Unpacking the complexity of the polyethylene food contact articles value chain: A chemicals perspective

Notable ecological risks of microplastics to Minjiang River ecosystem over headwater to upstream in Eastern Qinghai-Tibetan Plateau

Microplastics (MPs) in aquatic environments has been observed globally. However, the ecological risks of MP pollution in riverhead prior to highly urbanized region remain poorly understood. This study investigated MP pollution related to microbiome in sediments, and ecological risks of MPs in riverhead prior to urbanized area over 291 km of Minjiang River (MJR) in Qinghai-Tibetan Plateau (QTP). MPs in river water and sediments were averagely 245±128 items/L and 124±67 items/kg, respectively, over the investigated river range. The MP distribution indicated that MP abundance is low in headwater section and elevated in middle section and down section with increase of urbanized area. The MPs were found mainly in film, fragments, and fiber morphotypes, with size < 500 μm in both river water and sediments. The polymers of MPs were contributed by polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), and polycarbonate (PC) at 41.7 %, 22.7 %, 17.9 %, 1.8 %, and 1.2 % in river water, and 32.6 %, 15.0 %, 29.3 %, 3.1 %, and 0.8 % in sediments, respectively. Microbiome analyses of sediments revealed that the majority of microorganisms were aerobic bacteria, which contained potential plastic-degrading bacterial genes. Ecological risk assessment indexes of pollution load, polymeric risk assessment and pollution risk indicated that MPs in MJR river water and sediments displayed noticeable pollution levels, i.e., river water exhibited medium to very high pollution risk levels, and sediments showed from low to very high pollution risk levels in riverhead. Monte Carlo simulation revealed that PVC and PC MPs were considered as priority control pollutants although they were not the most abundant polymers identified due to their intrinsic chemical toxicity. Compared with risk levels of global rivers, the results indicate prominent ecological risks caused by MPs in MJR riverhead areas, and thus raise a warning sign.

Occurrence and migration of synthetic phenolic antioxidants in food packaging materials: Effects of plastic types and storage temperature

Synthetic phenolic antioxidants (SPAs) are widely used in food packaging materials to extend product shelf life. Not much attention has been paid to high molecular weight SPAs (HMW SPAs) so far, despite their potential health risks. In this study, we first analyzed the concentrations of ten HMW SPAs in food plastic packaging materials (including 6 plastic categories, n = 116). The total concentrations of HMW SPAs (∑SPAs) ranged from 0.0844 to 894 mg/kg, with a geometric mean of 71.7 mg/kg. The predominant HMW SPAs included AO1010 (accounting for 71.8 % of total concentrations of HMW SPAs), AO1076 (21.4 %), and AO3114 (3.14 %), with AO1010 detected in all samples. Higher concentrations were notably found in polypropylene (PP), polyethylene (PE), and polyethylene terephthalate (PET) materials. Migration tests revealed that HMW SPAs could readily transfer into food simulants, with PP exhibiting the lowest migration levels. Migration of SPAs into fatty foods was pronounced, increasing with temperature (temperature gradients: 4 °C, 25 °C, and 60 °C). In the 95 % ethanol food simulants, the maximum migration amounts of AO1076 in PE (7.05 mg/kg at 25 °C) and PET (9.79 mg/kg at 25 °C; 10.8 mg/kg at 60 °C) surpassed the specific migration limit (SML) set by the national standards, posing potential food safety risks. This was the first report on the presence and migration patterns of ten HMW SPAs in food plastic packaging materials, providing crucial insights into food packaging material safety.

Polyethylene Transformation Chain: Evaluation of Migratable Compounds

Polyethylene (PE) is a widely used material for packaging food. However, certain additives and their degradation products, which may be generated during transformation processes, may pose risks to consumers health if they migrate into food at levels exceeding safety thresholds. Therefore, identifying and quantifying these potential migrant compounds is crucial to ensuring consumer safety. In the present work, PE films and the raw materials used in their production were kindly provided by the industry to evaluate undesired compounds throughout the PE transformation chain. For that purpose, volatile and semi-volatile organic compounds were evaluated using gas chromatography coupled to mass spectrometry (GC-MS). Alkanes were identified as the most abundant compounds, along with antioxidants, lubricants, or Non-Intentionally Added Substances (NIAS), like 7,9-di-tert-butyl-1-oxaspiro(4,5)deca-6,9-diene-2,8-dione in the films. For the unidentified compounds, evaluations were conducted at various stages of the transformation chain, and migration assays were performed to assess their behavior.

