Spatial distribution and source apportionment of potentially toxic elements in residential soil from Nsuta, a typical manganese mine community in Tarkwa, Southwestern Ghana

The environmental quality of residential areas of urban communities has been threatened by rapid industrial growth, substantial technological innovation, and urban expansion. The present study provides chemometric receptor model-based source apportionment, the ecotoxicological status, and the spatial distribution of arsenic, cadmium, lead, mercury, manganese and iron in residential soils in a mining community in Tarkwa. The distributions of the heavy metals showed a widespread pattern, while the eastern fringe of the study area was identified as a hotspot for mercury contamination. Agreement among the cluster analysis (CA), principal component analysis (PCA), and positive matrix factorization (PMF) along with the correlation matrix (CM) reasonably identified the sources of arsenic, manganese, and iron contamination of residential soils of the Nsuta community to be governed by geogenic influences such as the weathering and hydromorphic dispersion from the metavolcanic rocks. Noteworthily, atmospheric deposition is considered a prioritized source for mercury contamination, with a PMF contribution of 78.50%. Vehicular emission as well as other anthropogenic activities contribute to lead (48.00%) and cadmium (66.20%) contamination of the residential soil within the study area. Ecotoxicological assessment reveals a combined toxic risk index (TRI) of 29.80, with mercury contributing to about 97.50% of the total risk. Moreover, the modified hazard quotient (mHQ_i) for the single metals also indicated that mercury (Hg) has the highest ecological toxicity level with a mHQ_i value of 7.00. The present study provides baseline data that could be valuable for proper environmental management and policy-making to reduce the myriad influx of heavy metal contamination in the study area. To provide a thorough understanding of metal pollution in the Nsuta community, future research on metal speciation, bioavailability, bioaccumulation, potential modes of action in soils, and the implications for human health is also necessary.