Multivariate statistical assessment of heavy metal pollution sources of groundwater around a lead and zinc plant

The contamination of groundwater by heavy metal ions around a lead and zinc plant has been studied. as a casestudy groundwater contamination in bonab industrial estate (zanjan-iran) for iron, cobalt, nickel, copper, zinc,cadmium and lead content was investigated using differential pulse polarography (dpp). although, cobalt, copperand zinc were found correspondingly in 47.8%, 100.0%, and 100.0% of the samples, they did not contain thesemetals above their maximum contaminant levels (mcls). cadmium was detected in 65.2% of the samples and17.4% of them were polluted by this metal. all samples contained detectable levels of lead and iron with 8.7% and13.0% of the samples higher than their mcls. nickel was also found in 78.3% of the samples, out of which 8.7%were polluted. in general, the results revealed the contamination of groundwater sources in the studied zone. thehigher health risks are related to lead, nickel, and cadmium ions. multivariate statistical techniques were applied forinterpreting the experimental data and giving a description for the sources. the data analysis showed correlationsand similarities between investigated heavy metals and helps to classify these ion groups. cluster analysis identifiedfive clusters among the studied heavy metals. cluster 1 consisted of pb, cu, and cluster 3 included cd, fe; also eachof the elements zn, co and ni was located in groups with single member. the same results were obtained byfactor analysis. statistical investigations revealed that anthropogenic factors and notably lead and zinc plant andpedo-geochemical pollution sources are influencing water quality in the studied area.