Additives and Chemicals in Plastics

Plastics and climate change—Breaking carbon lock-ins through three mitigation pathways

Due to the rapid growth in global plastic production, in short-term applications, and negative impacts on natural ecosystems, plastics have received much attention. Additionally, the entire plastic value chain generates a significant amount of GHGs, and plastic use reductions should be considered as interventions addressing the climate crisis. This work investigates the life cycle of plastics in non-durable goods holistically. It identifies interventions to improve the sustainability and circularity of the system of production and analyzes the potential benefit of these interventions as climate change solutions. A baseline global market for plastics is defined and forecast to 2050, to which four interventions are applied: (1) plastic reduction through elimination and reuse; (2) replacement with paper; (3) replacement with recycled feedstock, (4) replacement with bioplastics. The highest potential in GHG emissions reduction lies in plastic reduction, followed by replacement with recycled plastics, paper, and, finally, bioplastics. Together the integrated system can reduce between 9.5 and 14.9 Gt CO2-eq from 2020 to 2050. The environmental and social impact of applying all these interventions in parallel is significant, as plastics are at the intersection of many challenges, including waste production, energy use, ocean pollution, and land disruption from fossil extraction.

"Microplastics are plastic particles smaller than 5 mm in size that are now ubiquitous in the environment. It is a problem that is becoming a major concern for marine and terrestrial ecosystems as well as for human health. Microplastics can reach the final receiving environment from a variety of sources, but one of the major contributors is the breakdown of discarded large plastic products. Data shows that global plastic production has now reached 367 million tons. A significant proportion of plastic waste generated on land inevitably reaches water bodies. The fact that microplastic waste has become a serious problem, harming the environment and society, has led to the need for sustainable management approaches. A sustainable management approach to microplastic waste requires first identifying the root sources of the problem, reducing the generation of plastic waste and developing effective waste management strategies. An important way to reduce plastic waste generation is through recycling and the use of biodegradable alternatives. In addition, reducing the dependence on single-use plastics should be encouraged, and even going one step further, necessary regulations should be made in the legislation for such plastic products."

Ingestion of marine debris can have lethal and sublethal effects on sea turtles and other wildlife. Although researchers have reported on ingestion of anthropogenic debris by marine turtles and implied incidences of debris ingestion have increased over time, there has not been a global synthesis of the phenomenon since 1985. Thus, we analyzed 37 studies published from 1985 to 2012 that report on data collected from before 1900 through 2011. Specifically, we investigated whether ingestion prevalence has changed over time, what types of debris are most commonly ingested, the geographic distribution of debris ingestion by marine turtles relative to global debris distribution, and which species and life-history stages are most likely to ingest debris. The probability of green (Chelonia mydas) and leatherback turtles (Dermochelys coriacea) ingesting debris increased significantly over time, and plastic was the most commonly ingested debris. Turtles in nearly all regions studied ingest debris, but the probability of ingestion was not related to modeled debris densities. Furthermore, smaller, oceanic-stage turtles were more likely to ingest debris than coastal foragers, whereas carnivorous species were less likely to ingest debris than herbivores or gelatinovores. Our results indicate oceanic leatherback turtles and green turtles are at the greatest risk of both lethal and sublethal effects from ingested marine debris. To reduce this risk, anthropogenic debris must be managed at a global level.Análisis Global de la Ingesta de Residuos Antropogénicos por Tortugas MarinasLa ingesta de residuos marinos puede tener efectos letales y subletales sobre las tortugas marinas y otros animales. Aunque hay investigadores que han reportado la ingesta de residuos antropogénicos por tortugas marinas y la incidencia de la ingesta de residuos ha incrementado con el tiempo, no ha habido una síntesis global del fenómeno desde 1985. Por esto analizamos 37 estudios publicados, desde 1985 hasta 2012, que reportan datos colectados desde antes de 1900 y a lo largo del 2011. Investigamos específicamente si el predominio de la ingesta ha cambiado con el tiempo, qué tipos de residuos se ingieren comúnmente, la distribución geográfica de la ingesta de residuos por tortugas marinas en relación a la distribución global de residuos y cuáles especies y etapas de vida tienen más probabilidad de ingerir residuos. La probabilidad de que las tortugas verdes (Chelonia mydas) y laúd (Dermochelys coriacea) ingieran escombros incrementa significativamente con el tiempo; plástico fue el residuo que más se ingirió. Las tortugas en casi todas las regiones estudiadas ingieren residuos, pero la probabilidad de ingesta no estuvo relacionada con las densidades modeladas de residuos. Además de esto, tortugas más pequeñas, en etapa oceánica de vida, tuvieron una mayor probabilidad de ingerir residuos que las tortugas forrajeras terrestres, mientras que las especies carnívoras tuvieron menos probabilidad de ingerir residuos que las herbívoras o las gelatinívoras. Nuestros resultados indican que las tortugas verdes y laúd tienen el mayor riesgo de efectos letales y subletales de la ingesta de residuos marinos. Para reducir el riesgo, los residuos antropogénicos deben manejarse en un nivel global.

