Flame Retardant Exposure in Vehicles Is Influenced by Use in Seat Foam and Temperature.

Flame retardants (FRs) are added to vehicles to meet flammability standards, such as US Federal Motor Vehicle Safety Standard FMVSS 302. However, an understanding of which FRs are being used, sources in the vehicle, and implications for human exposure is lacking. US participants (n = 101) owning a vehicle of model year 2015 or newer hung a silicone passive sampler on their rearview mirror for 7 days. Fifty-one of 101 participants collected a foam sample from a vehicle seat. Organophosphate esters (OPEs) were the most frequently detected FR class in the passive samplers. Among these, tris(1-chloro-isopropyl) phosphate (TCIPP) had a 99% detection frequency and was measured at levels ranging from 0.2 to 11,600 ng/g of sampler. TCIPP was also the dominant FR detected in the vehicle seat foam. Sampler FR concentrations were significantly correlated with average ambient temperature and were 2-5 times higher in the summer compared to winter. The presence of TCIPP in foam resulted in ∼4 times higher median air sampler concentrations in winter and ∼9 times higher in summer. These results suggest that FRs used in vehicle interiors, such as in seat foam, are a source of OPE exposure, which is increased in warmer temperatures.

Organophosphate ester flame retardants and plasticizers in house dust and mental health outcomes among Canadian mothers: A nested prospective cohort study in CHILD.

Organophosphate ester flame retardants and plasticizers (OPEs) are common exposures in modern built environments. Toxicological models report that some OPEs reduce dopamine and serotonin in the brain. Deficiencies in these neurotransmitters are associated with anxiety and depression. We hypothesized that exposure to higher concentrations of OPEs in house dust would be associated with a greater risk of depression and stress in mothers across the prenatal and postpartum periods. We conducted a nested prospective cohort study using data collected on mothers (n = 718) in the CHILD Cohort Study, a longitudinal multi-city Canadian birth cohort (2008-2012). OPEs were measured in house dust sampled at 3-4 months postpartum. Maternal depression and stress were measured at 18 and 36 weeks gestation and 6 months and 1 year postpartum using the Centre for Epidemiologic Studies for Depression Scale (CES-D) and Perceived Stress Scale (PSS). We used linear mixed models to examine the association between a summed Z-Score OPE index and continuous depression and stress scores. In adjusted models, one standard deviation increase in the OPE Z-score index was associated with a 0.07-point (95% CI: 0.01, 0.13) increase in PSS score. OPEs were not associated with log-transformed CES-D (ß: 0.63%, 95% CI: -0.18%, 1.46%). The effect of OPEs on PSS score was strongest at 36 weeks gestation and weakest at 1 year postpartum. We observed small increases in maternal perceived stress levels, but not depression, with increasing OPEs measured in house dust during the prenatal and early postpartum period in this cohort of Canadian women. Given the prevalence of prenatal and postpartum anxiety and the ubiquity of OPE exposures, additional research is warranted to understand if these chemicals affect maternal mental health.

Bioplastics: No solution to healthcare's plastic pollution problem.

As Canadian policy-makers recognize the urgency for concerted actions to reduce plastics (e.g., Canada's involvement in the international plastics treaty negotiations, zero plastic waste strategy, and single-use plastics regulations), the healthcare sector must also consider a more sustainable plastics system. In this context, the potential for novel bioplastics to mitigate healthcare's substantial plastic waste problem must be carefully interrogated. Our analysis examines the complexities of bioplastics, highlighting the technical challenges of identifying legitimate sustainable alternatives, and the practical barriers for implementing bioplastics as substitutes for consumable plastics in healthcare. We focus on the Canadian healthcare sector and regulatory landscape with the insights gained being applicable to other sectors and countries. Given the limitations identified, the focus on reducing consumption should remain the priority.

Addressing chemical pollution in biodiversity research.

