Arsenic is a metalloid element found ubiquitously in the environment in either an organic or inorganic state. General populations are widely exposed to arsenic via digestion and inhalation. Environmental arsenic exposure is associated with multiple adverse health outcomes, including male reproductive toxicity. Arsenic is endocrine disruptors and classified as the reproductive toxicants. However, the mode of disruption for arsenic is still inconsistent at environmentally relevant exposure levels.

Recently, researchers from the Institute of Urban Environment of the Chinese Academy of Sciences (IUE-CAS), and Harvard T.H. Chan School of Public Health have collaborated to identify new mode of male endocrine disruption for environmental arsenic exposure by integrating epidemiological and in vitro toxicological studies.

In this study, the researchers detected urine arsenic and sex hormones among 451 reproductive-age males. They observed general populations are commonly exposed to arsenic and found arsenic exposure positively associated with urine sex hormones excretion. The researchers employed mouse testicular cells (Leydig MLTC-1 cell) as in vitro arsenic exposure models, they further verified low dose arsenic stimulating testicular cells sex hormones testosterone production.

The findings underscore that low-dose arsenic exposure exhibits a novel endocrine disrupting effect by stimulating Leydig cell sex hormones production and accelerating urinary sex hormones excretion, which extends previous knowledge of the inverse association of high-dose arsenic exposure with sex hormones production that is assumed to be anti-androgen.

Dr. TIAN Meiping from IUE-CAS, one co-first author of this study, explained that urinary hormone excretion may serve as complementary strategies and sensitive noninvasive tool for arsenic endocrine disruption assessment.

The work entitled "Environmental doses of arsenic exposure are associated with increased reproductive-age male urinary hormone excretion and in vitro Leydig cell steroidogenesis" has been published in Journal of Hazardous Materials.

The work was supported by the Crossing-Group Project of KLUEH, the National Natural Science Foundation of China and Science and Technology Foundation of Medicine and Health of Zhejiang Province.

Endocrine disruption mode for environmental dose arsenic exposure