Christopher Harman

Calibration and use of the polar organic chemical integrative sampler—a critical review

The implementation of strict environmental quality standards for polar organic priority pollutants poses a challenge for monitoring programs. The polar organic chemical integrative sampler (POCIS) may help to address the challenge of measuring low and fluctuating trace concentrations of such organic contaminants, offering significant advantages over traditional sampling. In the present review, the authors evaluate POCIS calibration methods and factors affecting sampling rates together with reported environmental applications. Over 300 compounds have been shown to accumulate in POCIS, including pesticides, pharmaceuticals, hormones, and industrial chemicals. Polar organic chemical integrative sampler extracts have been used for both chemical and biological analyses. Several different calibration methods have been described, which makes it difficult to directly compare sampling rates. In addition, despite the fact that some attempts to correlate sampling rates with the properties of target compounds such as log K(OW) have been met with varying success, an overall model that can predict uptake is lacking. Furthermore, temperature, water flow rates, salinity, pH, and fouling have all been shown to affect uptake; however, there is currently no robust method available for adjusting for these differences. Overall, POCIS has been applied to a wide range of sampling environments and scenarios and has been proven to be a useful screening tool. However, based on the existing literature, a more mechanistic approach is required to increase understanding and thus improve the quantitative nature of the measurements.

In Situ Calibration of a Passive Sampling Device for Selected Illicit Drugs and Their Metabolites in Wastewater, And Subsequent Year-Long Assessment of Community Drug Usage

Polar organic chemical integrative samplers (POCIS) were calibrated in situ for selected illicit drugs and their metabolites at a sewage treatment works. Eleven out of 13 target compounds were detected and eight of those exhibited linear uptake kinetics with sampling rates between 0.035 and 0.150 L d(-1). Subsequently POCIS were deployed for 2 week periods over the course of a whole year, in order to examine trends in drug usage. Amphetamine and methamphetamine showed several similar peaks in concentration during the course of the year as did cocaine and two of its metabolites. Low levels of ecstasy were observed, with a prominent peak in May and a steady increase toward the end of the year. The antihistamine Cetirizine showed a clear increase in use during the summer months as expected and back calculation of the yearly dosage from POCIS accumulations yielded very similar results to that registered in the Norwegian prescription database. Estimations of cocaine usage using the parent compound averaged between 0.31 and 2.8 g d(-1) per 1000 inhabitants. POCIS is a cost-effective technique for the long-term monitoring of drug usage of a defined population and may overcome the difficulties of representative sampling associated with autosampling equipment.

Uptake rates of alkylphenols, PAHs and carbazoles in semipermeable membrane devices (SPMDs) and polar organic chemical integrative samplers (POCIS).

Passive sampling devices provide a useful contribution to the monitoring of contaminants in the aquatic environment. However, calibration data needed for the calculation of water concentrations from sampler accumulations are restricted to a limited number of compound classes. Thus uptake of a range of alkylated phenols (AP), polycyclic aromatic hydrocarbons (PAH) and carbazoles was determined for semipermeable membrane devices (SPMDs) and polar organic chemical integrative samplers (POCIS) using a flow through exposure system. Sampling rates ranged from 0.02 to 0.26 l d(-1) for POCIS and 0.02 to 13.83 l d(-1) for SPMDs. Observed SPMD uptake was also compared to that predicted by an empirical model including the use of performance reference compounds (PRCs). Predicted sampling rates did not differ by more than a factor of 1.3 from experimental values for PAH, providing further evidence that the PRC approach can be successfully used to determine in situ sampling rates for these compounds. Experimental sampling rates for AP in SPMDs were, however, much lower than predicted. This discrepancy was too large to be explained by small uncertainties in the calibration system or in the calculations. Based on these data we conclude that while hydrophobic AP are accumulated by SPMDs their partitioning cannot be predicted from their logK(ow) using current methods. Due to this lower than expected uptake, sampling rates were only higher in SPMDs than POCIS in the range of logK(ow)>5.0. Simultaneous deployment of both sampler types allows the study of compounds with a broad range of physicochemical properties.