Plastics have conveyed great benefits to humanity and made possible some of the most significant advances of modern civilization in fields as diverse as medicine, electronics, aerospace, construction, food packaging, and sports. It is now clear, however, that plastics are also responsible for significant harms to human health, the economy and the earth’s environment. These harms occur at every stage of the plastic life cycle: production, use, and disposal.Plastics are complex, highly heterogeneous, synthetic chemical materials comprised of a carbon-based polymer backbone (derived from coal, oil, or gas) and thousands of additional chemicals. Many 16,000 chemicals used in plastic production are toxic, and they include carcinogens, neurotoxicants and endocrine disruptors. Current annual plastic production exceeds 400 Megatons globally, a 230-fold increase from 1950. Production is on track to treble by 2050, with greatest projected increases in manufacture of single-use, disposable plastics.Workers in the fossil fuel industry suffer increased mortality from injuries, pulmonary and cardiovascular disease, and lung cancer. Plastic production workers are at increased risk of cancer, neurotoxic injury, and decreased fertility. Plastic recycling workers have increased rates of cardiovascular disease, toxic metal poisoning, neuropathy, and lung cancer. Residents of communities adjacent to plastic production and waste disposal sites experience increased risks of premature birth, low birthweight, asthma, and childhood leukemia.The extraction, production of plastics and transport processes are responsible for greenhouse gas (GHG) emissions equivalent to nearly 2 Gigatons of carbon dioxide annually. Plastics therefore also contribute to climate change, which also has direct and indirect consequences for human health.During use, plastics release toxic chemicals including additives and residual monomers into the environment and into people. Plastic additives disrupt endocrine function and increase risk for premature births, neurodevelopmental disorders, male reproductive birth defects, infertility, obesity, cardiovascular disease, renal disease, and cancers. Emerging, albeit still incomplete evidence indicates that MNPs may cause toxicity due to their physical and toxicological effects as well as by acting as vectors that transport toxic chemicals and bacterial pathogens into tissues and cells.Plastics and plastic chemicals are responsible for widespread pollution. They contaminate marine, freshwater, terrestrial, and atmospheric environments globally. Adverse impacts of plastic pollution occur at multiple levels from molecular and biochemical to population and ecosystem. MNP contamination of seafood results in direct, though not well quantified human exposure to plastics and plastic chemicals. Marine plastic pollution endangers the ocean ecosystems upon which all humanity depends for food, oxygen, livelihood, and well-being.Plastics are both a boon to humanity and a stealth threat to human and planetary health. Plastics convey enormous benefits, but current linear patterns of plastic production, use and disposal with little attention to sustainable design and a near absence of recovery, reuse and recycling are responsible for grave harms to health, great economic costs, and deep societal injustices. These harms are rapidly worsening. Knowledge of plastics’ harms is still incomplete, but this Commission concludes there is sufficient evidence of plastics’ clear and present danger to require urgent intervention against the plastic crisis at global scale.

Environmental-friendly plastics (EFP) are new alternatives of fossil-based plastics. The EFP family mainly constitutes bio-plastics/bio-attributed plastics and post-consumer recycled plastics (PCR). EFP contributes around 10% of total plastics production in global plastic production. Presently EFP are mostly used in grocery bags, bin liners, compostable garbage bags and single-use plastics with single or spot color printing. Multi-color printing can add value or open new horizons for these materials, leading to high-value applications. It can also be used for high-speed printing or flexible packaging applications. Plastics available in this category come from both fossil-based and bio-based sources. Fossil-based bioplastics has almost similar degree of print suitability but materials coming from bio-based sources are yet to be explored for print suitability, especially with high-speed multi-color printing machines. Flexographic printing is known for high-quality and high-speed printing on different substrates, including paper, conventional plastics and fossil-based bio-plastics. The advantage of having a common impression cylinder (CIC) arrangement and the requirement of less pressure during printing makes it suitable for consideration for printing on EFP. Hence, this study, print suitability of EFP using flexography printing, is an attempt to explore the mutual compatibility of these substrates and printing process, which will prove to be a boon in the future for establishing EFP as a strong substitute for replacing conventional plastics.

