Para-Dichlorobenzene Exposure Is Associated with Thyroid Dysfunction in US Adolescents.

OBJECTIVE: To examine the association between exposure to para-dichlorobenzene, measured as urinary concentrations of 2,5-dichlorophenol (2,5-DCP), and thyroid function in US adolescents.

STUDY DESIGN: A nationally representative subsample of 618 adolescents aged 12-19 years in the 2007-2008 and 2011-2012 National Health and Nutrition Examination Survey was analyzed for the association of urinary 2,5-DCP with serum thyroid function measures using multivariate logistic and general linear regression models.

RESULTS: After adjusting for potential confounders, we found a significantly positive association between urinary concentrations of 2,5-DCP and serum levels of thyroid-stimulating hormone and thyroglobulin in adolescents. Furthermore, urinary 2,5-DCP was associated with an increased prevalence of hypothyroidism in the study population.

CONCLUSIONS: This study demonstrates a potential relationship between para-dichlorobenzene exposure, measured as urinary 2,5-DCP, and thyroid dysfunction in adolescents; however, further studies are needed to confirm our findings and to elucidate mechanisms of action.