Arsenic pollution assessment in surface sediment of the inner Gulf of Thailand

Abstract

Surface sediments of the inner Gulf of Thailand and four main river estuaries were collected for total arsenic analysis in order to assess spatial distribution pattern, contamination status, regulating factors and potential ecological risk. The study reveals that the arsenic concentrations in the surface sediment samples varied from 5.43-18.01 mg/kg dry weight. Higher arsenic concentrations were found in the Chao Phraya river estuary toward in the eastern of the inner Gulf of Thailand. Based on the sediment quality guidelines (SQGs), arsenic was investigated most unlikely to cause any adverse effects. The result of geo-accumulation index (Igeo) was found to be less than 1, which indicated "unpolluted" state. Moreover, the potential risk of individual metal (Er) values directed that arsenic at all stations posed low ecological risks.