• Exposure and ecological effects of toxic mixtures at field-relevant concentrations. Model validation and integration of the SSEO programme

      Posthuma L; Vijver MG; LER; SEC (Rijksinstituut voor Volksgezondheid en Milieu RIVMAlterraWageningenRadboud Universiteit NijmegenVrije UniversiteitAmsterdamWageningen University and Research Centre WURIMARES, 2007-12-14)
      Local environmental conditions need be taken into account to assess the impacts of diffuse environmental pollution on ecosystems. This was shown in an evaluation of the scientific results of the Dutch Stimulation Programme System-Oriented Ecotoxicological Research, led by RIVM.<br>Effects of diffuse pollution on the environment were studied at three contaminated areas in the Netherlands: the flood plains of a large lowland river (Waal), a tidal area (Biesbosch) and a peat soil area (near Vinkeveen). Diffuse pollution is present in these areas. Type and magnitudes of effects were determined and analysed.<br>The integrated results analysis showed that effects ranged from absent or low, to clearly visible and large. The magnitude of effects depended on the local composition of the mixture, the local characteristics of the soil, the water or the sediment, and the sensitivity of the local micro-organisms, plants and animals being exposed. The combination of these three characteristics influenced the type and magnitude of impacts.<br>The measurement methods and the modelling analyses used in the research programme appeared to be useful for managing the risks of diffuse site contamination. Application of these methods and analyses is useful for the Dutch situation, given the large areas with diffuse contamination. Sanitation of large, diffusely contaminated areas is not a practicable solution. RIVM recommends the development of a toolbox for ecological risk assessment. Application of such a toolbox will lead to a better assessment of local risks, and the assessment will be based more on ecological approaches. Eventually, this will result in linkage between substance-oriented policies and the management of contaminated sites.<br>
    • Follow-up study on the chemical status of Lake Goto, Bonaire : Measurements and risk assessment

      de Zwart D; de Groot A; Kotterman M; van der Aa M; Aalbers T; Slijkerman D; Bodar C; IMG; mev (Rijksinstituut voor Volksgezondheid en Milieu RIVMIMARES, 2013-03-13)
      On 8 and 9 September 2010 there was a big petrochemical fire at the BOPEC facility on Bonaire. In a study on the environmental impact it was concluded by RIVM that for perfluorooctane sulfonate (PFOS) environmental quality criteria were exceeded in Lake Goto and Salina Tam, two lagunas which are located in the vicinity of BOPEC. These substances originated from the fire fighting foams that were used on the BOPEC site. The study was inconclusive about the nature and size of possible ecological effects that could result from this. It was noted that concentrations might gradually decrease in time, however at an unknown speed. At present the results from a follow-up study in 2012 performed by RIVM show that the concentrations of PFOS in water and sediments of Lake Goto and Salina Tam, although a little lower than in 2010, are still exceeding environmental quality criteria. This means that ecotoxicological riks because of this exposure that has been going on for 2 years now, can not be excluded. Examples are direct effects on waterorganisms such as mortality, or indirect effects for example when higher organisms leave because their food has disappeared. It is impossible to make any firm conclusions on the question whether the higher concentrations in Lake Goto and Salina Tam are the (only) causative factors influencing the observed ecological deterioration as indicated by a disappeared flamingo population from Lake Goto. In order to address this question an ecological study is needed, which will be performed by research institute IMARES. This follow-up study was performed by order of The Dutch Ministry of Infrastructure and the Environment (I&M) upon request of the Public Entity of Bonaire.