Natural Resources and the Environment, Council for Scientific and Industrial Research, PO Box 320, 7599, Stellenbosch, South Africa.
Environment and Health Research Unit, South African Medical Research Council, Corner of Sherwell and Beit Streets, Health Clinic Building, University of Johannesburg, Johannesburg, South Africa.
Chemosphere. 2018 May;199:1-9. doi: 10.1016/j.chemosphere.2018.01.160. Epub 2018 Feb 1.
Anthropogenic pollution was identified as an environmental problem of concern when, in 2008, dozens of crocodiles died in the Olifants River catchment near the border of South Africa and Mozambique. Given the close proximity of households to the river and their making use of river water, we aimed to determine to what extent water pollution has an impact on health of indigent communities in South Africa and Mozambique in the catchment area.
Water and vegetable samples were collected from the study areas. Biota samples were washed with double de-ionized Milli-Q water and freeze-dried. Heavy metal analyses in water and vegetables were done by means of Inductively Coupled Plasma Optical Emission Spectroscopy. Metal concentrations were applied in a human health risk assessment to estimate health risks.
Mean concentrations of antimony, arsenic, cadmium, chromium, mercury, molybdenum, nickel and selenium in water samples from South Africa exceeded the World Health Organization guidelines for safe levels of intake. Only iron exceeded the recommended guidelines in water samples from Mozambique. Metals/metalloids were found in lower concentrations at Mozambique sites downstream of South African sites. In vegetables, uranium was between 10 and 20 times above safe guidelines in South Africa and between 3 and 6 times in Mozambique. Arsenic in water samples posed the highest cancer risk.
Even with a reduction in the metal concentrations in river water from South Africa to Mozambique, the potential to cause adverse human health impacts from direct use of polluted river water is evident in both countries.
2008 年，数十只鳄鱼在南非和莫桑比克边境附近的奥利凡茨河集水区死亡，人为污染被确定为一个令人关注的环境问题。鉴于家庭与河流的距离如此之近，以及他们对河水的利用，我们旨在确定在多大程度上水污染会对集水区南非和莫桑比克贫困社区的健康造成影响。
从研究区域采集水和蔬菜样本。生物样本用双去离子 Milli-Q 水清洗并冷冻干燥。通过电感耦合等离子体发射光谱法对水和蔬菜中的重金属进行分析。金属浓度应用于人体健康风险评估，以估计健康风险。
南非水样中锑、砷、镉、铬、汞、钼、镍和硒的平均浓度超过世界卫生组织安全摄入水平指南。只有莫桑比克水样中的铁超过了推荐的指南。南非水样下游的莫桑比克水样中金属/类金属的浓度较低。在蔬菜中，铀在南非的安全标准的 10 到 20 倍之间，在莫桑比克的安全标准的 3 到 6 倍之间。水样中的砷造成的癌症风险最高。
即使南非河水中的金属浓度降低到莫桑比克，直接使用受污染河水对两国人类健康造成不利影响的可能性仍然存在。
