Can Living in the Surroundings of a Petrochemical Complex be a Risk Factor for Autoimmune Thyroid Disease

Abstract Background Based on a suspicion raised by a health professional and due to a subsequent legal request, a cross-sectional study was made with a comparison group to investigate a possible excess of Hashimoto's thyroiditis—HT and antibodies—ATA in the surroundings of a Petrochemical Complex. Methods People of both sexes aged over 20 years were investigated in a random sample of residents in the area surrounding the Petrochemical Complex. Controls were investigated in an area with steel industries. In the areas searched, participants were chosen randomly and stratified a priori by sex and age group. As a result, 90.5% of the expected sample was obtained, totaling 1533 individuals. HT and ATA prevalences were compared by the chi-square test. Logistic regression was used to control the possible confounding factors for HT and ATA. Results Both TH (9.3%) and ATA (17.6%) prevalences were higher in the Petrochemical Complex area than in the control area (3.9% and 10.3%, respectively). After controlling the possible confounding factors, the POR for living in the surroundings of the Complex and presenting HT was 2.39 (CI95%: 1.42–4.03). According to the ATA criterion, the POR for living in the surroundings of the Complex was 1.78 (CI95%: 1.23–2.60). Conclusions The authors have found higher prevalence and risk of developing thyroiditis and anti-thyroid antibodies among residents of areas surrounding the Petrochemical Complex and think these findings need to be further studied in similar areas.