Toxicological Risk Assessment of Lead (Pb) Contamination in Public Water System in Lagos Metropolis, Nigeria

Abstract

Study Background: Lead continues to be a significant public health problem in developing countries, where there are considerable variations in the sources and pathways of exposure. Aim: This study investigates the level of lead in drinking water sources in Shomolu, Yaba and Bariga areas of Lagos State, Nigeria and the human risk exposure using a mice model. Materials and Methods: Water samples were collected in public water sources (borehole, sachet water, bottle water and tap water) and analyzed for lead using Flame Atomic Absorption Spectrophotometer (Varian model-AA240FS) equipped with a lead hollow cathode lamp. Contamination factor was determined. Healthy Mature female albino-mice, weighing 25.3 ± 2.5 g were exposed to the contaminated drinking water for 28 days to the different concentrations of lead nitrate: 1 mg/l, 10 mg/l, 50 mg/l, 500 mg/l and 1000 mg/l. Blood and liver were collected for hematology liver function test and histopathology. Results: Lead concentrations in public water sources in Shomolu, Bariga and Yaba areas of Lagos State were below 5.0 µg/l and contamination factor were less than 1.0. At 1.0 mg/l (1000 µg/l) Lead exposure, the relative weight increase in this group (as compared to the controlled group) was very slow, up to the 14 th day (with weight loss of 3.17 g and relative weight loss of 23.1%), then increased up to the 28 th day (with weight loss of 7.34 g, and relative weight gain of 18.4%). At 50.0 mg/l Lead exposure, there was a rapid weight decrease, a greater relative weight loss was experienced at the 14 th day (weight gain, 1.36 g and 67.0% relative weight loss), then there was weight recovery at the 28 th day (weight gain of 4.60 g, 25.8% relative weight loss). The 100.0 mg/l Lead exposed group showed steady decrease in weight, 14 th day had a weight gain of 2.02 g and relative weight loss of 51.0% while the 28 th day had 2.10 weight gain and 66.1% weight loss respectively. In the 500.0 mg/l Lead exposure group, a similar trend was observed as with 1.

Selective capacitive removal of Pb2+ ion contaminants from drinking water via nickel foam/Mn2CoO4@tannic acid-Fe3+ electrodes

“…Even trace concentrations of lead can cause damage to human brain cells and then cause damage to the hematopoietic, digestive and immune systems. 1,2 Moreover, lead is bioaccumulated, so long-term exposure to it in extremely low levels can cause damage to brain, liver, kidneys and other organs, and easily produce irreversible damage to the intelligence of infants. For these reasons, heavy metal lead ranks first in the list of environmental threats.…”