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Background: Parametric g-computation is an attractive analytic framework to study the health effects of air pollution. Yet, the ability to explore biologically relevant exposure windows within this framework is underdeveloped., Objectives: We outline a novel framework for how to incorporate complex lag-responses using distributed lag models (DLMs) into parametric g-computation analyses for survival data. We call this approach "g-survival-DLM" and illustrate its use examining the association between PM 2.5 during pregnancy and the risk of preterm birth (PTB)., Methods: We applied the g-survival-DLM approach to estimate the hypothetical static intervention of reducing average PM 2.5 in each gestational week by 20% on the risk of PTB among 9,403 deliveries from Beth Israel Deaconess Medical Center, Boston, Massachusetts, 2011-2016. Daily PM 2.5 was taken from a 1 -km grid model and assigned to address at birth. Models were adjusted for sociodemographics, time trends, nitrogen dioxide, and temperature. To facilitate implementation, we provide a detailed description of the procedure and accompanying R syntax., Results: There were 762 (8.1%) PTBs in this cohort. The gestational week-specific median PM 2.5 concentration was relatively stable across pregnancy at ∼ 7 μ g / m 3 . We found that our hypothetical intervention strategy changed the cumulative risk of PTB at week 36 (i.e., the end of the preterm period) by - 0.009 (95% confidence interval: - 0.034 , 0.007) in comparison with the scenario had we not intervened, which translates to about 86 fewer PTBs in this cohort. We also observed that the critical exposure window appeared to be weeks 5-20., Discussion: We demonstrate that our g-survival-DLM approach produces easier-to-interpret, policy-relevant estimates (due to the g-computation); prevents immortal time bias (due to treating PTB as a time-to-event outcome); and allows for the exploration of critical exposure windows (due to the DLMs). In our illustrative example, we found that reducing fine particulate matter [particulate matter (PM) with aerodynamic diameter ≤ 2.5 μ m ( PM 2.5 )] during gestational weeks 5-20 could potentially lower the risk of PTB. https://doi.org/10.1289/EHP13891.

Objective: To examine the association between ambient temperature and antral follicle count (AFC), a standard measure of ovarian reserve., Design: Prospective cohort study., Setting: Fertility center at an academic hospital in the northeastern United States., Patient(s): 631 women attending the Massachusetts General Hospital Fertility Center (2005-2015) who participated in the Environment and Reproductive Health Study., Intervention(s): Daily temperature at the women's residential address was estimated for the 90 days before their antral follicle scan using a spatially refined gridded climate data set. We evaluated the associations between temperature and AFC using Poisson regression with robust standard errors, adjusting for relative humidity, fine particulate matter exposure, age, education, smoking status, year and month of AFC, and diagnosis of diminished ovarian reserve and ovulation disorders., Main Outcome Measure(s): Antral follicle count as measured with transvaginal ultrasonography., Result(s): A 1°C increase in average maximum temperature during the 90 days before ovarian reserve testing was associated with a -1.6% (95% confidence interval [CI], -2.8, -0.4) lower AFC. Associations remained negative, but were attenuated, for average maximum temperature exposure in the 30 days (-0.9%, 95% CI, -1.8, 0.1) and 14 days (-0.8%, 95% CI, -1.6, 0.0) before AFC. The negative association between average maximum temperature and AFC was stronger in November through June than during the summer months, suggesting that timing of heat exposure and acclimatization to heat may be important factors to consider in future research., Conclusion(s): Exposure to higher temperatures was associated with lower ovarian reserve. These results raise concern that rising ambient temperatures worldwide may result in accelerated reproductive aging among women., (Copyright © 2021 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)

