RESUMEN

The problem of environmental pollution is a global concern as it affects the entire ecosystem. There is a cyclic revolution of pollutants from industrial waste or anthropogenic sources into the environment, farmlands, plants, livestock and subsequently humans through the food chain. Most of the toxic metal cases in Africa and other developing nations are a result of industrialization coupled with poor effluent disposal and management. Due to widespread mining activities in South Africa, pollution is a common site with devastating consequences on the health of animals and humans likewise. In recent years, talks on toxic metal pollution had taken center stage in most scientific symposiums as a serious health concern. Very high levels of toxic metals have been reported in most parts of South African soils, plants, animals and water bodies due to pollution. Toxic metals such as Zinc (Zn), Lead (Pb), Aluminium (Al), Cadmium (Cd), Nickel (Ni), Iron (Fe), Manganese (Mn) and Arsenic (As) are major mining effluents from tailings which contaminate both the surface and underground water, soil and food, thus affecting biological function, endocrine systems and growth. Environmental toxicity in livestock is traceable to pesticides, agrochemicals and toxic metals. In this review, concerted efforts were made to condense the information contained in literature regarding toxic metal pollution and its implications in soil, water, plants, animals, marine life and human health.

Asunto(s)

Metales Pesados/toxicidad , Contaminantes del Suelo/toxicidad , Animales , Organismos Acuáticos , Ecosistema , Monitoreo del Ambiente , Humanos , Minería , Plantas , Suelo , Sudáfrica

RESUMEN

Food security remains an important aspect of human lives and the vital role of soil in the global agricultural and food crops production is obvious. The quality of agricultural products which is being consumed by human through the food chain is dependent on the condition of the soil. Previous gold mining activities resulted in the discharge of tailing materials containing various hazardous trace metals such as manganese (Mn), nickel (Ni), arsenic (As), cadmium (Cd), cobalt (Co), copper (Cu), chromium (Cr), lead (Pb), and zinc (Zn). 20 representative soil samples were collected from the Gold one Mine tailing dump located in Ekuhurleni, Gauteng Province, South Africa and used in describing the prevalence and concentrations of selected trace metals using inductively coupled plasma optical emission spectrometry (ICP-OES). The concentration of identified trace metals in decreasing order is as follows: Cr > Al > As > Fe > Pb > Co > Ni > Ti > Cd > Zn > Cu. Contamination levels of trace metals in the soils were evaluated using various pollution indices such as contamination factor, degree of contamination, geo-accumulation index, pollution load index and the United States Environmental Protection Agency. These evaluations revealed a high degree and the ultra-high degree of contamination classes of soils. Based on the observed concentrations of trace metals and contamination levels, this study strongly support the call for analysis of the nearby stream and drinking water quality, including the staple crops that are cultivated within the vicinity of the dump site, to ascertain the levels of heavy metals within such crops. Stringent mitigation plans or conversion of the tailing dump into value-added products should be considered.