The origin of faeces by means of biomarker detection.

One of the defining characteristics of a biomarker is the retention, during diagenesis, of structural characteristics indicative of its original biogenic source (Peters and Moldowan, 1993). Since the 1960s an increasing interest has developed in the use of environmental biomarker compounds to monitor levels of human and animal waste introduced to marine and terrestrial environments; the relative stability of these compounds enabling both spatial and long-term temporal studies to be realized (e.g., Walker et al., 1982; Vivian, 1986; Evershed and Bethell, 1996 and references therein). The specificity of particular biomarkers for different faecal sources makes their use particularly attractive especially in circumstances where deducing the origin of sewage constituting a pollution event is crucial. Research into organicmatter in the marine and terrestrial environments over the last 20 years has led to the development of two main groups of organic compounds found in faecal matter that can be used to monitor sewage, namely: 5b-stanols and bile acids. This communication provides an overview for researchers not necessarily familiar with molecular methods of sewage monitoring. The two compound classes will be considered separately, and then their integration and future development discussed.