Semipermeable Membrane Devices Research Articles

Investigation of organic micropollutant pollution in İzmit Bay: a comparative study of passive sampling and instantaneous sampling techniques.

In this study, we used a comprehensive array of sampling techniques to examine the pollution caused by organic micropollutants in İzmit Bay for the first time. Our methodology contains spot seawater sampling, semi-permeable membrane devices (SPMDs) passive samplers for time-weighted average (TWA), and sediment sampling for long-term pollution detection in İzmit Bay, together. Additionally, the analysis results obtained with these three sampling methods were compared in this study. Over the course of two seasons in 2020 and 2021, we deployed SPMDs for 21days in the first season and for 30days in the second season. This innovative approach allowed us to gather sea water samples and analyze them for the presence of polycyclic aromatic hydrocarbons (Σ15 PAHs), polychlorinated biphenyls (Σ7 PCBs), and organochlorine pesticides (Σ11 OCPs). Using SPMD-based passive sampling, we measured micropollutant concentrations: PAHs ranged from 1963 to 10342pg/L in 2020 and 1338 to 6373pg/L in 2021; PCBs from 17.46 to 61.90pg/L in 2020 and 8.37 to 78.10pg/L in 2021; and OCPs from 269.2 to 8868pg/L in 2020 and 141.7 to 1662pg/L in 2021. Our findings revealed parallels between the concentrations of PAHs, PCBs, and OCPs in both SPMDs and sediment samples, providing insights into the distribution patterns of these pollutants in the marine ecosystem. However, it is worth noting that due to limited data acquisition, the suitability of spot sampling in comparison to instantaneous sampling remains inconclusive, highlighting the need for further investigation and data collection.

Dissolved polycyclic aromatic compounds in Canada’s Athabasca River in relation to Oil Sands from 2013 through 2019

The Canada-Alberta Oil Sands Monitoring (OSM) Program began long-term surface water quality monitoring on the lower Athabasca River in 2012. Sampling of low level, bio-accumulative polycyclic aromatic compounds (PACs) targeted a suite of parent and alkylated compounds in the Athabasca River (AR) mainstem using semi-permeable membrane devices (SPMDs). Samples were collected along a gradient from upstream reference near Athabasca, Alberta, through exposure to the Athabasca oil sands deposit (AOSD), various tributary inflows, and mining activities within the OSMA, to downstream recovery near Wood Buffalo National Park (WBNP) and reference on the Slave River. The program adapted over the years, shifting in response to program review and environmental events. The AOSD chemical fingerprint was present in samples collected within the AOSD, through the oil sands mineable area (OSMA), downstream to recovery from 2013 to 2019. PACs were dominated by alkylated phenanthrenes/anthracenes (PAs) and dibenzothiophenes (Ds), with elevated levels of alkylated fluorenes (Fs), naphthalenes (Ns), fluoranthenes/pyrenes (FlPys) and benzo[a]anthracenes/chrysenes (BaACs), increasing in concentration from C1 < C2 < C3 < C4. Concentrations of these petrogenic PACs were at their highest within the OSMA and downstream of tributaries. The AOSD fingerprint was absent from sites located outside of the influence of the AOSD and downstream of the Peace-Athabasca Delta on the Slave River. PAC concentrations in the AR increased with mainstem discharge and loadings from tributaries, were moderated by the PAD, and diluted by the Peace River. This work bolsters the baseline PAC information previously reported for the Athabasca River and waters downstream, reporting 7 years of data, from all sites within the mainstem monitoring program, and exploring potential regional and hydrological drivers of these between sites and over time.

