Pheiffer Wihan, Quinn Laura P, Bouwman Hindrik, Smit Nico J, Pieters Rialet
Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa.
National Metrology Institute of South Africa, Pretoria, South Africa.
Ecotoxicology. 2018 Apr;27(3):336-351. doi: 10.1007/s10646-018-1898-4. Epub 2018 Feb 5.
Soweto and Lenasia, the most densely populated area of South Africa, is simultaneously a thriving metropolis, with a fair share of people still living in squalor conditions directly dependant on the natural resources. Because of industrialisation the populace and environment in this urban area are exposed to various pollutants. The aquatic environment was selected as a proxy to study the effect of industrial pollution in this area. The concentrations, source identification, and various environmental risks of polycyclic aromatic hydrocarbons (PAHs) were determined in sediments of the upper reaches of the Klip River. Composite sediment samples collected in low-flow conditions in 2013 and 2014 ranged from 270-5400 ng/g. The PAHs in this aquatic ecosystem were dominated by 4-ring congeners and could be attributed to combustion of organic fuels by chemical mass balance. Heavy traffic and industrial complexes in the northern part of the study area were responsible for the PAH fingerprints. Probable adverse effects such as toxicity to benthic biota were proven after comparison with international sediment quality guidelines (SQG) both survey years. Toxic equivalence quotients (TEQs) calculated for the sediments using fish potency factors (FPFs) were up to 30 times greater than the Canadian guideline for dioxin-like compounds, indicating high probability of carcinogenic effect to fish mediated through the aryl-hydrocarbon receptor. Finally, sediments in the area posed moderate to high ecological risk, which corroborates the other toxicity assessments. The advantage of investigating multiple risk endpoints, is the comprehensive results obtained that allows for a more realistic representation of the study area. Consequently more aspects are kept into account that results in better conclusions.
索韦托和莱纳西亚是南非人口最密集的地区，它同时也是一个繁荣的大都市，但仍有相当一部分人生活在直接依赖自然资源的恶劣环境中。由于工业化，该城市地区的民众和环境暴露于各种污染物中。选择水生环境作为研究该地区工业污染影响的替代对象。对克利普河上游沉积物中的多环芳烃（PAHs）浓度、来源识别及各种环境风险进行了测定。2013年和2014年在低流量条件下采集的复合沉积物样本浓度范围为270 - 5400 ng/g。该水生生态系统中的多环芳烃以四环同系物为主，通过化学质量平衡可归因于有机燃料的燃烧。研究区域北部的繁忙交通和工业园区是多环芳烃特征的来源。与两个调查年份的国际沉积物质量准则（SQG）比较后，证实了对底栖生物群等可能的不利影响。使用鱼类毒性因子（FPFs）计算的沉积物毒性当量商（TEQs）比加拿大二噁英类化合物准则高出30倍，表明通过芳烃受体对鱼类有很高的致癌效应可能性。最后，该地区的沉积物具有中度至高生态风险，这与其他毒性评估结果相符。研究多个风险终点的优势在于获得的综合结果能够更真实地反映研究区域情况。因此考虑了更多方面，从而得出更好的结论。
