Environmental Fate and Transportation of Cadmium, Lead and Manganese in a River Environment using the EPISUITE Program

Abstract

The Mekong River is an essential source of water and protein for the inhabitants of Thailand and the Lao Peoples’ Democratic Republic. It is hypothesized that pollution may be adversely affecting the water and sediment quality, which directly affects the health and population of aquatic life and ultimately human health. The quality of the river can be assessed using various chemical and physical parameters, one of which is the metal content of both the water and the sediment. The introduction of environmental quality standards allows comparison of the values obtained with the guidelines. Furthermore, the modeling program EPISUITE was used to determine the environmental partitioning of pollutants within different environmental compartments. Using the data produced for metals, the experimental model was compared to the default model. This involved experimentally measuring the log K_oc (the organic carbon partition coefficient ) and from this determining the log K_ow (octanol-water partition coefficient). High availability of metals in sediment may lead to greater biomagnification in fish, finally accumulating in humans. The potential for this was shown by accumulative values exceeding both the chronic value (ChrV) and lethal concentration 50 (LC₅₀) for fish in comparison with the
guidelines, as the amount of cadmium and lead in sediment was above the lowest effect level but below the severe effect level.