Background: Individuals are exposed to air pollution and ionizing radiation from natural sources through inhalation of particles. This study investigates the association between cardiac arrhythmias and short-term exposures to fine particulate matter (particulate matter ≤2.5 µm aerodynamic diameter; PM 2.5 ) and particle radioactivity., Methods: Ventricular arrhythmic events were identified among 176 patients with dual-chamber implanted cardioverter-defibrillators in Boston, Massachusetts between September 2006 and June 2010. Patients were assigned exposures based on residential addresses. Daily PM 2.5 levels were estimated at 1-km×1-km grid cells from a previously validated prediction model. Particle gross β activity was used as a surrogate for particle radioactivity and was measured from several monitoring sites by the US Environmental Protection Agency's monitoring network. The association of the onset of ventricular arrhythmias (VA) with 0- to 21-day moving averages of PM 2.5 and particle radioactivity (2 single-pollutant models and a 2-pollutant model) before the event was examined using time-stratified case-crossover analyses, adjusted for dew point and air temperatures., Results: A total of 1,050 VA were recorded among 91 patients, including 123 sustained VA among 25 of these patients. In the single-pollutant model of PM 2.5 , each interquartile range increase in daily PM 2.5 levels for a 21-day moving average was associated with 39% higher odds of a VA event (95% CI, 12%-72%). In the single-pollutant model of particle radioactivity, each interquartile range increase in particle radioactivity for a 2-day moving average was associated with 13% higher odds of a VA event (95% CI, 1%-26%). In the 2-pollutant model, for the same averaging window of 21 days, each interquartile range increase in daily PM 2.5 was associated with an 48% higher odds of a VA event (95% CI, 15%-90%), and each interquartile range increase of particle radioactivity with a 10% lower odds of a VA event (95% CI, -29% to 14%). We found that with higher levels of particle radioactivity, the effect of PM 2.5 on VAs is reduced., Conclusions: In this high-risk population, intermediate (21-day) PM 2.5 exposure was associated with higher odds of a VA event onset among patients with known cardiac disease and indication for implanted cardioverter-defibrillator implantation independently of particle radioactivity.

Few studies examined the impact of maternal socioeconomic status and of its combined effects with environmental exposures on birthweight. Our goal was to examine the impact of maternal homelessness (mothers ever homeless or who lived in shelters during pregnancy) and participation in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) during pregnancy in conjunction with air pollution exposure on birthweight in the Boston-based Children's HealthWatch cohort from 2007 through 2015 (n = 3366). Birthweight was obtained from electronic health records. Information on maternal homelessness and WIC participation during pregnancy were provided via a questionnaire. Prenatal fine particulate matter (PM 2.5 ) exposures, estimated at the subject's residential address, were calculated for each trimester. We fit linear regression models adjusting for maternal and child characteristics, seasonality, and block-group-level median household income and examined the interactions between PM 2.5 and each covariate. Prenatal maternal homelessness was associated with reduced birthweight (-55.7 g, 95% CI: -97.8 g, -13.7 g), while participating in WIC was marginally associated with increased birthweight (36.1 g, 95% CI: -7.3 g, 79.4 g). Only average PM 2.5 during the second trimester was marginally associated with reduced birthweight (-8.5 g, 95% CI: -19.3, 2.3) for a 1 µg/m 3 increase in PM 2.5 . The association of PM 2.5 during the second trimester with reduced birthweight was stronger among non-Hispanic Black mothers and trended toward significance among immigrants and single mothers. Our study emphasizes the independent and synergistic effects of social and environmental stressors on birthweight, particularly the potentially protective effect of participating in WIC for vulnerable populations.