Field Calibration of Semipermeable Membrane Devices (SPMDs) for Persistent Organic Pollutant Monitoring in a Reservoir

Persistent Organic Pollutants (POPs) in water can reach levels below ppt (ng L−1), representing a challenge for risk assessment using long-term exposure. Therefore, sampling devices to monitor trace levels of organic compounds are suitable due to their sensitivity and low detection limits. In this work, the field calibration and monitoring for POPs, such as Polycyclic Aromatic Hydrocarbons (PAHs) and pesticides, in a drinking water reservoir were carried out using semipermeable membrane devices (SPMDs). The SPMDs were spiked with deuterated PCBs used as PRCs, and their dissipation was measured at 5, 10, 15 and 24 days. The SPMDs were dialyzed in hexane twice and the initial amount (N) and final amount (No) of PRCs in extracts were estimated by GC/MS to calculate the sampling rate (Rs) for target compounds. The PCBs were dissipated more than 30% at 24 days, and Rs were calculated between 27.8 and 72.7 L day−1 for PAHs and 35.8 and 71.3 L day−1 for pesticides. Finally, PAH congeners such as Naphthalene, Acenaphthylene, Acenaphthene, Fluorene, Phenanthrene, Anthracene, Fluoranthene and Pyrene were detected at water concentration (Cw) ranges between 0.5 and 2.7 ng L−1, whilst chlorpyrifos was the only pesticide detected at 19.0 ng L−1 in the reservoir. This calibration showed that PRCs do not dissipate entirely in 24 days and that dissipation modelling may be applied for Cw estimation of POPs in reservoirs.

The Application of Passive Sampling Devices in Wastewater Surveillance

Wastewater-based epidemiology (WBE) is a surveillance approach used to examine chemical and biological targets within a population. Historically, the most common approaches to wastewater sampling include grab sampling and composite sampling, which can be performed manually or using an automated sampler. However, there are inherent flaws with these sampling methods. They can miss analytes due to fluctuation events in wastewater and can have high cost and labour implications. Alternately, passive sampling is a technique that involves a sampling medium that can stay in an aqueous matrix for extended periods of time to provide a greater temporal coverage. This literature review examines the current passive sampling devices used in wastewater surveillance and the general contaminants they are targeting. The polar organic chemical integrated sampler, Chemcatcher®, diffusive gradients in thin films sampler and semipermeable membrane devices were among the most frequently deployed samplers in wastewater matrices. Chemical contaminants and pharmaceuticals were identified as the most common targets. Passive sampling of biological targets has received recent attention due to the surveillance of SARS-CoV-2; however, overall, there is a lack of critical knowledge relating to the deployment and associated variability of passive samplers used for biological targets. Notwithstanding, the ability of passive sampling to capture temporal fluctuation of analytes in wastewater make it a useful sampling technique for the surveillance of pathogens in the community. Future research should focus on addressing the gaps in knowledge to optimise the use of these sampling devices.

Spatial Comparison of Persistent Organic Pollutants in the Boardman River Following Impoundment Removal and Channel Restoration.

Semi-permeable membrane devices (SPMDs) were used to quantify dissolved concentrations of persistent organic pollutants (POPs) along a 40-km reach of the Boardman River in Traverse City, Michigan that has recently undergone dam and impoundment pond sediment removal. Concentrations of polychlorinated biphenyls (ΣPCBs; 7.7-65.0 pg/L), dichloro-diphenyl-trichloroethane and metabolites (ΣDDTs; 7.6-202.5 pg/L) and cyclodiene compounds (3.7-220.7 pg/L) were below regulatory guidelines considered to pose chronic risks to aquatic health. POP concentrations estimated from SPMD monitoring were not representative of potential residual contamination from legacy sediment impoundments. Spatial patterns in POP profiles were present among the different deployment sites and were reflective of differences in land-use patterns along the rural to urban gradient of the monitored area of the river. These results represent baseline POP data prior to the removal of remaining dam infrastructure in the Boardman River. Overall, this study supports the utility of SPMDs for monitoring trace environmental contamination and helps assess the efficacy of environmental remediation for mitigating legacy pollutant releases following dam and impoundment pond sediment removal.

