The Rising Threat of Microplastics to Human Health and Marine Ecosystems

As global plastic production rises and improper waste management becomes more prevalent, plastic litter is increasingly common in the environment. Plastic waste, when exposed to environmental elements, breaks down into smaller particles known as microplastics through processes such as photodegradation, mechanical impact, and weathering (Haque & Fan, 2023).

While the issue of macroplastics is well-known, a growing concern has emerged around microplastics – particles smaller than 5 mm, primarily made of polyethylene, polypropylene and other polymers (Carr et al., 2016) – which pose a different set of challenges. These microplastics can either be intentionally produced for certain products or result from the fragmentation of larger plastic items. Their persistence in the environment is concerning, as they not only threaten ecosystems but may also pose serious health risks.

Microplastics have been detected in human tissues and organs, entering the body through ingestion and inhalation, and causing physical blockages and chemical exposure that can lead to harmful effects.

Types and Properties of Microplastics

In terms of their origin, microplastics can be divided into two main categories: primary and secondary microplastics. Primary microplastics are synthetic plastic pellets, nurdles, beads, fibres, powders, and pellets, which are commonly used as raw materials in the production of plastic products, such as resins, and industrial items like cosmetics and textiles. In contrast, secondary microplastics are formed when larger plastic debris breaks down through processes such as weathering, photolysis, abrasion, and even microbial decomposition (Sulaiman et al., 2023). The key difference between these two categories lies in how they enter the environment. Primary microplastics are released into the environment in their manufactured form, while secondary microplastics are formed by weathering and wear of macroplastics, into smaller particles directly in the environment (Cverenkárová et al., 2021).

Unlike macroplastics, microplastics are more challenging to detect due to their diminutive size and heightened durability. These characteristics make microplastics particularly hazardous, as their small size enables them to infiltrate the digestive systems of organisms with ease, posing a far greater threat than their larger counterparts. The diversity of microplastics in the environment further complicates detection, as they come in various shapes, including fibres, fragments, pellets, films, microbeads, and foams. These various forms arise from different transformation processes, each of which alters their physicochemical properties over time (Rushdi et al., 2023).

Additionally, microplastics come in a wide range of colours, just like their size and shape, which is crucial for understanding their interaction with aquatic organisms. Certain species may ingest microplastics based on colour preferences, mistaking them for food. Furthermore, colour can serve as an indicator of contamination levels, with yellow and black microplastics being the most polluted by persistent organic pollutants, while transparent and white microplastics are more frequently consumed by marine animals (Cverenkárová et al., 2021).

Microplastic Pollution in Malaysia’s Marine Ecosystem

The occurrence of microplastic pollution, particularly in aquatic environments, is a growing global concern. In Malaysia, significant contributions to microplastic pollution in the marine ecosystem have been linked to the dumping of personal care and cosmetic products, with approximately 0.199 trillion microplastics entering marine waters (Sulaiman et al., 2023).

Universiti Putra Malaysia’s Assoc. Prof. Dr Sarva Mangala Praveena Appalanaidu has revealed that facial scrubs, toothpaste, liquid soap, shower gel, and cosmetics are potential sources of microplastics. These particles enter water bodies through wastewater discharge and runoff, raising concerns about their accumulation in the food chain and potential health implications for marine life and humans.

The penetration of microplastics into water bodies, driven by hydrodynamic forces and adhesion effects, leads to their widespread uptake by aquatic life, posing a significant threat to the environment (Sulaiman et al., 2023). Microplastics have been reported at various levels of the food chain, including in zooplankton, chaetognatha, ichthyoplankton, copepods, and salps at lower trophic levels, as well as in higher trophic levels such as polychaetes, crustaceans, echinoderms, bivalves, fish, seabirds, and mammals (Cverenkárová et al., 2021).

This widespread contamination of microplastics is further exacerbated by plastics used in fishing and fish farming, which release toxic substances into the water. As organisms ingest these microplastics, they accumulate in their tissues, potentially harming their health and disrupting the broader ecosystem, demonstrating the compounded effects of microplastic pollution.

Human Exposure to Microplastics

Human exposure to microplastics occurs predominantly through the consumption of contaminated food and water, with seafood products being a notable source. Once ingested, microplastics enter the gastrointestinal tract and can be absorbed, leading to oxidative stress, cytotoxicity, and potential translocation to other tissues (Alberghini et al., 2022).

Microplastic contamination is not limited to seafood; it also affects other foods. For example, a study from China found microplastics in sea salt, likely due to production from seawater (Cverenkárová et al., 2021). The widespread presence of microplastics in food poses a direct ingestion risk and raises concerns about cumulative exposure from various dietary sources.

In conclusion, the pervasive presence of plastic and microplastics in the environment, daily use items, and food supply underscores a pressing public health issue. More plastics means more microplastics and thus more pollution and contamination which affects our health and the environment. By reducing plastic production and consumption, using safer alternatives, and enhancing public awareness, we can mitigate this threat and protect human health.

References

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