Abstract :
The toxicity and persistence of antifouling booster biocides are of major concern. This study
reports the occurrence of Irgarol 1051 and its degradation product M1, in coastal waters of
Southern England, during 2004–2005. The highest concentrations of Irgarol 1051 were 89 ng/
L in water and 45 ng/g dry weight in sediments, with an overall mean (n=108) of 13 ng/L and
16 ng/g in water and sediments, respectively. As the degradation product of Irgarol 1051, M1
was less widespread, with the highest concentration of 30 ng/L in water and 14 ng/g in
sediments, with an overall mean (n=108) of 5 ng/L and 4 ng/g in water and sediments,
respectively. Overall, the concentration of Irgarol 1051 and M1 decreased significantly
during the sampling period and in comparison to earlier studies during 2000 to early 2004,
indicating that control measures by restricting the use of Irgarol 1051 are effective in
reducing its concentrations in coastal waters. The distribution of Irgarol 1051 between
sediments and water was significantly related to sediment organic carbon content. In
addition, significantly higher concentrations of Irgarol 1051 were detected in paint particles
than in sediment. The rate of release of Irgarol 1051 from paint residues is very slow, with a
half life of approximately 1 y. Two important findings are emerging, first the importance of
organic rich sediments and paint residues as major sites of storage for Irgarol 1051, and
secondly Irgarol 1051 may be classified as a persistent organic pollutant due to its long half
life.