Probabilistic Risk Assessment of Polycyclic Aromatic Hydrocarbons in a Colombian Reservoir

The purpose of this research was to evaluate the concentrations, sources and ecological risk assessment of sixteen polycyclic aromatic hydrocarbons (PAHs) present in water from the La Fe reservoir, Colombia in the months of October and November of 2017 and 2018. Concentrations of PAHs in water were measured with semipermeable membrane devices (SPMD) which allow obtaining the dissolved concentrations of the PAHs in the reservoir, emphasizing the reactivity and bioavailability in the environment. The PAHs analyses were carried out by means of gas chromatography, coupled with tandem mass spectrometry (GC/MS–MS) with triple quadrupole (QqQ). The environmental risk assessment using the estimation of risk quotient with deterministic and probabilistic method, the predictive no-effect concentration (PNEC) and environmental exposure concentration (EEC) in water indicate a negligibe risk for probabilistic method for all PAHs evaluated (RQ < 0.1).

Passive sampling as an alternative strategy to monitor metals and PAHs trends at an upstream and rural catchment: a French case study

The study presents an alternative strategy to conventional spot sampling for monitoring metals and polycyclic aromatic hydrocarbons (PAHs) at an upstream, rural and karstic catchment in the north eastern part of France, in order to get insight into their spatial and temporal variability. Passive samplers, as diffusive gradients in thin films (DGT) and semipermeable membrane device (SPMD), are monthly deployed from August 2012 to March 2016 at five of the catchment monitoring stations located on the Saulx and Ornain Rivers. An improvement of the frequency of quantification (by a factor 2 to 8, depending on the targeted compound) is observed allowing us to better identify spatial and temporal variability. For instance, the upstream monitoring station on the Saulx River is characterized by high concentrations of Ni and Mn whereas the upstream monitoring station on the Ornain River is enriched in Cu and Zn. Furthermore, five metals (Al, Fe, Mn, Ni, Zn) and three PAHs (fluoranthene, pyrene and chrysene) show significant variations with water levels when grouped in three categories (low, medium and high water levels) in relation with hydrological and climatic patterns. This study leads to a more accurate assessment of the background pollution in metals and PAHs within surface waters than when based on spot sampling data.

Survey of bioavailable PCDDs, PCDFs, dioxin-like PCBs, and PBBs in air, water, and sediment media using semipermeable membrane devices (SPMDs) deployed in the Hartbeespoort Dam area, South Africa.

A survey of bioavailable polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like PCBs (dl-PCBs), and polybrominated biphenyls (PBBs) from ambient air, water and sediment was performed in the Hartbeespoort Dam area in South Africa, a region where data on highly toxic Stockholm Convention persistent organic pollutants (POPs) is scanty. The sampling was designed to simulate POP bioaccumulation in benthic and aquatic dwelling organisms as well as ambient air for estimation of ecological risk. The objective was to survey the spatiotemporal distribution and fate of bioavailable priority persistent organic compounds in the Hartbeespoort Dam in summer, autumn and winter seasons and to validate the utility of a comprehensive two-dimensional gas chromatography-time of flight mass spectrometry (GCxGC-TOF) method for PCDD/F, PCB, and PBB analysis. The highest detection rates for bioavailable priority POPs were for PCB 77 and PCB 126 which were detected in 15 and 16 of the 22 samples, though the majority of the detections were < LOQ for PCB 77. Overall, PCB 126, PBB 10 and PBB 49 recorded the highest quantified bioavailable concentrations per site in SPMDs deployed in the Hartbeespoort Dam. The SPMDs deployed in air at the Magalies River site in winter recorded the highest toxic equivalency quotient (TEQ) of 29.77pg TEQ SPMD-1. The highest TEQs recorded for SPMDs deployed in the sediment phase were 10.2, 3.3, and 3.2pg TEQ SPMD-1, recorded at the Harbour site in summer, Dam wall in summer and Harbour in winter respectively. In water, SPMDs deployed at the Crocodile River site recorded the highest TEQ of 0.81pg TEQ SPMD-1 in summer. TEQ data shows that air carries significant bioavailable dl-toxicity compared to the water phase, and sediment generally carries the highest dl-toxicity. Detection rates for bioavailable PBBs were generally very low, with < 3 detections being quantified above the LOQ for the majority of the sites. Statistical analysis of TEQs computed at all sites, using AVOVA shows that the dispersion of TEQs in the Hartbeespoort Dam is largely homogenous as the differences between the TEQs were insignificant (p > 0.05).

