GREENS TRUST Environmental Health and Pollution Research 3115-9281 1 1 2026 01 01 Assessing mercury levels in two dental clinic wastewaters in Tehran 49 53 235897 10.22034/ehpr.2025.554427.1003 EN Serveh Fardi Department of Knowledge and Information Science, Faculty of Educational Sciences and Psychology, Alzahra University, Tehran, Iran 0009-0000-5592-5068 Hady Mohammadi Cancer and Immunology Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran 0009-0007-8932-1028 Journal Article 2025 10 20 <span style="font-size: 10.0pt; line-height: 107%; font-family: 'Times New Roman',serif; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-bidi-font-family: 'B Nazanin'; color: black; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: FA;">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.<strong> </strong>We collected 30 wastewater samples from two dental clinics at the end of each day. Then the samples were digested by the USEPA 245.1 method. The samples were used for mercury determination by an atomic absorption spectrometer (Spectra AA 220 FS, Varian).</span><span dir="RTL" style="font-size: 10.0pt; line-height: 107%; font-family: 'B Nazanin'; mso-ascii-font-family: 'Times New Roman'; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-hansi-font-family: 'Times New Roman'; color: black; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: FA;"> </span><span style="font-size: 10.0pt; line-height: 107%; font-family: 'Times New Roman',serif; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-bidi-font-family: 'B Nazanin'; color: black; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: FA;">The results showed that the amount of mercury in the wastewater resulting from the treatment of amalgam and other</span><span lang="EN-GB" style="font-size: 10.0pt; line-height: 107%; font-family: 'Times New Roman',serif; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-bidi-font-family: 'B Nazanin'; color: black; mso-ansi-language: EN-GB; mso-fareast-language: EN-US; mso-bidi-language: FA;">s </span><span style="font-size: 10.0pt; line-height: 107%; font-family: 'Times New Roman',serif; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-bidi-font-family: 'B Nazanin'; color: black; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: FA;">(68.7170 µg/L) was higher than in non-amalgam treatments (0.7290 µg/L). The amount of mercury in the wastewater samples was higher than the maximum allowed (0.002 mg/L). The relationship between the type of dental treatment and the amount of mercury was significant (P<0.0001).</span><span dir="RTL" style="font-size: 10.0pt; line-height: 107%; font-family: 'B Nazanin'; mso-ascii-font-family: 'Times New Roman'; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-hansi-font-family: 'Times New Roman'; color: black; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: FA;"> </span><span style="font-size: 10.0pt; line-height: 107%; font-family: 'Times New Roman',serif; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-bidi-font-family: 'B Nazanin'; color: black; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: FA;">The amount of mercury in samples treated with amalgam was higher than in other</span><span lang="EN-GB" style="font-size: 10.0pt; line-height: 107%; font-family: 'Times New Roman',serif; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-bidi-font-family: 'B Nazanin'; color: black; mso-ansi-language: EN-GB; mso-fareast-language: EN-US; mso-bidi-language: FA;">s</span><span style="font-size: 10.0pt; line-height: 107%; font-family: 'Times New Roman',serif; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-bidi-font-family: 'B Nazanin'; color: black; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: FA;">. Moreover, the output of mercury from the clinic's wastewater was higher than the maximum amount recommended by the EPA.</span><span style="font-size: 10.0pt; line-height: 107%; font-family: 'Times New Roman',serif; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-bidi-font-family: 'B Nazanin'; color: black; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> </span><span style="font-size: 10.0pt; line-height: 107%; font-family: 'Times New Roman',serif; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-bidi-font-family: 'B Nazanin'; color: black; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: FA;">Therefore, it is necessary to monitor the mercury output of the clinics' wastewater and treat it.</span> https://www.ehpr.ir/article_235897_ad2de94f49c14bd7feaa6cb3befcfeb6.pdf