A novel plastic material, poly(ethylene-co-vinyl acetate-co-carbon monoxide) (PEVAC), was evaluated as an absorptive passive equilibrium sampler for determination of the freely dissolved fraction of ...seven polar organic contaminants (POCs) in the presence of fulvic acid and sediment. The seven compounds selected were imidacloprid, carbendazim, metoprolol, atrazin, carbamazepine, diazinon and chlorpyrifos, i.e. a mixture of pharmaceuticals and pesticides having logarithmic octanol/water partition coefficients (log K OW) ranging from 0.2 to 4.77. The experiments demonstrated that the PEVAC sampler is well suited for determination of the freely dissolved fraction of chemicals in aquatic environments. Generally, the freely dissolved fraction of the POCs decreased with increasing hydrophobicity. However, strong interactions with functional groups of the organic matter seemed to dominate the partitioning for imidacloprid and carbendazim, having logarithmic dissociation partition coefficient log D < 1.47, and for metoprolol, which is positively charged at neutral pH.
Untargeted analysis of a composite house dust sample has been performed as part of a collaborative effort to evaluate the progress in the field of suspect and nontarget screening and build an ...extensive database of organic indoor environment contaminants. Twenty-one participants reported results that were curated by the organizers of the collaborative trial. In total, nearly 2350 compounds were identified (18%) or tentatively identified (25% at confidence level 2 and 58% at confidence level 3), making the collaborative trial a success. However, a relatively small share (37%) of all compounds were reported by more than one participant, which shows that there is plenty of room for improvement in the field of suspect and nontarget screening. An even a smaller share (5%) of the total number of compounds were detected using both liquid chromatography–mass spectrometry (LC-MS) and gas chromatography–mass spectrometry (GC-MS). Thus, the two MS techniques are highly complementary. Most of the compounds were detected using LC with electrospray ionization (ESI) MS and comprehensive 2D GC (GC×GC) with atmospheric pressure chemical ionization (APCI) and electron ionization (EI), respectively. Collectively, the three techniques accounted for more than 75% of the reported compounds. Glycols, pharmaceuticals, pesticides, and various biogenic compounds dominated among the compounds reported by LC-MS participants, while hydrocarbons, hydrocarbon derivatives, and chlorinated paraffins and chlorinated biphenyls were primarily reported by GC-MS participants. Plastics additives, flavor and fragrances, and personal care products were reported by both LC-MS and GC-MS participants. It was concluded that the use of multiple analytical techniques was required for a comprehensive characterization of house dust contaminants. Further, several recommendations are given for improved suspect and nontarget screening of house dust and other indoor environment samples, including the use of open-source data processing tools. One of the tools allowed provisional identification of almost 500 compounds that had not been reported by participants.
Abstract-The aim of the present study was to develop a passive a bsorptive equilibrium sampler that would enable the determination of the concentrations of polar organic compound (POC) in water more ...efficiently than existing techniques. To this end, a novel plastic material, poly(ethylene-co-vinyl acetate-co-carbon monoxide) (PEVAC), was evaluated and the results were compared with an existing silicone-based passive absorptive equilibrium device. Seven compounds (imidacloprid, carbendazim, metoprolol, atrazin, carbamazepine, diazinon, and chlorpyrifos), a mixture of pharmaceuticals, and pesticides with a logarithmic octanol-water partition coefficient ranging from 0.2 to 4.77 were selected as model substances for the experiments. The results showed that six of the seven selected POCs reached distribution equilibrium within 4 d in the two materials tested. A linear relation with a regression coefficient of more than 0.8906 between the established logarithmic absorbent-water partition coefficient and the calculated logarithmic dissociation partition coefficient of the selected compounds in the two polymers was observed. The correlation between these two coefficients was within one order of magnitude for the compounds that reached equilibrium in the two polymers, which demonstrates that both materials are suitable for mimicking biological uptake of POCs. The PEVAC material showed an enhanced sorption for all selected compounds compared to the silicone material and up to five times higher enrichment for the most polar compound. Fluorescence analysis of the sampler cross-section, following the uptake of fluoranthene, and proof that the sorption was independent of surface area variations demonstrated that the PEVAC polymer possessed absorptive rather than adsorptive enrichment of organic compounds.
