Assessment of radionuclides and heavy metals along the Upper Gulf of Thailand was very important to address the concern about human risk to exposure. The benthic communities could be used as a biological index of a tolerance level guideline for primary producers and consumers. Continuous monitoring of toxic materials not only radionuclides and heavy metals but organic compounds (PAH s,VOCs, pesticides and others) was very important in marine surveillance and could be used as baseline data for management of marine ecology. The amount of toxic substances should be evaluated together with soil parameters: pH and organic matters, to determine the kinetic and thermodynamic parameters.