Mercury health risk assessment among petrochemical workers in Rayong Province, Thailand

Abstract

Background: Mercury occurs naturally in environment; thus, retention of fossil fuels used as feedstock in petrochemical plants is commonly found. The purpose of this study was to assess mercury health risks among petrochemical workers. Methods: In all, 188 operators and 30 office workers were recruited from 3 petrochemical plants. A total of 83 and 56 air samples were collected during normal working days and turnaround (TA) periods, respectively. Three main meals over 5 consecutive days, drinking water and spot urine samples were collected. Demographics and lifestyle data were collected using questionnaires. USEPA guidelines for mercury health risks were applied. Results: The inhalation exposure during normal working days of the two groups was lower than 5% of the Threshold Limit Value (TLV), but during TA some operators' exposure exceeded the TLV. The average urinary mercury concentrations of the two groups did not significantly differ. The mercury concentration in the water samples was undetected and did not differ in the food samples of the two groups. Sixty-six operators presented a hazard quotient, HQ(inh) greater than 0.2, but none of office staff, and 98 of 218 participants had hazard index, HI >1. Conclusion: Unacceptable mercury health risk among the petrochemical worker mostly cause by mercury in cooked food.