TITLE:
Heavy Metal Contamination in Soil and Purslane (Portulaca oleracea) in Bassa Industrial Zone, Douala-Cameroon: Implications for EnvironmentalHealth and Ecosystem Sustainability
AUTHORS:
Roland Lemlack Londe, Ebot Veronica Manga, Lawrence Tatanah Nanganoa, Guilen-Noel Nghokapin Tataw, Levai Nuvadga Fofung
KEYWORDS:
Ecological Risk Index, Heavy Metals, Pollution Load Index, Portulaca oleracea, Soil Contamination
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.13 No.8,
August
18,
2025
ABSTRACT: The contamination of soils with heavy metals (HMs) and their accumulation in local plants has become an increasing issue because of industrial activities. This study investigated the extent of HMs contamination in soils and Purslane (Portulaca oleracea) in the Bassa Industrial Zone, Douala-Cameroon, focusing on the implications for environmental health and ecosystem sustainability. We collected 17 surface soil samples and 4 composite purslane leaf samples from different sampling locations in the industrial site. The HMs (Cd, Pb, As, Cr, Cu and Ni) were analyzed with an Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). The results revealed that, the HM concentrations (except for Cd and Ni) in most locations exceeded the Soil Quality Guidelines for industrial land use. The Pollution Load Index confirmed the presence of heavy metal pollution in all the sample locations. Potential Ecological Risk Index highlighted varying levels of risk across locations, presenting moderate, high, and significantly high ecological risk. The primary contributors to ecological risk were Pb, Cd, and Cu. Furthermore, the geo-accumulation index revealed heavily to extremely high contamination in several locations. Principal Component Analysis suggested that Cd, As, Cr, Cu, and Ni likely originated from common sources, while Pb had a distinct source, all due to anthropogenic activities. Additionally, Cr concentrations in purslane leaves exceeded the normal range, with one location recording a value (5.41 mg kg−1) which was within the maximum toxicity threshold for plants. These findings underline the need for remedial measures to mitigate the adverse effects of heavy metal contamination in the Bassa Industrial Zone.