.59 (1.42, 1.78)], respiratory diseases [1.51 (1.33, 1.72)], digestive diseases [1.74 (1.58, 1.92)], skin diseases [1.39 (1.22, 1.58)], musculoskeletal diseases [1.62 (1.45, 1.81)], genitourinary diseases [1.54 (1.36, 1.74)] and cancer [1.42 (1.24, 1.63)]. We observed similar associations for PM10 and SO2 with 14 diseases (but not with all-cause mortality); increases in NO2 and NOx were positively associated with 14 diseases and all-cause mortality.
Conclusions:
This study supports potential associations between ambient air pollution exposure and morbidity as well as mortality. Findings also emphasize the importance of maintaining consistently low levels of air pollution to protect the public’s health.

Published Sep 30, 2024

Chen, G., Qian, Z., Zhang, J., Wang, X., Zhang, Z., Cai, M., Arnold, L. D., Abresch, C., Wang, C., Liu, Y., Fan, Q., & Lin, H. (2024). Associations between Changes in Exposure to Air Pollutants due to Relocation and the Incidence of 14 Major Disease Categories and All-Cause Mortality: A Natural Experiment Study. Environmental Health Perspectives, 132(9), 097012-1-097012–12. https://doi.org/10.1289/EHP14367

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

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

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

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

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

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

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

Published May 28, 2024

Newbury, J. B., Heron, J., Kirkbride, J. B., Fisher, H. L., Bakolis, I., Boyd, A., Thomas, R., & Zammit, S. (2024). Air and Noise Pollution Exposure in Early Life and Mental Health From Adolescence to Young Adulthood. JAMA Network Open, 7(5), e2412169–e2412169. https://doi.org/10.1001/JAMANETWORKOPEN.2024.12169

Electric school buses have been proposed as an alternative to reduce the health and climate impacts of the current U.S. school bus fleet, of which a substantial share are highly polluting old diesel vehicles. However, the climate and health benefits of electric school buses are not well known. As they are substantially more costly than diesel buses, assessing their benefits is needed to inform policy decisions. We assess the health benefits of electric school buses in the United States from reduced adult mortality and childhood asthma onset risks due to exposure to ambient fine particulate matter (PM2.5). We also evaluate climate benefits from reduced greenhouse-gas emissions. We find that replacing the average diesel bus in the U.S. fleet in 2017 with an electric bus yields $84,200 in total benefits. Climate benefits amount to $40,400/bus, whereas health benefits amount to $43,800/bus due to 4.42*10−3 fewer PM2.5-attributable deaths ($40,000 of total) and 7.42*10−3 fewer PM2.5-attributable new childhood asthma cases ($3,700 of total). However, health benefits of electric buses vary substantially by driving location and model year (MY) of the diesel buses they replace. Replacing old, MY 2005 diesel buses in large cities yields $207,200/bus in health benefits and is likely cost-beneficial, although other policies that accelerate fleet turnover in these areas deserve consideration. Electric school buses driven in rural areas achieve small health benefits from reduced exposure to ambient PM2.5. Further research assessing benefits of reduced exposure to in-cabin air pollution among children riding buses would be valuable to inform policy decisions.

Published May 20, 2024

Choma, E. F., Robinson, L. A., & Nadeau, K. C. (2024). Adopting electric school buses in the United States: Health and climate benefits. Proceedings of the National Academy of Sciences of the United States of America, 121(22), e2320338121. https://doi.org/10.1073/PNAS.2320338121/SUPPL_FILE/PNAS.2320338121.SD06.CSV

Importance: Students who ride older school buses are often exposed to high levels of exhaust during their commutes, which may adversely affect health and school attendance. As a result, the US Environmental Protection Agency (EPA) has awarded millions of dollars to school districts to replace older, highly polluting school buses with newer, cleaner buses.

Objective: To leverage the EPA’s randomized allocation of funding under the 2012-2016 School Bus Rebate Programs to estimate the association between replacing old, highly polluting buses and changes in district-average standardized test scores.

