Environmental monitoring of the sediment pollution along the Thai-Laos Mekong

The Mekong is an essential source of water and protein for the denizens of Thai Laos countries. However historic pollution is adversely affecting the water and sediment quality that threatens the short- and long-term supply-use of this major river system. This can have a major impact on the health and population of the marine life and ultimately adversely affect human health and the economy for both countries. As a first stage in the assessment of the scale and extent of the pollution problem, an in-depth program of sampling and analysis has been carried out for both water and sediments for three seasons since 2000. A range of water quality parameters were measured from ten sampling stations. These included the PolyAromatic Hydrocarbons (PAHs) initially measured as chrysene equivalents, then as individual compounds of fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene, and indeno(1,2,3,cd)pyrene. A range of heavy metals were measured including chromium, cadmium, mercury, copper, zinc, lead, and titanium. This paper presents the results of the field study to date and provides a preliminary evaluation of the extent of the pollution and potential for bioaccumulation within the local food chain.