Plastic Pollution Working Group Publications
Youth Can Promote Marine Debris Concern and Policy Support among Local Voters and Political Officials
Many of the most sweeping social movements throughout history have been youth-led, including those related to environmental challenges. Emerging research suggests youth can build environmental concern among parents via intergenerational learning, in some cases overcoming socio-ideological differences that normally stymie attempts at collective action. What has not been studied is the potential for youth to also influence adults outside their immediate families. This study based in North Carolina, USA, explores the potential of today's young people as environmental change-agents in their communities on the topic of marine debris. Specifically, this evaluation examines responses from voters and local officials after participating in youth-led civic engagement events. After engaging with a youth-led civic engagement event, voters, and local officials completed a retrospective pretest survey that asked questions about levels of marine debris concern and their likelihood of supporting a local marine debris ordinance. Young people encouraged both concern and policy support among both voters and officials, and that concern and policy support increased independently of whether adults were voters or officials, liberals or conservatives, or knew the students personally. Further, participation in the youth-led engagement event reduced political differences in marine debris concern. This study suggests youth can play a critical role addressing marine debris challenges by promoting support for marine debris management policy, and doing so across political barriers.
Plastic Pollution Solutions: Emerging Technologies to Prevent and Collect Marine Plastic Pollution
As plastic waste accumulates in the ocean at alarming rates, the need for efficient and sustainable remediation solutions is urgent. One solution is the development and mobilization of technologies that either 1) prevent plastics from entering waterways or 2) collect marine and riverine plastic pollution. To date, however, few reports have focused on these technologies, and information on various technological developments is scattered. This leaves policymakers, innovators, and researchers without a central, comprehensive, and reliable source of information on the status of available technology to target this global problem. The goal of this study was to address this gap by creating a comprehensive inventory of technologies currently used or in development to prevent the leakage of plastic pollution or collect existing plastic pollution. Our Plastic Pollution Prevention and Collection Technology Inventory can be used as a roadmap for researchers and governments to 1) facilitate comparisons between the scope of solutions and the breadth and severity of the plastic pollution problem and 2) assist in identifying strengths and weaknesses of current technological approaches. We created this inventory from a systematic search and review of resources that identified technologies. Technologies were organized by the type of technology and target plastics (i.e., macroplastics, microplastic, or both). We identified 52 technologies that fall into the two categories of prevention or collection of plastic pollution. Of these, 59% focus specifically on collecting macroplastic waste already in waterways. While these efforts to collect plastic pollution are laudable, their current capacity and widespread implementation are limited in comparison to their potential and the vast extent of the plastic pollution problem. Similarly, few technologies attempt to prevent plastic pollution leakage, and those that do are limited in scope. A comprehensive approach is needed that combines technology, policymaking, and advocacy to prevent further plastic pollution and the subsequent damage to aquatic ecosystems and human health.
PAH Sorption to Nanoplastics and the Trojan Horse Effect as Drivers of Mitochondrial Toxicity and PAH Localization in Zebrafish
Plastics are world-wide pollutants that pose a potential threat to wildlife and human health. Small plastic particles, such as microplastics and nanoplastics, are easily ingested, and can act as a Trojan Horse by carrying microorganisms and pollutants. This study investigated the potential role of the Trojan Horse effect in the toxicity of nanoplastics to the vertebrate model organism, zebrafish (Danio rerio). First, we investigated if this effect could affect the toxicity of nanoplastics. Second, we analyzed if it could contribute to the biodistribution of the associated contaminants. And third, we focused on its effect on the mitochondrial toxicity of nanoplastics. We incubated 44 nm polystyrene nanoparticles with a real-world mixture of polycyclic aromatic hydrocarbons (PAHs) for 7 days and removed the free PAHs by ultrafiltration. We dosed embryos with 1 ppm of nanoplastics (NanoPS) or PAH-sorbed nanoplastics (PAH-NanoPS). Neither type of plastic particle caused changes in embryonic and larval development. Fluorescence microscopy and increased EROD activity suggested the uptake of PAHs in larvae exposed to PAH-NanoPS. This coincided with higher concentrations in the yolk sac and the brain. However, PAH-only exposure leads to their accumulation in the yolk sac but not in the brain, suggesting that that the spatial distribution of bioaccumulated PAHs can differ depending on their source of exposure. Both nanoplastic particles affected mitochondrial energy metabolism but caused different adverse effects. While NanoPS decreased NADH production, PAH-NanoPS decreased mitochondrial coupling efficiency and spare respiratory capacity. In summary, the addition of PAHs to the surface of nanoplastics did not translate into increased developmental toxicity. Low levels of PAHs were accumulated in the organisms, and the transfer of PAHs seems to happen in tissues and possibly organelles where nanoplastics accumulate. Disruption of the energy metabolism in the mitochondria may be a key factor in the toxicity of nanoplastics, and the Trojan Horse effect may amplify this effect.
