Pollution status, ecological and human health risks of heavy metals in soil from some selected active dumpsites in Southeastern, Nigeria using energy dispersive X-ray spectrometer

Abstract

ABSTRACT Thestudyevaluatedthepollutionstatus, ecologicalandhumanhealthrisksofheavymetalsin some selected active dumpsite[Aba(dumpsite-1), Nnewi (dumpsite-2), Abakaliki (dumpsite-3) and Nekede (dumpsite-4)] in south-eastern Nigeria. Quintuplicate sub-samples were collected using soil auger at a depth of 0–20 cm from four different points (North, East, West and South) of each dumpsite while control samples for each dumpsite were collected 20 km away, where there were little human activities and no presence of active dumpsites. Elemental analysis was carried out on samples using energy dispersive x-ray fluorescence spectrometer. Ten heavy metals selected were in the order; dumpsite-1 (Cu > Fe > Pb > Zn > As > Co > Ni > Mn > Cr > Cd), dumpsite-2 (Fe > Pb > Zn > Cu > Co > Mn > Ni > As > Cr > Cd), dumpsite-3 (Fe > Zn > Mn > Ni > Co > Cu > Pb > As > Cr > Cd) and dumpsite-4 (Fe > Zn > Pb > Co > Ni > Cu > Mn > Cr > As > Cd). Pollution status of the dumpsites was determined using metal pollution index, enrichment factor, pollution load index, and geoaccumulation index. The dumpsites studied were polluted in the order; dumpsite-1> dumpsite-2> dumpsite-4 > dumpsite-3. Health risk evaluation by ingestion, inhalation and dermal pathways for adults and children was modelled. Results showed children are more at risk than adult with As, Pb and Ni identified with the highest risks. The ingestion exposure pathway was the major contributor to both non-cancer and excess lifetime cancer risk followed by dermal and then inhalation. This quantitative evidence demonstrates the need for remediation of soils within dumpsites so as to protect residents, especially children from heavy metal pollution in the environment.