Can environmental toxins contribute to thyroid nodules?

What's actually in it

Your thyroid gland sits at the front of your neck and controls metabolism, energy, and growth. It's highly sensitive to chemicals in your blood because it concentrates iodine and other substances from the bloodstream. PFAS from nonstick cookware, bisphenols from plastic containers, phthalates from flexible plastics, and heavy metals like cadmium and mercury all reach the thyroid through daily exposure.

Thyroid nodules, lumps that form within the gland, are found in up to 60% of adults when checked by ultrasound. Most are harmless, but some require monitoring or treatment.

What the research says

A 2026 review in Endocrine examined the connection between environmental toxins and thyroid nodule formation. The review found that chemical exposure contributes through inflammation, hormone disruption, and micronutrient interference.

PFAS altered thyroid hormone production and transport, creating hormonal imbalances that stimulate abnormal cell growth in the gland. BPA and phthalates mimicked or blocked thyroid hormones, confusing the feedback loop between the thyroid and pituitary gland.

Cadmium and mercury caused direct oxidative damage to thyroid cells. They also competed with iodine and selenium, two micronutrients the thyroid needs to function. When these nutrients are displaced, the gland works harder and may develop nodules as a result.

If you've been told you have thyroid nodules, reducing chemical exposure may help prevent new ones. Switch to PFAS-free cookware, use glass food containers, choose fragrance-free products, and make sure your diet includes adequate iodine and selenium.