Background: It is not known whether environmental gamma radiation measured in US cities has detectable adverse health effects. We assessed whether short-term exposure to gamma radiation emitted from ambient air particles [gamma particle activity (PRγ)] is associated with reduced pulmonary function in chronic obstructive pulmonary disease (COPD) patients., Objective: We hypothesize that the inhalation of gamma radiation emitted from ambient air particles may be associated with reduced pulmonary function in individuals with COPD., Methods: In 125 patients with COPD from Eastern Massachusetts who had up to 4 seasonal one-week assessments of particulate matter ≤2.5 μm (PM 2.5 ), black carbon (BC), and sulfur followed by spirometry. The US EPA continuously monitors ambient gamma (γ) radiation including γ released from radionuclides attached to particulate matter that is recorded as 9 γ-energy spectra classes (i = 3-9) in counts per minute (CPMγ) in the Boston area (USA). We analyzed the associations between ambient and indoor PRγi (up to one week) and pre and post-bronchodilator (BD) forced expiratory volume in 1 s (FEV 1 ) and with forced vital capacity (FVC) using mixed-effects regression models. We estimated indoor PRγi using the ratio of the indoor-to-outdoor sulfur in PM 2.5 as a proxy for infiltration of ambient radionuclide-associated particles., Results: Overall, exposures to ambient and indoor PRγi were associated with a similar decrease in pre- and post-BD FEV 1 and FVC. For example, ambient PRγ 3 exposure averaged from the day of pulmonary function testing through the previous 3 days [IQR of 55.1 counts per minute (CPMγ)] was associated with a decrease in pre-BD FEV 1 of 21.0 ml (95%CI: -38.5 to -3.0 ml; p < 0.01) and pre-BD FVC of 27.5 ml [95% confidence interval (CI): -50.7 to -5.0 ml; p < 0.01] with similar effects adjusting for indoor and outdoor BC and PM 2.5 ., Conclusion: Our results show that short-term ambient and indoor exposures to environmental gamma radiation associated with particulate matter are associated with reduced pre- and post-BD pulmonary function in patients with COPD., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: A few studies suggest that air pollution may decrease fertility, but prospective studies and examinations of windows of susceptibility remain unclear., Objective: We aimed to examine the association between time-varying exposure to nitrogen dioxide ([Formula: see text]), ozone ([Formula: see text]), fine particulate matter [Formula: see text] ([Formula: see text]), and black carbon (BC) on in vitro fertilization (IVF) outcomes., Methods: We included 345 women (522 IVF cycles) for the [Formula: see text], [Formula: see text], and [Formula: see text] analyses and 339 women (512 IVF cycles) for the BC analysis enrolled in a prospective cohort at a Boston fertility center (2004–2015). We used validated spatiotemporal models to estimate daily residential exposure to [Formula: see text], [Formula: see text], [Formula: see text], and BC. Multivariable discrete time Cox proportional hazards models with four periods [ovarian stimulation (OS), oocyte retrieval to embryo transfer (ET), ET to implantation, implantation to live birth] estimated odds ratios (OR) and 95% confidence intervals (CI) of failing at IVF. Time-dependent interactions were used to identify vulnerable periods., Results: An interquartile range (IQR) increase in [Formula: see text], [Formula: see text], and BC throughout the IVF cycle was associated with an elevated odds of failing at IVF prior to live birth ([Formula: see text], 95% CI: 0.95, 1.23 for [Formula: see text]; [Formula: see text], 95% CI: 0.88, 1.28 for [Formula: see text]; and [Formula: see text], 95% CI: 0.96, 1.41 for BC). This relationship significantly varied across the IVF cycle such that the association with higher exposure to air pollution during OS was strongest for early IVF failures. An IQR increase in [Formula: see text], [Formula: see text], and BC exposure during OS was associated with 1.42 (95% CI: 1.20, 1.69), 1.26 (95% CI: 0.96, 1.67), and 1.23 (95% CI: 0.96, 1.59) times the odds of failing prior to oocyte retrieval, and 1.32 (95% CI: 1.13, 1.54), 1.27 (95% CI: 0.98, 1.65), and 1.32 (95% CI: 1.10, 1.59) times the odds of failing prior to ET., Conclusion: Increased exposure to traffic-related pollutants was associated with higher odds of early IVF failure. https://doi.org/10.1289/EHP4601.

Background: The few previous studies on the onset of paroxysmal atrial fibrillation and meteorologic conditions have focused on outdoor temperature and hospital admissions, but hospital admissions are a crude indicator of atrial fibrillation incidence, and studies have found other weather measures in addition to temperature to be associated with cardiovascular outcomes., Methods: Two hundred patients with dual chamber implantable cardioverter-defibrillators were enrolled and followed prospectively from 2006 to 2010 for new onset episodes of atrial fibrillation. The date and time of arrhythmia episodes documented by the implanted cardioverter-defibrillators were linked to meteorologic data and examined using a case-crossover analysis. We evaluated associations with outdoor temperature, apparent temperature, air pressure, and three measures of humidity (relative humidity, dew point, and absolute humidity)., Results: Of the 200 enrolled patients, 49 patients experienced 328 atrial fibrillation episodes lasting ≥30 seconds. Lower temperatures in the prior 48 hours were positively associated with atrial fibrillation. Lower absolute humidity (ie, drier air) had the strongest and most consistent association: each 0.5 g/m decrease in the prior 24 hours increased the odds of atrial fibrillation by 4% (95% confidence interval [CI]: 0%, 7%) and by 5% (95% CI: 2%, 8%) for exposure in the prior 2 hours. Results were similar for dew point but slightly weaker., Conclusions: Recent exposure to drier air and lower temperatures were associated with the onset of atrial fibrillation among patients with known cardiac disease, supporting the hypothesis that meteorologic conditions trigger acute cardiovascular episodes.

