Heavy metal pollution in the Chao Phraya River estuary, Thailand

A study on heavy metal pollution in the Chao Phraya River estuary indicated that the accumulation of Cd, Cu, Cr and Pb in water in the river mouth vicinity was significant, which may have a long term impact on the aquatic environment through precipitation of heavy metals to the bottom sediments and bio-accumulation and bio-magnification of heavy metals in various food chains. Although the seasonal and spatial variations of heavy metals in the sediments and fish did not conform to a definite pattern, the heavy metal contents of samples were higher than those previously reported in the area and in some cases were higher than the mean world concentrations. Thus, Thai people may ingest Hg and Pb in fish in the Chao Phraya River estuary at quantities more than those reported for other countries.