Associations of Exposure to Air Pollution during the Male Programming Window and Mini-Puberty with Anogenital Distance and Penile Width at Birth and at 1 Year of Age in the Multicenter U.S. TIDES Cohort

Background: Ambient air pollution may be a developmental endocrine disruptor. In animal models, gestational and perinatal exposure to diesel exhaust and concentrated particulate matter alters anogenital distance (AGD), a marker of prenatal androgen activity, in both sexes. Little is known in humans. Objectives: We examined exposure to fine particulate matter (PM2.5) and nitrogen dioxide (NO2) in relation to human AGD at birth and at 1 year of age, focusing on exposures during critical windows of reproductive development: the male programming window (MPW; gestational weeks 8–14) and mini-puberty (postnatal months 1–3). Methods: The Infant Development and Environment Study (TIDES) recruited first trimester pregnant women (n=687) at four U.S. sites (Minneapolis, Minnesota; Rochester, New York; San Francisco, California; and Seattle, Washington) from 2010 to 2012. We measured anus to clitoris (AGD-AC) and anus to fourchette (AGD-AF) in female infants at birth; in males, we measured anus to penis (AGD-AP), anus to scrotum (AGD-AS), and penile width at birth and at 1 year of age. Using advanced spatiotemporal models, we estimated maternal exposure to PM2.5 and NO2 in the MPW and mini-puberty. Covariate-adjusted, sex-stratified linear regression models examined associations between PM2.5 and NO2 and AGD. Results: In males, a 1-μg/m3 increase in PM2.5 exposure during the MPW was associated with shorter AGD at birth, but a longer AGD at 1 year of age (e.g., birth AGD-AP: β=−0.35mm; 95% CI: −0.62, −0.07; AGD-AS: β=0.37mm; 95% CI: 0.02, 0.73). Mini-pubertal PM2.5 exposure was also associated with shorter male AGD-AP (β=−0.50mm; 95% CI: −0.89, −0.11) at 1 year of age. Although not associated with male AGD measures, 1-ppb increases in NO2 exposure during the MPW (β=−0.07mm; 95% CI: −0.02, −0.12) and mini-puberty (β=−0.04mm; 95% CI: −0.08, 0.01) were both associated with smaller penile width at 1 year of age. Results were similar in multipollutant models, where we also observed that in females AGD-AC was inversely associated with PM2.5 exposure, but positively associated with NO2 exposure. Discussion: PM2.5 and NO2 exposures during critical pre- and postnatal windows may disrupt reproductive development. More work is needed to confirm these novel results and clarify mechanisms. https://doi.org/10.1289/EHP12627


Table of Contents
Table S1.Comparison of covariates in TIDES participants with complete case data versus missing data (2010)(2011)(2012).
Table S2.Distributions of exposures to NO2 and PM2.5 by study site in the TIDES cohort, 2010-2012.
Table S4.Estimated exposure to NO2 and PM2.5 during the male programming window (gestational weeks 8-14) and the mini-puberty (postnatal months 1-3) in relation to participant characteristics in the TIDES cohort, 2010-2012.
Table S5.Unadjusted associations of PM2.5 and NO2 during the male programming window and mini-puberty with AGD (in mm) at birth and age 1 as estimated from linear regression models in the TIDES cohort, 2010-2012.Estimates are per 1 ug/m 3 increase in PM2.5 or 1 ppb increase in NO2.
Table S6.Associations of PM2.5 and NO2 during the male programming window and minipuberty with AGD (in mm) at birth and age 1 as estimated from multivariable linear regression models in the TIDES cohort, 2010-2012.Figures 1 and 2 provide visualizations of these results.
Table S7.Associations of PM2.5 and NO2 (by trimester) with AGD and PW at birth (in mm) as estimated from sex-stratified multivariable linear regression models in the TIDES cohort, 2010-2012.
Table S8.Associations of PM2.5 and NO2 by trimester with AGD and PW at age 1 (in mm) in male offspring as estimated from multivariable linear regression models in the TIDES cohort, 2010-2012.
Table S9.Associations of PM2.5 and NO2 during the male programming window and minipuberty with AGD (in mm) in the TIDES cohort (2010)(2011)(2012) as estimated from multivariable linear regression models that additionally adjust for temperature and humidity during the relevant time windows.
Table S10.Associations of estimated air pollutants during the male programming window and mini-puberty with AGD (in mm) in the TIDES cohort (2010)(2011)(2012) as estimated from multivariable linear regression models that are mutually adjusted for PM2.5 and NO2.
Table S11.Associations of estimated PM2.5 and NO2 with AGD (in mm) at age 1 in the TIDES cohort (2010)(2011)(2012) as estimated from multivariable linear regression models that are mutually adjusted for exposures at both the male programming window and mini-puberty.
Table S12.Associations of PM2.5 and NO2 during the male programming window and minipuberty with AGD (in mm) in offspring of non-smokers only in the TIDES cohort (2010-2012) as estimated from multivariable linear regression models.
Table S13.Associations of PM2.5 and NO2 during the male programming window and minipuberty with AGD (in mm) at age 1 (in males only) in the TIDES cohort (2010-2012) as estimated from linear regression models without adjustment for the equivalent AGD measure at birth.Estimates are per 1 ug/m 3 increase in PM2.5 or 1 ppb increase in NO2.