Exploring the influence of concentration fluctuation and matrix effects on a passive sampler of triolein-embedded cellulose acetate membrane measuring polychlorinated biphenyls in water

A membrane of triolein-embedded cellulose acetate membrane (TECAM), as an integrative passive sampler, was applied to adsorb 28 polychlorinated biphenyls (PCBs) from pure water and sea water in order to probe into the influence of concentration fluctuation and water matrix. The results demonstrated the temporal variations of PCBs concentrations in TECAM followed the first-order kinetics model. The periodic refreshment of solution and matrix effects of sea water significantly prolonged the time that PCBs reached equilibrium stage. The refreshment facilitated the uptake mass in TECAM. On the contrary, the matrix effects of sea water and dissolved organic matter (DOM) declined the PCBs absorption to TECAM. The average logKP values of PCBs in pure water were about 1.2 log unit higher than those in sea water in the experiments that the solution was not refreshed, while the difference of average logKP values narrowed to 0.3 log unit if the PCBs solutions were periodically refreshed. The correlation between logKP and logKOW values fitted the quadratic curve well, which was similar to semi-permeable membrane device (SPMD). The appropriate sampling times (t94%) ranged from 98.8 to 819 h (mean 500 h) for pure water with refreshment, much longer than those in sea water with refreshment (80.1~410 h, mean 189 h). The t94% values in the solution with high DOM content increased significantly, up to 409 h. Furthermore, comparing the twoexperiments that the spiked pure water and sea watersolution were refreshedfrequently, the estimated sampling rates (Rs) in pure water (0.154~2.06 L/day with a mean value of 0.605 L/day) were slightlylower than those in sea water (0.292~3.84 L/day with a mean value of 1.69 L/day). However, the Rs values in sea water with DOM declined sharply to 0.042 L/day. Therefore, concentration fluctuation, matrix effect, and DOM contents of sea water evidently posed significant influence on dynamic parameters of TECAM absorption, which would be screened and probed detailed in future.

Improving the Adsorption Efficiencies of Polychlorinated Biphenyls and Polybrominated Diphenyl Ethers Using a Passive Water Sampling Device in Marine Environment

This study focused on improving the adsorption efficiencies of organic micropollutants, such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) using a passive water sampling device (PWSD) in a marine environment during summer. Two factors were considered when increasing the adsorption efficiency by improving the sampling rate (Rs) of PWSDs for target PCBs and PBDEs: 1. Controlling the invasion of the sticky organisms that cause biofouling by tearing the semipermeable membrane device (SPMD) inside the PWSD canister; 2. Preventing various suspended solids from clogging the PWSD pores. To resolve these problems, two types of enhanced PWSD samplers were devised, namely a round prest-type PWSD canister with zooplankton netting (netted), and a copper-coated prest-type PWSD canister. Copper is generally toxic to marine organisms. The netted and copper-coated PWSD samplers were deployed in Masan Bay and Ulsan Bay and their adsorption efficiencies for PCBs and PBDEs were compared with that of the prest-type PWSD sampler. The copper-coated PWSD had an Rs 1.5~1.8 times higher than that of the netted and prest-type PWSDs. A comparison of the adsorption amount of PCBs and PBDEs showed similar results, and copper-coated PWSD adsorbed more target compounds than the netted and prest-type PWSDs. The adsorption patterns of PCB homologues were similar regardless of the sampling site and sampler type, but those of PBDE homologues in the netted and prest-type PWSDs deployed in Ulsan Bay were somewhat different from the others. By comparing the adsorption amounts of PCB and PBDE homologues according to the octanol-water partition coefficients, it was found that the coppercoated PWSD adsorbed more PCBs and PBDEs than the netted and prest-type PWSDs, especially high molecular homologues. Based on these results, the copper-coated PWSD could be used to effectively prevent the biofouling of the SPMD membrane and clogging of the PWSD canister during both summer and winter.

