Linear Alkylbenzene Sulphonate in Freshwater Ecosystems: Sources, Persistence, Bioaccumulation and Impacts on Fish Health – A Critical Review

Abstract

Linear alkylbenzene sulphonate (LAS) is one of the most widely used anionic surfactants and so it is used mainly in detergents for the household, cleaning, and personal care products. The massive quantity of LAS consumed makes it very often introduce into freshwater environments through different routes such as domestic sewage, industrial discharge, and urban drainage. Environmental monitoring data collected from different places show that LAS levels in surface waters are usually between 0.01 to 1.2 mg L⁻¹ and in untreated sewage systems it is much higher ranging from 5 to 20 mg L⁻¹. Although LAS is recognized as readily biodegradable under aerobic conditions, its environmental persistence in sediment and oxygen-depleted zones increases with degradation half-lives of 30-40 days. Studies on bioaccumulation performed on different types of fish have already shown the existence of bioconcentration factors in the range of 100 to 500, where variation comes mainly from the differences in the length of alkyl chains. The chronic exposure scenarios reveal that Las (Linear Alkylbenzene Sulfonates) have a negative impact on fish health through various physiological mechanisms such as damage to gill tissues, the development of oxidative stress, disturbance of the activity of enzymes, and the impairment of the reproductive system. The current paper reviews very comprehensively the whole process of exposure of freshwater fish to LAS, which includes the sources in the environment, fate processes, bioaccumulation dynamics, and toxicological consequences, especially the ecological risks linked with the continuous low-level exposure of the aquatic systems receiving wastewater inputs to the environment.

Keywords: water pollution, cuticle agent, piscine toxicity, Shrimp batter, additional environmental endurance, and seepage of wastewater