Objectives Ionising radiation can alter thyroid function, and workers at a nuclear weapons facility may be exposed to elevated levels of radiation. The Pantex Plant, located in Amarillo, Texas, is the only remaining facility in the United States that assembles and disassembles nuclear weapons, and since 1958 it has manufactured 60–70% of the country's nuclear weapons arsenal.

Methods As part of an on-going health surveillance program, hypothyroid status was determined for 622 former workers of Pantex, using a combination of measured thyroid stimulating hormone levels and thyroid medication history. Next, 916 unique job titles identified in questionnaires were classified into 35 job categories.

Results Fifty-five (34.8%) females and seventy-eight (16.8%) males were hypothyroid. In logistic regression analysis adjusted for age, gender and smoking, only ‘material handlers’ (n=18) exhibited an elevated risk of developing hypothyroidism (OR 3.64, 95% CI 1.30 to 9.97) compared to other job categories. This is one of the groups with suspected exposure to radiation.

Conclusions There is suggestive evidence that some occupational groups exposed to radiation at Pantex may have an elevated risk of hypothyroidism. Further evaluation of thyroid health in this population is warranted.