Quality Assessment and Potentially Toxic Metals Related Human Health Risks of Groundwaters Close to Electrical Waste Dumpsites in Lagos, Nigeria

The quality and potentially toxic metals associated human health risks of groundwaters near the Alaba and Olusosun electronic waste dumpsites in Lagos, Nigeria was assessed. Groundwater samples were collected and analysed for their physicochemical properties and potentially toxic metals. Using a Microwave Induced Plasma Optical Emission Spectrometer potentially toxic metals were analysed. Electrical conductivity, nickel and lead of groundwater samples ranged from 30.00 ± 2.01 to 5910 ± 3 µS/cm, 0.007 ± 0.006 to 0.3602 ± 0.0105 mg/L and 0.0296 ± 0.0108 to 0.0660 ± 0.0033 mg/L, respectively. The water quality index, heavy metal pollution index, heavy metal evaluation index, and ecological risks index of the samples ranged from 97 to 1049, 162 to 3936, 24.4 to 120.6 and 490 to 1391 respectively. Base on water quality index, values 75% of the groundwater samples were unfit for drinking. Heavy metal pollution index and heavy metal evaluation index values showed that all of the water samples were heavily contaminated with potentially toxic metals and ecological risks index values showed that all of the groundwater were associated with high ecological risk. These groundwater bodies poses cancer risk of 10.7 × 10–1 to 1783.3 × 10–1 to children and 3.7 × 10–1 to 3371.7 × 10–1 for adult if used as drinking water sources. These cancer risks are unacceptable because they are above the United States Environmental Protection Agency acceptable range of 1 in 10,000 chances of developing cancer. This study demonstrated that there are ecological and human health problems associated with the groundwater near electronic waste dumpsites.