Does exposure to PM10 decrease age at menarche?

ABSTRACT

BACKGROUND: There has been a consistent decrease in age at menarche in South Korea. A potential risk factor for early menarche is exposure to particulate matter (PM), because endocrine-disrupting compounds emitted into air from anthropogenic sources may be incorporated into PM. The objective of this study was to examine the association between pre-menarcheal exposure to PM ≤ 10 µm in diameter (PM10) and age at menarche in adolescents of South Korea using Korea National Health and Nutrition Examination Survey (KNHANES) 2010-2012 data. METHODS: We used self-reported age at menarche of 639 girls aged 13-17 years in this study. The cut-off age for early menarche was set to 12 years. Based on each subject's address, 1-year, 2-year, and 3-year averages of annual mean PM10 concentrations (models 1-3) were linked to KNHANES. Models were adjusted for body mass index (BMI), city size, household income level, maternal age at menarche, and second-hand smoke exposure at home. SURVEYREG and SURVEYLOGISTIC procedures were used to address the complex survey design of KNHANES. RESULTS: Overall analysis showed that exposure to PM10 has a significant effect on decreasing age at menarche. Multiple linear regression results suggested that each 1 µg/m3 increase in 1-year, 2-year, 3-year averages of annual mean PM10 concentrations accelerated age at menarche by 0.046 years (95% CI -0.064, -0.027; p < .0001), 0.038 years (95% CI -0.059, -0.018; p = 0.0003),and 0.031 years (95% CI -0.047, -0.015; p = 0.0002), respectively. Adjusted ORs for a 1 µg/m3 increase in PM10 concentration were 1.08 (95% CI 1.04 -1.12) for model 1, 1.06 (95% CI 1.02 -1.10) for model 2, and 1.05 (95% CI 1.01 -1.09) for model 3. CONCLUSION: Our findings suggest that elevated PM10 concentration can decrease age at menarche. This is the first study that investigates the association between exposure to PM10 and age at menarche using a nationally representative sample of Koreans.