Maternal Transfer of Nanoplastics to Offspring in Zebrafish (Danio Rerio): a Case Study With Nanopolystyrene
Plastics are ubiquitous anthropogenic contaminants that are a growing concern in aquatic environments. The ecological implications of macroplastics pollution are well documented, but less is known about nanoplastics. The current study investigates the potential adverse effects of nanoplastics, which likely contribute to the ecological burden of plastic pollution. To this end, we examined whether a dietary exposure of adult zebrafish (Danio rerio) to polystyrene nanoparticles (PS NPs) could lead to the transfer of nanoplastics to the offspring, and whether nanoplastics exposure affects zebrafish physiology. Specifically, adult female and male zebrafish (F0 generation) were exposed to PS NPs via diet for one week and bred to produce the F1 generation. Four F1 groups were generated: control (unexposed females and males), maternal (exposed females), paternal (exposed males), and co-parental (exposed males and females). Co-parental PS NP exposure did not significantly affect reproductive success. Assessment of tissues from F0 fish revealed that exposure to PS NPs significantly reduced glutathione reductase activity in brain, muscle, and testes, but did not affect mitochondrial function parameters in heart or gonads. Assessment of F1 embryos and larvae revealed that PS NPs were present in the yolk sac, gastrointestinal tract, liver, and pancreas of the maternally and coparentally exposed F1 embryos/larvae. Bradycardia was also observed in embryos from maternal and co-parental exposure groups. In addition, the activity of glutathione reductase and the levels of thiols were reduced in F1 embryos/ larvae from maternal and/or co-parental exposure groups.Mitochondrial function and locomotor activity were not affected in F1 larvae. This study demonstrates that (i) PS NPs are transferred from mothers to offspring, and (ii) exposure to PS NPs modifies the antioxidant system in adult tissues and F1 larvae. We conclude that PS NPs could bioaccumulate and be passed on to the offspring, but this does not lead to major physiological disturbances.
20 Years of Government Responses to the Global Plastic Pollution Problem
Plastic pollution in the ocean is a global problem that requires cooperation from a wide range of groups (e.g., governments, producers, consumers, researchers, civil society). However, by virtue of their core regulatory powers, governments have a critical role to play in helping to solve this problem. This study aims to synthesize the policy response of governments to the global plastic pollution problem, as a basis for more rigorous monitoring of progress (as called for in Resolution 4/6 of the 2019 United Nations Environment Assembly (UNEA) meeting) and to inform future public policies.
The scope of the study is limited to public policies introduced during the period from January 2000 to July 2019, prior to the onset of the COVID-19 pandemic.
Plastic Pellets Trigger Feeding Responses in Sea Anemones
Multiple mechanisms for plastic consumption by marine animals have been proposed based on the feeding cues and behavior of the animal studied. We investigated plastic consumption in sea anemones. We found that anemones readily consumed pristine National Institute of Standards and Technology low-density polyethylene and high-density polyethylene II and III pre-production pellets. Anemone weight, crown area, and number of tentacles were measured before and after 12 days of daily pellet consumption. Crown area significantly increased for control anemones only. Fresh anemones were then sequentially fed consumed and egested pellets from two of the earlier daily trials to measure feeding retention time, which decreased over three to four feedings. The concentrations of elements in anemones (zinc, iron, arsenic, manganese, chromium, copper, vanadium, selenium, nickel, cadmium, and cobalt) were similar to control anemones that were not exposed to pellets. Lead concentrations were significantly higher in anemones fed HDPE III pellets as compared to control. Plastic consumption by marine animals might be reduced by reducing the amount of plastic that enters the ocean and understanding the chemical triggers underlying plastic consumption.
Bioengineering a Future Free of Marine Plastic Waste
Plastic waste has reached epidemic proportions worldwide, and the production of plastic continues to rise steadily. Plastic represents a diverse array of commonly used synthetic polymers that are extremely useful as durable, economically beneficial alternatives to other materials; however, despite the wide-ranging utility of plastic, the increasing accumulation of plastic waste in the environment has had numerous detrimental impacts. In particular, plastic marine debris can transport invasive species, entangle marine organisms, and cause toxic chemical bioaccumulation in the marine food web. The negative impacts of plastic waste have motivated research on new ways to reduce and eliminate plastic. One unique approach to tackle the plastic waste problem is to turn to nature’s solutions for degrading polymers by leveraging the biology of naturally occurring organisms to degrade plastic. Advances in metagenomics, next generation sequencing, and bioengineering have provided new insights and new opportunities to identify and optimize organisms for use in plastic bioremediation. In this review, we discuss the plastic waste problem and possible solutions, with a focus on potential mechanisms for plastic bioremediation. We pinpoint two key habitats to identify plastic-biodegrading organisms: (1) habitats with distinct enrichment of plastic waste, such as those near processing or disposal sites, and (2) habitats with naturally occurring polymers, such as cutin, lignin, and wax. Finally, we identify directions of future research for the isolation and optimization of these methods for widespread bioremediation applications.
