Environmental and health impact of potentially harmful elements distribution in the Panyam (Sura) volcanic province, Jos Plateau, Central Nigeria

Abstract

The Panyam volcanic province is a plateau covering a superficial area of about 1200 km 2 , dotted by a number of dormant volcanoes forming prominent landmarks above the host continental gneiss-migmatite-granite rocks and stretching for about 12 km. The volcanism is basaltic, characterized by alkaline-calc-alkaline compositions. Large population of people live and depend on the volcanic environment for potable water and agriculture, most of whom display various forms of health problems ranging from dental caries, goitre, podoconiosis, etc. This study therefore seeks to evaluate the concentration levels of potentially harmful elements (PHEs) in the various components of the volcanic environment and their relationship with the inherent human health problems in the area. Volcanic soils and underground waters (springs/boreholes waters) were collected from within the volcanic province for the analysis of major cations and anions. Samples of the volcanic soils were analyzed for the following heavy elements; Be, Co, Cr, Cu, As, Cd, Pb, Sb, Se, V, and Zn. The significantly lower La/Ce ratios (0.30-0.57) in the volcanic soils attest to the moderate to slightly severe intensity of weathering the parent basaltic rock was subjected to. The waters are predominantly (80 %) of Ca-Mg-HCO 3 type with the remaining 20 % of Na-K-HCO 3 type suggesting a control by water-rock alteration process from the host granitic basement and the overlying basaltic rocks. The fluoride content in all the water sources is positively correlated with the contents of Mg 2? , Na ? , and K ? suggesting a similar source and geochemical process. Tooth decay, a common tooth disease conditions in the volcanic province, could be linked to the low F content in the waters.

Mapping the global distribution of podoconiosis: Applying an evidence consensus approach

“…The evidence in these countries is mostly from surveys and published case reports. There was moderate evidence of presence in Equatorial Guinea and Nigeria; the evidence in Equatorial Guinea was based on a survey conducted in 1988[2, 40], whereas the evidence in Nigeria is based on a case report in 2015[41]. In addition, both WHO and Price indicated the presence of podoconiosis in Equatorial Guinea and Nigeria.…”

Potential accumulation of toxic trace elements in soils during enhanced rock weathering

“…None of such adverse effects associated with farming on these soils could for instance be found in the Plateau of the Rio Grande do Sul or in the Sabzevar Range. In the Panyam Province, health issues were mainly associated with more mobile and often unregulated TE such as selenium (Lar & Gusikit, 2015). Conversely, in basaltic Xuyi County in eastern China, Wang et al (2020) reported nickel accumulations in crop grains beyond national food safety recommendations associated with ingestion health risks.…”

“…Many volcanic soils exceed indeed the legal limits presented in this study. In the basaltic Panyam province of Nigeria for instance, the nickel content in soils ranges between 89 and 411 ppm (Lar & Gusikit, 2015). In the basaltic Plateau of the Rio Grande do Sul (Brazil), soils display an average copper content of 101 ppm (Althaus et al, 2018) while the basaltic-derived soils from the Sabzevar Range in Iran contain between 85 and 109 ppm copper, 149-153 ppm nickel and 154-183 ppm chromium (Mazhari et al, 2017).…”

“…None of such adverse effects associated with farming on these soils could for instance be found in the Plateau of the Rio Grande do Sul or in the Sabzevar Range. In the Panyam Province, health issues were mainly associated with more mobile and often unregulated TE such as selenium (Lar & Gusikit, 2015).…”

“…Instead, mafic rocks such as basalts have been suggested as relatively safe sources, with nickel and chromium contents an order of magnitude lower than in ultramafic rocks (Anda et al, 2015; Beerling et al, 2018). When compared with most agricultural soils, however, basalts are still highly enriched in certain TE (Bradl, 2005; Kabata‐Pendias, 2010; Lar & Gusikit, 2015). Of special concern are nickel, chromium, copper and zinc, all known for their relatively low mobility in the soil profile as well as their toxic effects at elevated concentrations on crops, soil organisms and humans (Kabata‐Pendias, 2010; Sharma & Agrawal, 2005).…”