Climate change, biodiversity loss, and chemical pollution are planetary-scale emergencies requiring urgent mitigation actions. As these "triple crises" are deeply interlinked, they need to be tackled in an integrative manner. However, while climate change and biodiversity are often studied together, chemical pollution as a global change factor contributing to worldwide biodiversity loss has received much less attention in biodiversity research so far. Here, we review evidence showing that the multifaceted effects of anthropogenic chemicals in the environment are posing a growing threat to biodiversity and ecosystems. Therefore, failure to account for pollution effects may significantly undermine the success of biodiversity protection efforts. We argue that progress in understanding and counteracting the negative impact of chemical pollution on biodiversity requires collective efforts of scientists from different disciplines, including but not limited to ecology, ecotoxicology, and environmental chemistry. Importantly, recent developments in these fields have now enabled comprehensive studies that could efficiently address the manifold interactions between chemicals and ecosystems. Based on their experience with intricate studies of biodiversity, ecologists are well equipped to embrace the additional challenge of chemical complexity through interdisciplinary collaborations. This offers a unique opportunity to jointly advance a seminal frontier in pollution ecology and facilitate the development of innovative solutions for environmental protection.

Optimizing Chemicals Management in the United States and Canada through the Essential-Use Approach.

Chemicals have improved the functionality and convenience of industrial and consumer products, but sometimes at the expense of human or ecological health. Existing regulatory systems have proven to be inadequate for assessing and managing the tens of thousands of chemicals in commerce. A different approach is urgently needed to minimize ongoing production, use, and exposures to hazardous chemicals. The premise of the essential-use approach is that chemicals of concern should be used only in cases in which their function in specific products is necessary for health, safety, or the functioning of society and when feasible alternatives are unavailable. To optimize the essential-use approach for broader implementation in the United States and Canada, we recommend that governments and businesses (1) identify chemicals of concern for essentiality assessments based on a broad range of hazard traits, going beyond toxicity; (2) expedite decision-making by avoiding unnecessary assessments and strategically asking up to three questions to determine whether the use of the chemical in the product is essential; (3) apply the essential-use approach as early as possible in the process of developing and assessing chemicals; and (4) engage diverse experts in identifying chemical uses and functions, assessing alternatives, and making essentiality determinations and share such information broadly. If optimized and expanded into regulatory systems in the United States and Canada, other policymaking bodies, and businesses, the essential-use approach can improve chemicals management and shift the market toward safer chemistries that benefit human and ecological health.

Conflicts of Interest in the Assessment of Chemicals, Waste, and Pollution.

Pollution by chemicals and waste impacts human and ecosystem health on regional, national, and global scales, resulting, together with climate change and biodiversity loss, in a triple planetary crisis. Consequently, in 2022, countries agreed to establish an intergovernmental science-policy panel (SPP) on chemicals, waste, and pollution prevention, complementary to the existing intergovernmental science-policy bodies on climate change and biodiversity. To ensure the SPP's success, it is imperative to protect it from conflicts of interest (COI). Here, we (i) define and review the implications of COI, and its relevance for the management of chemicals, waste, and pollution; (ii) summarize established tactics to manufacture doubt in favor of vested interests, i.e., to counter scientific evidence and/or to promote misleading narratives favorable to financial interests; and (iii) illustrate these with selected examples. This analysis leads to a review of arguments for and against chemical industry representation in the SPP's work. We further (iv) rebut an assertion voiced by some that the chemical industry should be directly involved in the panel's work because it possesses data on chemicals essential for the panel's activities. Finally, (v) we present steps that should be taken to prevent the detrimental impacts of COI in the work of the SPP. In particular, we propose to include an independent auditor's role in the SPP to ensure that participation and processes follow clear COI rules. Among others, the auditor should evaluate the content of the assessments produced to ensure unbiased representation of information that underpins the SPP's activities.

Addressing systemic problems with exposure assessments to protect the public's health.