Nanoplastics Decrease the Toxicity of a Complex PAH Mixture but Impair Mitochondrial Energy Production in Developing Zebrafish
Plastics are recognized as a worldwide threat to the environment, possibly affecting human health and wildlife. Small forms of plastics such as micro- and nanoplastics can interact with other organic contaminants, potentially acting as chemical carriers and modulating their toxicity. In this study, we investigated the toxicity of polystyrene nanoparticles (Nano-PS) and a real-world environmental PAH mixture (Elizabeth River Sediment Extract, ERSE, comprised of 36 detected PAHs) to zebrafish embryos and larvae. Embryos were exposed to Nano-PS (0.1–10 ppm) or ERSE (0.1–5% v/v, equivalent to ΣPAH 5.07–25.36 ppb) or coexposed to a combination of both. Larvae exposed to Nano-PS did not exhibit developmental defects, while larvae exposed to ERSE (2–5%) showed classic signs of PAH toxicity such as heart malformation and deformities in the jaw, fin, and tail. ERSE (5%) also impaired vascular development in the brain. When coexposed, Nano-PS decreased the developmental deformities and impaired vascular development caused by ERSE. This was strongly correlated to the lower PAH bioaccumulation detected in the coexposed animals (whole larvae, as well as the yolk sac, brain, and heart). Our data suggest that PAHs are sorbing to the surface of the Nano-PS, decreasing the concentration, uptake, and toxicity of free PAHs during the exposure. Such sorption of PAHs increases the agglomeration rate of Nano-PS during the exposure time, potentially decreasing the uptake of Nano-PS and associated PAHs. Despite that, similar induction of EROD activity was detected in animals exposed to ERSE in the presence or not of Nano-PS, suggesting that enough PAHs were accumulated in the organisms to induce cellular defense mechanisms. Nano-PS exposure (single or combined with ERSE) decreased the mitochondrial coupling efficiency and increased NADH production, suggesting an impairment on ATP production accompanied by a compensatory mechanism. Our data indicate that nanoplastics can sorb contaminants and potentially decrease their uptake due to particle agglomeration. Nanoplastics also target and disrupt mitochondrial energy production and act as vectors for the mitochondrial uptake of sorbed contaminants during embryonic and larval stages. Such negative effects of nanoplastics on energy metabolism and efficiency could be detrimental under multiple-stressors exposures and energy-demanding scenarios, which remains to be validated.
Uptake, Tissue Distribution, and Toxicity of Polystyrene Nanoparticles in Developing Zebrafish (Danio Rerio)
Plastic pollution is a critical environmental concern and comprises the majority of anthropogenic debris in the ocean, including macro, micro, and likely nanoscale (less than 100 nm in at least one dimension) plastic particles. While the toxicity of macroplastics and microplastics is relatively well studied, the toxicity of nanoplastics is largely uncharacterized. Here, fluorescent polystyrene nanoparticles (PS NPs) were used to investigate the potential toxicity of nanoplastics in developing zebrafish (Danio rerio), as well as to characterize the uptake and distribution of the particles within embryos and larvae. Zebrafish embryos at 6 h post-fertilization (hpf) were exposed to PS NPs (0.1, 1, or 10 ppm) until 120 hpf. Our results demonstrate that PS NPs accumulated in the yolk sac as early as 24 hpf and migrated to the gastrointestinal tract, gallbladder, liver, pancreas, heart, and brain throughout development (48–120 hpf). Accumulation of PS NPs decreased during the depuration phase (120–168 hpf) in all organs, but at a slower rate in the pancreas and gastrointestinal tract. Notably, exposure to PS NPs did not induce significant mortality, deformities, or changes to mitochondrial bioenergetics, but did decrease the heart rate. Lastly, exposure to PS NPs altered larval behavior as evidenced by swimming hypoactivity in exposed larvae. Taken together, these data suggest that at least some nanoplastics can penetrate the chorion of developing zebrafish, accumulate in the tissues, and affect physiology and behavior, potentially affecting organismal fitness in contaminated aquatic ecosystems.