We compared the human exposure to organophosphate flame retardants (PFRs) via inhalation, dust ingestion, and dermal absorption using different sampling and assessment strategies. Air (indoor ...stationary air and personal ambient air), dust (floor dust and surface dust), and hand wipes were sampled from 61 participants and their houses. We found that stationary air contains higher levels of ΣPFRs (median = 163 ng/m3, IQR = 161 ng/m3) than personal air (median = 44 ng/m3, IQR = 55 ng/m3), suggesting that the stationary air sample could generate a larger bias for inhalation exposure assessment. Tris(chloropropyl) phosphate isomers (ΣTCPP) accounted for over 80% of ΣPFRs in both stationary and personal air. PFRs were frequently detected in both surface dust (ΣPFRs median = 33 100 ng/g, IQR = 62 300 ng/g) and floor dust (ΣPFRs median = 20 500 ng/g, IQR = 30 300 ng/g). Tris(2-butoxylethyl) phosphate (TBOEP) accounted for 40% and 60% of ΣPFRs in surface and floor dust, respectively, followed by ΣTCPP (30% and 20%, respectively). TBOEP (median = 46 ng, IQR = 69 ng) and ΣTCPP (median = 37 ng, IQR = 49 ng) were also frequently detected in hand wipe samples. For the first time, a comprehensive assessment of human exposure to PFRs via inhalation, dust ingestion, and dermal absorption was conducted with individual personal data rather than reference factors of the general population. Inhalation seems to be the major exposure pathway for ΣTCPP and tris(2-chloroethyl) phosphate (TCEP), while participants had higher exposure to TBOEP and triphenyl phosphate (TPHP) via dust ingestion. Estimated exposure to ΣPFRs was the highest with stationary air inhalation (median =34 ng·kg bw–1·day–1, IQR = 38 ng·kg bw–1·day–1), followed by surface dust ingestion (median = 13 ng·kg bw–1·day–1, IQR = 28 ng·kg bw–1·day–1), floor dust ingestion and personal air inhalation. The median dermal exposure on hand wipes was 0.32 ng·kg bw–1·day–1 (IQR = 0.58 ng·kg bw–1·day–1) for ΣTCPP. The selection of sampling and assessment strategies could significantly affect the results of exposure assessment.
The fate of pharmaceutical residues in treatment of WWTP sludge was evaluated during mesophilic anaerobic digestion (AD) and six sanitization technologies (pasteurization, thermal hydrolysis, ...advanced oxidation processes using Fenton's reaction, ammonia treatment, thermophilic dry digestion, and thermophilic anaerobic digestion). Sludge spiked with a selection of 13 substances was used and in total 23 substances were detected. A correlation between substance lipophilicity and sludge partitioning was found after sample centrifugation, with e.g., SSRI drugs (90–99%) and estrogens (96–98%) mainly found in the solid phase. A correlation between lipophilicity and persistence of pharmaceutical residues during AD was also detected, indicating that hydrophobic substances are less available to degrading microorganisms. Overall, AD was found to be the most effective technology in reducing a wide spectrum of organic substances (in average ca 30% reduction). Similar effects were obtained for both AD treatments, suggesting that temperature (mesophilic or thermophilic) is less important for micropollutant reduction. Advanced oxidation processes using Fenton's reaction also affected several compounds, including substances showing general stability over the range of treatments such as carbamazepine, propranolol, and sertraline. Pasteurization, ammonia treatment, and thermophilic dry digestion exhibited relatively modest reductions. Interestingly, only thermal hydrolysis efficiently removed the ecotoxicologically potent estrogenic compounds from the sludge.
•7 sludge treatment processes were compared for effect on pharmaceutical residues.•AD was the most effective process in reducing a wide spectrum of organic substances.•Temperature (meso- or thermophilic) was not important for the reduction of residues.•Thermal hydrolysis efficiently removed the estrogens from sludge.•There was a correlation between lipophilicity and persistence of residues during AD.
Alternative plasticizers to phthalate esters have been used for over a decade, but data regarding emissions, human exposure and health effects are limited. Here we review 20 alternative plasticizers ...in current use and their human exposure, hazard and risk. Physicochemical properties are collated for these diverse alternatives and log KOW values range over 15 orders of magnitude and log KAW and log KOA values over about 9 orders of magnitude. Most substances are hydrophobic with low volatility and are produced in high volumes for use in multiple applications. There is an increasing trend in the total use of alternative plasticizers in Sweden compared to common phthalate esters in the last 10years, especially for DINCH. Evaluative indoor fate modeling reveals that most alternatives are distributed to vertical surfaces (e.g. walls or ceilings). Only TXIB and GTA are predicted to be predominantly distributed to indoor air. Human exposure data are lacking and clear evidence for human exposure only exists for DEHT and DINCH, which show increasing trends in body burdens. Human intake rates are collected and compared with limit values with resulting risk ratios below 1 except for infant's exposure to ESBO. PBT properties of the alternatives indicate mostly no reasons for concern, except that TEHPA is estimated to be persistent and TCP toxic. A caveat is that non-standard toxicological endpoint results are not available and, similar to phthalate esters, the alternatives are likely “pseudo-persistent”. Key data gaps for more comprehensive risk assessment are identified and include: analytical methods to measure metabolites in biological fluids and tissues, toxicological information regarding non-standard endpoints such as endocrine disruption and a further refined exposure assessment in order to consider high risk groups such as infants, toddlers and children.
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•Alternative plasticizers are generally low-volatile, hydrophobic substances•High production volumes with increasing trend in use•More refined human exposure assessments necessary•Data gaps exist regarding non-standard toxicological endpoints•Human risks are low although exposure to DINCH and DEHT are increasing
•Pharmaceutical residues removal efficiency of membrane distillation was tested.•Integration approaches of district heating with membrane distillation at pilot plant scale has been assessed.•Membrane ...distillation system’s specific energy demand was determined.•Techno-economy of large-scale MD systems were analyzed.