First Report of a Chinese PFOS Alternative Overlooked for 30 Years: Its Toxicity, Persistence, and Presence in the Environment

This is the first report on the environmental occurrence of a chlorinated polyfluorinated ether sulfonate (locally called F-53B, C8ClF16O4SK). It has been widely applied as a mist suppressant by the chrome plating industry in China for decades but has evaded the attention of environmental research and regulation. In this study, F-53B was found in high concentrations (43-78 and 65-112 μg/L for the effluent and influent, respectively) in wastewater from the chrome plating industry in the city of Wenzhou, China. F-53B was not successfully removed by the wastewater treatments in place. Consequently, it was detected in surface water that receives the treated wastewater at similar levels to PFOS (ca. 10-50 ng/L) and the concentration decreased with the increasing distance from the wastewater discharge point along the river. Initial data presented here suggest that F-53B is moderately toxic (Zebrafish LC50-96 h 15.5 mg/L) and is as resistant to degradation as PFOS. While current usage is limited to the chrome plating industry, the increasing demand for PFOS alternatives in other sectors may result in expanded usage. Collectively, the results of this work call for future assessments on the effects of this overlooked contaminant and its presence and fate in the environment.

Monitoring the freely dissolved concentrations of polycyclic aromatic hydrocarbons (PAH) and alkylphenols (AP) around a Norwegian oil platform by holistic passive sampling

In order to assess the environmental impact of aquatic discharges from the offshore oil industry, polar organic chemical integrative samplers (POCIS) and semipermeable membrane devices (SPMDs) were deployed around an oil platform and at reference locations in the North Sea. Exposure to polycyclic aromatic hydrocarbons (PAH) and alkylated phenols (AP) was determined from passive sampler accumulations using an empirical uptake model, the dissipation of performance reference compounds and adjusted laboratory derived sampling rates. Exposure was relatively similar within 1-2 km of the discharge point, with levels dominated by short chained C1-C3 AP isomers (19-51 ngL(-1)) and alkylated naphthalenes, phenanthrenes and dibenzothiophenes (NPD, 29-45 ngL(-1)). Exposure stations showed significant differences to reference sites for NPD, but not always for more hydrophobic PAH. These concentrations are several orders of magnitude lower than those reported to give both acute and sub-lethal effects, although their long term consequences are unknown.

Small but Different Effect of Fouling on the Uptake Rates of Semipermeable Membrane Devices and Polar Organic Chemical Integrative Samplers

Semipermeable membrane devices (SPMD) and polar organic chemical integrative samplers (POCIS) were exposed to a cocktail of organic chemicals using a flow-through system. Samplers were removed and analyzed every 7 d over a four-week period in order to determine sampling rates (Rs) for individual compounds. Prior to laboratory exposure, half of the samplers were allowed to foul naturally for six weeks, in order to examine differences in uptake due to fouling. The amount of fouling ranged from 0.2 to 2.8 g dry weight/dm2 for POCIS and 0.1 to 1.4 g dry weight/dm2 for SPMDs, and the pattern of accumulation was also different between them. The Rs values were determined by fitting curves to time course uptake data and also by using performance reference compounds (PRCs) for SPMDs. Sampling rates ranged from 2.7 to 14.2 L/d for SPMDs and 0.01 to 0.27 L/d for POCIS. Fouled SPMDs showed a reduction in Rs (<20%) for all but one compound, and there was a similar reduction in the release of PRCs. However, PRC-predicted R, values were overall somewhat higher than those from fitted curves. Uptake of alkylated phenols in POCIS was generally higher (up to 55%) in fouled samplers. The reason for this is not known, but is possibly due to some reduction in interactions with the membrane in fouled samplers. There was no overall pattern in the relationship of sampling rate differences with log Kow or over time for either sampler. Release of compounds from POCIS after a drop in exposure water concentrations provides some encouragement for the application of a PRC approach to polar passive samplers.

Water Column Monitoring of the Biological Effects of Produced Water from the Ekofisk Offshore Oil Installation from 2006 to 2009

The Norwegian water column monitoring program investigates the biological effects of offshore oil and gas activities in Norwegian waters. In three separate surveys in 2006, 2008, and 2009, bioaccumulation and biomarker responses were measured in mussels (Mytilus edulis) and Atlantic cod (Gadus morhua) held in cages at known distances from the produced water (PW) discharge at the Ekofisk oil field. Identical monitoring studies performed in all three years have allowed the biological effects and bioaccumulation data to be compared, and in addition, enabled the potential environmental benefits of a PW treatment system (CTour), implemented in 2008, to be evaluated. The results of the 2009 survey showed that caged animals were exposed to low levels of PW components, with highest tissue concentrations in mussels located closest to the PW discharge. Mussels located approximately 1–2 km away demonstrated only background concentrations of target compounds. Concentrations of polycyclic aromatic hydrocarbons (PAH) and alkyl phenol (AP) metabolites in the bile of caged cod were elevated at stations 200–250 m from the discharge. There was also a signal of exposure relative to discharge for the biomarkers CYP1A in fish and micronuclei in mussels. All other fish and mussel biomarkers showed no significant exposure effects in 2009. The mussel bioaccumulation data in 2009 indicated a lower exposure to the PW effluent than seen previously in 2008 and 2006, resulting in an associated general improvement in the health of the caged mussels. This was due to the reduction in overall discharge of PW components (measured as oil in water) into the area in 2009 compared to previous years as a result of the improved PW treatment system.