Outdoor ambient weather has been hypothesized to be responsible for the seasonal distribution of cardiac arrhythmias. Because people spend most of their time indoors, we hypothesized that weather-related arrhythmia risk would be better estimated using an indoor measure or an outdoor measure that correlates well with indoor conditions, such as absolute humidity. The clinical records of 203 patients in eastern Massachusetts, USA, with an implantable cardioverter-defibrillator were abstracted for arrhythmias between 1995 and 2002. We used case-crossover methods to examine the association between weather and ventricular arrhythmia (VA). Among 84 patients who experienced 787 VAs, lower estimated indoor temperature (odds ratio (OR)=1.16, 95% confidence interval (CI) 1.05-1.27 for a 1 °C decrease in the 24-h average) and lower absolute humidity (OR=1.06, 95% CI 1.03-1.08 for a 0.5 g/m(3) decrease in the 96-h average) were associated with increased risk. Lower outdoor temperature increased risk only in warmer months, likely attributable to the poor correlation between outdoor and indoor temperature during cooler months. These results suggest that lower temperature and drier air are associated with increased risk of VA onset among implantable cardioverter-defibrillator patients.

Objective: Chronic psychosocial stressors, including violence, and neuropsychological and behavioral development in children as well as physiologic alterations that may lead to broader health effects., Methods: We studied the relationship between violence and childhood lung function in a prospective birth cohort of 313 urban children (age range = 6-7 years). Mothers reported on their child's lifetime exposure to community violence (ETV) and interparental conflict in the home (Conflict Tactics Scale (CTS)) within 1 year of the lung function assessment., Results: In linear regression analyses, adjusting for maternal education, child's age, race, birthweight, tobacco smoke exposure, and medical history, girls in the highest CTS verbal aggression tertile had a 5.5% (95% confidence interval (CI) = -9.6, -1.5) decrease in percent predicted forced expiratory volume (FEV(1)) and a 5.4% (95% CI = -9.7, -1.1) decrease in forced vital capacity (FVC) compared with girls in the lowest tertile. The CTS verbal aggression subscale was associated with lung function among boys in the same direction, albeit this was not statistically significant. Boys in the highest ETV tertile had a 3.4% (95% CI = -8.0, 1.1) lower FEV(1) and 5.3% lower FVC (95% CI = -10.2, -0.4) compared with boys in the lowest tertile. The ETV score was not a significant predictor of girls' lung function., Conclusions: Interparental conflict, specifically verbal aggression, and ETV were associated with decreased childhood lung function independent of socioeconomic status, tobacco smoke exposure, birthweight, and respiratory illness history. Gender differences were noted based on the type of violence exposure, which may warrant further exploration.

Air pollution exposure patterns may contribute to known spatial patterning of asthma morbidity within urban areas. While studies have evaluated the relationship between traffic and outdoor concentrations, few have considered indoor exposure patterns within low socioeconomic status (SES) urban communities. In this study, part of a prospective birth cohort study assessing asthma etiology in urban Boston, we collected indoor and outdoor 3-4 day samples of nitrogen dioxide (NO2) and fine particulate matter (PM2.5) in 43 residences across multiple seasons from 2003 to 2005. Homes were chosen to represent low SES households, including both cohort and non-cohort residences in similar neighborhoods, and consisted almost entirely of multiunit residences. Reflectance analysis and X-ray fluorescence spectroscopy were performed on the particle filters to determine elemental carbon (EC) and trace element concentrations, respectively. Additionally, information on home characteristics (e.g. type, age, stove fuel) and occupant behaviors (e.g. smoking, cooking, cleaning) were collected via a standardized questionnaire. The contributions of outdoor and indoor sources to indoor concentrations were quantified with regression analyses using mass balance principles. For NO2 and most particle constituents (except outdoor-dominated constituents like sulfur and vanadium), the addition of selected indoor source terms improved the model's predictive power. Cooking time, gas stove usage, occupant density, and humidifiers were identified as important contributors to indoor levels of various pollutants. A comparison between cohort and non-cohort participants provided another means to determine the influence of occupant activity patterns on indoor-outdoor ratios. Although the groups had similar housing characteristics and were located in similar neighborhoods, cohort members had significantly higher indoor concentrations of PM2.5 and NO2, associated with indoor activities. We conclude that the effect of indoor sources may be more pronounced in high-density multiunit dwellings, and that future epidemiological studies in these populations should explicitly consider these sources in assigning exposures.