title: Long-term exposure to organochlorine pesticides and thyroid status in adults in a heavily contaminated area in Brazil.
abstract: Organochlorine (OC) pesticides are endocrine disruptors altering the thyroid hormonal system. The aim of this study is to investigate the relationship between exposure to OC pesticides and thyroid status in adults from a rural area in Rio de Janeiro, Brazil, heavily contaminated with OC pesticides. A cross-sectional study was carried out in 303 men and 305 women >14 years old. Concentrations of 19 OC pesticides and levels of free thyroxine (T4), total triiodothyronine (T3), thyroid-stimulating hormone (TSH), anti-thyroperoxidase (TPOAb) and anti-thyroglobulin (TgAg) antibodies were analyzed in serum samples. Associations between OC pesticides concentrations and values of biochemical thyroid parameters were determined using multivariate regression models stratified by gender. Prevalence of subclinical hyperthyroidism and the presence of TPOAb antibodies were higher than those described for euthyroid populations elsewhere. After adjusting for confounders, total T3 levels were associated with lower concentrations of endosulphan 2 in men and with higher alpha-chlordane, p,p'-dichlorodiphenyltrichloroethane (DDT), endosulphan 2, and methoxychlor in women. Levels of free T4 showed inverse association with beta-hexachlorocyclohexane (HCH) and p,p'-DDT in men, and were positively associated with hexachlorobenzene (HCB), heptachlor, o,p'-DDT, and p,p'-DDT in women. TSH levels were associated with higher beta-HCH in men. A positive association was observed between exposure methoxychlor in males and presence of TPOAb, but no association with TPOAb was found in women. These results suggest that OC pesticides can affect the thyroid system through gender-specific mechanisms that may differ among compounds. Further detailed investigations and health monitoring should be warranted for this population.
authors.affiliation: National School of Public Health, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil; University of Granada, Granada, Spain. Electronic address: cfreire@ugr.es.
authors.forename: Carmen
authors.initials: C
authors.lastname: Freire
authors.forename: Rosalina Jorge
authors.initials: RJ
authors.lastname: Koifman
authors.forename: Paula Novaes
authors.initials: PN
authors.lastname: Sarcinelli
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Simões Rosa
authors.forename: Ruth
authors.initials: R
authors.lastname: Clapauch
authors.forename: Sergio
authors.initials: S
authors.lastname: Koifman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood / Q000276:immunology; D001938:Brazil; D003430:Cross-Sectional Studies; D003634:DDT / Q000097:blood / Q000633:toxicity; D052244:Endocrine Disruptors / Q000633:toxicity; D005260:Female; D001556:Hexachlorocyclohexane / Q000097:blood / Q000633:toxicity; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000097:blood* / Q000633:toxicity; D006980:Hyperthyroidism / Q000097:blood / Q000139:chemically induced / Q000453:epidemiology; D007453:Iodide Peroxidase / Q000097:blood / Q000276:immunology; D008297:Male; D008731:Methoxychlor / Q000097:blood / Q000633:toxicity; D008875:Middle Aged; D010575:Pesticides / Q000097:blood* / Q000633:toxicity*; D013961:Thyroid Gland / Q000187:drug effects* / Q000503:physiopathology; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D052244:Endocrine Disruptors; D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; C006606:anti-thyroglobulin; D014284:Triiodothyronine; D001556:Hexachlorocyclohexane; D013972:Thyrotropin; D003634:DDT; D007453:Iodide Peroxidase; D013974:Thyroxine; D008731:Methoxychlor; C023888:beta-hexachlorocyclohexane
keywords: Adults; Anti-thyroid antibodies; Organochlorine pesticides; Thyroid hormones; Thyroid-stimulating hormone