In this study, an air gap membrane distillation (AGMD) system at pilot scale is applied for purification of effluent from a municipal wastewater treatment plant. A district heating network (DHN) is considered as a heat source for the membrane distillation system. Removal performance of pharmaceutical residuals, specific heat demand, and economic assessments were analyzed on the membrane distillation plant. Almost all targeted pharmaceutical compounds were removed to a very high degree, often below the method detection limit. The heat requirement for the MD process could be sufficiently supplied by the low-temperature district heating return line. Specific heat demands for the AGMD ranges from 692 to 875kWh/m3 without heat recovery and as low as 105kWh/m3 when heat recovery is possible. Different approaches to integrating the MD within the DHN system were analyzed; the advantages and shortcomings of each are discussed with emphasis on the MD system’s capacity requirement and annual heat demand. The thermoeconomic analyses from this study presented the potential for energy optimization regarding heat recovery and module design improvement of the current MD equipment.
Phthalate esters are substances mainly used as plasticizers in various applications. Some have been restricted and phased out due to their adverse health effects and ubiquitous presence, leading to ...the introduction of alternative plasticizers, such as DINCH. Using a comprehensive dataset from a Norwegian study population, human exposure to DMP, DEP, DnBP, DiBP, BBzP, DEHP, DINP, DIDP, DPHP and DINCH was assessed by measuring their presence in external exposure media, allowing an estimation of the total intake, as well as the relative importance of different uptake pathways. Intake via different uptake routes, in particular inhalation, dermal absorption, and oral uptake was estimated and total intake based on all uptake pathways was compared to the calculated intake from biomonitoring data. Hand wipe results were used to determine dermal uptake and compared to other exposure sources such as air, dust and personal care products. Results showed that the calculated total intakes were similar, but slightly higher than those based on biomonitoring methods by 1.1 to 3 times (median), indicating a good understanding of important uptake pathways. The relative importance of different uptake pathways was comparable to other studies, where inhalation was important for lower molecular weight phthalates, and negligible for the higher molecular weight phthalates and DINCH. Dietary intake was the predominant exposure route for all analyzed substances. Dermal uptake based on hand wipes was much lower (median up to 2000 times) than the total dermal uptake via air, dust and personal care products. Still, dermal uptake is not a well-studied exposure pathway and several research gaps (e.g. absorption fractions) remain. Based on calculated intakes, the exposure for the Norwegian participants to the phthalates and DINCH was lower than health based limit values. Nevertheless, exposure to alternative plasticizers, such as DPHP and DINCH, is expected to increase in the future and continuous monitoring is required.
•Diet is the major route of human exposure to phthalates and DINCH.•Human risk related to phthalates and DINCH is low for the adult study population.•Indoor environmental concentrations can be successfully linked to human body burden.•Dermal uptake of phthalates needs further investigation.
Pharmaceutical residues, which pass naturally through the human body into sewage, are in many cases virtually unaffected by conventional wastewater treatment. Accumulated in the environment, however, ...they can significantly impact aquatic life. The present study indicates that many pharmaceutical residues found in wastewater can be removed with activated carbon in a cost-efficient system that delivers higher resource utilisation and security than other carbon systems. The experiment revealed a substantial separation of the analysed compounds, notwithstanding their relatively high solubility in water and dissimilar chemical structures. This implies that beds of activated carbon may be a competitive alternative to treatment with ozone. The effluent water used for the tests, performed over 20 months, originated from Stockholm's largest sewage treatment plant. Passing through a number of different filters with activated carbon removed 90-98% of the pharmaceutical residues from the water. This paper describes pilot-scale tests performed by IVL and the implications for an actual treatment plant that has to treat up to several thousand litres of wastewater per second. In addition, the advantages, disadvantages and costs of the method are discussed. This includes, for example, the clogging of carbon filters and the associated hydraulic capacity limits of the activated carbon.
In the present study, a multi-residue method based on a bag-solid phase extraction (bag-SPE) technique was evaluated for determination of 10 pharmaceuticals in surface water close to the effluent of ...a sewage treatment plant (STP) and along a coastal gradient from a STP effluent.
The 10 compounds selected were caffeine, atenolol, metoprolol, oxazepam, carbamazepine, ketoprofen, naproxen, ibuprofen, diclofenac and gemfibrozil. All analyses were performed using ultra-performance liquid chromatography (UPLC) combined with quadrupole time-of-flight (QTOF) mass spectrometry. The detection limits (LOD) ranged from 1.0 to 13
ng
L
−1. The method showed linear concentration ranges from 25 to 800
ng
L
−1 with regression coefficients (
R
2) better than 0.9801. The recoveries of the selected analytes ranged from 11 to 65% with relative standard deviations (RSD) of <16% and inter-day variations of less than 18%. Isotopically labeled surrogate standards were used to compensate for sampling losses and matrix effects.
Four of the selected 10 pharmaceuticals (caffeine, metoprolol, oxazepam and carbamazepine) were quantified, at concentrations ranging from 4 to 210
ng
L
−1.
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