BACKGROUND: Understanding, characterizing, and quantifying human exposures to environmental chemicals is critical to protect public health. Exposure assessments are key to determining risks to the general population and for specific subpopulations given that exposures differ between groups. Exposure data are also important for understanding where interventions, including public policies, should be targeted and the extent to which interventions have been successful. In this review, we aim to show how inadequacies in exposure assessments conducted by polluting industries or regulatory agencies have led to downplaying or disregarding exposure concerns raised by communities; that underestimates of exposure can lead regulatory agencies to conclude that unacceptable risks are, instead, acceptable, allowing pollutants to go unregulated; and that researchers, risk assessors, and policy makers need to better understand the issues that have affected exposure assessments and how appropriate use of exposure data can contribute to health-protective decisions. METHODS: We describe current approaches used by regulatory agencies to estimate human exposures to environmental chemicals, including approaches to address limitations in exposure data. We then illustrate how some exposure assessments have been used to reach flawed conclusions about environmental chemicals and make recommendations for improvements. RESULTS: Exposure data are important for communities, public health advocates, scientists, policy makers, and other groups to understand the extent of environmental exposures in diverse populations. We identify four areas where exposure assessments need to be improved due to systemic sources of error or uncertainty in exposure assessments and illustrate these areas with examples. These include: (1) an inability of regulatory agencies to keep pace with the increasing number of chemicals registered for use or assess their exposures, as well as complications added by use of 'confidential business information' which reduce available exposure data; (2) the failure to keep assessments up-to-date; (3) how inadequate assumptions about human behaviors and co-exposures contribute to underestimates of exposure; and (4) that insufficient models of toxicokinetics similarly affect exposure estimates. CONCLUSION: We identified key issues that impact capacity to conduct scientifically robust exposure assessments. These issues must be addressed with scientific or policy approaches to improve estimates of exposure and protect public health.

A science-based agenda for health-protective chemical assessments and decisions: overview and consensus statement.

The manufacture and production of industrial chemicals continues to increase, with hundreds of thousands of chemicals and chemical mixtures used worldwide, leading to widespread population exposures and resultant health impacts. Low-wealth communities and communities of color often bear disproportionate burdens of exposure and impact; all compounded by regulatory delays to the detriment of public health. Multiple authoritative bodies and scientific consensus groups have called for actions to prevent harmful exposures via improved policy approaches. We worked across multiple disciplines to develop consensus recommendations for health-protective, scientific approaches to reduce harmful chemical exposures, which can be applied to current US policies governing industrial chemicals and environmental pollutants. This consensus identifies five principles and scientific recommendations for improving how agencies like the US Environmental Protection Agency (EPA) approach and conduct hazard and risk assessment and risk management analyses: (1) the financial burden of data generation for any given chemical on (or to be introduced to) the market should be on the chemical producers that benefit from their production and use; (2) lack of data does not equate to lack of hazard, exposure, or risk; (3) populations at greater risk, including those that are more susceptible or more highly exposed, must be better identified and protected to account for their real-world risks; (4) hazard and risk assessments should not assume existence of a "safe" or "no-risk" level of chemical exposure in the diverse general population; and (5) hazard and risk assessments must evaluate and account for financial conflicts of interest in the body of evidence. While many of these recommendations focus specifically on the EPA, they are general principles for environmental health that could be adopted by any agency or entity engaged in exposure, hazard, and risk assessment. We also detail recommendations for four priority areas in companion papers (exposure assessment methods, human variability assessment, methods for quantifying non-cancer health outcomes, and a framework for defining chemical classes). These recommendations constitute key steps for improved evidence-based environmental health decision-making and public health protection.

Time to Break the "Lock-In" Impediments to Chemicals Management.