Additional File-Excel Document
Supplemental Tables and Figures.Supplemental Table 1 2 Some evidence of non-linearity between the pollutant and AGD was observed.More detailed plots of these associations are provided in Supplemental Figure 3.

Table 5 . Unadjusted associations of PM 2.5 and NO 2 during the male programming window and mini-puberty with AGD (in mm) at birth and age 1 as estimated from linear regression models in the TIDES cohort, 2010-2012. Estimates are per 1 ug/m 3 increase in PM 2.5 or 1 ppb increase in NO 2 . .
AGD: anogenital distance; AGD-AP: anogenital distance, anus to penis; AGD-AS: anogenital distance, anus to scrotum; AGD-AC: anogenital distance, anus to clitoris; AGD=AF: anogenital distance, anus to fourchette; CI: confidence interval; NO 2 =nitrogen dioxide; PM 2.5 =fine particulate matter; PW: penile width.

11 (0.03, 0.19); 0.007 AGD-AF 339 0.08 (0.02, 0.15); 0.02 Supplemental Table 6. Associations of PM 2.5 and NO 2 during the male programming window and mini-puberty with AGD (in mm) at birth and age 1 as estimated from multivariable linear regression models in the TIDES cohort, 2010-2012. 1 Figures 1 and 2 provide visualizations of these results.
NO 2 =nitrogen dioxide; PM 2.5 =fine particulate matter; PW: penile width 1 Adjusted for center, parity, race/ethnicity, education, maternal age, post-conception age at AGD exam, weight-forlength/height z-score at AGD exam.Models examining age 1 outcomes are also adjusted for AGD (or PW) at birth.Estimates are per 1 ug/m3 increase in PM 2.5 or 1 ppb increase in NO 2 .

Associations of PM 2.5 and NO 2 by trimester with AGD and PW at age 1 (in mm) in male offspring as estimated from multivariable linear regression models in the TIDES cohort, 2010-2012.
Adjusted for center, parity, race/ethnicity, education, smoking, maternal age, post-conception age at AGD exam, weight-for-length/height z-score at age 1 AGD exam, and AGD (or PW) at birth.Estimates are per 1 ug/m3 increase in PM2.5 or 1 ppb increase in NO2.

Table 9 . Associations of PM 2.5 and NO 2 during the male programming window and mini-puberty with AGD (in mm) in the TIDES cohort (2010-2012) as estimated from multivariable linear regression models that additionally adjust for temperature and humidity during the relevant time windows.
NO 2 =nitrogen dioxide; PM 2.5 =fine particulate matter; PW: penile width 1 Adjusted for center, parity, race/ethnicity, education, smoking, maternal age, post-conception age at AGD exam, weight-for-length/height z-score at AGD measurement, average temperature and average humidity during the window of interest.Models examining age 1 outcomes are also adjusted for AGD (or PW) at birth.Estimates are per 1 ug/m3 increase in PM2.5 or 1 ppb increase in NO2.

Supplemental Table 10. Associations of estimated air pollutants during the male programming window and mini-puberty with AGD (in mm) in the TIDES cohort (2010- 2012) as estimated from multivariable linear regression models that are mutually adjusted for PM 2.5 and NO 2 1
NO 2 =nitrogen dioxide; PM 2.5 =fine particulate matter; PW: penile width 1 Adjusted for center, parity, race/ethnicity, education, maternal age, post-conception age at AGD exam, weightfor-length/height z-score at AGD exam.Models examining age 1 outcomes are also adjusted for AGD (or PW) at birth.Estimates are per 1 ug/m3 increase in PM2.5 or 1 ppb increase in NO2.

Supplemental Table 12. Associations of PM 2.5 and NO 2 during the male programming window and mini-puberty with AGD (in mm) in offspring of non-smokers only in the TIDES cohort (2010-2012) as estimated from multivariable linear regression models.
Adjusted for center, parity, race/ethnicity, education, maternal age, post-conception age at AGD exam, weight-for-length/height z-score at AGD exam.Models examining age 1 outcomes are also adjusted for AGD (or PW) at birth.Estimates are per 1 ug/m3 increase in PM2.5 or 1 ppb increase in NO2.

Supplemental Table 13. Associations of PM 2.5 and NO 2 during the male programming window and mini-puberty with AGD (in mm) at age 1 (in males only) in the TIDES cohort (2010-2012) as estimated from linear regression models without adjustment for the equivalent AGD measure at birth. Estimates are per 1 ug/m 3 increase in PM 2.5 or 1 ppb increase in NO 2 . .
: anogenital distance; AGD-AP: anogenital distance, anus to penis; AGD-AS: anogenital distance, anus to scrotum; AGD-AC: anogenital distance, anus to clitoris; AGD=AF: anogenital distance, anus to fourchette; CI: confidence interval; NO 2 =nitrogen dioxide; PM 2.5 =fine particulate matter; PW: penile width.1 Adjusted for center, parity, race/ethnicity, education, maternal age, post-conception age at AGD exam, weight-forlength/height z-score at AGD exam.Models examining age 1 outcomes are also adjusted for AGD (or PW) at birth.Estimates are per 1 ug/m3 increase in PM 2.5 or 1 ppb increase in NO 2 . AGD