Highlights IPSW 2016
IPSW 2016 featured 35 platform presentations and 17 posters, covering many different passive sampling aspects. The main highlights were as follows:
Dealing with flow effects on sampling of polar compounds is not yet well sorted out. Four approaches are used: 1. apply sampling rate calibrations only at sites that have flow rates beyond a defined minimum, 2. calibrate samplers at the approximate flow rate of the sites at which it is to be applied, 3. determine empirical correlations between sampling rates and flow velocities, 4. take the flow effect into account using measured mass transfer coefficients of the water boundary layer.
The use of PRCs with samplers for polar compounds is not encouraging yet.
An increasing number of organic compounds can now be sampled by PSDs. Some compounds that were considered to be difficult to sample are now on board, including glyphosate. Some compound groups, such as explosives and their metabolites, remain a challenge. Significant progress has been made for the sampling of perfluorinated compounds, including the use of new sampler designs, and different membrane and sorption materials with POCIS.
Nontarget screening and mixture toxicity testing of passive sampler extracts yields valuable information on the environmental occurrence and risk of a wide variety of compounds, despite the challenges in the interpretation of such data.
Biota-PSD relationships become better established, including the passive sampling in lean biota tissue, the comparison of passive sampler based concentrations in biota lipids, and the assessment of exposure of humans using explanted breast prostheses.
Improved deployment techniques, including ship-based passive sampling, and passive sampling of ground water and the hyporeic zone, are being developed
The number of different sampler designs is continuously increasing. Some new designs are a clear improvement for the sampling of particular compound groups, but this is not always the case. Some degree of standardization and harmonisation of passive sampling designs would be beneficial for the use of these samplers in a regulatory context.
Biofouling was again shown to have little effect on aqueous concentrations estimated with samplers for nonpolar compounds. For metal sampling with DGT moderate effects for metal cations may exist, but not for metal oxyanions
Our mechanistic understanding of samplers for polar compounds improves, but a lot of work still needs to be done. Despite the existence of several knowledge gaps, these samplers are successfully being used in the assessment of the concentration levels and toxicity of polar and nonpolar chemicals.