Microplastic contamination of packaged meat: Occurrence and associated risks
Introduction
Between 1950 and 2015, 7800 million tons of plastic were produced, half of which between 2002 and 2015 Geyer, Jambeck, & Law, 2017). The physical properties of plastic materials make them essential in industrialized societies. In Europe, the packaging, construction, and automotive sectors account for nearly 70 % of the demand for plastic, with nearly 40 % for packaging alone (PlasticsEurope, 2018). In the food sector, the use of plastic packaging helps in the storage, transport, protection, and preservation of products while reducing their waste (Lange & Wyser, 2003; Mathlouthi, 2013; Piringer & Baner, 2008; PlasticsEurope, 2012). Because some plastics such as expanded polystyrene (EPS) or extruded polystyrene (XPS) provide a good protection barrier from oxygen, water vapour, and microorganisms, they facilitate the preservation of food products at a desired temperature; hence, they are widely used in food packaging. However, it has been recently reported that packaging may release plastic particles and subsequently contaminate our food with plastic fragments (Oßmann et al., 2018; Schymanski, Goldbeck, Humpf, & Fürst, 2018; Winkler et al., 2019).
The presence of small plastic particles in the natural environment has been known since the early 1970s (Buchanan, 1971), but it is only in the early 2010s that their presence in food was reported (Barboza, Dick Vethaak, Lavorante, Lundebye, & Guilhermino, 2018). Among these, microplastics, namely plastic particles smaller than 5 mm in size (GESAMP, 2019), were found. In 2013, a study carried out on honey and sugar coming from different countries revealed contamination by fibres and fragments (Liebezeit & Liebezeit, 2013). Although no chemical analysis was performed to assess the chemical nature of these particles, a connection was established between the morphology of these fragments and the plastic bags used by beekeepers to supply sugar to bees. In 2014, the identification of microplastics in mussels (Mytilus edulis) grown for human consumption suggests that humans ingest these particles (Van Cauwenberghe & Janssen, 2014). To date, several studies have reported the presence of plastic particles in seafood and fish for human consumption (Azevedo-Santos et al., 2019; Barboza & Gimenez, 2015). Microplastics have also been observed in salt (Gündoğdu, 2018; Iñiguez, Conesa, & Fullana, 2017; Karami et al., 2017; Yang et al., 2015), in beers (Kosuth, Mason, & Wattenberg, 2018; Liebezeit & Liebezeit, 2014), and in water bottles (Mason, Welch, & Neratko, 2018). These microplastics, generally smaller than 100 μm, probably come partly from the packaging and/or bottling process (Mason et al., 2018). A large-scale study of tap water showed that 81 % of the water sampled was contaminated mainly by fibres of which an unknown part is of synthetic origin (Kosuth et al., 2018). Fibres can be defined as particles of equal thickness along their entire length, the difference between artificial and natural fibres being based on the presence or absence of visible cellular or organic structures (Hidalgo-Ruz, Gutow, Thompson, & Thiel, 2012). For the purposes of this publication, no distinction will be made between artificial and natural fibres. The origin of the fibres observed in food is not always clear, but airborne contamination is often thought of. The atmosphere is an important vector of microplastics, as shown by the atmospheric deposition of synthetic fibres in Paris (Boucher & Friot, 2017; Dris, Gasperi, Saad, Mirande, & Tassin, 2016). These fibres are also omnipresent in our indoor environment to the point of posing a significant risk of contamination of samples (Dehaut, Hermabessiere, & Duflos, 2019). It is commonly accepted that synthetic textiles are the main source of these fibres (Boucher & Friot, 2017; Prata, 2018).
This study is part of the OceanWise project, a European project supported by the European funding program INTERREG Atlantic Area. OceanWise aims to jointly develop a set of long-term measures to reduce the impact of expanded and extruded polystyrene (EPS/XPS) products in the North-East Atlantic Ocean. Some economic activities, which generate EPS/XPS waste, are particularly investigated in the OceanWise project: the fishing industry (fisheries, aquaculture, sea-food), the food industry (supermarket chains, distribution of vegetables, fish, meat, fruit), consumer goods, outdoor festivals, and tourism. In this context, several observations of more or less free sub-millimetre particles inside food packaging with an XPS bottom containing meat were made during a preliminary study for the OceanWise project tests. These microparticles have the same colour as the XPS food packaging that contained them. Faced with these elements, it was therefore decided to verify the following hypotheses: Are these particles microplastics of extruded polystyrene (MP-XPS)? What is the estimated mass of MP-XPS per mass of meat? How many fibres are present on the surface and inside the food packaging? In an attempt to determine the origin of the particles and fibres as well as the timing of the deposition, the distribution of MP-XPS was studied inside and outside the tray. Thus, this preliminary study, limited to the case of France, seeks to answer these questions and identify some elements of discussion regarding the possible origins of these particles, as well as the possible consequences of ingesting them for human health.
