Environmental risk assessment

Environmental risk assessment

Eleveted copper concentrations in marinas

Today, the dominant biocide in antifouling paints is copper (e.g. copper(I)oxide). However, several countries have recognized adverse effects on water quality due to widespread use of copper-based antifouling paints. For example, in Shelter Island Yacht Basin (San Diego Bay) the copper concentration in the water exceed federal and state standards. To improve the water quality, a regulatory order require the Port of San Diego, marinas, yacht clubs, hull cleaners and boaters to reduce copper pollution in this area by 76 percent by 2022.

The knowledge on metal concentrations in leisure boat harbours located in the Baltic Sea is however extremely limited. Thus, within CHANGE we will analyze water collected from several leisure boat harbours during the boating season.

Release rate determination of biocides

In the European Union, antifouling paint formulation needs to be registered before being put out on the market (Directive 98/8/EC). This registration process requires environmental risk assessments whereby model predictions are performed to predict the environmental concentration (PEC) of the used biocide(s) in a leisure boat harbour. In this model calculation it is assumed that the input of biocides depends exclusively on the release rate of biocides from painted boat hulls moored in the leisure boat harbour. Currently, a mass-balance calculation method (CEPE-method) is used in EU for estimating the release rate of biocides which is known to produce release rates with large uncertainties. Within CHANGE, we will use a new antifouling paint application developed for handheld X-ray Fluorescence (XRF) analyzers to measure release rates of copper and zinc from antifouling paints coated on panels submerged at 10 different leisure boat harbours in the Baltic Sea.

Improved risk assessment of antifouling paints

Many boat yards are highly polluted with biocides due to hull maintenance work. In a recent questionnaire survey we found that as many as 86% of boat owners in Sweden leave paint disposals on the ground after scraping. Many boat yards are located close to the leisure boat harbours and leaching of toxicants from the soil to the harbour may constitute a significant load of biocides. The total load of biocides to a typical leisure boat harbour will be estimated by combining XRF-measured release rates of biocides with groundwater data. The modeling program used for risk assessment of antifouling paints within EU, i.e. MAMPEC, will be used to determine predicted environmental concentrations (PEC) of biocides in the leisure boat harbour and its (MAMPEC) performance will be compared with our own measured environmental concentrations (MEC).