Integrated biomarker assessment of the effects exerted by treated produced water from an onshore natural gas processing plant in the North Sea on the mussel Mytilus edulis

The biological impact of a treated produced water (PW) was investigated under controlled laboratory conditions in the blue mussel, Mytilus edulis. Mussel health status was assessed using an integrated biomarker approach in combination with chemical analysis of both water (with SPMDs), and mussel tissues. Acyl-CoA oxidase activity, neutral lipid accumulation, catalase activity, micronuclei formation, lysosomal membrane stability in digestive cells and haemocytes, cell-type composition in digestive gland epithelium, and the integrity of the digestive gland tissue were measured after 5 week exposure to 0%, 0.01%, 0.1%, 0.5% and 1% PW. The suite of biomarkers employed were sensitive to treated PW exposure with significant sublethal responses found at 0.01-0.5% PW, even though individual chemical compounds of PW were at extremely low concentrations in both water and mussel tissues. The study highlights the benefits of an integrated biomarker approach for determining the potential effects of exposure to complex mixtures at low concentrations. Biomarkers were integrated in the Integrative Biological Response (IBR/n) index.

Effect of sampler material on the uptake of PAHs into passive sampling devices

Increasing demand for simple and reliable passive samplers for monitoring hydrophobic organic contaminants in water has led to increased frequency of use of single-phase polymeric sampling devices. In this study, we evaluate the effect of sampler material on the passive sampling of polycyclic aromatic hydrocarbons (PAHs) in two Norwegian rivers. Low density polyethylene membranes (LDPE), silicone strips and semipermeable membrane devices (SPMDs) with the exact same surface area and conformation were exposed in the Drammen River for overlapping exposures of 24 and 51 d, under identical hydrodynamic conditions. Dissipation rates of performance reference compounds (PRCs) spiked in all samplers were consistent and demonstrated no significant differences in sampler-water analyte exchange kinetics between the two exposures. The transition to fully boundary layer-controlled uptake shown by PRC dissipation rates was confirmed by investigating PAH masses absorbed by the samplers. Masses of analytes with log K(ow)>4.5 absorbed into the samplers were similar and independent of the sampler material used, generally indicating for these compounds that the boundary layer dominated the resistance to mass transfer. The very low variability in analyte masses absorbed across sampler types observed here indicates that much of the overall variability in dissolved contaminant concentrations seen in passive sampler intercomparison studies is likely the result of the uncertainty associated with sampler-water partition coefficients and PRC dissipation rates. PRC dissipation rates and ratios of masses absorbed over 51 and 24 d for these compounds demonstrated integrative sampling over 51 d and no major effects of biofouling on sampling. The equivalence of data obtained using silicone strips and SPMDs supports the use of single-phase polymeric passive sampling devices.

Passive sampling for target and nontarget analyses of moderately polar and nonpolar substances in water.

The applicability of silicone rubber and low-density polyethylene (LDPE) as passive sampling materials for target and nontarget analyses of moderately polar and nonpolar substances was assessed through a field deployment of samplers along a small, polluted stream in Oslo, Norway. Silicone and LDPE samplers of identical surface area (but different volumes) were deployed at 6 sites in the River Alna for 49 d. Quantitative target analysis by gas chromatography-mass spectrometry (quadrupole, single-ion monitoring mode) demonstrated that masses of polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine compounds absorbed in the 2 polymeric materials were consistent with the current understanding of the control and mode of accumulation in these sampler materials. Some deviation was observed for decabromodiphenyl ether (BDE-209) and may be linked to the large molecular size of this substance, resulting in lower diffusivity in the LDPE. Target and nontarget analyses with gas chromatography coupled to high resolution time-of-flight mass spectrometry allowed the identification of a wide range of chemicals, including organophosphate compounds (OPCs) and musk compounds (galaxolide and tonalid). Semiquantitative analysis revealed enhanced quantities of the OPCs in silicone material, indicating some limitation in the absorption and diffusion of these substances in LDPE. Overall, silicone allows nontarget screening analysis for compounds with a wider range of log octanol-water partition coefficient values than what can be achieved with LDPE.