Department of Civil Engineering, Midlands, Durban University of Technology, Pietermaritzburg, South Africa.
Institute for Water and Wastewater Technology, Durban University of Technology, Durban, South Africa.
Environ Sci Pollut Res Int. 2023 Nov;30(55):118013-118024. doi: 10.1007/s11356-023-30534-4. Epub 2023 Oct 24.
A quantitative chemical risk assessment was performed using published data as well as data from the official monitoring programme for the uMsunduzi River in KwaZulu-Natal, South Africa. The chemicals assessed were organochlorinated pesticides (OCPs), pharmaceuticals and personal care products (PPCPs), heavy metals, and nitrates and phosphates. The water from uMsunduzi River is used locally without treatment. Consequently, the exposure routes investigated were via ingestion during domestic drinking and incidental ingestion during recreational activities, which were swimming and non-competitive canoeing, for both adults and children. For the individual chemicals, non-carcinogenic risks using the hazard quotient (HQ) and carcinogenic risks using the cancer risk (CR) were quantified. It was found that the exposed population is likely to experience non-carcinogenic effects from pesticides and phosphates, but not from PPCPs, heavy metals and nitrates. This study also found that the carcinogenic risks for OCPs were higher than the tolerable limit of 10, while for lead the risk was below the tolerable limit. Some of the activities that potentially contribute to chemicals onto the uMsunduzi River are subsistence farming, small plantations, illegal dumping, industries, and broken sewers. The findings of this study may act as the technical foundation for the introduction of pollution reduction measures within the catchment, including public education.
采用已发表的数据和南非夸祖鲁-纳塔尔省乌姆宗迪兹河官方监测计划的数据，对该河流域进行了定量化学风险评估。评估的化学物质包括有机氯农药（OCPs）、药品和个人护理产品（PPCPs）、重金属、硝酸盐和磷酸盐。乌姆宗迪兹河的水未经处理就在当地使用。因此，调查的暴露途径包括成人和儿童在国内饮用水时摄入以及在游泳和非竞技性皮划艇等娱乐活动中偶然摄入。对于个别化学物质，采用危害商数（HQ）评估非致癌风险，采用癌症风险（CR）评估致癌风险。结果发现，暴露人群可能会受到农药和磷酸盐的非致癌影响，但不会受到 PPCPs、重金属和硝酸盐的影响。本研究还发现，OCPs 的致癌风险高于可接受限值 10，而铅的风险则低于可接受限值。一些可能将化学物质带入乌姆宗迪兹河的活动包括自给农业、小种植园、非法倾倒、工业和破裂的下水道。本研究的结果可以作为引入集水区内减少污染措施的技术基础，包括公众教育。
