Tatsiana Rusina

Calibration of silicone rubber passive samplers: experimental and modeled relations between sampling rate and compound properties.

Sampling rates (Rs) for silicone rubber (SR) passive samplers were measured under two different hydrodynamic conditions. Concentrations were maintained in the aqueous phase by continuous equilibration with SR sheets of a large total surface area which had been spiked with polycyclic aromatic hydrocarbons and/or polychlorinated biphenyls. Test sheets made of the same SR but of much smaller surface area were used to measure the uptake rate. Measured Rs values decreased with increasing passive sampler-water partition coefficient (Kpw) according to Rs approximately Kpw(-0.08) under both hydrodynamic conditions. This decrease is not significantly different from modeled values if the uncertainty of the diffusion coefficients in water is included. Modeling also confirmed that uptake of the test compounds under the experimental conditions was entirely controlled by diffusion in the water phase. A model using Rs approximately M(-0.47) is suggested for extrapolation of Rs estimated from the dissipation of performance reference compounds to target compounds in a higher hydrophobicity range.

Air and seawater pollution and air-sea gas exchange of persistent toxic substances in the Aegean Sea: spatial trends of PAHs, PCBs, OCPs and PBDEs

Near-ground air (26 substances) and surface seawater (55 substances) concentrations of persistent toxic substances (PTS) were determined in July 2012 in a coordinated and coherent way around the Aegean Sea based on passive air (10 sites in 5 areas) and water (4 sites in 2 areas) sampling. The direction of air–sea exchange was determined for 18 PTS. Identical samplers were deployed at all sites and were analysed at one laboratory. hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs) as well as dichlorodiphenyltrichloroethane (DDT) and its degradation products are evenly distributed in the air of the whole region. Air concentrations of p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE) and o,p′-DDT and seawater concentrations of p,p′-DDE and p,p′-DDD were elevated in Thermaikos Gulf, northwestern Aegean Sea. The polychlorinated biphenyl (PCB) congener pattern in air is identical throughout the region, while polybrominated diphenylether (PBDE)patterns are obviously dissimilar between Greece and Turkey. Various pollutants, polycyclic aromatic hydrocarbons (PAHs), PCBs, DDE, and penta- and hexachlorobenzene are found close to phase equilibrium or net-volatilisational (upward flux), similarly at a remote site (on Crete) and in the more polluted Thermaikos Gulf. The results suggest that effective passive air sampling volumes may not be representative across sites when PAHs significantly partitioning to the particulate phase are included.

Effect-based monitoring of the Danube River using mobile passive sampling

Many aquatic pollutants can be present at low concentrations, but their mixtures can still affect health or behavior of exposed organisms. In this study, toxicological and chemical analyses were combined for spatial contamination profiling using an innovative passive sampling approach. A novel Dynamic Passive Sampler (DPS) was employed as a mobile sampler from a ship cruising along 2130km of the Danube river during the Joint Danube Survey 3 (JDS3). The sampling was performed in eight subsequent river stretches with two types of complementary passive samplers: silicone rubber sheets (SR) used for non-polar chemicals and SDB-RPS Empore™ disks (ED) for more hydrophilic compounds. Besides extensive chemical analyses, the bioactivity of samples was characterized by a battery of reporter gene bioassays. Cross-calibration of the employed passive samplers enabled robust estimation of water concentrations applicable for compounds with a wide range of physicochemical properties. DPS was suitable for sampling of water contaminants even at pgL-1 levels, with 209 of 267 analyzed compounds detected in the samples. Biological effects were detected in both ED and SR extracts across all river stretches by bioassays focused on xenobiotic metabolism mediated by the aryl hydrocarbon and pregnane X receptors, endocrine disruptive potential mediated by estrogen and androgen receptors and the oxidative stress response. The bioassay responses expressed as bioanalytical equivalent concentrations (BEQbio) were comparable with data obtained from large volume active sampling. The extracts of the ED samplers were more biologically active than extracts of SR samplers. Except of estrogenicity, where the analyzed chemicals explained on average 62% of the effects in ED samples, the detected chemicals explained <8% of BEQbio values. The study shows the utility of the combination of the innovative passive sampling approach with effect-based tools for efficient and fast monitoring even in water bodies with relatively low levels of contamination.

Equilibrium Passive Sampling of POP in Lipid-Rich and Lean Fish Tissue: Quality Control Using Performance Reference Compounds

Passive sampling is widely used to measure levels of contaminants in various environmental matrices, including fish tissue. Equilibrium passive sampling (EPS) of persistent organic pollutants (POP) in fish tissue has been hitherto limited to application in lipid-rich tissue. We tested several exposure methods to extend EPS applicability to lean tissue. Thin-film polydimethylsiloxane (PDMS) passive samplers were exposed statically to intact fillet and fish homogenate and dynamically by rolling with cut fillet cubes. The release of performance reference compounds (PRC) dosed to passive samplers prior to exposure was used to monitor the exchange process. The sampler-tissue exchange was isotropic, and PRC were shown to be good indicators of sampler-tissue equilibration status. The dynamic exposures demonstrated equilibrium attainment in less than 2 days for all three tested fish species, including lean fish containing 1% lipid. Lipid-based concentrations derived from EPS were in good agreement with lipid-normalized concentrations obtained using conventional solvent extraction. The developed in-tissue EPS method is robust and has potential for application in chemical monitoring of biota and bioaccumulation studies.