Assessing mercury levels in two dental clinic wastewaters in Tehran

Document Type : Short Paper

Authors
Serveh Fardi 1
Hady Mohammadi 2
1 Department of Knowledge and Information Science, Faculty of Educational Sciences and Psychology, Alzahra University, Tehran, Iran
2 Cancer and Immunology Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran
10.22034/ehpr.2025.554427.1003
Abstract
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 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). The results showed that the amount of mercury in the wastewater resulting from the treatment of amalgam and others (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). 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.

Graphical Abstract

Assessing mercury levels in two dental clinic wastewaters in Tehran

Highlights

·       Mercury in dental wastewater exceeds environmental safety limits.

·       Amalgam procedures significantly elevate clinic effluent mercury levels.

·       Clinic-specific mercury loads vary, indicating differing amalgam use or management.

·       Non-amalgam treatments show minimal mercury, below detection limits.

·       Study underscores urgent need for amalgam separators in Iranian clinics.

Keywords
Clinic Wastewater
Cold Vapor AAS
Dental Amalgam
EPA Limit
Mercury
Subjects
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Environmental Health and Pollution Research
Volume 1, Issue 1
Winter 2026
Pages 49-53

  • Receive Date 20 October 2025
  • Revise Date 09 December 2025
  • Accept Date 10 December 2025
  • First Publish Date 10 December 2025
  • Publish Date 01 January 2026