Highly branched alkylbenzenesulfonate surfactants(ABS) were used in detergents in industrialized countries in the past. ABS were replaced by LAS in industrialized
countries in the 1960s because they were found to have poor biodegradability. Nevertheless, TABs, the precursors for the ABS, are found in sediments [6,25,28] as well
as in marine organisms [22]. This is partly because TABs are recalcitrant to degradation and well preserved in sediments. Detection of TABs in surface sediments can
be ascribed to mixing of sediments deposited in 1960s into surface sediments through vertical mixing and remobilization of sediments in the coastal zone. This
can also partially explain the detection of TABs in sediments in the present study, especially in coastal sediments such as those collected from Manila Bay. However, Tsutsumi et al. [22] reported that the presence of TABs in green mussels collected from South and Southeast Asian coasts indicates that non-degradable surfactants are still being used in some Asian countries.In fact, they confirmed that the commercially available synthetic detergents in Jakarta contained ABS [22]. The fact that the TABs concentrations in sediments from Jakarta and Phnom Penh City were comparable to or
even exceeded LABs concentrations further supports the current usage of ABS detergents in the region.