Presence of heavy metals in drinking water resources of Iran: a systematic review and meta-analysis

• Published in: Environmental science and pollution research international Vol. 28; no. 21; pp. 26223 - 26251
• Main Authors: Ravanipour, Masoumeh, Hadi, Mahdi, Rastkari, Noushin, Hemmati Borji, Saeedeh, Nasseri, Simin
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2021; Springer Nature B.V
• Subjects: Aluminum; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Cadmium; Chromium; Copper; Drinking behavior; Drinking water; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Groundwater; Heavy metals; Heterogeneity; Iron; Lead; Literature reviews; Manganese; Meta-analysis; Metal concentrations; Metals; Molybdenum; Nickel; Pollutants; Public health; Review Article; Reviews; Selenium; Subgroups; Surface water; Surface-groundwater relations; Systematic review; Vanadium; Waste Water Technology; Water Management; Water Pollution Control; Water quality; Water resources; Iran; Drinking water; Groundwater; Iran; Surface water; Systematic review; Heavy metals; Meta-analysis
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-021-13293-y

Water quality is one of the most important indices for public health especially for drinking water consumptions. This study was conducted to survey the presence of heavy metals in drinking water resources of Iran using a systematic review and meta-analysis. The literature search was conducted in data bases of PubMed, Web of Science, EMBASE, Scopus, Google Scholar, and some Persian databases up to 31 July 2018. Of all the articles reviewed (1151 articles), 61 papers were eligible for systematic review. Results indicated variable heterogeneity between studies for different pollutants ( I 2 between 0 and 100). A subgroup analysis was performed for three different types of water resources such as drinking water, groundwater, and surface water to find the possible source of the heterogeneity. The pooled mean concentration level of iron was the highest at 255.8 (95% CI = 79.48–432.13 μg/l) and vanadium the lowest at 3.21 (95% CI = 1.45–4.98 μg/l). The sequence of metal concentration (μg/l) in descending order is as follows: Fe (255.8) > B (159.81) > Al (158.5) > Zn (130.73) > As (85.85) > Mn (51.61) > Cu (47.98) > Se (42.68) > Pb (37.22) > Co (22.76) > Mo (18.92) > Ni (16.79) > Cr (13.47) > Hg (4.49) > Cd (4.19) > V (3.21). The mean pooled concentration level of Al, As, Se, Pb, and Cd was higher than the WHO guideline and Iran Standard, and the rest of the metals had lower mean pooled concentration level. Pb and Cd were the common heavy metals that existed in all subgroups. As a recommendation, the relationship assessment of water parameters and heavy metals could be addressed in future studies of Iran’s water resources. Graphical abstract