Low-Dose Occupational Exposure to Nickel and Thyroid Hormones

Area of Science:

• Environmental Health
• Endocrinology
• Occupational Medicine

Background:

• Urban air contains low doses of nickel, a potential environmental pollutant.
• Outdoor workers are frequently exposed to urban air pollutants.
• Thyroid hormones play a crucial role in metabolic regulation.

Purpose of the Study:

• To investigate the effects of low-dose nickel exposure on thyroid hormones and thyrotropin (TSH) in outdoor workers.
• To assess the relationship between nickel levels and thyroid function markers in an occupational setting.

Main Methods:

• A cohort of 164 outdoor workers was studied, stratified by sex and smoking status.
• Urinary nickel levels and serum concentrations of triiodothyronine (T3), L-thyroxine (T4), and thyrotropin (TSH) were measured.
• Statistical analyses were performed to determine correlations between nickel exposure and thyroid parameters.

Main Results:

• A significant positive correlation was observed between urinary nickel levels and L-thyroxine (T4) concentrations.
• This correlation was evident in the total study sample and specifically in male participants.
• No significant correlations were reported for triiodothyronine (T3) or thyrotropin (TSH) with nickel levels.

Conclusions:

• Occupational exposure to low-dose nickel, as found in urban air, may influence thyroid function, particularly L-thyroxine levels.
• These findings suggest potential risks for outdoor workers, including municipal police, and may inform health surveillance for similar occupational groups.
• Further research is warranted to elucidate the mechanisms of nickel's impact on thyroid health.