The Stockholm Convention at a Crossroads: Questionable Nominations and Inadequate Compliance Threaten Its Acceptance and Utility.

Twenty years since coming into force, the Stockholm Convention has become a "living" global agreement that has allowed for the addition of substances that are likely, as a result of their long-range environmental transport (LRET), to lead to significant adverse effects. The recent listing of the phenolic benzotriazole UV-328 in Annex A and a draft nomination of three cyclic volatile methylsiloxanes (cVMS) for Annex B draw attention to the fact that many chemicals are subject to LRET and that this can lead to questionable nominations. The nomination of UV-328 and the draft nomination of cVMS also raise the spectre of regrettable substitutions.

Influence of Season on Biodegradation Rates in Rivers.

Biodegradation plays a key role in the fate of chemicals in the environment. The variability of biodegradation in time can cause uncertainty in evaluating the environmental persistence and risk of chemicals. However, the seasonality of biodegradation in rivers has not yet been the subject of environmentally relevant testing and systematic investigation for large numbers of chemicals.

approaches for the prediction of the breakthrough of organic contaminants in wastewater treatment plants.

The removal efficiency (RE) of organic contaminants in wastewater treatment plants (WWTPs) is a major determinant of the environmental impact of chemicals which are discharged to wastewater. In a recent study, non-target screening analysis was applied to quantify the percentage removal efficiency (RE%) of more than 300 polar contaminants, by analyzing influent and effluent samples from a Swedish WWTP with direct injection UHPLC-Orbitrap-MS/MS. Based on subsets extracted from these data, we developed quantitative structure-property relationships (QSPRs) for the prediction of WWTP breakthrough (BT) to the effluent water.

A framework for understanding the bioconcentration of surfactants in fish.

Surfactants are a class of chemicals released in large quantities to water, and therefore bioconcentration in fish is an important component of their safety assessment. Their structural diversity, which encompasses nonionic, anionic, cationic and zwitterionic molecules with a broad range of lipophilicity, makes their evaluation challenging. A strong influence of environmental pH adds a further layer of complexity to their bioconcentration assessment.

Seasonal and latitudinal variability in the atmospheric concentrations of cyclic volatile methyl siloxanes in the Northern Hemisphere.

Field data from two latitudinal transects in Europe and Canada were gathered to better characterize the atmospheric fate of three cyclic methylsiloxanes (cVMSs), , octamethyl-cyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6). During a year-long, seasonally resolved outdoor air sampling campaign, passive samplers with an ultra-clean sorbent were deployed at 15 sampling sites covering latitudes ranging from the source regions (43.7-50.

The Emissions Fractions Approach to Assessing the Long-Range Transport Potential of Organic Chemicals.

The assessment of long-range transport potential (LRTP) is enshrined in several frameworks for chemical regulation such as the Stockholm Convention. Screening for LRTP is commonly done with the OECD Pov and LRTP Screening Tool employing two metrics, characteristic travel distance (CTD) and transfer efficiency (TE). Here we introduce a set of three alternative metrics and implement them in the Tool's model.

Socioeconomic status and public health in Australia: A wastewater-based study.

Analysis of untreated municipal wastewater is recognized as an innovative approach to assess population exposure to or consumption of various substances. Currently, there are no published wastewater-based studies investigating the relationships between catchment social, demographic, and economic characteristics with chemicals using advanced non-targeted techniques. In this study, fifteen wastewater samples covering 27% of the Australian population were collected during a population Census.

European scale assessment of the potential of ozonation and activated carbon treatment to reduce micropollutant emissions with wastewater.

Micropollutants (MPs) in wastewater pose a growing concern for their potential adverse effects on the receiving aquatic environment, and some countries have started requiring that wastewater treatment plants remove them to a certain extent. Broad spectrum advanced treatment processes, such as ozonation, activated carbon or their combination, are expected to yield a significant reduction in the toxicity of effluents. Here we quantify the reduction of effluent toxicity potentially achieved by implementing these advanced treatment solutions in a selection of European wastewater treatment plants.

Bioconcentration of 10 Anionic Surfactants in Rainbow Trout Explained by Data on Partitioning and S9 Clearance.

Bioconcentration factors (BCFs) in rainbow trout were measured for 10 anionic surfactants with a range of alkyl chain lengths and different polar head groups. The BCFs ranged from 0.04 L kg ww (for CSO) to 1370 L kg ww (CSO).

Background release and potential point sources of per- and polyfluoroalkyl substances to municipal wastewater treatment plants across Australia.

Wastewater treatment plants (WWTPs) are known to be significant sources of per- and polyfluoroalkyl substances (PFAS) to the environment. In this study, PFAS were measured in the influent of 76 municipal wastewater treatment plants (WWTPs) serving approximately 53% of the Australian population. Of fourteen target PFAS, twelve analytes including six C5-C10 perfluoroalkyl carboxylic acids (PFCAs), four C4-10 perfluoroalkyl sulfonic acids (PFSAs) and two fluorotelomer sulfonates (6:2 and 8:2 FTS) were detected.

Screening the baseline fish bioconcentration factor of various types of surfactants using phospholipid binding data.

Fish bioconcentration factors (BCFs) are commonly used in chemical hazard and risk assessment. For neutral organic chemicals BCFs are positively correlated with the octanol-water partition ratio (), but is not a reliable parameter for surfactants. Membrane lipid-water distribution ratios () can be accurately measured for all kinds of surfactants, using phospholipid-based sorbents.