Despite enormous national, regional, and global efforts on chemical management, the widespread use of hazardous chemicals continues in many parts of the world even after decades of there being well-known risks to public and/or ecosystem health. This continued supply and use, despite strong evidence of negative impacts, is not unique to chemicals management. In the field of climate change, the concept of "lock-in" has been used to explain the complex interactions among economic, social, technological, and political dynamics that reinforce global reliance on the extraction and use of fossil fuels. Learning from carbon "lock-in" phenomena, this Perspective explores the challenges of chemicals management from the perspective of lock-in through three case studies: paraquat, perfluorooctanesulfonic acid (PFOS), and asbestos. These case studies illustrate that most current chemicals management frameworks fail to address the concerns arising from this complex interplay by not involving all relevant stakeholder groups that are part of lock-in, from producers to consumers. This results in a relatively narrow consideration (e.g., only demand but not supply) of the effectiveness and consequences of regulations. We submit that to break lock-in and address the global threat of chemical pollution, current approaches to managing hazardous chemicals should be broadened to take a comprehensive approach to understanding and managing factors contributing to lock-in, notably both supply and demand on national and international scales.

Modeling Clothing as a Vector for Transporting Airborne Particles and Pathogens across Indoor Microenvironments.

Evidence suggests that human exposure to airborne particles and associated contaminants, including respiratory pathogens, can persist beyond a single microenvironment. By accumulating such contaminants from air, clothing may function as a transport vector and source of "secondary exposure". To investigate this function, a novel microenvironmental exposure modeling framework (ABICAM) was developed. This framework was applied to a para-occupational exposure scenario involving the deposition of viable SARS-CoV-2 in respiratory particles (0.5-20 µm) from a primary source onto clothing in a nonhealthcare setting and subsequent resuspension and secondary exposure in a car and home. Variability was assessed through Monte Carlo simulations. The total volume of infectious particles on the occupant's clothing immediately after work was 4800 µm3 (5th-95th percentiles: 870-32 000 µm3). This value was 61% (5-95%: 17-300%) of the occupant's primary inhalation exposure in the workplace while unmasked. By arrival at the occupant's home after a car commute, relatively rapid viral inactivation on cotton clothing had reduced the infectious volume on clothing by 80% (5-95%: 26-99%). Secondary inhalation exposure (after work) was low in the absence of close proximity and physical contact with contaminated clothing. In comparison, the average primary inhalation exposure in the workplace was higher by about 2-3 orders of magnitude. It remains theoretically possible that resuspension and physical contact with contaminated clothing can occasionally transmit SARS-CoV-2 between humans.

Occupational Exposure of Canadian Nail Salon Workers to Plasticizers Including Phthalates and Organophosphate Esters.

Personal exposure of nail salon workers to 10 phthalates and 19 organophosphate esters (OPEs) was assessed in 18 nail salons in Toronto, Canada. Active air samplers (n = 60) and silicone passive samplers, including brooches (n = 58) and wristbands (n = 60), were worn by 45 nail salon workers for ∼8 working hours. Diethyl phthalate (median = 471 ng m-3) and diisobutyl phthalate (337 ng m-3) were highest in active air samplers. Most abundant OPEs in active air samplers were tris(2-chloroisopropyl)phosphate or TCIPP (303 ng m-3) and tris(2-chloroethyl)phosphate or TCEP (139 ng m-3), which are used as flame retardants but have not been reported for use in personal care products or nail salon accessories. Air concentrations of phthalates and OPEs were not associated with the number of services performed during each worker's shift. Within a single work shift, a combined total of 16 (55%) phthalates and OPEs were detected on passive silicone brooches; 19 (66%) were detected on wristbands. Levels of tris(2-chloroisopropyl)phosphate, tris(1,3-dichloro-2-propyl)phosphate or TDCIPP, and triphenyl phosphate or TPhP wristbands were significantly higher than those worn by e-waste workers. Significant correlations (p < 0.05) were found between the levels of some phthalates and OPEs in silicone brooches and wristbands versus those in active air samplers. Stronger correlations were observed between active air samplers versus brooches than wristbands. Sampler characteristics, personal characteristics, and chemical emission sources are the three main factors proposed to influence the use of passive samplers for measuring semi-volatile organic compound exposure.

Stormwater Bioretention Cells Are Not an Effective Treatment for Persistent and Mobile Organic Compounds (PMOCs).

