Background: An increasing number of studies have linked air pollution to decreased fertility. Whether this is due to an effect on ovarian reserve is unknown. Method: Our study included 632 women attending the Massachusetts General Hospital Fertility Center (2004–2015) who had a measured antral follicle count. Validated spatiotemporal models estimated daily particulate matter <2.5 µg/m³ (PM_2.5) (based on residential address) for the 3 months before the antral follicle count. We analyzed associations with Poisson regression. Results: Every 2 µg/m³ increase in estimated PM_2.5 exposure was associated with a −7.2% (95% confidence interval = −10.4%, −3.8%) lower antral follicle count adjusting for age, body mass index, smoking status, and year and season of the count. The association of PM_2.5 with antral follicle count was stronger among women with female factor infertility (−16.3% per 2 µg/m³). Conclusions: Among women from an infertility clinic, higher PM_2.5 exposure was associated with lower ovarian reserve, raising concern that air pollution may accelerate reproductive aging.

Background: Studies have long associated PM2.5 with daily mortality, but few applied causal-modeling methods, or at low exposures. Short-term exposure to NO2, a marker of local traffic, has also been associated with mortality but is less studied. We previously found a causal effect between local air pollution and mortality in Boston. Objectives: We aimed to estimate the causal effects of local pollution, PM2.5, and NO2 on mortality in 135 U.S. cities. Methods: We used three methods which, under different assumptions, provide causal marginal estimates of effect: a marginal structural model, an instrumental variable analysis, and a negative exposure control. The instrumental approach used planetary boundary layer, wind speed, and air pressure as instruments for concentrations of local pollutants; the marginal structural model separated the effects of NO2 from the effects of PM2.5, and the negative exposure control provided protection against unmeasured confounders. Results: In 7.3 million deaths, the instru...

Features of the environment may modify the effect of particulate matter ≤2.5 µm in aerodynamic diameter (PM_2.5) on health. Therefore, we investigated how neighborhood sociodemographic and land-use characteristics may modify the association between PM_2.5 and cardiovascular mortality. We obtained residence-level geocoded cardiovascular mortality cases from the Massachusetts Department of Public Health (n = 179,986), and PM_2.5 predictions from a satellite-based model (2001–2011). We appended census block group-level information on sociodemographic factors and walkability, and calculated neighborhood greenness within a 250 m buffer surrounding each residence. We found a 2.54% (1.34%; 3.74%) increase in cardiovascular mortality associated with a 10 µg/m³ increase in two-day average PM_2.5. Walkability or greenness did not modify the association. However, when stratifying by neighborhood sociodemographic characteristics, smaller PM_2.5 effects were observed in greener areas only among cases who resided in neighborhoods with a higher population density and lower percentages of white residents or residents with a high school diploma. In conclusion, the PM_2.5 effects on cardiovascular mortality were attenuated by higher greenness only in areas with sociodemographic features that are highly correlated with lower socioeconomic status. Previous evidence suggests health benefits linked to neighborhood greenness may be stronger among lower socioeconomic groups. Attenuation of the PM_2.5–mortality relationship due to greenness may explain some of this evidence.

Environmental Health Perspectives is an Open Access journal published by the National Institute of Environmental Health Sciences. Environmental Health Perspectives is an Open Access journal published by the National Institute of Environmental Health Sciences.

Natural vegetation, or greenness, may benefit maternal health and consequently, fetal growth, by providing opportunities for physical activity and psychological restoration, and decreasing detrimental environmental exposures. We retrieved Massachusetts Birth Registry data from 2001–2013 and investigated the association between residential greenness and birthweight in full-term births (≥37 weeks gestation). We calculated average residential greenness during pregnancy using 250 m normalized difference vegetation index (NDVI) from satellites. We estimated associations between greenness and continuous birthweight, term low birthweight (TLBW: <2500 g), and small for gestational age (SGA: <10th percentile of birthweight stratified by sex and gestational age) adjusted for individual and neighborhood covariates and considered nonlinearity and effect modification. Higher greenness exposure was associated with higher birthweight with stronger associations in the lower than higher range of greenness. Greenness was associated with lower odds of TLBW (OR 0.98; 95% CI 0.97, 0.99 per 0.1 increase in NDVI) and SGA (OR 0.98; 95% 0.97, 0.99) and associations varied by population density (TLBW) and socioeconomic status (TLBW, SGA). Our results suggest that greenness is beneficial to fetal growth exhibited by higher birthweight and lower odds of TLBW and SGA. Unlike prior studies, associations with TLBW and SGA appeared stronger among those with higher socioeconomic status.