Impacts of nano/micro-plastics on safety and quality of aquatic food products

Abstract

The spread of nano/microplastics (N/MPs) pollution has gained importance due to the associated health concerns. Marine environment including fishes, mussels, seaweed and crustaceans are largely exposed to these potential threats. N/MPs are associated with plastic, additives, contaminants and microbial growth, which are transmitted to higher trophic levels. Foods from aquatic origin are known to promote health and have gained immense importance. Recently, aquatic foods are traced to transmit the nano/microplastic and the persistent organic pollutant poising hazard to humans. However, microplastic ingestion, translocation and bioaccumulation of the contaminant have impacts on animal health. The level of pollution depends upon the pollution in the zone of growth for aquatic organisms. Consumption of contaminated aquatic food affects the health by transferring the microplastic and chemicals. This chapter describes the sources and occurrence of N/MPs in marine environment, detailed classification of N/MPs based on the properties influencing associated hazard. Additionally, occurrence of N/MPs and their impact on quality and safety in aquatic food products are discussed. Lastly, existing regulations and requirements of a robust framework of N/MPs are reviewed.

Introduction

Plastic is regarded as a convenience product due to its durability, having applications across all segments from packaging, infrastructure, food, automobile, electronics, etc., with huge production, has gained them ubiquitous status (Galafassi et al., 2021; Jia, Evans, & van der Linden, 2019). However, lower recycling aspects (non-biodegradable nature) and huge production tune, leading to its release in the environment causing pollution. Around 10% of plastic produced is estimated to end up in the marine water environment; plastic is around 80% of the pollutants found in water bodies (Dehaut, Hermabessiere, & Duflos, 2019; Laglbauer et al., 2014). The pollution caused by plastics has reached alarming levels in aquatic foods, with an estimate to be more than fish by weight by 2050 (MacArthur, 2017; Simon & Schulte, 2017). The improper management of plastic waste from landfills, polluted rivers, aquatic activities, etc., is adding huge quantities of plastics in the marine ecosystem. Making oceans a largest reservoir of plastics, with an estimate of plastic waste around 23 million metric tons (Borrelle et al., 2020; Hale, Seeley, La Guardia, Mai, & Zeng, 2020; Lebreton et al., 2017; Park et al., 2020).

Plastic are known to breakdown/fragment/degrade due to several biotic and abiotic process into particles in size ranging < 5–1 mm/<1 mm − 1 μm/<1 μm forming microplastic (MP)/Mini-microplastic/nanoplastic (NP) (EFSA, 2016; Kershaw, Turra, Galgani, et al., 2019). Micro/nanoplastics (M/NPs) are categorized based on their origin into primary and secondary particles. M/NPs could be a mixture of different shapes from fragments, fibers, spherical, granular, pellets, flakes or beads. Manufacturing of plastic involves incorporation of several harmful/toxic chemicals improving the quality having significant impacts on the surrounding environment, by releasing them (especially aquatic ecosystem) (EFSA, 2016; Park et al., 2020; Wright, Thompson, & Galloway, 2013; Zettler, Mincer, & Amaral-Zettler, 2013). In addition, large surface area of M/NPs causes concentration or interaction of different kinds of pollutants such as persistent organic pollutants, polycyclic aromatic hydrocarbons, organochlorine pesticides and polychlorinated biphenyls, etc. Some studies have also reported growth of pathogenic microorganisms on M/NPs (EFSA, 2016; Wright, Rowe, Thompson, & Galloway, 2013; Wright, Thompson, et al., 2013; Zettler et al., 2013). Lack of analytical development in detection, characterization and quantification of M/NPs has led to underreporting of actual presence and translocation (Kershaw et al., 2019).

All the M/NPs and the associated chemicals pollute the aquatic environment and transfer across the food web through bioaccumulation ending up on our table. M/NPs has been reported in the majority of aquatic food products (AFPs) moving across all the trophic levels of the marine environment (Gündogdu et al., 2022; Lusher, Hollman, & Mendoza-Hill, 2017; Tanaka & Takada, 2016). The consumption of M/NPs is either intentional (resemblance to food) or unintentional (feeding behavior) in the aquatic food system. It is not only the M/NPs but also the associated pollutant (released or absorbed) or pathogen that further increases the risk to the consumer.

AFP is a myriad of nutrition with established health benefits. They are a cheap source of proteins for large populations worldwide (Rathod, Ranveer, Benjakul, et al., 2021). The pollution of water bodies by M/NPs has raised a concern about the safety and quality of AFP. M/NPs are ingested and having size > 1.5 μm could enter the circulation and further accumulate (EFSA, 2016). Usually M/NPs ingested are held in the digestive tract, which is not usually consumed. Loss in the quality of AFP was reported due to physical stress induced by M/NPs ingestion (Lusher, 2015). In exceptional cases where whole fish are dried or used as such for consumption, while the tract portion is used for fish meal. This is used as animal feed which is further used for human consumption. Apart from this, the toxicant accumulated or transmitted by M/NPs further lowers the nutritional status of AFP. Several cases of growth of pathogenic microorganisms on M/NPs are reported (Amaral-Zettler et al., 2015). Hence, AFP could be regarded as a source for transmission of M/NPs, associated organic chemical and pathogenic microorganism to humans.