The Variability of the Concentrations of PAHs and PCBs in the Urban Air of Dalian with Ambient Temperature by Semipermeable Membrane Devices Monitoring

Bioavailable air concentration of 18 indicator and dioxin-like polychlorinated biphenyls (PCBs) and 16 EPA priority polycyclic aromatic hydrocarbons (PAHs) in the urban air of Dalian, China were simultaneously measured by semipermeable membrane devices (SPMDs). PCB#28, 52, 101, 105 and 118 were the most abundant PCB congeners in Dalian urban air. Phenanthrene, Fluoranthene and Pyrene were the predominat PAH in the air. PCBs were detected with magnitude ranging from non-detectable to 2151 pg SPMD−1. PAHs ranged from non-detectable to 12464 ng SPMD−1. The linear uptake stages of different PCBs and PAHs with SPMD sampling were different. There were much more PCBs during warmer sampling period than colder sampling period, however, there were a reverse results for PAHs. The concentration of some PCBs and PAHs sequestrated by SPMD (C SPMD) in the air has linear correlation with the reciprocal of the average ambient atmospheric temperature (T). The C SPMD of PAHs had negative correlation with T, while the C SPMD of the PCBs had positive correlation with T. The above research results provide basic reference data for the promotion and application of SPMD passive samplers.

Sediment Remediation with New Composite Sorbent Amendments to Sequester Phosphorus, Organic Contaminants, and Metals.

This study tested two sediment amendments with active sorbents: injection of aluminum (Al) into sediments and thin-layer capping with Polonite (calcium–silicate), with and without the addition of activated carbon (AC), for their simultaneous sequestration of sediment phosphorus (P), hydrophobic organic contaminants (HOCs), and metals. Sediment cores were collected from a eutrophic and polluted brackish water bay in Sweden and incubated in the laboratory to measure sediment-to-water contaminant release and effects on biogeochemical processes. We used diffusive gradients in thin-film passive samplers for metals and semi-permeable membrane devices for the HOC polychlorinated biphenyls and polycyclic aromatic hydrocarbons. Al injection into anoxic sediments completely stopped the release of P and reduced the release of cadmium (Cd, −97%) and zinc (Zn, −95%) but increased the sediment fluxes of PAH (+49%), compared to the untreated sediment. Polonite mixed with AC reduced the release of P (−70%), Cd (−67%), and Zn (−89%) but increased methane (CH4) release. Adding AC to the Al or Polonite reduced the release of HOCs by 40% in both treatments. These results not only demonstrate the potential of innovative remediation techniques using composite sorbent amendments but also highlight the need to assess possible ecological side effects on, for example, sedimentary microbial processes.

Ecotoxicological risks from dissolved organic contaminants in a contaminated bay: Combining passive sampling with in vivo bioassays

