Assessment of heavy metals in sediments of the Don Hoi Lot area in the Mae Klong estuary, Thailand

Abstract

The status and seasonal variation of heavy metals in surface sediment were investigated at Don Hoi Lot, located in the Mae Klong estuary, Thailand. Results revealed that all the measured heavy metals, except Zn, in the sediments had lower concentrations than in other nearby estuaries. Only Zn may be of concern for potential negative effects on estuarine biota in the study area. With the exception of Fe, all the studied heavy metals showed seasonal variation, but the patterns were diverse. Organic matter and the clay fraction in sediments were good sinks for heavy metals, excluding Zn, while Fe and Mn were good catchers. Principal component analysis suggested that Zn might have different origins and/or mechanisms of transport, accumulation and circulation, compared with the other heavy metals studied. A better understanding of sources and the behavior of Zn would enhance the efficiency of the estuary management plan in this study area.

Keywords:

• Heavy metals
• surface sediment
• seasonal variation
• coastal wetland

Acknowledgments

The authors wish to acknowledge funding by the Marine and Coastal Resources Research Center, the Upper Gulf of Thailand, Ministry of Natural Resources and Environment, for supporting this research. Thanks also to the Special Track Staff (STS) program of the Faculty of Science, Kasetsart University.