The nonionic surfactant pollution profile of Israel Mediterranean Sea coastal water

Abstract

Anionic and nonionic surfactants, as core components of detergent formulations, contribute significantly to the pollution profile of sewage and wastewaters of all kinds. In Israel about 15% of the total amount of ca. 4×108 m3/year of sewage is discharged, directly, or via receiving streams/rivers, into the Mediterranean Sea. Based on our previous findings that about 85% of the nonionic surfactants in the country's sewage are nonbiodegradable alkylphenol-based ethoxylates, we have undertaken this study, aiming at mapping the receiving eastern Mediterranean seawater with respect to its nonionic surfactant pollution profile. The total concentrations of nonionic surfactants were found – via reverse phase HPLC determinations – to be within the range of 4.2–25.0 ppb in seawater samples taken 2–3 m off the coastline at those locations where sewage-containing streams flow into the sea. Thus, neither the existing sewage treatment facilities nor natural biodegradation processes in receiving surface water systems are capable of avoiding this coastal water pollution. The potential estrogenic health risk of such concentrations of the anthropogenic EPEOs is dependent, among other things, on their specific homological distribution, biodegradation rate (slower for those having >10 EO units) and survival.