Innovative and robust methods are needed to evaluate the risks to native aquatic organisms exposed to organic compounds released from contaminated sediments. In the present study, we deployed semi-permeable membrane devices (SPMDs) above sediments in a contaminated harbor at a location in the Laurentian Great Lakes (i.e. Owen Sound Bay) and prepared extracts from these passive samplers for analysis of organic contaminants and for toxicity testing using early life stages of Japanese medaka (Oryzias latipes) and lake whitefish (Coregonus clupeaformis). The concentrations of several classes of organic contaminants estimated from analysis of the SPMD extracts indicated that several polynuclear aromatic hydrocarbon (PAHs) were present in the water column in the inner harbor of Owen Sound Bay at concentrations higher than water quality standards for the protection of aquatic life. Several medaka exposed to the SPMD extract from the inner harbor as well as a positive control compound, benzo[a]pyrene, developed yolk sac edema. However, whitefish did not show the same response. Overall, these data indicate this contamination could contribute to toxicity in sensitive species. The coupling of passive sampling and in vivo bioassays with early life stages of fish shows promise as a method to assess the potential for risks from biologically available fractions of organic contaminants in water. A novel aspect of the present study is the development of a bioassay procedure with early life stages of lake whitefish involving exposures at low temperatures over durations of time that are longer than the bioassays with more conventional model fish species.

Identifying Chemicals and Mixtures of Potential Biological Concern Detected in Passive Samplers from Great Lakes Tributaries Using High-Throughput Data and Biological Pathways.

Waterborne contaminants were monitored in 69 tributaries of the Laurentian Great Lakes in 2010 and 2014 using semipermeable membrane devices (SPMDs) and polar organic chemical integrative samplers (POCIS). A risk‐based screening approach was used to prioritize chemicals and chemical mixtures, identify sites at greatest risk for biological impacts, and identify potential hazards to monitor at those sites. Analyses included 185 chemicals (143 detected) including polycyclic aromatic hydrocarbons (PAHs), legacy and current‐use pesticides, fire retardants, pharmaceuticals, and fragrances. Hazard quotients were calculated by dividing detected concentrations by biological effect concentrations reported in the ECOTOX Knowledgebase (toxicity quotients) or ToxCast database (exposure–activity ratios [EARs]). Mixture effects were estimated by summation of EAR values for chemicals that influence ToxCast assays with common gene targets. Nineteen chemicals—atrazine, N,N‐diethyltoluamide, di(2‐ethylhexyl)phthalate, dl‐menthol, galaxolide, p‐tert‐octylphenol, 3 organochlorine pesticides, 3 PAHs, 4 pharmaceuticals, and 3 phosphate flame retardants—had toxicity quotients >0.1 or EARs for individual chemicals >10–3 at 10% or more of the sites monitored. An additional 4 chemicals (tributyl phosphate, triethyl citrate, benz[a]anthracene, and benzo[b]fluoranthene) were present in mixtures with EARs >10–3. To evaluate potential apical effects and biological endpoints to monitor in exposed wildlife, in vitro bioactivity data were compared to adverse outcome pathway gene ontology information. Endpoints and effects associated with endocrine disruption, alterations in xenobiotic metabolism, and potentially neuronal development would be relevant to monitor at the priority sites. The EAR threshold exceedance for many chemical classes was correlated with urban land cover and wastewater effluent influence, whereas herbicides and fire retardants were also correlated to agricultural land cover. Environ Toxicol Chem 2021;40:2165–2182. Published 2021. This article is a U.S. Government work and is in the public domain in the USA. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Passive sampling of toluene (and benzene) in indoor air using a semipermeable membrane device

The distribution and concentration of organic compounds in the environment have attracted great interest mainly due to their capability of bioaccumulation, dispersion, and danger to living organisms. Factors such as urbanization, population growth, and the emergence of new technologies contribute to the increase in pollutant emissions, especially volatile organic compounds (VOCs), such as benzene, toluene, ethylbenzene, and xylenes (BTEX). These compounds are emitted by several sources, becoming more common in work environments, influencing indoor air quality (IAQ), which can cause health damage, in addition to increasing the likelihood of cancer development. In this context, we developed a semipermeable membrane device (SPMD), consisting of low density polyethylene membrane (8 cm long × 3 cm wide), filled with 3 mL of acetonitrile, for passive sampling of toluene (and benzene) in gas phase. With this configuration, the SPMD needed 24 h exposure to the indoor air in order to achieve equilibrium. The target compounds were quantified in the acceptor phase by HPLC-DAD. The optimized SPMD was tested for the collection of toluene and benzene in six chemistry laboratories at Fluminense Federal University and in five nail salons in the city of Niterói, in the state of Rio de Janeiro, Brazil. The developed sampling method was able to identify the analytes in the indoor air of the studied environments, and was easy to operate, with no need to clean up the extracts, allowing their direct injection into the chromatographic system.

