Exposure to Particulate Matter Air Pollution and Age of Menarche in a Nationwide Cohort of U.S. Girls

Background: It remains unclear whether in utero and childhood exposure to air pollution affects pubertal development, particularly age of menarche in girls. Objective: The aim of this study was to determine whether residential ambient particulate matter (PM) exposure in utero and during childhood is associated with age of menarche. Methods: We studied 5,201 girls in the Growing Up Today Study 2 (2004–present) who were 10–17 y of age at enrollment (47.7% premenarchal; 52.3% postmenarchal). Exposure to three size fractions of PM [fine PM with aerodynamic diameter ≤2.5μm (PM2.5), PM with aerodynamic diameters between 2.5μm and 10μm (PM2.5–10), and PM with aerodynamic diameter 10μm (PM10)] was assigned based on maternal residential address, updated every 2 y, using nationwide spatiotemporal models. We estimated average PM exposure in utero, and time-varying windows: annual average exposure in the prior 1 and 2 y and cumulative average from birth. Age of menarche was self-reported on three surveys administered in 2004, 2006, and 2008. We calculated hazard ratios (HR) for menarche for an interquartile range (IQR) increase in PM exposure using Cox proportional hazard models adjusting for potential confounders. Results: Girls attained menarche at 12.3 y of age on average. In the adjusted model, higher residential exposure to ambient PM2.5 during all time windows was associated with earlier age of menarche. The HRs of menarche for each IQR (4 μg/m3) increase in exposure to PM2.5 during the in utero period, 1 y prior to menarche, and throughout childhood were 1.03 [95% confidence interval (CI): 1.00, 1.06], 1.06 (95% CI: 1.02, 1.10) and 1.06 (95% CI: 1.02, 1.10), respectively. Effect estimates for PM10 exposure were similar, albeit attenuated, for all time windows. PM2.5–10 exposure was not associated with age of menarche. Discussion: Among a large, nationwide, prospective cohort of U.S. girls, higher exposure to PM2.5 and PM10 in utero and throughout childhood was associated with an earlier age of menarche. Our results suggest that PM2.5 and PM10 may have endocrine-disrupting properties that could lead to altered timing of menarche. https://doi.org/10.1289/EHP12110


Table of Contents
Table S1.Pearson correlations between particulate matter (PM) exposures among 5,201 girls in the Growing Up Today Study from 1989 to 2008.Table S2.Hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations between residential ambient PM10, PM2.5-10, and PM2.5 exposures and age at menarche using Cox proportional hazard models in the Growing Up Today Study 2, 1988Study 2, -2008 (n = 5,201) (n = 5,201).
Table S3.Hazard ratios (HRs) and 95% confidence intervals (Cis) for the association between residential ambient PM2.5 exposure and age at menarche using restricted cubic splines in the Growing Up Today Study 2, 1988Study 2, -2008 (n=5,201) (n=5,201).Table S4.Predicted survival time for girls in the Growing Up Today Study 2 (n=5,201) exposed to the 10 th and 90 th percentile for the cumulative average PM exposure from 1988 to 2008 using Cox proportional hazard model.Table S5.Predicted survival time for girls in the Growing Up Today Study 2 (n=4,906) exposed to the 10 th and 90 th percentile for the in utero PM average from 1988 to 2008 using Cox proportional hazard model.Table S6.Predicted survival time for girls in the Growing Up Today Study 2 (n=5,201) exposed to the 10 th and 90 th percentile for the 1-year PM average from 1988 to 2008 using Cox proportional hazard model.Table S7.Predicted survival time for girls in the Growing Up Today Study 2 (n=5,201) exposed to the 10 th and 90 th percentile for the 2-year PM average from 1988 to 2008 using Cox proportional hazard model.Table S8.Hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations between residential PM10, PM2.5-10, and PM2.5 exposures and age at menarche using Cox proportional hazard models in the Growing Up Today Study 2, 1988-2008 who did not move during the study period (n = 1827).

Figure S1 .
Figure S1.Overview of exclusion criteria applied to the Growing Up Today Study 2 participants from 1988 to 2008.

Figure S3 .
Figure S3.Predicted survival time for girls in the Growing Up Today Study 2 (n=5,201) exposed to the 10 th and 90 th percentile for the in utero PM average from 1988 to 2008 using Cox proportional hazard model (see TableS5).

Figure S4 .
Figure S4.Predicted survival time for girls in the Growing Up Today Study 2 (n=5,201) exposed to the 10 th and 90 th percentile for the 1-year PM average from 1988 to 2008 using Cox proportional hazard model (see TableS6).

Figure S5 .
Figure S5.Predicted survival time for girls in the Growing Up Today Study 2 (n=5,201) exposed to the 10 th and 90 th percentile for the 2-year PM average from 1988 to 2008 using Cox proportional hazard model (see TableS7).