Sterols in marine sediment and fauna at Davis station 2009/10

Wastewater containing human sewage is often discharged with little or no treatment into the Antarctic marine environment. Faecal sterols (primarily coprostanol) in sediments have been used for assessment of human sewage contamination in this environment, but in situ production and indigenous faunal inputs can confound such determinations. Using GC-MS profiles of both C27 and C29 sterols, potential sources of faecal sterols were examined in near shore marine sediments, encompassing sites proximal and distal to the wastewater outfall at Davis Station, Antarctica. Faeces from indigenous seals and penguins were also examined. Several indigenous species faeces contained significant quantities of coprostanol but not 24-ethylcoprostanol, which is present in human faeces. In situ coprostanol and 24-ethylcoprostanol production was identified by co-production of their respective epi-isomers at sites remote from the wastewater source and in high total organic matter sediments. A C29 sterols-based polyphasic likelihood assessment matrix for human sewage contamination is presented which distinguishes human from local fauna faecal inputs and in situ production in the Antarctic environment. Sewage contamination was detected up to 1.5 km from Davis Station.Abstract from - Rhys Leeming, Jonathan S. Stark, James J. Smith (2014), Novel use of faecal sterols to assess human faecal contamination in Antarctica: a likelihood assessment matrix for environmental monitoring.

携带人类生活污水的废水常未经处理或仅经轻度处理，即被排放至南极海洋环境中。沉积物中的粪便甾醇（faecal sterols，主要为粪甾醇（coprostanol））曾被用于评估该环境中的人类生活污水污染状况，但原位生成（in situ production）过程与本土动物源输入会干扰此类判定结果。本研究通过分析C27与C29甾醇的气相色谱-质谱联用仪（GC-MS）谱图，对南极戴维斯站（Davis Station）污水排放口附近及远端的近岸海洋沉积物中粪便甾醇的潜在来源展开了检测，同时对本土海豹与企鹅的粪便样本进行了分析。部分本土物种的粪便中含有大量粪甾醇，但不含人类粪便中存在的24-乙基粪甾醇（24-ethylcoprostanol）。在远离污水源的采样点以及总有机质含量较高的沉积物中，研究通过同时检测粪甾醇与24-乙基粪甾醇各自的差向异构体（epi-isomers），证实了二者的原位生成过程。本研究构建了一套基于C29甾醇的人类生活污水污染多相似然评估矩阵，可在南极环境中区分人类源、本土动物源粪便输入以及原位生成的粪便甾醇。研究在距离戴维斯站1.5公里的范围内均检测到了污水污染痕迹。——摘自理斯·利明、乔纳森·S·斯塔克、詹姆斯·J·史密斯（2014）《粪便甾醇在南极人类粪便污染评估中的新应用：环境监测用似然评估矩阵》