en تخصصي Special مقاله اصیل Original Article <div style="text-align: justify;">Background: Wastewater treatment plants are important sources of emissions of greenhouse gases (GHSs) such as carbon dioxide and methane in the atmosphere. Also, energy consumption in the wastewater treatment process causes indirect carbon dioxide emissions.<br> Methods: One hundred thirty-three operating wastewater treatment plants in Iran treat municipal wastewater. The carbon dioxide and methane emissions from the wastewater treatment plants for the year 2022 were estimated by establishing a calculation model according to the methods recommended<br> by the Intergovernmental Panel on Climate Change for National Greenhouse Gas Inventories (2006) and United States Environmental Protection Agency (USEPA) guidelines.<br> Results: Based on the Intergovernmental Panel on Climate Change guideline, the total methane emission was 158.63 tons. Based on the USEPA guideline, the total emissions of methane and carbon dioxide were 47.61 and 351.47 tons, respectively. This amount is 3.2% of all the methane and carbon dioxide emissions of Iran. Isfahan and Tehran provinces have the highest emissions rates of methane at 31.85 and 22.91 tons, respectively. While South Khorasan and Kerman provinces have the lowest methane emissions rates of 0.46 and 0.67 tons, respectively.<br> Conclusion: The results will provide a scientific basis and effective strategies for policymakers to reduce the methane and carbon dioxide emissions from the wastewater treatment plants of Iran.</div> Methane, Carbon dioxide, Greenhouse gases, Wastewater, Iran 161 166 http://ehemj.com/browse.php?a_code=A-10-1-341&slc_lang=en&sid=1 Kamyar Yaghmaeian kamyar.yaghmaeian@gmail.com 100319475328460015316 100319475328460015316 No Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran Masoud Panahi Fard masoudpanahifard@gmail.com 100319475328460015317 100319475328460015317 No Student Research Committee, School of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran Mehdi Ahmadi Moghadam Ahmadi241@gmail.com 100319475328460015318 0009-0007-2207-8692 No Environmental Technologies Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran Maryam Mousavi MARYAM.MUSAVI@gmail.com 100319475328460015319 100319475328460015319 No Student Research Committee, School of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran Neematollah Jaafarzadeh N.jaafarzade@gmail.com 100319475328460015320 100319475328460015320 Yes Corresponding author: Environmental Technologies Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran Maryam Omidinasab omidinasab.maryam@gmail.com 100319475328460015321 100319475328460015321 No Department of Environmental Health Engineering, Abadan Faculty of Medical Sciences, Abadan, Iran Bamshad Shenavar bamshadshenavar@yahoo.com 100319475328460015322 100319475328460015322 No Human Environment Office of the Khuzestan Department of Environment, Ahvaz, Iran Rozhan Feizi rozhanfeizi@gmail.com 100319475328460015323 100319475328460015323 No Student Research Committee, School of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran