Methyl and Total Mercury Evaluation from a Dental Clinic

Methyl and Total Mercury Evaluation from a Dental Clinic Muntasar Talib Al Hinai M.Sc. School of public Health University of Illinois at Chicago Chicago, Illinois (2012) Dissertation Chairperson: Michael Cailas Hypothesis: There is no mercury methylation in dental waste water. There is no correlation between amount of total and methyl mercury in dental waste water and the number of fillings per day. Methods: Dental Waste water samples from the faculty practice in the College of Dentistry at the University of Illinois at Chicago were collected from a 10-chair dental clinic over a two month period. For the restorative patients, all amalgam fillings placed, replaced or removed were recorded during the entire sampling period. Dental waste water was settled for 24 h s and samples were collected from the top and bottom of the supernatant to simulate a range of particles that may escape in-line traps the total mercury was determined using EPA standard method 1631 and for the determination of the methyl mercury, EPA method 1630 was used. Objectives: The objective of this study was to confirm the methylation of mercury in dental waste water and to find out if there is a correlation between the amounts of mercury used in the clinic and total and methyl mercury amounts in dental waste water. Total mercury was present in high levels (23,445-1,223,100 ng/l) while methyl mercury levels were (18- 861ng/l). Results: The result showed that total mercury showed a statistically significant correlation (CI 90%) with the number of fillings for all days of the week. While the methyl mercury showed statically non significant correlation with the number of fillings for all days of the week except for Tuesday. Also there was a week correlation (95% CI) between the amounts of total mercury and methyl mercury.