Ocean current modulation of the spatial distribution of microplastics in the surface sediments of the Beibu Gulf, China

Microplastic pollution, a major global environmental issue, is gaining heightened attention worldwide. Marginal seas are particularly susceptible to microplastic contamination, yet data on microplastics in marine sediments remain scarce, especially in the Beibu Gulf. This study presents a large-scale investigation of microplastics in the surface sediments of the Beibu Gulf to deciphering their distribution, sources and risk to marginal seas ecosystems. The results reveal widespread microplastic contamination, with an average abundance of 391 ± 27 items/kg in sediments. The spatial variability of microplastic abundance was significant, with lower levels in the western Beibu Gulf and higher concentrations in the northeastern and southeastern regions. The spatial distribution of microplastics was largely driven by geological features, hydrodynamic conditions, and human activity, with minimal influence from local environmental factors such as water depth, sediment grain size, organic carbon content, and sediment types. The pollution load index (PLI) suggests a low level of microplastic contamination, but the polymer hazard index (PHI) identified a high ecological risk, likely due to the presence of PVC, a polymer with higher chemical toxicity. Our findings highlight the significant role of hydrodynamic processes in determining microplastic distribution in the Beibu Gulf. These insights enhance our understanding of microplastic dispersal and its governing factors in semi-enclosed marginal seas, providing foundation for targeted pollution control strategies.

Biotechnology in Food Packaging Using Bacterial Cellulose

Food packaging, which is typically made of paper/cardboard, glass, metal, and plastic, is essential for protecting and preserving food. However, the impact of conventional food packaging and especially the predominant use of plastics, due to their versatility and low cost, bring serious environmental and health problems such as pollution by micro and nanoplastics. In response to these challenges, biotechnology emerges as a new way for improving packaging by providing biopolymers as sustainable alternatives. In this context, bacterial cellulose (BC), a biodegradable and biocompatible material produced by bacteria, stands out for its mechanical resistance, food preservation capacity, and rapid degradation and is a promising solution for replacing plastics. However, despite its advantages, large-scale application still encounters technical and economic challenges. These include high costs compared to when conventional materials are used, difficulties in standardizing membrane production through microbial methods, and challenges in optimizing cultivation and production processes, so further studies are necessary to ensure food safety and industrial viability. Thus, this review provides an overview of the impacts of conventional packaging. It discusses the development of biodegradable packaging, highlighting BC as a promising biopolymer. Additionally, it explores biotechnological techniques for the development of innovative packaging through structural modifications of BC, as well as ways to optimize its production process. The study also emphasizes the importance of these solutions in promoting a circular economy within the food industry and reducing its environmental impact.

A meta-research analysis on the biological impact of plastic litter in the marine biota

Marine litter and more specifically plastic marine litter is nowadays considered a global issue with unprecedented impact and consequences to the entire marine ecosystem and biota. The current situation that has been created worldwide due to the abundance of plastic litter in the Earth's Seas has been characterized as alarming, necessitating the immediate action for an overall reduction of plastic waste, better collection and recycling schemes and beach-shoreline clean-ups. In this article we attempt to delve into the details of the magnitude of the impact that plastic litter have caused to marine biota via a meta-research analysis, by compiling, combining, analysing and presenting data from various relative works, using primarily scientific and, secondarily, grey literature. Apart from the threats that plastic marine litter pose to the marine ecosystem, they present potential threats to humans, as well, via food chain. Aside from understating the risks and uncertainties contained in the hereby collected and presenting information, this study can provide an evidence base for decision and policy makers into implementing the appropriate action plans for reducing and, in time, mitigating this immense problem.

The hidden diet: Synthetic antioxidants in packaged food and their impact on human exposure and health

Synthetic antioxidants (AOs) are commonly used in everyday items and industrial products to inhibit oxidative deterioration. However, the presence of AOs in food packaging and packaged foods has not been thoroughly documented. Moreover, studies on human exposure to AOs through skin contact with packaging or ingesting packaged foods are limited. In this study, we analyzed twenty-three AOs-including synthetic phenolic antioxidants (SPAs) and organophosphite antioxidants (OPAs)-along with six transformation products in various food samples and their packaging materials. We found AOs in food products at concentrations ranging from 1.30 × 103 to 1.77 × 105 ng/g, which exceeded the levels in both outer packaging (6.05 × 102-3.07 × 104 ng/g) and inner packaging (2.27 × 102-1.09 × 105 ng/g). The most common AOs detected in foodstuffs were tris(2,4-di-tert-butylphenyl) phosphate (AO168O), butylated hydroxytoluene (BHT), and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (AO1076), together constituting 95.7 % of the total AOs found. Our preliminary exposure assessment revealed that dietary exposure-estimated at a median of 2.55 × 104 ng/kg body weight/day for children and 1.24 × 104 ng/kg body weight/day for adults-is a more significant exposure route than dermal contact with packaging. Notably, four AOs were identified in food for the first time, with BHT making up 76.8 % and 67.6 % of the total BHT intake for children and adults, respectively. These findings suggest that food consumption is a significant source of BHT exposure. The estimated daily intakes of AOs via consumption of foodstuffs were compared with the recommended acceptable daily intake to assess the risks. This systematic investigation into AOs contributes to understanding potential exposure and health risks associated with AOs in packaged foods. It emphasizes the need for further evaluation of human exposure to these substances.