Cleaning Up without Messing Up: Maximizing the Benefits of Plastic Clean-Up Technologies through New Regulatory Approaches.

As the global plastics crisis grows, numerous technologies have been invented and implemented to recover plastic pollution from the environment. Although laudable, unregulated clean-up technologies may be inefficient and have unintended negative consequences on ecosystems, for example, through bycatch or removal of organic matter important for ecosystem functions. Despite these concerns, plastic clean-up technologies can play an important role in reducing litter in the environment. As the United Nations Environment Assembly is moving toward an international, legally binding treaty to address plastic pollution by 2024, the implementation of plastic clean-up technologies should be regulated to secure their net benefits and avoid unintended damages. Regulation can require environmental impact assessments and life cycle analysis to be conducted predeployment on a case-by-case basis to determine their effectiveness and impact and secure environmentally sound management. During operations catch-efficiency and bycatch of nonlitter items, as well as waste management of recovered litter, should be documented. Data collection for monitoring, research, and outreach to mitigate plastic pollution is recommended as added value of implementation of clean-up technologies.

Risk assessment of sediment PAH, BTEX, and emerging contaminants in Chanomi Creek Niger Delta, Nigeria.

This study assessed the levels of polycyclic aromatic hydrocarbons (PAHs), benzene, toluene, ethylbenzene, and xylene (BTEX), and emerging contaminants in Chanomi Creek. Sediment samples were collected between March 2019 and July 2020 to evaluate the concentrations of PAH, BTEX, and emerging contaminants using GC-MS and GC-FID with Headspace extraction. Results indicated mean PAH concentrations were 22.691 ± 15.09 µg/kg. The highest individual PAH concentrations were fluorene (7.085 µg/kg), naphthalene (4.517 µg/kg), and phenanthrene (3.081 µg/kg). Carbazole (0.828 µg/kg) was discovered as a novel environmental toxin with dioxin-like toxicity and widespread prevalence in sediments. The most common congener (25%) was ethylbenzene, followed by toluene and ortho- and meta-xylene (21%) and benzene (13%). The analysis of diagnostic ratios revealed that the main factors responsible for the presence of PAHs in the study area are the residential use of firewood, emissions from industrial activities, bush burning, and petroleum slicks. The risk assessment indicated that most PAHs exceeded the permissible risk quotient values, suggesting a moderate to high ecological risk. However, cutaneous exposure to PAHs and BTEX was found to have minimal impact on human health, with no significant hazards identified in adults and children. Nevertheless, the study revealed low cancer risks associated with PAH and BTEX compounds for both age groups. The continued discharge of PAHs and BTEX compounds into Chanomi Creek could have significant long-term negative effects on human and aquatic health. Thus, contamination risk awareness programs and the development of stringent contextual thresholds for identified contaminants could enhance environmental and public health protection.

Comparative analysis of the contribution of municipal waste management policies to GHG reductions in China.

Waste generation and disposal have been a global issue for decades. The total global greenhouse gas (GHG) emissions in 2019 were 49,758 MtCO2e with waste disposal accounting for 3.2%. With rapid urbanization trends, municipal solid waste (MSW) has become a global challenge which needs to be addressed. A large fraction of MSW such as food wastes, e-waste among others still ends up with unregulated dumps or openly burned in low-income countries. As a response, China initiated the 'zero-waste' pilot program which has been running since 2019. To investigate the potential contribution of MSW management to GHG reductions, this study selected four 'zero-waste' cities in China, namely Shenzhen, Panjin, Xining and Tongling, as case studies to assess the impacts of different MSW management policies on GHG reductions from 2015 to 2019. Results demonstrated that Shenzhen city achieved progress in reducing GHGs, which decreased by more than 40% between 2015 and 2019. This study provides policy recommendations and waste management approaches and practices to optimize MSW management and reduction of GHGs.

Green synthesized Ag-nanoparticles using Scutellaria multicaulis stem extract and their selective cytotoxicity against breast cancer.

