Organic micropollutants in the environment: concerns and impacts

The paper presented the global distribution of water which showed that only a small percentage is available for human consumption, in fact, some areas do not really have access to potable water. Standard water regulations mandated by WHO, EU and USEPA on the acceptable levels of organic substances in drinking water were also compared. The use of disinfectants such as chlorine compounds in treating waters especially for drinking purposes may produce toxic and hazardous by-products (DBPs) like trihalomethanes (THMs) which have been known to be either mutagenic, carcinogenic or teratogenic. The results of 2 research papers were briefly discussed: a) polycyclic aromatic hydrocarbons or PAHs (listed as 16 priority pollutants by USEPA) analysis on water, sediment and biota of Laguna de Bay [Philippines] (with Prof. C.R. Barril, L.S.P. Madamba and T.E. Tumlos). Naphthalene was present in all water samples (1.96-21.52 ug/L) but none in sediment samples. Benzo (a) pyrene levels of 0.33 to 1.41 ug/L were detected in the South and West Bays. Napindan Channel showed 14 PAHs compounds with most highest levels in the sediment samples. Fish and shrimp samples showed concentrations of 0.17 to 1.68 mg/kg. b) Linear and branched alkyl benzenesulfonates analysis in some tributaries of Laguna de Bay up to Pasig river (a collaborative study with Dr. Thomas Knepper of ESWE, Weisbaden, Germany). Anionic surface-active agents such as alkylbenzensulfonates are widely used in households as detergents but the manufacture and use of these chemicals have been banned due to environmental problems especially in the waterways. Six samples were taken from tributaries and streams along Laguna de Bay to assess the levels of ABS and LAS (linear type) as well as their homologues. Degradation of these detergents can be followed from upstream to downstream by comparing their homologue distribution