Associations between land cover categories, gaseous PAH levels in ambient air and endocrine signaling predicted from gut bacterial metagenome of the elderly

There is evidence that polycyclic aromatic hydrocarbons (PAHs) and human gut microbiota are associated with the modulation of endocrine signaling pathways. Independently, studies have found associations between air pollution, land cover and commensal microbiota. We are the first to estimate the interaction between land cover categories associated with air pollution or purification, PAH levels and endocrine signaling predicted from gut metagenome among urban and rural populations.The study participants were elderly people (65–79 years); 30 lived in rural and 32 in urban areas. Semi-Permeable Membrane devices were utilized to measure air PAH concentrations as they simulate the process of bioconcentration in the fatty tissues. Land cover categories were estimated using CORINE database and geographic information system. Functional orthologues for peroxisome proliferator-activated receptor (PPAR) pathway in endocrine system were analyzed from gut bacterial metagenome with Kyoto Encyclopaedia of Genes and Genomes.High coverage of broad-leaved and mixed forests around the homes were associated with decreased PAH levels in ambient air, while gut functional orthologues for PPAR pathway increased along with these forest types. The difference between urban and rural PAH concentrations was not notable. However, some rural measurements were higher than the urban average, which was due to the use of heavy equipment on active farms.The provision of air purification by forests might be an important determining factor in the context of endocrine disruption potential of PAHs. Particularly broad-leaved forests around homes may reduce PAH levels in ambient air and balance pollution-induced disturbances within commensal gut microbiota.

Pine needle and semi-permeable membrane device derived organochlorine compounds (OCPs) concentrations in air in Mersin Province to Taurus, Turkey

Organochlorine pesticides (OCPs) were analyzed in three different ages (half-, 1.5-, 2.5-year-old) for needles and semi permeable membrane devices (SPMDs) at three deployment periods from sea level to 1881 meter above sea level. Individual HCHs concentrations ranged between 1.4 and 129 pg/g fw depending on the age and sampling season while 2.5-year-old needles showed higher HCHs levels compared to half and 1.5- year-old. Correlation between elevation and HCH concentration in SPMDs was found but not in needle samples. Concentrations of HCHs in SPMDs indicated clearly cold condensation effect on accumulation in winter period and increased with altitude. Concentrations of DDTs in half and 1.5-year-old needles were lower than 2.5-year-old needles. The highest total concentration of DDTs was detected in 1-year-period SPMD. Higher concentrations were found in 2.5-year-old needles for other OCPs. Seasonal and altitude-dependent changes were not observed for other OCPs in SMPDs. Total accumulation of OCPs in SPMDs were found higher than in needles. On the contrary, an increased accumulation rate was observed for HCHs in SPMD. In general, Total concentrations of DDTs and HCHs were similar to total of other OCPs in all altitudes when dominating endosulfan wasnot taken into account in the computation of total concentration of other OCPs.

Sources, distribution, and risk assessment of organochlorine pesticides in Nairobi City, Kenya