Scutellaria multicaulis is a medicinal herb which has been extensively prescribed in Iranian traditional medicine for treatment of infections, constipation, wounds, and also as medication for anxiety. To evaluate biological activities of biosynthesized silver nanoparticles (Sm-AgNPs), Sm-AgNPswere synthesized using S. multicaulis stem extract as capping and reducing agent. Characterization studies using UV-vis, XRD, DLS, Zeta potential, FESEM, EDX, TEM, FTIR, RAMAN and TGA assays indicated that Sm-AgNPs had optimal shape, size (∼60 nm) and stability (-46.4 mV) to be used as a drug. Findings also demonstrated that Sm-AgNPs display higher Total Phenolics and Total Flavonoids Content and possesses higher antioxidant activity. HPLC-MSn analysis of constituents in the S. multicaulis stem extract and Sm-AgNPs-free supernatant in negative ion mode showed that flavonoids, mainly jaceidin, skullcapflavon II, wogonin, oroxylin A and dihydroxy, trimethoxyflavone from extract have contributed to the synthesis of Sm-AgNPs. Additionally, Sm-AgNPs demonstrated effective anticarcinogenic properties on MDA-MB231 cells proliferation with IC50 value of 81.2 µg/mL at 48 h by inducing cell apoptosis. Overall, results confirmed the potential role of S. multicaulis stem extract as a potential raw material for synthesis of biologically active Sm-AgNPs, for development of new antitumor agents which could be utilized to combat breast cancer.

Characterization, source apportionment and risk assessment of PAHs in urban surface dust in Shenyang city, China.

Characteristics, profile composition, ecological and human health risk of polycyclic aromatic hydrocarbons in surface dust collected from Shenyang city, China, were investigated. Concentrations of 16 USEPA priority PAHs ranged between 371.57 and 3300.04 µg/kg (mean 1244.76 ± 715.25 µg/kg). Fluoranthene was the most abundant individual PAHs, followed by pyrene, and high molecular weight PAHs, more than three times of low molecular weight PAHs, were the predominant components. Profiles of PAHs showed that 4-ring PAHs were dominant, followed by 3-ring and 5-ring PAHs, and indicated that combustion sources accounted for the most PAHs. Results of diagnostic ratios and positive matrix factorization all suggested that pyrogenic sources were the most important source of PAHs in urban dust, followed by natural gas combustion and petrogenic sources, and traffic emissions would play an increasingly critical role with the increasing of vehicles. Health risk assessment suggested children were the most vulnerable to PAHs compared to adolescents and adults. Ingestion was the most important exposure pathway. The total lifetime cancer risk of 43.33% of sampling sites was higher than 10-6, but the TLCR at all sites was much lower than the highest acceptable risk established by USEPA (10-4).

Increased plastic pollution due to COVID-19 pandemic: Challenges and recommendations.

Plastics have become a severe transboundary threat to natural ecosystems and human health, with studies predicting a twofold increase in the number of plastic debris (including micro and nano-sized plastics) by 2030. However, such predictions will likely be aggravated by the excessive use and consumption of single-use plastics (including personal protective equipment such as masks and gloves) due to COVID-19 pandemic. This review aimed to provide a comprehensive overview on the effects of COVID-19 on macroplastic pollution and its potential implications on the environment and human health considering short- and long-term scenarios; addressing the main challenges and discussing potential strategies to overcome them. It emphasises that future measures, involved in an emergent health crisis or not, should reflect a balance between public health and environmental safety as they are both undoubtedly connected. Although the use and consumption of plastics significantly improved our quality of life, it is crucial to shift towards sustainable alternatives, such as bio-based plastics. Plastics should remain in the top of the political agenda in Europe and across the world, not only to minimise plastic leakage and pollution, but to promote sustainable growth and to stimulate both green and blue- economies. Discussions on this topic, particularly considering the excessive use of plastic, should start soon with the involvement of the scientific community, plastic producers and politicians in order to be prepared for the near future.