Microscopic particles of plastic, known as microplastics, have become a ubiquitous contaminant in the environment. Their presence in the marine environment has been correlated to the exponential increase in global plastic production over the past 70 years and the subsequent increased abundance of plastic litter in the oceans. Other sources of microplastics include synthetic microfibers associated with the washing of textiles and tire particles associated with the abrasion and wear of the tread on automobile tires. Microplastics are recognized as contaminants of emerging concern because they occupy the same size fraction as plankton and sediment, making them bioavailable to a wide range of organisms, and they have the potential to adversely impact environmental health. Ingestion of microplastics by humans is likely, but confounding any assessment of health impacts is the lack of estimates on the total human exposure to these particles. This article will review the magnitude of plastic production and waste, provide an overview of the major sources of microplastics in the aquatic environment and the hazards they pose to both environmental and human health, and present a case study of ongoing efforts to characterize the sources and fate of microplastic contamination in Charleston Harbor, SC, USA.

Global plastics production has grown rapidly in recent decades and is leading to an increased discharge of plastic waste into the environment, presenting a complex socio-ecological problem. The southern North Sea and its tributaries are affected by plastic pollution due to dense population, industrial use, as well as tourism and recreational activities. A paradigm shift is necessary to reduce the outflow of plastic waste from rivers and inland waters into the North Sea. In order to foster a socio-ecological transformation, one opportunity is to involve stakeholders from all sectors, who regulate, produce, trade, use, recycle and dispose plastic products, through a transdisciplinary process. Real-world laboratories as a science-practice interaction approach are conceptualised to produce robust knowledge to solve real-world environmental and societal challenges. The aim of this study is to determine how the design and early implementation phases of real-world laboratories should be executed to achieve socio-ecological transformation. We assessed the case study of an inaugural regional stakeholder meeting of the real-world laboratory ‘Plastic-FREE-sia’ in Northwest Germany by in-event observations and a subsequent participant survey. Our findings of this stakeholder workshop highlight the significance of involving diverse stakeholders from multiple sectors in the real-world laboratory process and emphasise the need for balanced representation. The interests, benefits and goals of individual stakeholders must be identified from the outset and aligned with the socio-ecological problem setting, in order to prevent conflicting objectives. Concluding recommendations for the design and early implementation phases of future real-world laboratories are formulated.

Liver toxicity is a major adverse drug reaction that accounts for drug failure in clinical trials and withdrawal from the market. Therefore, predicting potential liver toxicity at an early stage in drug discovery is crucial to reduce costs and the potential for drug failure. However, current in vivo animal toxicity testing is very expensive and time consuming. As an alternative approach, various machine learning models have been developed to predict potential liver toxicity in humans. This chapter reviews current advances in the development and application of machine learning models for prediction of potential liver toxicity in humans and discusses possible improvements to liver toxicity prediction.

Modeling the impact of pesticide drift deposition on off-field non-target receptors

Here, we develop further the national chemical footprint assessment methods using Sweden as an example to enhance the precision of calculations. First, we integrate grid data on population density and distance-to-seacoast into the analytical framework to better match the European Pollutant Release and Transfer Register on the sub-compartment level with USEtox toxicity characterisation factors. Second, we use the latest USEtox 2.12 model version and its more punctual North European characterisation factors. Third, we conduct trend and geographic analysis and rank Swedish facilities in terms of toxicity potential. We show that total human toxicity potential in Sweden was smaller than previously estimated when using the North European USEtox landscape settings and sloped downwards over time. We confirm toxicity potential of major pollutants in previous research papers (Zn, Hg, Pb, Ni) and find that Hg’s relative human toxicity potential in a longer period can be larger than previously estimated on shorter periods. Human toxicity is estimated to be mostly non-cancer type in Sweden. Results are largely invariant to the choice of air sub-compartments. Companies in the metals manufacturing sector are estimated to have the largest human toxicity potential in Sweden in the period between 2001 and 2017 and companies in the paper manufacturing industry have the largest ecotoxicity potential.

