Determination of Mercury Exposure among Dental Health Workers in Nakhon Si Thammarat Province, Thailand

Abstract

Objectives. The main objective of this study was to assess the mercury exposure levels in dental health workers that work in dental clinics. The study evaluated the airborne and urinary mercury levels, the type of work done in the clinic, and the effect of mercury exposure on health of dental health workers. Material and Methods. A case-control study was conducted with 124 exposed and 124 matched nonexposed subjects. Personal and area samplings were conducted to quantify mercury concentrations by solid sorbent tube. Urine samples were collected to determine mercury levels by cold-vapor atomic absorption spectrometer mercury analyzer. Results and Discussion. 17.6% ( n = 32/182) of the air samples were higher than the occupational exposure limit (OEL). A multiple regression model was constructed. Significant predictors of urinary mercury levels included dietary consumption (fish or seafood), duration of work (yrs), work position, personal protection equipment used (PPE), and personal hygiene behaviors. Significant correlations were observed between mercury levels in urine and mercury in storage areas ( r = 0.499, P < 0.05) and between mercury levels in urine and airborne mercury in personal samplings ( r = 0.878, P < 0.001). Conclusion. Improvements in working conditions, occupational health training, and PPE use are recommended to reduce mercury exposure.