Bioretention cells are a stormwater management technology intended to reduce the quantity of water entering receiving bodies. They are also used to reduce contaminant releases, but their performance is unclear for hydrophilic persistent and mobile organic compounds (PMOCs). We developed a novel eight-compartment one-dimensional (1D) multimedia model of a bioretention cell ("Bioretention Blues") and applied it to a spike and recovery experiment conducted on a system near Toronto, Canada, involving PMOC benzotriazole and four organophosphate esters (OPEs). Compounds with (log DOC) (organic carbon-water distribution coefficients) < ∼2.7 advected through the system, resulting in infiltration or underdrain flow. Compounds with log DOC > 3.8 were mostly sorbed to the soil, where subsequent fate depended on transformation. For compounds with 2.7 ≤ log DOC ≤ 3.8, sorption was sensitive to event size and compound-specific diffusion parameters, with more sorption expected for smaller rain events and for compounds with larger diffusion coefficients. Volatilization losses were minimal for all compounds tested. Direct uptake by vegetation also played a negligible role regardless of the compounds' physicochemical properties. Nonetheless, model simulations showed that vegetation could play a role by increasing transpiration, thereby increasing sorption to the bioretention soil and reducing PMOC release. Model results suggest design modifications to bioretention cells.

Persistent Problem: Global Challenges to Managing PCBs.

Polychlorinated biphenyls (PCBs), "famous" as persistent organic pollutants (POPs), have been managed nationally since the 1970s and globally under the Stockholm Convention on POPs since 2004, requiring environmentally sound management (ESM) of PCBs by 2028. At most, 30% of countries are on track to achieve ESM by 2028. Globally over 10 million tonnes of PCB-containing materials remain, mostly in countries lacking the ability to manage PCB waste. Canada (Ontario) and Czechia, both parties to the Stockholm Convention, are close to achieving the 2028 goal, having reduced their stocks of pure PCBs by 99% in the past 10 years. In contrast, the USA, not a party to the Stockholm Convention, continues to have a substantial but poorly inventoried stock of PCBs and only ∼3% decrease in mass of PCBs since 2006. PCB management, which depends on Stockholm Convention support and national compliance, portends major challenges for POP management. The failure to manage global PCB stocks >30 years after the end of production highlights the urgent need to prioritize reducing production and use of newer, more widely distributed POPs such as chlorinated paraffins and per- and polyfluorinated alkyl substances, as these management challenges are unlikely to be resolved in the coming decades.

Per- and Polyfluoroalkyl Substances in North American School Uniforms.

We analyzed 72 children's textile products marketed as stain-resistant from US and Canadian stores, particularly school uniforms, to assess if clothing represents a significant route of exposure to per- and polyfluoroalkyl substances (PFAS). Products were first screened for total fluorine (total F) using particle-induced γ-ray emission (PIGE) spectroscopy (n = 72), followed by targeted analysis of 49 neutral and ionic PFAS (n = 57). PFAS were detected in all products from both markets, with the most abundant compound being 6:2 fluorotelomer alcohol (6:2 FTOH). Total targeted PFAS concentrations for all products collected from both countries ranged from 0.250 to 153 000 ng/g with a median of 117 ng/g (0.0281-38 100 µg/m2, median: 24.0 µg/m2). Total targeted PFAS levels in school uniforms were significantly higher than in other items such as bibs, hats, stroller covers, and swimsuits, but comparable to outdoor wear. Higher total targeted PFAS concentrations were found in school uniforms made of 100% cotton than synthetic blends. Perfluoroalkyl acids (PFAAs) precursors were abundant in school uniforms based on the results of hydrolysis and total oxidizable precursor assay. The estimated median potential children's exposure to PFAS via dermal exposure through school uniforms was 1.03 ng/kg bw/day. Substance flow analysis estimated that ∼3 tonnes/year (ranging from 0.05 to 33 tonnes/year) of PFAS are used in US children's uniforms, mostly of polymeric PFAS but with ∼0.1 tonne/year of mobile, nonpolymeric PFAS.