The distribution and sources of organochlorine pesticides (OCPs) in air and surface waters were monitored in Nairobi City using triolein-filled semipermeable membrane devices (SPMDs). The SPMDs were extracted by dialysis using n-hexane, followed by cleanup by adsorption chromatography on silica gel cartridges. Sample analysis was done by GC-ECD and confirmed by GC–MS. Separation of means was achieved by analysis of variance, followed by pair-wise comparison using the t-test (p≤ 0.05). The total OCPs ranged between 0.018 – 1.277 ng/m3 in the air and <LOD – 1391.000 ng/m3 in surface waters. Based on the results, the means of Industrial Area, Dandora and Kibera were not significantly different (p≤ 0.05), but were higher (p≤ 0.05) than those of City square and Ngong’ Forest. The results revealed non-significant (p≤ 0.05) contribution of long-range transport to OCP pollution in Nairobi City. This indicated possible presence of point sources of environmental OCPs in the city. The water-air fugacity ratios indicated that volatilization and deposition played an important role in the spatial distribution of OCPs in Nairobi City. This indicated that contaminated surface waters could be major sources of human exposure to OCPs, through volatilization. The incremental lifetime cancer risks (ILCR) determined from inhalation of atmospheric OCPs were 2.3745 × 10−13 – 1.6845 × 10−11 (adult) and 5.5404 × 10−13 – 3.9306 × 10−11 (child) in the order: Dandora > Kibera > Industrial Area > City Square > Ngong’ Forest. However, these were lower than the USEPA acceptable risks, 10−6 – 10−4. This study concluded that atmospheric OCPs did not pose significant cancer risks to the residents.

Petroleum hydrocarbons in semipermeable membrane devices deployed in the Northern Gulf of Mexico and Florida keys following the Deepwater Horizon incident.

The Deepwater Horizon (DWH) oil spill from April to July of 2010 contaminated Gulf of Mexico waters through release of an estimated 4.1 × 106 barrels of oil. Beginning in June of 2010, semipermeable membrane devices (SPMDs) were deployed near areas with sensitive marine habitats (Alabama Alps and Western Shelf) potentially exposed to that oil. Elevated TPAH50 concentrations, flux rates and similarity of histograms and diagnostic ratios for polycyclic aromatic hydrocarbons (PAH) from SPMDs to weathered floating oil collected during the DWH spill indicates the Alabama Alps habitats were affected. While not affected by oil from the DWH spill, the temporal pattern of PAH contamination of SPMDs deployed near the Western Shelf between July 2010 and March 2011 could indicate prevailing currents affected contaminant transport to the Western Shelf Area (East and West Flower Garden, Sonnier, and Stetson Banks) from non-DWH sources, including oil and gas exploration, shipping, and Mississippi River effluent.

Cadmium(II) determination in production waters from petroleum exploration after its separation from the highly saline matrix mediated by a semipermeable membrane device

This paper reports the development of a novel approach for the separation of Cd(II) from production waters generated during petroleum prospection. The analyte was separated from the highly saline waters as a dithiocarbamate (DDTC) complex using a low-density polyethylene semipermeable membrane device (SPMD) filled with chloroform. The quantification of cadmium(II) in the extracts was performed by graphite furnace atomic absorption spectrometry (GF AAS). Several parameters that could affect the performance of the SPMD (pH of the sample, concentration of DDTC, type and volume of solvent used to fill the device, and extraction time) were evaluated in order to achieve maximum transference of Cd(II) and sensitivity. Under the best conditions, the SPMD was filled with 3.0 mL of CHCl3 and used to extract Cd(II) (as Cd(DDTC)2 complex) from a solution containing 3.75 × 10−4 mol L−1 of sodium dithiocarbamate at pH = 9.0. The SPMD was maintained in contact, under shaking, with the sample solution for 90 min. After that, the inner solvent containing the extracted Cd was collected and diluted to 5.0 mL with ethanol prior to analyte quantification by GF AAS. External calibration was possible using Cd(II) standard solutions prepared in a 10% (m/v) NaCl medium. The limits of detection and quantification of the method were 0.08 and 0.24 µg L−1, respectively. The method was employed for the quantification of Cd(II) in four samples of real production waters with high salinity and in a certified reference material of seawater (MX014, from National Measurement Institute of Australia). Recovery tests were also performed by spiking the samples Cd(II), resulting in the recovery percentages in the range of 90 – 132%.