Contamination of Organotin Alternative Antifoulants in Coastal Sediment of Hiroshima Bay

Abstract

In this study, the levels of Diuron, Irgarol 1051, and the latter's degradation product M1 were investigated in the sediment from Hiroshima Bay. Concentrations of Diuron, Irgarol 1051 and M1 in sediment samples were in the range of ND-73 ng/g, ND-28 ng/g, ND-9 ng/g, respectively.
Over the study period, the detection rate percentage and the average concentration level of Irgarol for each year was 33.3 % and 2.5 ng/g in 2002, 71.4 % and 2.8 ng/g in 2003, 70.0 % and 4.0 ng/g in 2004 and 81.8 % and 6.0 ng/g in 2005.
The figures for M1 were 66.6 % and 3.3 ng/g in 2002, 85.7 % and 3.6 ng/g in 2003, 70.0 % and 2.7 ng/g in 2004 and 100 % and 4.8 ng/g in 2005. Diuron's figures were 83.3 % and 12 ng/g in 2002, 50.0 % and 10.8 ng/g in 2003, 83.3 % and 14.8 ng/g in 2004 and 72.7 % and 19.6 ng/g in 2005.
The detection rates percentages didn't show an upward tendency in any of the investigated materials. But the average concentration levels of the investigated materials did show an upward tendency. Especially, Diuron which had the highest average concentration levels of the three materials. So, it was shown that Diuron's concentration levels in the sediment accumulated significantly over the study period.
The concentration levels were higher at the ports and dock while at the environmental standard points they were lower. It was determined that the sources of the chemicals were the ports and dock.