Survey of heavy metals concentration in Mashhad drinking water in 2011

Heavy metals are one of the compounds that can enter the water sources through different ways. Consumption of heavy metals in amounts that exceed standard levels is associate with risks such as toxicity and carcinogenesis and development of disease.. This study was carried out to determine heavy metals concentration (Cr،Cd &Pb) in Mashhad drinking water and its comparison with national and international standards.

This cross study was done in spring and summer 2011، samples were collected from different points of urban drinking water network according to the standard methods، and tested by atomic absorption spectrophotometeric method. Health centers were selected as sampling stations because they cover the entire city. Data were analysed by SPSS and One-way ANOVA، Paired t- test and One sample t- test on the significant level p<0. 05.

Cadmium (Cd) and Chrome (Cr) concentrations did not exceed national and international standards، only Lead (Pb) concentration was slightly higher than standard level in some areas and its mean difference in spring and summer was significant (p=0. 03)، while this difference was not significant for Cr and Cd. There was no significant correlation between the metals concentrations and water sources.

It seems the old water pipes can lead to an increase in metals concentrations particularly Pb in some areas of the city since that Cr&Cd concentrations in whole and Pb concentration in major areas were lower than the standard. There for، due to cumulative effects of these metals، it is necessary to conduct needful measures by responsible agencies.