Thyroid gland and male reproductive anomalies among fuel handlers in Gampaha district, Sri Lanka

Abstract

Introduction:Fuel handlers at petrol stations are continuously exposed to organic solvents from fuel and vehicle emissions. Endocrine disrupting chemicals (EDC) are present in fuel, which are harmful to endocrine organs. Thyroiditis and hypogonadism are reported among fuel handlers. Thyroid gland and male reproductive function anomalies were investigated among fuel handlers in the Gampaha district of Sri Lanka. Method: 43 were recruited from 6 fuel stations in the Gampaha district for the study and 28 age matched male workers who were not exposed to fuel in an occupational setting were recruited as controls. Thyroid gland was examined clinically and TSH, free T4, FSH, LH and Testosterone were done on all the participants. TPO antibody and a thyroid scan was done on the fuel handlers. Results: Median (IQR) age was 38 years (27-46 years). The mean TSH value was 1.62 IU/mL (1.15-2.35) vs 1.33 IU/mL (0.83-1.79) respectively in study and control populations with significantly higher levels in the study population (p=0.023). The median (IQR) TSH value above the reference range was identified in 7% of fuel handlers and all controls were within the normal range, while 16.9% of fuel handlers had a derangement in the TPO levels. On examination, only one control had a small goiter but his T4 and TSH levels were normal. On ultrasound thyroid scans, benign nodules were seen in 2 fuel handlers. TPO levels did not correlate with the TSH levels among the fuel handlers (r=-0.078, p=0.652). Inability to sustain an erection was reported by 35.5% fuel handlers which was significantly higher than controls who reported 5.6% (p=0.019). Premature ejaculation was reported by 27.9% of fuel handlers which was significantly higher than controls (p=0.023). The testosterone levels were significantly higher among fuel handlers compared to controls (p=0.048). The FSH and LH levels positively correlated with each other as expected in each subgroup and the total population (p<0.005). The TSH levels significantly negatively correlated with the testosterone levels among the fuel handlers. (r=- 0.338, p=.0.023). When the fuel handlers with premature ejaculation was considered the FSH, LH, Testosterone levels were not significantly different between the two groups, however the duration of employment was significantly longer among those reporting premature ejaculation. (p=0.024). Conclusion: There are thyroid and reproductive abnormalities among those exposed to fuel in an occupational setting. Disturbances to sexual functions may also be related to alteration of autonomic functions. Limiting exposure to fuel vapor will eliminate these detrimental effects and we propose self-service fuel pumps to be the best alternative to avoid occupational health hazards among fuel handlers.