A preliminary study on the association between blood lead, cadmium and mercury and pubertal development in boys aged 6 to 19

Abstract

The time of pubertal development has historically been used as an indicator of adequate growth. Environmental exposure has been reported to be associated with the pubertal development. There are some reports on the association between lead exposure and delayed pubertal development in girls. However, epidemiologic data in boys are limited. We examined the association between blood lead, cadmium and mercury concentrations and pubertal development in boys aged 6-19 years who participated in the cross-sectional pilot study for the Korean Environmental Health Survey in Children and Adolescents (KorEHS-C).Children and adolescents were recruited from the two regions, industrial and rural areas. Of 199 boys participated, 177 were analyzed in this study after excluding those who were not examined the blood levels of heavy metals. Lead(?/?), cadmium(?/?) and mercury(?/?) was measured in whole blood. Besides obtaining information reported via questionnaire, the pubertal development (Tanner stage) was evaluated by students themselves, graded from 1(not initiated pubertal development) to 5 (fully matured) through visual inspection and self-examination using photographs according to internationally accepted criteria and a Prader orchidometer(for testicular development). We used multivariable logistic regression models to assess associations between blood heavy metals and pubertal development. After adjustment for potential confounders, boys with high blood lead level(1.49-4.03?/?, highest tertile) showed a delayed pubic hair growth compared to those with low level (0.67-1.15?/?, lowest tertile)(Odds Ratio (OR)=0.15; 95% confidence intervals(CIs)= 0.03-0.90). High blood cadmium level(0.39-1.05?/?, highest tertile) also showed a delayed effect on testicular development compared to the low level(0.13-0.27?/?, lowest tertile)(OR=0.10; 95% CIs= 0.02-0.92). Blood mercury did not show any significant effects on pubertal development in boys.We found delayed effects of high blood levels of lead and cadmium on the pubertal development in Korean boys.