Air and heavy metal pollution around a steel foundry in Ogijo, Ogun State, Nigeria

Abstract

A whole range of bye-products from industries such as steel plants and metal processing facilities create serious pollution
to the environment, with negative health implications. In this study, we examined environmental pollution around African
Steel Foundry in Ogun State, Nigeria. Air sampling was carried out using Land Duo Multi gas monitor to determine air
pollutants such as Total Suspended Particulate Matter (TSP), Carbon monoxide (CO), Carbon dioxide (CO2), Nitrous oxide
(NO), Nitrous oxide and Nitrogen dioxide (NOx), Hydrogen sulphide (H2S) and Sulphur dioxide (SO2). Thirty soil and plant
samples were collected from Steel Foundry. Concentrations of selected heavy metals (Fe, Cu, Cd, Ni and Pb) were
determined in both soil and plant (cassava, pawpaw and maize leaves) samples using an Atomic Absorption Spectroscopy
(AAS). The results show that total suspended particulate matter (TSP) ranged from 123.46 ?gm–3-353.74 ?gm–3, while CO,
CO2, NO, NOx, H2S, and SO2 ranged from 3.20-13.33 ppm, 3.55-5.04 ppm, 1.36-5.69 ppm, 2.02- 8.50 ppm, 0.96-1.93 ppm and
1.63-3.96 ppm respectively. Some of these values exceeded the USEPA guideline limit of clean air. Mean concentrations of
Fe, Cu, Cd, Pb and Ni found in the plants and soils were below WHO guideline limit of heavy metals. The results revealed
the high concentration TSP, NO, and SO2 which may lead to health risk after long time of exposure and also accumulation
of these metals overtime may lead to contamination of the agricultural soils which eventually pose threat to organisms that
feed on the plants.