Design, Setting, and Participants: This study examined changes in reading and language arts (RLA) and math test scores among US school district applicants to the EPA’s 2012-2016 national School Bus Rebate Programs 1 year before and after each lottery by selection status. Data analysis was conducted from January 15 to July 30, 2023.

Exposure: Selection to receive EPA funding to replace older school buses with newer, cleaner alternatives.

Main Outcomes and Measures: School district changes in RLA and math test scores among students in grades 3 through 8 before and after the EPA funding lotteries by selection status were measured using an intention-to-treat approach.

Results: This study included 1941 school district applicants to the 2012-2106 EPA School Bus Rebate Programs. These districts had a mean (SD) of 14.6 (33.7) schools per district, 8755 (23 776) students per district, and 41.3% (20.2%) of students with free lunch eligibility. Among the applicants, 209 districts (11%) were selected for the clean bus funding. District-average student test scores did not improve among selected districts overall. In secondary analyses, however, districts replacing the oldest, highest polluting buses (ie, pre-1990) experienced significantly greater improvements in district-average test scores in the year after the lottery for RLA and math (SD improvement in test scores, 0.062 [95% CI, 0.050-0.074] and 0.025 [95% CI, 0.011-0.039], respectively) compared with districts without replacements.

Conclusions and Relevance: In this study, the EPA funding was not associated with student test scores overall, but in secondary analyses, the replacement of the oldest school buses was associated with improved educational performance. These findings support prioritizing clean bus replacement of the oldest buses as an actionable way for improving students’ educational performance.

Published Mar 20, 2024

Pedde, M., Szpiro, A., Hirth, R. A., & Adar, S. D. (2024). School Bus Rebate Program and Student Educational Performance Test Scores. JAMA Network Open, 7(3), e243121–e243121. https://doi.org/10.1001/JAMANETWORKOPEN.2024.3121

Background:
Respiratory distress is the leading cause of neonatal morbidity and mortality worldwide, and prenatal exposure to air pollution is associated with adverse long-term respiratory outcomes; however, the impact of prenatal air pollution exposure on neonatal respiratory distress has not been well studied.
Objectives:
We examined associations between prenatal exposures to fine particular matter (PM2.5) and nitrogen dioxide (NO2) with respiratory distress and related neonatal outcomes.
Methods:
We used data from the Maternal–Infant Research on Environmental Chemicals (MIREC) Study, a prospective pregnancy cohort (𝑛=2,001) recruited in the first trimester from 10 Canadian cities. Prenatal exposures to PM2.5 (𝑛=1,321) and NO2 (𝑛=1,064) were estimated using land-use regression and satellite-derived models coupled with ground-level monitoring and linked to participants based on residential location at birth. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) for associations between air pollution and physician-diagnosed respiratory distress in term neonates in hierarchical logistic regression models adjusting for detailed maternal and infant covariates.
Results:
Approximately 7% of newborns experienced respiratory distress. Neonates received clinical interventions including oxygen therapy (6%), assisted ventilation (2%), and systemic antibiotics (3%). Two percent received multiple interventions and 4% were admitted to the neonatal intensive care unit (NICU). Median PM2.5 and NO2 concentrations during pregnancy were 8.81⁢ μ⁢g/m3 and 18.02 ppb, respectively. Prenatal exposures to air pollution were not associated with physician-diagnosed respiratory distress, oxygen therapy, or NICU admissions. However, PM2.5 exposures were strongly associated with assisted ventilation (OR per 1-μ⁢g/m3 increase in PM2.5=1.17; 95% CI: 1.02, 1.35), multiple clinical interventions (OR per 1⁢-μ⁢g/m3 increase in PM2.5=1.16; 95% CI: 1.07, 1.26), and systemic antibiotics, (OR per 1⁢-μ⁢g/m3 increase in PM2.5=1.12; 95% CI: 1.04, 1.21). These associations were consistent across exposure periods—that is, during prepregnancy, individual trimesters, and total pregnancy—and robust to model specification. NO2 exposure was associated with administration of systemic antibiotics (OR per 1-ppb increase in NO2=1.03; 95% CI: 1.00, 1.06).
Discussion:
Prenatal exposures to PM2.5 increased the risk of severe respiratory distress among term newborns. These findings support the development and prioritization of public health and prenatal care strategies to increase awareness and minimize prenatal exposures to air pollution.

