Defended PhD: The use of passive samplers as a central tool in integrated environmental risk assessment
The doctoral research of Michiel Claessens (Laboratory of Environmental Toxicology and Aquatic Ecology) focused on the use of passive samplers as a central tool in integrated environmental assessments in marine environments.
Passive samplers of polydimethylsiloxane (PDMS) were, in a first phase, used to sample mixtures of organic contaminants in the Belgian marine environment. Subsequently, the effect of these mixtures on the growth of an important marine diatom was determined by reversed applying of the principle of passive samplers: the contaminated samplers were transferred into clean sea water which allowed the contaminants to be released by passive diffusion. As such, the freely dissolved concentrations and effects of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in Belgian marine waters were determined by passive samplers. Based on these data, the concentration of these substances in the sediment, suspended particles and organisms were successfully predicted using newly developed equilibrium models.
This study shows that PDMS samplers can be used in integrated environmental assessments to (1) determine the ecological effects of environmentally relevant mixtures (and of individual substances), and to (2) estimate the environmental concentrations of chemicals in all major marine compartments. This research can significantly simplify environmental risk assessments of chemicals in marine environments and reduce associated costs.
Figure: Polydimethylsiloxane passive samplers mounted in a stainless steel cage prior to field deployment.