Outside the Safe Operating Space of the Planetary Boundary for Novel Entities.

We submit that the safe operating space of the planetary boundary of novel entities is exceeded since annual production and releases are increasing at a pace that outstrips the global capacity for assessment and monitoring. The novel entities boundary in the planetary boundaries framework refers to entities that are novel in a geological sense and that could have large-scale impacts that threaten the integrity of Earth system processes. We review the scientific literature relevant to quantifying the boundary for novel entities and highlight plastic pollution as a particular aspect of high concern. An impact pathway from production of novel entities to impacts on Earth system processes is presented. We define and apply three criteria for assessment of the suitability of control variables for the boundary: feasibility, relevance, and comprehensiveness. We propose several complementary control variables to capture the complexity of this boundary, while acknowledging major data limitations. We conclude that humanity is currently operating outside the planetary boundary based on the weight-of-evidence for several of these control variables. The increasing rate of production and releases of larger volumes and higher numbers of novel entities with diverse risk potentials exceed societies' ability to conduct safety related assessments and monitoring. We recommend taking urgent action to reduce the harm associated with exceeding the boundary by reducing the production and releases of novel entities, noting that even so, the persistence of many novel entities and/or their associated effects will continue to pose a threat.

Enhancing Scientific Support for the Stockholm Convention's Implementation: An Analysis of Policy Needs for Scientific Evidence.

The Stockholm Convention is key to addressing the global threats of persistent organic pollutants (POPs) to humanity and the environment. It has been successful in identifying new POPs, but its national implementation remains challenging, particularly by low- and middle-income Parties. Concerted action is needed to assist Parties in implementing the Convention's obligations. This analysis aims to identify and recommend research and scientific support needed for timely implementation of the Convention. We aim this analysis at scientists and experts from a variety of natural and social sciences and from all sectors (academia, civil society, industry, and government institutions), as well as research funding agencies. Further, we provide practical guidance to scientists and experts to promote the visibility and accessibility of their work for the Convention's implementation, followed by recommendations for sustaining scientific support to the Convention. This study is the first of a series on analyzing policy needs for scientific evidence under global governance on chemicals and waste.

Quantitative filter forensics for semivolatile organic compounds in social housing apartments.

Residents from low-income social housing are vulnerable to adverse health effects from indoor air pollution. Particle-bound concentrations of eight phthalates and 12 polycyclic aromatic hydrocarbons (PAHs) in indoor air were measured using quantitative filter forensics with portable air cleaners deployed for three one-week periods from 2015 to 2017. The sample included 143 apartments across seven multi-unit social housing buildings in Toronto, Canada, that went through energy retrofits in 2016. Eight phthalates and six PAHs were found in more than 50% of the apartments in either of the three sampling periods. Di(2-ethylhexyl) phthalate (DEHP) and phenanthrene were the dominant phthalate and PAH, with median concentrations of 146, 143, and 130 ng/m3 and 1.51, 0.58, and 0.76 ng/m3 in the late spring of 2015, and after retrofits in late spring 2017 and winter of 2017, respectively. SVOC concentrations were generally lower after energy retrofits, with significant differences for phenanthrene, fluoranthene, and pyrene. Lower concentrations post-retrofit may be related to less overheating and less need for opening windows. Concentrations of phthalates and PAHs in this study were similar to or higher than those reported in the literature. Results suggest that the use of portable air filters is a promising method to assess concentrations of indoor particle-bound SVOCs.

Textile Washing Conveys SVOCs from Indoors to Outdoors: Application and Evaluation of a Residential Multimedia Model.

