Simulated conservative tracer as a proxy for S-metolachlor concentration predictions compared to POCIS measurements in Arcachon Bay.

The work presented here aims at comparing monitoring of S-metolachlor, the major pesticide in use in the Arcachon Bay (South West of France, transitional coastal area), by chemical analysis (monthly passive sampling) and contaminant dissipation modeling from sources (Mars-2D model). The global strategy consisted in i) identifying the major sources of S-metolachlor to the Bay, ii) monitoring these sources for 12 months, and iii) comparing modeled data in the Bay based on measured inputs, to chemical measurements made inside the Bay along with the 12-month source monitoring. Results first showed that the major S-metolachlor surface inputs to the Arcachon Bay are mainly from one single source.

Analyzing the uncertainty of diffusive gel-based passive samplers as tools for evaluating the averaged contamination of surface water by organic pollutants.

Agarose gel-based passive samplers are nowadays one of the most effective sampling devices able to provide a quantitative evaluation of water contamination level for a broad range of organic contaminants. These devices show significant improvements in comparison to the previous passive samplers dedicated to hydrophilic compounds because they tend to reduce the effect of hydrodynamic flow conditions on the uptake rate of compounds and thus subsequently to improve their accuracy. However, albeit their effects minimized, hydrodynamic water flow and temperature are reported as variables likely to change the uptake rate of compounds that may lead to some inaccuracy if they are not adequately taken into account.

Understanding and predicting the diffusivity of organic compounds in polydimethylsiloxane material for passive sampler applications using a simple quantitative structure-property relationship model.

The diffusivity of 145 compounds in polydimethylsiloxane (PDMS) material was determined in the laboratory using a film stacking technique. The results were pooled with available literature data, providing a final data set of 198 compounds with diffusivity (D ) spanning over approximately 5 log units. The principal variables controlling the diffusivity of penetrants were investigated by comparing D within and between different homologous series.

Near-surface distribution of pollutants in coastal waters as assessed by novel polyethylene passive samplers.

We report a novel and inexpensive method to provide high resolution vertical measurements of temporally integrated organic contaminants in surface and sub-surface waters in polluted coastal environments. It employs a strip of polyethylene deployed as a passive sampler. Verifications are confirmed via conventional spot sample analyses and against Performance Reference Compound (PRC) calibration methods.

Calibration and response of an agarose gel based passive sampler to record short pulses of aquatic organic pollutants.

A passive sampler inspired from previous devices was developed for the integrative sampling of a broad range of contaminants in the water column. Our primary objective was to improve the performance of the device to provide accurate and averaged pollutant water concentrations. For this purpose, an agarose diffusive gel was used as the boundary layer that drives the analyte uptake rate.

Assessing the transport of PAH in the surficial sediment layer by passive sampler approach.

A new method based on passive samplers has been developed to assess the diffusive flux of fluorene, fluoranthene and pyrene in the sediment bed and across the sediment-water interface. The dissolved compound concentration gradient in the sediment in the vertical direction was measured at the outlet of a storm water pond by using polyethylene strips as passive samplers. Simultaneously, the dissipation of a set of tracer compounds preloaded in the passive samplers was measured to estimate the effective diffusion coefficients of the pollutants in the sediment.

A new application of passive samplers as indicators of in-situ biodegradation processes.

In this paper, a method for evaluating the in-situ degradation of nitro polycyclic aromatic hydrocarbons (nitro-PAH) in sediments is presented. The methodology is adapted from the passive sampler technique, which commonly uses the dissipation rate of labeled compounds loaded in passive sampler devices to sense the environmental conditions of exposure. In the present study, polymeric passive samplers (made of polyethylene strips) loaded with a set of labeled polycyclic aromatic hydrocarbons (PAH) and nitro-PAH were immersed in sediments (in field and laboratory conditions) to track the degradation processes.

Relationship between the water-exchangeable fraction of PAH and the organic matter composition of sediments.