Section snippets
Sample collection and preparation
This study focuses on meat products (chicken) packed in extruded polystyrene trays (230 × 140 × 20 mm). The mass of the pieces of meat was determined by reading the mass displayed on the label on the plastic packaging. Samples of meat from brands B, C, D had a roughly equivalent mass (on average close to 250 g), while brand A meat samples were slightly larger in mass (about 315 g) (Table 1). Products from four different brands (named A, B, C, and D) were purchased in a local supermarket (n = 3
Particles
The characteristics of the microparticles were the same as those of the XPS tray: presence of vacuoles, identical colour, and identical chemical nature. There is therefore no doubt that they came from the tray. FTIR spectra and the microscopic observations of the collected particles showed the presence of MP-XPS microparticles inside the packaging as well as on its outer surface. It should also be noted that some MP-XPS were found between the meat and the plastic seal (Fig. 1). The MP-XPS
Sources of MP-XPS
To our knowledge, this study is the first one to draw attention to the microplastics found on the surface of meat products sealed in their packaging. This contamination necessarily raises the question of the origin of the microplastics. The observation of the presence of MP-XPS inside and outside the tray, as well as between the tray and the meat, and between the meat and the protective film, leads to the hypothesis that the deposition of particles starts before the meat was deposited and lasts
Conclusion
Only few scientific studies report the presence of microplastics that contaminate food. Our study, by assessing the presence of microplastics on the surface of meat products, extends the state of knowledge on the contamination of human food by microplastics. These microplastics are highly adherent to the meat surface and are likely to be eaten by consumers. Although polystyrene trays are made of polystyrene suitable for food contact, the presence of MP-XPS on the food surface is potentially
CRediT authorship contribution statement
Mikaël Kedzierski: Conceptualization, Methodology, Formal analysis, Supervision, Writing - original draft, Writing - review & editing. Benjamin Lechat: Validation, Investigation, Data curation. Olivier Sire: Methodology, Supervision, Writing - review & editing. Gwénaël Le Maguer: Project administration, Writing - review & editing. Véronique Le Tilly: Methodology, Supervision, Writing - review & editing. Stéphane Bruzaud: Supervision, Funding acquisition, Writing - review & editing.
Acknowledgement
The authors are grateful to the OceanWise project that made this publication possible. OceanWise is funded by the European Regional Development Fund (ERDF) INTERREG Atlantic Area, under Priority Axis 4: Enhancing biodiversity and the natural and cultural assets.
References (55)
- et al.
Evidence of microplastic ingestion in the shark Galeus melastomus Rafinesque, 1810 in the continental shelf off the western Mediterranean Sea
Environmental Pollution
(2017) - et al.
Plastic ingestion by fish: A global assessment
Environmental Pollution
(2019) - et al.
Microplastics in the marine environment: Current trends and future perspectives
Marine Pollution Bulletin
(2015) - et al.
Marine microplastic debris: An emerging issue for food security, food safety and human health
Marine Pollution Bulletin
(2018) - et al.
Environmentally relevant microplastic exposure affects sediment-dwelling bivalves
Environmental Pollution
(2018) Pollution by synthetic fibres
Marine Pollution Bulletin
(1971)- et al.
Current frontiers and recommendations for the study of microplastics in seafood
TrAC Trends in Analytical Chemistry
(2019) - et al.
Synthetic fibers in atmospheric fallout: A source of microplastics in the environment?
Marine Pollution Bulletin
(2016) - et al.
Microplastics in air: Are we breathing it in?
Current Opinion in Environmental Science & Health
(2018) - et al.
Styrene toxicity: An ecotoxicological assessment
Ecotoxicology and Environmental Safety
(1997)
Research needs to improve risk assessment of fiber toxicity
Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis
Efficient microplastics extraction from sand. A cost effective methodology based on sodium iodide recycling
Marine Pollution Bulletin
Polystyrene microplastics induce gut microbiota dysbiosis and hepatic lipid metabolism disorder in mice
The Science of the Total Environment
A detailed investigation of the products of the thermal degradation of polystyrene
Polymer Degradation and Stability
Small-sized microplastics and pigmented particles in bottled mineral water
Water Research
Airborne microplastics: Consequences to human health?
Environmental Pollution
Microplastics, a food safety issue?
Trends in Food Science & Technology
A critical perspective on early communications concerning human health aspects of microplastics
The Science of the Total Environment
Plastic ingestion by pelagic and demersal fish from the North sea and Baltic sea
Marine Pollution Bulletin
Wild gudgeons (Gobio gobio) from French rivers are contaminated by microplastics: Preliminary study and first evidence
Environmental Research
Cytotoxic effects of commonly used nanomaterials and microplastics on cerebral and epithelial human cells
Environmental Research
Analysis of microplastics in water by micro-Raman spectroscopy: Release of plastic particles from different packaging into mineral water
Water Research
Microplastics in bivalves cultured for human consumption
Environmental Pollution
Microplastics are taken up by mussels (Mytilus edulis) and lugworms (Arenicola marina) living in natural habitats
Environmental Pollution
The ecotoxicological effects of microplastics on aquatic food web, from primary producer to human: A review
Ecotoxicology and Environmental Safety
Does mechanical stress cause microplastic release from plastic water bottles?
Water Research
Microscopic anthropogenic litter in terrestrial birds from Shanghai, China: Not only plastics but also natural fibers
The Science of the Total Environment
Cited by (153)
Integrating aggregate exposure pathway and adverse outcome pathway for micro/nanoplastics: A review on exposure, toxicokinetics, and toxicity studies
2024, Ecotoxicology and Environmental SafetyExposure of U.S. adults to microplastics from commonly-consumed proteins
2024, Environmental PollutionMicroplastics in oral healthcare products (OHPs) and their environmental health risks and mitigation measures
2024, Environmental Pollution