Effect of Low-Level Environmental Lead Exposure on the Onset of Male Puberty

Abstract

The objective of this study was to evaluate male pubertal changes associated with environmental low-level lead (Pb) exposure. The study was conducted on 180 boys aged 15 years divided into 3 equal size groups: group 1 from El-Newayrat village, group 2 from Al-Shorafaa (0.5 and 10 km, respectively, from an industrialized area), and group 3 from Talla (25 km). Blood Pb levels (BLLs) were measured and pubertal changes evaluated by measurement of testicular volume (T_V), and estimation of the follicle-stimulating hormone, luteinizing hormone, testosterone, estradiol, and prolactin. Blood Pb levels of children of El-Newayrat and Al-Shorafaa were significantly higher (6.38 [1.32] and 3.84 [0.79] μg/dL, respectively) than that of Talla children (1.85 [0.72]; P < 0.001), while height, weight, and T_V were lower in boys in groups 1 and 2, compared to group 3. Genitalia and pubarche staging showed greatest retardation and marked bone growth delay in boys of group 1. Hormonal assays reported significant differences in boys of the industrialized areas when compared to that of Talla. Low-level Pb exposure in boys located near an industrial area was accompanied with altered male puberty indicators.

Keywords: children; environmental toxicity; lead; puberty.