Indoor environments have elevated concentrations of numerous semivolatile organic compounds (SVOCs). Textiles provide a large surface area for accumulating SVOCs, which can be transported to outdoors through washing. A multimedia model was developed to estimate advective transport rates (fluxes) of 14 SVOCs from indoors to outdoors by textile washing, ventilation, and dust removal/disposal. Most predicted concentrations were within 1 order of magnitude of measurements from a study of 26 Canadian homes. Median fluxes to outdoors [µg·(year·home)-1] spanned approximately 4 orders of magnitude across compounds, according to the variability in estimated aggregate emissions to indoor air. These fluxes ranged from 2 (2,4,4'-tribromodiphenyl ether, BDE-28) to 30 200 (diethyl phthalate, DEP) for textile washing, 12 (BDE-28) to 123 200 (DEP) for ventilation, and 0.1 (BDE-28) to 4200 (bis(2-ethylhexyl) phthalate, DEHP) for dust removal. Relative contributions of these pathways to the total flux to outdoors strongly depended on physical-chemical properties. Textile washing contributed 20% tris-(2-chloroisopropyl)phosphate (TCPP) to 62% tris(2-butoxyethyl)phosphate (TBOEP) on average. These results suggest that residential textile washing can be an important transport pathway to outdoors for SVOCs emitted to indoor air, with implications for human and ecological exposure. Interventions should try to balance the complex tradeoff of textile washing by minimizing exposures for both human occupants and aquatic ecosystems.

Trace Organic Contaminant Transfer and Transformation in Bioretention Cells: A Field Tracer Test with Benzotriazole.

Bioretention cells can effectively infiltrate stormwater runoff and partly remove conventional water contaminants. A field tracer injection experiment in a conventionally designed bioretention cell was used to investigate the fate of benzotriazole, a model trace organic contaminant, during and between runoff events. Moderate (29%) benzotriazole load reductions were measured during the 6 h long injection experiment. The detection of 1-methyl benzotriazole, hydroxy benzotriazole, and methoxy benzotriazole provided in situ evidence of some rapid benzotriazole microbial transformation during the tracer test and more importantly between the events. The detection of benzotriazole alanine and benzotriazole acetyl alanine also showed fast benzotriazole phytotransformation to amino acid conjugates during the tracer test and suggests further transformation of phytotransformation products between events. These data provide conclusive full-scale evidence of benzotriazole microbial and phytotransformation in bioretention cells. Non-target chemical analysis revealed the presence of a diverse range of trace organic contaminants in urban runoff and exiting the bioretention cell, including pesticides and industrial, household, and pharmaceutical compounds. We have demonstrated the in situ potential of urban green infrastructure such as bioretention cells to eliminate polar trace organic contaminants from stormwater. However, targeted design and operation strategies, for example, hydraulic control and the use of soil amendments, should be incorporated for improved bioretention cell performance for such compounds.

Organophosphate Esters in the Canadian Arctic Ocean.

Eleven organophosphate esters (OPEs) were detected in surface water and sediment samples from yearly sampling (2013-2018) in the Canadian Arctic. In water samples, ∑chlorinated-OPEs (Cl-OPEs) concentrations exceeded ∑non-chlorinated-OPEs (non-Cl-OPEs) with median concentrations of 10 ng L-1 and 1.3 ng L-1, respectively. In sediment samples, ∑Cl-OPEs and ∑nonchlorinated-OPEs had median concentrations of 4.5 and 2.5 ng g-1, respectively. High concentrations of OPEs in samples from the Mackenzie River plume suggest riverine discharge as an OPE source to the Canadian Arctic. The prevalence of OPEs at other sites is consistent with long-range transport. The OPE inventory of the Canadian Arctic Ocean representative of years 2013-2018 was estimated at 450-16,000 tonnes with a median ∑11OPE mass of 4100 tonnes with >99% of the OPE inventory estimated to be in the water column. These results highlight the importance of OPEs as water-based Arctic contaminants subject to long-range transport and local sources. The high OPE inventory in the water column of the Canadian Arctic Ocean points to the need for international regulatory mechanisms for persistent and mobile organic contaminants (PMOCs) that are not covered by the risk assessment criteria of the Stockholm Convention.