zahra ahmadli department of environmental health engineering, school of public health, qom university of medical sciences, qom, iran. mohammad fahiminia research center for environmental pollutants, qom university of medical sciences, qom, iran. reza ansari qom water and wastewater company, qom, iran. maryam savadkouhi department of environmental health engineering, school of public health, qom university of medical sciences, qom, iran. azita anbaz department of environmental health engineering, school of public health, qom university of medical sciences, qom, iran. akbar escandari department of environmental health engineering, school of public health, qom university of medical sciences, qom, iran.