The sorption of PAH on 12 different sediments was investigated and was correlated to their corresponding organic matter (OM) content and quality. For this purpose, the OM was precisely characterized using thermal analysis consisting in the successive combustion and quantification of the increasingly thermostable fractions of the OM. Simultaneously, the water-exchangeable fraction of the sorbed PAH defined as the amount of PAH freely exchanged between the water and the sediment (by opposition to the PAH harshly sorbed to the sediments particles) was determined using a passive sampler methodology recently developed.

Thickness and material selection of polymeric passive samplers for polycyclic aromatic hydrocarbons in water: Which more strongly affects sampler properties?

Three configurations of single-phase polymer passive samplers made of polyoxymethylene (POM), silicone rubber, and polyethylene (PE) were simultaneously calibrated in laboratory experiments by determining their partitioning coefficients and the POM diffusion coefficients and by validating a kinetic accumulation model. In addition, the performance of each device was evaluated under field conditions. With the support of the developed model, the device properties are discussed with regard to material selection and polymer thickness.

Simulation of aromatic polycyclic hydrocarbons remobilization from a river sediment using laboratory experiments supported by passive sampling techniques.

Resuspension of bedded sediments was simulated under laboratory-controlled conditions in order to assess the amount of polycyclic aromatic hydrocarbons (PAH) remobilized in the dissolved fraction during one short and vigorous mixing. The desorbed amount of PAH was compared to the exchangeable fraction, the total amount of PAH sorbed on the sediment particles, and the dissolved PAH amount contained in the interstitial pore waters in order to evaluate the contribution of each fraction to the total amount of PAH released. To monitor the desorption of PAH and measure low trace level concentrations, passive samplers were used in an experimental open flow through exposure simulator.

Optimization of the polar organic chemical integrative sampler for the sampling of acidic and polar herbicides.

This paper presents an optimization of the pharmaceutical Polar Organic Chemical Integrative Sampler (POCIS-200) under controlled laboratory conditions for the sampling of acidic (2,4-dichlorophenoxyacetic acid (2,4-D), acetochlor ethanesulfonic acid (ESA), acetochlor oxanilic acid, bentazon, dicamba, mesotrione, and metsulfuron) and polar (atrazine, diuron, and desisopropylatrazine) herbicides in water. Indeed, the conventional configuration of the POCIS-200 (46 cm(2) exposure window, 200 mg of Oasis® hydrophilic lipophilic balance (HLB) receiving phase) is not appropriate for the sampling of very polar and acidic compounds because they rapidly reach a thermodynamic equilibrium with the Oasis HLB receiving phase. Thus, we investigated several ways to extend the initial linear accumulation.

Development of the performance reference compound approach for the calibration of "polar organic chemical integrative sampler" (POCIS).

The purpose of the Water Framework Directive is to ensure the quality of the natural water across Europe. In this context, passive samplers have shown interesting capacities for the monitoring of contaminants in aqueous ecosystems. They allow the measurement of time-weighted average concentrations, overcoming many drawbacks of the spot-sampling techniques known to be expensive and time consuming.

Development of an adapted version of polar organic chemical integrative samplers (POCIS-Nylon).

POCIS (polar organic chemical integrative samplers) are increasingly used for sampling polar compounds. Although very efficient for a wide range of pollutants, the classic configuration of the device has a number of limitations, in particular for the sampling of highly polar analytes and hydrophobic compounds. This study presents a new version of the POCIS passive sampler which uses a highly porous Nylon membrane of 30 μm pore size, enabling the sampling of hydrophobic pollutants and improving the accumulation rate of other pollutants.

Embryotoxic and genotoxic effects of heavy metals and pesticides on early life stages of Pacific oyster (Crassostrea gigas).

This study evaluated embryotoxicity and genotoxicity of two dissolved metals copper and cadmium (Cu and Cd) and two pesticides (metolachlor and irgarol) occurring in Arcachon Bay (SW France) in Pacific oyster (Crassostrea gigas) larvae and investigated the relationship between those two endpoints. Embryotoxicity was measured by calculating the percentage of abnormal D-shaped larvae and genotoxicity was evaluated with DNA strand breaks using the comet assay. After 24h exposure, significant increases of the percentage of abnormal D-larvae and the DNA strand breaks were observed from 0.