How does the global plastic waste trade contribute to environmental benefits: Implication for reductions of greenhouse gas emissions?

Plastic waste pollution has been identified as a serious global issue, posing environmental risks in terms of massive waste generation, ocean pollution, and increases in greenhouse gas (GHG) emissions. Despite documented environmental impacts, it remains debatable whether the global plastic waste trade (GPWT) for reutilization and recycling, as part of the global circular economy (CE), has historically contributed to environmental benefits. To investigate if historical GPWT has contributed to environmental benefits in terms of reductions of GHG emissions, this study analyzed GPWT between China and trading countries through their trajectories, characteristics and driving forces of reductions of GHG emissions between 1992 and 2017. Results indicated an increasing trend of reductions of GHG emissions in GPWT between China and trading countries over 25 years. A net reduction of 8.27 million metric tons carbon dioxide equivalent (CO2e) was observed in 2012, nearly 84 times levels observed in 1992. Policy implications after China's recent ban of imports of GPWT in December 2017 and recent changes of GPWT to other Asian countries are discussed. Dramatic changes in sustainable approaches to GPWT for reutilization and recycling are required.

COVID-19 Pandemic Repercussions on the Use and Management of Plastics.

Plastics are essential in society as a widely available and inexpensive material. Mismanagement of personal protective equipment (PPE) during the COVID-19 pandemic, with a monthly estimated use of 129 billion face masks and 65 billion gloves globally, is resulting in widespread environmental contamination. This poses a risk to public health as waste is a vector for SARS-CoV-2 virus, which survives up to 3 days on plastics, and there are also broad impacts to ecosystems and organisms. Concerns over the role of reusable plastics as vectors for SARS-CoV-2 virus contributed to the reversal of bans on single-use plastics, highly supported by the plastic industry. While not underestimating the importance of plastics in the prevention of COVID-19 transmission, it is imperative not to undermine recent progress made in the sustainable use of plastics. There is a need to assess alternatives that allow reductions of PPE and reinforce awareness on the proper public use and disposal. Finally, assessment of contamination and impacts of plastics driven by the pandemic will be required once the outbreak ends.

Aquatic ecological risk assessment frameworks in Canada: a case study using a single framework in South Baymouth, Ontario, Canada.

Ecological risk assessment (ERA) is used to determine potential effect of human activities and industries on the natural environment. Numerous ERA management approaches exist and vary based on jurisdiction or ecological media. This ERA focused on contaminants within an aquatic ecosystem in sediments and surface water at South Baymouth port facility in Ontario, Canada. Contaminants were evaluated using the Canada-Ontario Decision-Making Framework for Assessment of Great Lakes Contaminated Sediments (COA). Following COA, this study (1) examined historical data from South Baymouth to determine contaminants of potential concern, (2) delineated potential contamination by comparing sediment and surface water concentration data to sediment quality guidelines and water quality guidelines from Canada and from different jurisdictions if Canadian guidelines were unavailable, (3) compared sediment concentrations to reference concentrations, and (4) developed an ERA decision matrix (used to inform management decisions at this aquatic site). Although sediments exhibited negligible potential for ecological risk and required no remedial management action, this case study highlights strengths of using COA for this ERA which included use of iterative and consistent approaches, but also highlights weaknesses which included unclear linkages between cause and effects of aquatic contaminants. Recommendations for future ERAs at contaminated aquatic sites include use of passive samplers and incorporating recent macroecology techniques.

Pollution, management, and mitigation of idle and orphaned oil and gas wells in Alberta, Canada.

