Ambient air pollution and thyroid function in Spanish adults. A nationwide population-based study (Di@bet.es study)

Area of Science:

• Environmental Health
• Endocrinology
• Public Health

Background:

• Emerging evidence suggests air pollution may affect thyroid function, but data remains limited.
• This study investigates the association between air pollutants and thyroid function parameters in a representative Spanish adult population.

Purpose of the Study:

• To evaluate the relationship between exposure to specific air pollutants and thyroid function markers.
• To assess the impact of particulate matter (PM2.5) and Nitrogen Dioxide (NO2) on thyroid hormones and antibodies in a large population sample.

Main Methods:

• Utilized data from the national, cross-sectional Di@bet.es study (2008-2010) including 3859 adults without prior thyroid disease.
• Assigned air pollution exposure levels (PM2.5, NO2) using a validated modeling approach.
• Measured thyroid-stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), and thyroid peroxidase antibodies (TPO Abs) via immunoassay.

Main Results:

• Significant negative correlations were found between PM2.5 concentrations and both FT4 and FT3 levels (p<0.001).
• Increased PM2.5 exposure was associated with higher odds of elevated TSH, lower FT4, and low FT3 levels.
• No significant associations were observed between NO2 exposure and thyroid hormone levels.

Conclusions:

• Exposure to PM2.5 air pollution is associated with mild alterations in thyroid function in the general population.
• These findings contribute to understanding the environmental determinants of thyroid health.