The impact of environmental chemical toxins on thyroid gland: challenges to public health

Impact of environmental chemical toxins on thyroid gland

Abstract

The thyroid gland regulates metabolism, growth, and neurodevelopment through thyroid hormones, and even a minor disruption can cause significant health consequences. Globally, around 200 million people are affected by thyroid disease annually, with growing concern about environmental toxins as emerging threats. Industrial pollutants, heavy metals, pesticides, and endocrine-disrupting chemicals interfere with iodine uptake, hormone synthesis, transport, metabolism, and receptor signaling. The dependence of thyroid on iodine, its rich blood supply, and tightly regulated hypothalamic-pituitary-thyroid axis makes it especially vulnerable. Key disruptors include heavy metals, persistent organic pollutants, bisphenol-a, phthalates, flame retardants, and agricultural chemicals. The vulnerable groups include pregnant women, children, occupationally exposed workers, and iodine-deficient populations, particularly in low- and middle-income countries. Therefore, prevention requires integrated regulatory, environmental, public health, and individual strategies. Major research gaps remain regarding chemical mixtures, low-dose effects, and long-term outcomes, underscoring the need for advanced exposomic and analytical approaches.