Postflood Monitoring in a Subtropical Estuary and Benchmarking with PFASs Allows Measurement of Chemical Persistence on the Scale of Months.

Measurements of chemical persistence in natural environments can provide insight into behavior not easily replicated in laboratory studies. However, it is difficult to find environmental situations suitable for such measurements, particularly for substances with half-lives exceeding several weeks. The objective of this study was to demonstrate that a strategic postflood monitoring campaign can be used to quantify transformation half-lives on the scale of months in a real aquatic system.

Methodological Advances to Study Contaminant Biotransformation: New Prospects for Understanding and Reducing Environmental Persistence?

Complex microbial communities in environmental systems play a key role in the detoxification of chemical contaminants by transforming them into less active metabolites or by complete mineralization. Biotransformation, i.e.

Uptake of perfluorinated alkyl acids by crops: results from a field study.

Four crops with different edible plant parts (radish, lettuce, pea and maize) were grown in outdoor lysimeters on soil spiked with 13 perfluorinated alkyl acids (PFAAs) at 4 different levels. PFAA concentrations were measured in soil, soil pore water, and different plant parts at harvest. Edible part/soil concentration factors ranged over seven orders of magnitude and decreased strongly with increasing PFAA chain length, by a factor of 10 for each additional fluorinated carbon (n) for pea.

Introducing a nested multimedia fate and transport model for organic contaminants (NEM).

Some organic contaminants, including the persistent organic pollutants (POPs), have achieved global distribution through long range atmospheric transport (LRAT). Regulatory efforts, monitoring programs and modelling studies address the LRAT of POPs on national, continental (e.g.

Bioconcentration of Several Series of Cationic Surfactants in Rainbow Trout.

Cationic surfactants have a strong affinity to sorb to phospholipid membranes and thus possess an inherent potential to bioaccumulate, but there are few measurements of bioconcentration in fish. We measured the bioconcentration of 10 alkylamines plus two quaternary ammonium compounds in juvenile rainbow trout at pH 7.6, and repeated the measurements at pH 6.

Cross-platform validation of neurotransmitter release impairments in schizophrenia patient-derived -mutant neurons.

Heterozygous deletions constitute the most prevalent currently known single-gene mutation associated with schizophrenia, and additionally predispose to multiple other neurodevelopmental disorders. Engineered heterozygous deletions impaired neurotransmitter release in human neurons, suggesting a synaptic pathophysiological mechanism. Utilizing this observation for drug discovery, however, requires confidence in its robustness and validity.

Bioconcentration of cedarwood oil constituents in rainbow trout.

Cedarwood oil is an essential oil used as a fragrance material and insect repellent. Its main constituents are sesquiterpenes which are potentially bioaccumulative according to the REACH screening criteria. Cedarwood oil is a complex mixture of hydrophobic and volatile organic chemicals.

The presence of selected UV filters in a freshwater recreational reservoir and fate in controlled experiments.

UV filters present in sunscreen and other cosmetics are directly released into the environment during aquatic recreational activities. The extent to which the wide range of UV filters pose a risk to the environment remains unclear. This study investigated the occurrence and dissipation of selected organic UV filters at a recreational site (Enoggera Reservoir, Queensland, Australia) over 12 h.

Influence of soil on the uptake of perfluoroalkyl acids by lettuce: A comparison between a hydroponic study and a field study.

This study explores whether mechanistic understanding of plant uptake of perfluoroalkyl acids (PFAAs) derived from hydroponic experiments can be applied to soil systems. Lettuces (Lactuca sativa) were grown in outdoor lysimeters in soil spiked with 4 different concentrations of 13 PFAAs. PFAA concentrations were measured in soil, soil pore water, lettuce roots, and foliage.

Comparing non-targeted chemical persistence assessed using an unspiked OECD 309 test to field measurements.

Previous research has shown that unspiked OECD 309 tests can be used to quantify chemical biodegradation in surface waters, relying on chemical residues already present in the water. Here we test the hypothesis that unspiked OECD 309 tests can quantitatively predict chemical persistence in the environment by comparing chemical half-lives assessed in the laboratory against those measured in the field. The study object was a Swedish lake heavily impacted by treated municipal wastewater.

A simple field-based biodegradation test shows pH to be an inadequately controlled parameter in laboratory biodegradation testing.

Biodegradation tests are essential for characterizing the behavior of organic micropollutants in the environment, but they are carried out almost exclusively in the laboratory. Test parameters such as temperature and test chemical concentration are often applied in ways that affect observed biodegradation, and laboratory testing requires sophisticated temperature-controlled facilities. We developed a field-based test based on OECD 309 which minimizes the need for laboratory resources such as temperature-controlled facilities by using bottles incubated in the natural water body.

Tissue Distribution of Several Series of Cationic Surfactants in Rainbow Trout () Following Exposure via Water.

Bioaccumulation assessment is important for cationic surfactants in light of their use in a wide variety of consumer products and industrial processes. Because they sorb strongly to natural surfaces and to cell membranes, their bioaccumulation behavior is expected to differ from other classes of chemicals. Divided over two mixtures, we exposed rainbow trout to water containing 10 alkyl amines and 2 quaternary alkylammonium surfactants for 7 days, analyzed different fish tissues for surfactant residues, and calculated the tissues' contribution to fish body burden.