Effect of Continuous Exposure under High Voltage Overhead Powerline on Thyroid Function

Abstract

Thyroid hormones are essential for regulating metabolism, growth, and development. Exposure to electromagnetic fields (EMF) generated by high voltage overhead powerlines has been suggested to influence thyroid function by inducing oxidative stress and altering hormonal pathways. This study explored the impact of continuous EMF exposure on thyroid function, focusing on the levels of thyroid-stimulating hormone (TSH) and free T4 (fT4). Eighty (80) participants comprised of fifty (50) exposed individuals (test group) residing within 500 meters of the powerlines and control group from low-EMF areas were randomly recruited. Participants were aged between 18-60 years and were age matched. Five millilitre (5 ml) of fasting venous blood samples were collected into plain containers for the determination of TSH and fT4 levels using the Enzyme-Linked Immunosorbent Assay (ELISA) method. Comparative analysis between two and more groups was done using independent sample t-test and one-way analysis of variance. Statistical significance was assumed at p<0.05. The results showed no statistically significant difference in the mean serum levels of TSH and fT4 between the exposed and unexposed groups (p > 0.05). However, a significant increase in fT4 levels (p=0.042) was observed in individuals with prolonged EMF exposure (6-10 years) compared to those with less than one year of exposure. Continuous exposure to EMF from high voltage overhead power lines does not significantly alter TSH levels but may increase FT4 levels with prolonged exposure. Further studies with larger sample sizes and longer follow-up periods are needed to fully understand the health implications of chronic EMF exposure on thyroid function and overall health.