Antithyroid effects of coal‐derived pollutants

Abstract

Endemic goiter in iodide-sufficient areas of the United States and Colombia has been linked to watersheds rich in coal and shale, which several reports suggest are the source of water-borne goitrogens. In this report the potential antithyroid activities of aqueous coal and shale extracts and of compounds identified in aqueous effluents from coal conversion processes were assayed in thyroid peroxidase (TPO) and thyroid slice systems. Aqueous extracts of coal and black shale were potent inhibitors of TPO or 125I organification by thyroid slices. The most abundant water-soluble compounds derived from coal are dihydroxy-phenols, thiocyanate, disulfides, and hydroxypyridines. The dihydroxyphenols resorcinol, 2-methylresorcinol, and 5-methylresorcinol (orcinol) were 26.7, 22.5, and 7.2 times more potent, respectively, than the antithyroid drug 6-propylthiouracil (PTU). Other dihydroxyphenols and thiocyanate were less potent but comparable in activity to PTU. All dihydroxypyridines and 3-hydroxypyridine produced inhibitory effects comparable to PTU. None of the disulfides inhibited TPO. The antiperoxidase effects of combinations of two dihydroxyphenols or one dihydroxyphenol and SCN were additive, whereas the effects of a combination of four dihydroxyphenols at threshold inhibitory concentrations were synergistic, resulting in net effects equivalent to or greater than the sum of the individual effects. Thus, antithyroid effects may be greatly amplified by exposure to multiple coal-derived goitrogens and could be many times that produced by any one of the contributing pollutants. These results demonstrate that potent water-borne goitrogens are derived from coal and shale and that their contamination of water supplies could pose a serious threat of thyroid disorders.

Environmental triggers of autoimmune thyroiditis

“…The pollutants are organics produced from coal and found in air and water. In their study they found that these pollutants have potent anti-thyroid effects [45]. Two populations of school children from different geographical locations showed a high prevalence of goiter in equally iodine-sufficient areas [46].…”

Environmental Goitrogens and Goitrogenic Factors

“…В исследовании, проведенном Lindsay et al, изу чалась возможная антитиреоидная активность оса дочных пород угля и глинистого сланца. Оказалось, что осадочные породы угля и глинистого сланца яв ляются ингибиторами тиреоидной пероксидазы и органификации 125 I [30]. Gaitan E. et al исследовали антитиреоидные эф фекты экстрактов каменного угля у крыс после ост рого и хронического их перорального введения.…”

Dynamics of the Iodine-goitrogen Balance in the Thyroid Status of Catfish from Selected Fresh and Brackish Water Bodies

“…Iodide dietary supplementation programs have had only partial success against goitre; consequently, iodide lack cannot be seen as the only causative factor for goitre endemia. It has been shown that there are some connections between the origin of water and the incidence of goitre (Lindsay, 1997). Poor quality drinking water has been known for years to be associated with goitre (Gaitan, 1983;Ubom, 1991).…”

“…This anomaly has been attributed to the presence of goitrogens, which prevent the thyroid from being able to use the iodide (Gaitan, 1983). Endemic goitre in iodide-sufficient areas of the USA and Columbia has been linked to water-soluble goitrogens (Lindsay et al, 1997) such as compounds derived from coal; 2-and 5-methyl resorcinol. Other compounds with less potent activity include thiocyanates, disulphides and hydroxypyridines.…”