Human health risk of heavy metal contamination in groundwater and source apportionment

The local community residing in vicinity of cities in Pakistan utilizes groundwater for drinking purpose. The peri-urban areas of all cities are under wastewater irrigation, a common practice for vegetable cultivation. The study ascertained the human health risk from consuming heavy metals contaminated groundwater in vicinity of Multan city, Pakistan. Groundwater samples (n = 60) from six irrigation sites (four wastewater outlets, one canal and one tube-well water locations) were collected and analyzed for cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni) and lead (Pb) by inductively coupled plasma-optical emission spectrometry (ICP-OES). Samples of wastewater and soils from each site were also analyzed for the same metals for multivariate statistical analysis. Total target health quotient (TTHQ) of groundwater under wastewater irrigation fields ranged from 1.02 to 2.98 indicating carcinogenic risk to exposed population. TTHQ of groundwater under canal water site was 1.02 in children aged 4-15 years and < 1.0 for adults indicating carcinogenic health risk for child group and safe for adults. The groundwater under tube-well water irrigated site was health risk free. Multivariate statistical analyses showed the wastewater and soil as sources of groundwater contamination across all agricultural farms. The use of treated wastewater for irrigation may save the quality of groundwater. We suggest to monitor and evaluate the groundwater quality continuously to take preventive measures.

Automated summary

The study in Pakistan revealed a potential carcinogenic risk from heavy metal contaminated groundwater near the city of Multan, with groundwater under wastewater irrigation fields posing a higher health risk compared to tube-well water sites. The analysis suggests that monitoring and treating wastewater for irrigation could help preserve the quality of groundwater and reduce health risks to the local community.