The Pollution Control Department has monitored and reported coastal seawater quality in a yearly basis. In the past few years, the seawater quality of Map Ta Phut Industrial Estate, Rayong province, in the Eastern part of Thailand had also been studied particularly mercury contamination from industrial activities in Map Ta Phut area. The values represented during January 1995 to April 1997. The mercury contamination in seawater, sediment and tissue was reported. The study is certified and assured by laboratories both in-country and abroad.