Evaluation of Mercury Concentration in Hair of Dentists and Survey of Factors Influencing its Levels

The purpose of this study was to evaluate the exposure to mercury (Hg), and to examine the various parameters, which contribute to high levels of mercury of Iranian dentists in Tehran. One-hundred hair samples were collected from dentists. In addition, fifty samples from a control group were taken for comparison. The survey included a structured questionnaire designed to provide information about the parameters that influenced exposure to Hg. The parameters included: personal profile, life style, dental fillings, practice patterns, work habits, precautionary measures and fish consumption. The determination of mercury was carried out by Advanced Mercury Analyzer 254, LECO, and standard method D-6722. Overall mean concentrations in the hair of the dentists was 2.84±0.47 mg/kg. The equivalent values were 0.61±0.07 mg/kg in hair for the control group. The study showed that use of masks had a significant effect on hair (p=0.024) mercury. Also, fish consumption and number of patients seen per day had a significant effect on hair (p=0.025 and p=0.027 respectively) Hg. On the other hand, there was a significant effect of age in relation to mercury concentration in the hair of dentists (p=0.006). Multiple regressions were computed between mercury in hair and the various assessed variables. The only positive results were between mercury concentration and mask for the dentists (p= 0.04) and Hg concentration and the number of fish meal for the control group (p=0.009).