石油および環境バイオテクノロジージャーナル

概要

Health Risk Assessment and Statistical Modeling of Toxic Metals in Groundwater of Lahore, Pakistan

Iqra Khalid*

The groundwater of Lahore is now in great concern due to heavy metal pollution. That's why; carcinogenic and noncarcinogenic health risk assessment of the consumption of groundwater is currently needed. The objective of this research is to determine the heavy metals concentration in groundwater and to evaluate its potential health risks for the lifetime of exposure for residents using the USEPA model and probabilistic technique (monte carlo simulation).
The groundwater samples were collected from selected sampling sites of the study area and analyzed for physicochemical parameters, and heavy metals. Descriptive statistics showed that the mean concentration of Pb (0.77), Cr (1.828), and Ni (0.35) were higher than PEQS standards for drinking water while values of other parameters were within guidelines. The results of descriptive statistics and box whisker plots showed most of the data showed an un-symmetrical distribution of the parameters. Pearson correlation matrix showed that heavy metals correlate with physicochemical parameters. ANOVA results also supported the Pearson correlation matrix. The findings of PCA and CA identified the possible sources of pollution, i.e. Industrial discharges, landfill leachates, sewage effluent discharges, and leakage from sewers. EF was calculated with a reference metal i.e. Ca and the trend observed was Pb>Cr>Ni>Mg>As>Zn. Based on the total hazard quotient (HQing+HQder) the trend of heavy metals was found Cr>Pb>As>Ni>Zn for children, adult males, and adult females. The hazard index values (upto 79.12), (75.25), and (59.42) were calculated for children, adult males and, adult females respectively which showed high probability of non-carcinogenic risks. The Hazard Quotient (HQs) values for children (upto 57.89), for adult males (upto 55.18) and adult females (upto 45) were greater one (>1) for Cr, Pb, Ni and as, which indicates a significant non-cancer risk. Similarly, the cancer risk trend observed was of the order of Cr>Ni>As>Pb. While the cancer risk assessment has shown that 25 people could have carcinogenic effects of each 100 population. By monte carlo simulation, the Cancer risk trend observed was Cr>Ni>As>Pb for all age groups. The total hazard quotient trend observed was Cr>Pb>As>Ni>Zn which suggested that Cr has high probability of health risks in this study area.