This study aimed to identify the mobility, bioavailability, and potential toxicity of heavy metals (HM) in sediments of the Korle lagoon using metal partition. Sediments were analysed using the BCR (Bureau of reference) method. As (60%), Pb (50%), Zn (57%) and Fe (40%) were found in high concentration in the ion exchangeable fraction. The oxidisable fraction was dominated by Cu (51%), Cd (95%), Cr (61%), Ni (63%), As (35%), Fe (21%), Hg (30%), Pb (19%) and Zn (11%). The reducible fraction was dominated by Zn (29%), Pb (24%) and Hg (19%). The residual fraction was dominated by Hg (49%) and Fe (34%). PCA was used to identify pH and organic matter as the most important factors controlling the mobility and bioavailability of HM in the sediments. Arsenic, Pb, Zn and Fe were found to have the highest mobility. Chromium, Cu and Ni have medium mobility. Hg has low mobility. Most of the HM show potential bioavailability and toxicity.

The production of conventional plastics, which are essential to modern economies, primarily relies on fossil-based resources and is associated with significant environmental impacts. Global plastic production has increased markedly from 204 million tons in 2002 to 335 million tons in 2016 and is projected to rise further, leading to critical issues such as waste accumulation and increased greenhouse gas emissions. In response to these challenges, considerable research efforts have been directed toward the development of environmentally sustainable alternatives, particularly bioplastics. Among these, microbial derived polymers such as Polyhydroxyalkanoates and Polyhydroxybutyrate have attracted significant attention due to their biodegradable nature and the presence of hydrolysable ester bonds. These biopolymers are synthesized by microorganisms under specific stress conditions that are influenced by environmental and nutritional parameters, including pH, temperature, incubation period, and the availability of carbon and nitrogen sources, as well as the carbon to nitrogen ratio. In the present study, soil samples were collected from agricultural and coastal regions of South Gujarat and Goa for the isolation of potential Polyhydroxyalkanoate and Polyhydroxybutyrate producing bacteria. A total of isolates were screened and characterized based on their morphological and biochemical properties. Biopolymer production was further enhanced through the optimization of growth conditions under controlled laboratory settings. The developed bioplastic will be evaluated for safety prior to its potential application. This study demonstrates the potential of microbial bioplastics as sustainable alternatives to conventional plastics and underscores their relevance in promoting environmental protection and sustainable development.

Lanternfish as bioindicator of microplastics in the deep sea: A spatiotemporal analysis using museum specimens.

Traditional toxicity testing reliant on animal models is costly and low throughput, posing a significant challenge with the increasing numbers of chemicals that humans are exposed to in the environment. The purpose of this investigation was to build optimal prediction models for various human in vivo/organ-level toxicity end points (extracted from ChemIDPlus) using chemical structure and Tox21 in vitro quantitative high-throughput screening (qHTS) bioactivity assay data. Several supervised machine learning algorithms were applied to model 14 human toxicity end points pertaining to vascular, kidney, ureter and bladder, and liver organ systems. Three metrics were used to evaluate model performance: area under the receiver operating characteristic curve (AUC-ROC), balanced accuracy (BA), and Matthews correlation coefficient (MCC). The top four models, with AUC-ROC values >0.8, were derived for endocrine (0.90 ± 0.00), musculoskeletal (0.88 ± 0.02), peripheral nerve and sensation (0.85 ± 0.01), and brain and coverings (0.83 ± 0.02) toxicities, whereas the best model AUC-ROC values were >0.7 for the remaining 10 toxicities. Model performance was found to be dependent on the specific data set, model type, and feature selection method used. In addition, chemical structure and assay data showed different levels of contribution to the prediction of different toxicity end points. Although in vitro assay data, when combined with chemical structure, slightly improved the predictive accuracy for most end points (11 out of 14), a noteworthy finding was the near equal success of the structure-only models, which do not require Tox21 qHTS screening data, and the relatively poor performance of assay-only models. Thus, the top-performing structure-only models from this study could be applied for hazard screening of large sets of chemicals for potential human toxicity, whereas the largest assay contributions to models (i.e., cellular targets) could be used, along with the top-contributing structural features, to provide insight into toxicity mechanisms.