title: Environmental Issues in Thyroid Diseases.
abstract: Environmental factors are determinant for the appearance of autoimmune thyroid diseases (AITD) in susceptible subjects. Increased iodine intake, selenium, and vitamin D deficiency, exposure to radiation, from nuclear fallout or due to medical radiation, are environmental factors increasing AITD. Cigarette smoking is associated with Graves' disease and Graves' ophthalmopathy, while it decreases the risk of hypothyroidism and thyroid autoimmunity. Viral infections are important environmental factors in the pathogenesis of AITD, too, particularly human parvovirus B19 (EVB19) and hepatitis C virus. Among the many chemical contaminants, halogenated organochlorines and pesticides variably disrupt thyroid function. Polychlorinated biphenyls and their metabolites and polybrominated diethyl ethers bind to thyroid transport proteins, such as transthyretin, displace thyroxine, and disrupt thyroid function. Among drugs, interferon- and iodine-containing drugs have been associated with AITD. Moreover intestinal dysbiosis causes autoimmune thyroiditis. To reduce the risk to populations and also in each patient, it is necessary to comprehend the association between environmental agents and thyroid dysfunction.
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa , Pisa , Italy.
authors.forename: Silvia Martina
authors.initials: SM
authors.lastname: Ferrari
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa , Pisa , Italy.
authors.forename: Poupak
authors.initials: P
authors.lastname: Fallahi
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa , Pisa , Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Antonelli
authors.affiliation: Department of Clinical and Experimental Medicine, University of Messina School of Medicine, Messina, Italy; Master Program of Childhood, Adolescence and Women's Endocrine Health, University of Messina School of Medicine, Messina, Italy; Interdepartmental Program of Molecular & Clinical Endocrinology, and Women's Endocrine Health, University Hospital, Policlinico G. Martino, Messina, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Benvenga
keywords: antithyroid antibodies; autoimmune thyroid diseases; environmental influences; genetic influences; thyroid cancer