The concentration of antifouling paints used on leisure boats exceeds safety values in both water, sediment and soil, shows a new PhD thesis from ACES.
“My research shows that the use of antifouling paints pollutes the environment, not only when the boats are in the water but also when the hulls are subjected to maintenance activities on land. The results in my thesis also show that there is a need to improve the environmental risk assessment of these products,” says Maria Lagerström, PhD student at ACES and author of the thesis.
Antifouling paints used on boat hulls contain toxic substances known as biocides that are released from the coating in order to prevent the growth of organisms on the hull when it is immersed. Biocides have the potential to also negatively affect other organisms in the water. Antifouling paints are therefore subjected to environmental risk assessment before they are allowed to be sold.
“Antifouling paints are commonly used by boaters in the Baltic Sea, which may be of environmental concern given the sensitive nature of this particular water body and that biocide release is currently underestimated several-fold,” says Maria Lagerström.
Popular antifouling paint brands contain copper
Cuprous oxide, a copper-based compound, is the most common biocide used in antifouling paints today. In her studies, Maria Lagerström used a new technique referred to as x-ray fluorescence to measure how much copper is released from several different paint brands.
“Our results showed that these products should have never been available on the market in the first place. All the products we tested products failed to pass the environmental risk assessment. These results likely also explain why concentrations of copper that I had measured in marina waters were above the guideline value,” says Maria Lagerström. She continues: “I hope that my research will help improve risk assessment of antifouling paints in the future so that we can better protect the marine environment.”