Published Jan 25, 2024

Johnson, M., Mazur, L., Fisher, M., Fraser, W. D., Sun, L., Hystad, P., & Gandhi, C. K. (2024). Prenatal Exposure to Air Pollution and Respiratory Distress in Term Newborns: Results from the MIREC Prospective Pregnancy Cohort. Environmental Health Perspectives, 132(1). https://doi.org/10.1289/EHP12880

Air pollution is responsible worldwide for 9-12 million deaths annually. The major contributor to air pollution is particulate matter ≤2.5 µg per cubic meter of air (PM2.5) from vehicles, industrial emissions, and wildfire smoke. United States ambient air standards recommend annual average PM2.5 concentrations of ≤12 μg/m³ while European standards allow an average annual PM2.5 concentration of ≤20 μg/m3. However, significant PM2.5 cardiovascular and pulmonary health risks exist below these concentrations. Chronic PM2.5 exposure significantly increases major cardiovascular and pulmonary event risks in Americans by 8 to more than 20% for each 10-μg/m3 increase in PM2.5. PM2.5-induced increases in lipid peroxidation, induction of vascular inflammation and endothelial cell injury initiate and propagate respiratory diseases, coronary and carotid atherosclerosis. PM2.5 can cause atherosclerotic vascular plaque rupture and myocardial infarction and stroke by activating metalloproteinases. This article discusses PM2.5 effects on the cardiovascular and pulmonary systems, specific PM2.5 pathophysiologic mechanisms contributing to cardiopulmonary disease, and preventive measures to limit the cardiovascular and pulmonary effects of PM2.5.

Published Jan 1, 2024

Henning, R. J. (2024). Particulate Matter Air Pollution is a Significant Risk Factor for Cardiovascular Disease. Current Problems in Cardiology, 49(1), 102094. https://doi.org/10.1016/j.cpcardiol.2023.102094

Elevated exposure to ambient fine particulate matter (PM2.5) has been consistently associated with adverse outcomes on children’s test scores.1 However, previous research has often relied on relatively small or less representative samples and faced challenges in accounting for unobserved confounders at the individual level.2 In this cross-sectional study, we aimed to address these limitations by employing a 2-way fixed-effects model with a large administrative data set in North Carolina.

Published Oct 31, 2023

Lam, P. H., Zang, E., Chen, D., Liu, R., & Chen, K. (2023). Long-Term Exposure to Fine Particulate Matter and Academic Performance Among Children in North Carolina. JAMA Network Open, 6(10), e2340928–e2340928. https://doi.org/10.1001/JAMANETWORKOPEN.2023.40928

Approximately 25 million children ride buses to school in the United States. While school buses are the safest school transport from an accident perspective, older buses often expose students to high levels of diesel exhaust. Because these exposures can adversely impact health, which may lead to more missed school, the US Environmental Protection Agency (EPA) has spent millions of dollars to hasten the transition of school bus fleets to cleaner vehicles. Here, we leveraged the randomized allocation of the EPA’s 2012–2017 School Bus Rebate Program funding to causally assess the district attendance impacts of upgrading buses. Districts randomly selected for funding had greater attendance improvements after the lottery than unselected districts, resulting in over 350,000 estimated additional student days of attendance each year (95% confidence interval = −70,678 to 772,865) due to the use of EPA funds. Attendance improvements were greatest when the oldest buses were replaced and for districts with high ridership on applicant buses. Extrapolating our results nationwide, we expect that the replacement of all pre-2000 model year school buses would lead to more than 1.3 million additional student days of attendance per year (95% confidence interval = 247,443 to 2,406,511). Given the importance of attendance to educational success, we conclude that increasing the pace at which older, highly polluting buses are replaced positively impacts student attendance.

Published Apr 10, 2023

Pedde, M., Szpiro, A., Hirth, R., & Adar, S. D. (2023). Randomized design evidence of the attendance benefits of the EPA School Bus Rebate Program. Nature Sustainability, 6(7), 838–844. https://doi.org/10.1038/S41893-023-01088-7;SUBJMETA