摘要Nitrates,thiocyanates,and perchlorates are ubiquitous in the environment and can be introduced to the public through various dietary and environmental sources. Nitrates,thiocyanates,and perchlorates mainly affect health via the same mechanism. These toxins may act as endocrine disrupters and can result in decreased levels of thyroid hormones[1]. Animal studies have shown that exposure to nitrate alters the circulating concentrations of sex steroids;however,these studies are equivocal and contradictory. In rats,nitrite decreases serum testosterone levels[2],while in alligators,nitrate has been found to increase plasma testosterone levels[3]. Nevertheless,only few studies have evaluated whether exposure to these chemicals is associated with altered sex hormone levels in humans. The role of sex hormones in development and physical growth is critical in children and adolescents,as they are indispensable for the maintenance of muscle,bone,and metabolic homeostasis. Children may be vulnerable to environmental endocrine-disrupting chemicals,particularly because of developmentally appropriate discrepancies in toxicokinetics,behavior,anatomy,and physiology. Hence,the present study aimed to estimate the relationship between nitrate,thiocyanate,perchlorate,and sex hormones in children aged 6-19 years from the U.S. National Health and Nutrition Examination Study (NHANES) and to examine whether puberty-and age-sex differences,as well as body mass index (BMI),would modify these relationships.