Sterols as biomarkers in the surface microlayer of the estuarine areas

Steroid Fingerprint Analysis of Endangered Caspian Seal (Pusa caspica) through the Gorgan Bay (Caspian Sea)

“…In addition, the sedimentological features of Gorgan Bay and its adjacent areas indicate that the grain-size distribution of sediments in the bottom of the bay is associated with the sterol accumulations, since it is in the mud (i.e., silt and clay, particle sizes <63 μm) to sand (a sieve size >63 μm) range, with sand content increasing eastward, and the mean value of 30% OM in sediments of Gorgan Bay that decreases toward the inlet of the bay . In view of time, the high level of sterols observed herein during the wet season (December) indicates the influence of the seasonal movement of river runoff and agricultural/domestic wastewater (containing sterols) from residential/local areas into the bay watershed system …”

“…Fecal sterols and stanols, unsaturated steroid alcohols, are ubiquitous stable organic compounds with a fused ring structure. In aquatic systems, due to their hydrophobic nature, sterols are easily transferred from aqueous to organic phases, which are resistant to degradation in the environmental matrices, that is, sediments, suspended particulate materials (SPMs), and water, − and can also effect on metabolic and reproductive potential of aquatic organisms, that is, marine mammals . Sterols and their ratios (human/animal and plant steroids) have been used as reliable chemical markers to source assignment of long-term contamination of natural OM (e.g., fecal pollution), to the health state of current and past environmental systems as well as indicators of the level of sewage treatment and/or human interference. ,,, …”

A Unique Monitoring Method for Fecal and Sewage-Derived Chemical Pollution Utilizing International Pellet Watch Approach

“…7,8 Previous studies have demonstrated the utility of measuring fecal sterols, stanols, and stanones as chemical markers for source tracking of fecal contamination in both marine and freshwater environments. 6,9,10 Among the sterols, coprostanol (5β-cholestan-3β-ol), produced in the digestive tract of humans and higher vertebrates, has been widely used, along with other sterols, to indicate the presence of sewage in water environments. 11 Coprostanol constitutes approximately 60% of the total sterols excreted in human feces and has emerged as a powerful chemical marker for monitoring fecal contamination across different environmental matrices.…”