Assessing mercury levels in two dental clinic wastewaters in Tehran

Considering the presence of high amounts of mercury in amalgam, the importance of mercury, and the problems it creates for the environment, including humans and other living organisms, this study was conducted to measure the amount of mercury in the wastewater of two dental clinics. We collected ۳۰ wastewater samples from two dental clinics at the end of each day. Then the samples were digested by the USEPA ۲۴۵.۱ method. The samples were used for mercury determination by an atomic absorption spectrometer (Spectra AA ۲۲۰ FS, Varian). The results showed that the amount of mercury in the wastewater resulting from the treatment of amalgam and others (۶۸.۷۱۷۰ µg/L) was higher than in non-amalgam treatments (۰.۷۲۹۰ µg/L). The amount of mercury in the wastewater samples was higher than the maximum allowed (۰.۰۰۲ mg/L). The relationship between the type of dental treatment and the amount of mercury was significant (P<۰.۰۰۰۱). The amount of mercury in samples treated with amalgam was higher than in others. Moreover, the output of mercury from the clinic's wastewater was higher than the maximum amount recommended by the EPA. Therefore, it is necessary to monitor the mercury output of the clinics' wastewater and treat it.

کلیدواژه ها:

clinic wastewater ، cold vapor AAS ، Dental amalgam ، EPA limit ، Mercury