Alberta has extensive non-renewable energy resources which contribute to the Canadian economy. A downturn in oil and gas energy prices in 2014 contributed to increased idle and orphaned wells, posing potential environmental and human health risks, as well as an economic burden on the province of Alberta. Idle and orphaned wells contribute to local adverse environmental and human health effects from soil and groundwater contamination to greenhouse gas emissions. With increasing numbers of idle and orphaned wells, current monitoring measures, including regulation and cost to identify well leakage, are insufficient. Current policy measures to manage idle and orphaned well environmental liabilities were found to be inadequate to cover cleanup costs. With oil and gas prices showing no signs of rebound, these idle and orphaned well liabilities need to be addressed. This paper discusses potential environmental risks that idle and orphaned oil and gas wells pose, compares Alberta's current monitoring and policy initiatives to those in other provinces as well as the USA, and recommends future management strategies to mitigate the issue.

Characterization and spatial distribution of organic-contaminated sediment derived from historical industrial effluents.

Organic sediment contaminants [polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs), and polycyclic aromatic hydrocarbons (PAHs)] were assessed using secondary monitoring data from a former tidal estuary (Boat Harbour) impacted by historical industrial effluents. Spatiotemporal characterization of PCDD/Fs and PAHs in sediments was conducted to inform a sediment remediation program designed to return this contaminated aquatic site back to a tidal lagoon. Spatiotemporal variations of sediment PCDD/F and PAH concentrations across Boat Harbour and off-site reference locations were assessed using secondary monitoring data collected between 1992 and 2015. Sediment PCDD/F toxic equivalency (TEQ) and PAH concentrations were compared to sediment quality guidelines. Sediment PCDD/F concentrations exceeded the highest effect thresholds posing severe ecological health risks. High sediment PCDD/F concentrations have persisted in Boat Harbour despite implementation of Pulp and Paper Mill Effluent Chlorinated Dioxins and Furans Regulations in 1992. PAH concentrations varied greatly. Five individual PAH compounds frequently exceeded severe effect thresholds, in contrast to total PAHs, which were below severe effect thresholds. Forensic analysis using PAH diagnostic ratios suggests pyrogenic PAHs derived from wood processes or coal combustion were likely sources. Twenty-five years of monitoring data revealed large data gaps in our understanding of sediment characteristics in Boat Harbour. Gaps included spatial (vertical and horizontal) and temporal variations, presenting challenges for remediation to accurately delineate sediment contaminants. Deeper horizons were poorly characterized compared to shallow sediments (0-15 cm). Historical secondary monitoring data showed that spatial coverage across Boat Harbour was inadequate. Due to severe ecological health risks associated with high sediment PCDD/F concentrations, remediation of the entire sediment inventory is recommended. Detailed vertical and horizontal sampling within Boat Harbour, establishment of local baseline concentrations, and additional sampling in down-gradient-receiving environments for a suite of contaminants are required to better characterize sediments prior to remediation.

Industrial wind turbine post-construction bird and bat monitoring: A policy framework for Canada.

Electricity generation from wind energy has proliferated throughout North America and will continue to grow. Given Canada's expected increase in wind energy capacity, consideration of the potential adverse impacts to bird and bat populations is prudent given their sensitivity to these projects. The province of Ontario, Canada is currently the leading jurisdiction for wind energy development, and for provincial guidance on pre- and post-construction monitoring. With uniform monitoring guidance in Ontario, wind energy proponents, and third-party consultants, have developed post-construction monitoring protocols that meet provincial guidance, while also providing standardized reporting. In Atlantic Canada, post-construction guidelines vary between provinces, depending mostly on guidance from the Environment Canada Canadian Wildlife Service and relevant provincial agencies. To ensure quality post-construction monitoring results in Atlantic Canada and other provinces, it is imperative that all Canadian provinces adopt similar approaches to those employed in Ontario. This paper reviews major causes of bird and bat mortalities; reviews Canadian federal and Ontario provincial bird and bat monitoring guidelines to elucidate gaps between environmental assessment (EA) theory and application; summarizes post-construction monitoring protocols from eight bird and bat post-construction monitoring programs used in Ontario; and, proposes recommendations to support future wind development opportunities across Canada and specifically in Atlantic Canada.

Aquatic monitoring programs conducted during environmental impact assessments in Canada: preliminary assessment before and after weakened environmental regulation.

Aquatic monitoring programs are imperative for the functioning of the environmental impact assessment (EIA) process and a cornerstone for industrial compliance in Canada. However, in 2012, several leading pieces of federal environmental legislation (e.g., Canadian Environmental Assessment Act c.19, s. 52, 2012) were drastically altered, effectively weakening levels of environmental protection for aquatic ecosystems during project developments. This paper assesses the impact of CEAA 2012 on aquatic monitoring programs (and subsequent monitoring data reporting) across Canada for ten projects (five completed pre-CEAA 2012 and five completed post-CEAA 2012). Projects included four energy and six mining projects and were selected based on the following criteria: (i) representative of Canada's resource economy; (ii) project information was publicly available; and (iii) strong public interest. Projects pre- and post-CEAA 2012 exhibited few apparent differences before and after environmental regulatory changes. However, wide discrepancies exist in numbers and types of parameters reported, along with a lack of consistency in reporting. Projects pre-CEAA 2012 provided more follow-up monitoring commitments. Although qualitative differences remain inconclusive, this paper highlights requirements for further assessment of aquatic monitoring and follow-up programs in Canada. Recommendations for the government to consider during reviews of the federal environmental assessment processes include (i) improved transparency on the Canadian Environmental Assessment Agency website ( https://www.ceaa-acee.gc.ca/ ); (ii) creation of a legally binding standardized aquatic monitoring program framework to ensure that all Canadian aquatic ecosystems are monitored with equal rigour; and (iii) commitments and justification related to frequency of aquatic monitoring of water quality.

Spatiotemporal assessment (quarter century) of pulp mill metal(loid) contaminated sediment to inform remediation decisions.

A bleached kraft pulp mill in Nova Scotia has discharged effluent wastewater into Boat Harbour, a former tidal estuary within Pictou Landing First Nation since 1967. Fifty years of effluent discharge into Boat Harbour has created >170,000 m3 of unconsolidated sediment, impacted by inorganic and organic contaminants, including metal[loid]s, polycyclic aromatic hydrocarbons (PAHs), dioxins, and furans. This study aimed to characterize metal(loid)-impacted sediments to inform decisions for a $89 million CAD sediment remediation program. The remediation goals are to return this impacted aquatic site to pre-mill tidal conditions. To understand historical sediment characteristics, spatiotemporal variation covering ~quarter century, of metal(loid) sediment concentrations across 103 Boat Harbour samples from 81 stations and four reference locations, were assessed by reviewing secondary data from 1992 to 2015. Metal(loid) sediment concentrations were compared to current Canadian freshwater and marine sediment quality guidelines (SQGs). Seven metal(loid)s, As, Cd, Cr, Cu, Pb, Hg, and Zn, exceeded low effect freshwater and marine SQGs; six, As, Cd, Cr, Pb, Hg, and Zn, exceeded severe effect freshwater SQGs; and four, Cd, Cu, Hg, and Zn, exceeded severe effect marine SQGs. Metal(loid) concentrations varied widely across three distinct temporal periods. Significantly higher Cd, Cu, Pb, Hg, and Zn concentrations were measured between 1998 and 2000, compared to earlier, 1992-1996 and more recent 2003-2015 data. Most samples, 69%, were shallow (0-15 cm), leaving deeper horizons under-characterized. Geographic information system (GIS) techniques also revealed inadequate spatial coverage, presenting challenges for remedy decisions regarding vertical and horizontal delineation of contaminants. Review of historical monitoring data revealed that gaps still exist in our understanding of sediment characteristics in Boat Harbour, including spatial, vertical and horizontal, and temporal variation of sediment contamination. To help return Boat Harbour to a tidal estuary, more detailed sampling is required to better characterize these sediments and to establish appropriate reference (background) concentrations to help develop cost-effective remediation approaches for this decades-old problem.