Plastics – An Emerging Threat or Toxic Pollutants to Animals and Plants
Plastics, synthetic polymers made from monomers, are highly valued for their adaptability and durability but have become a pressing environmental hazard. Synthetic polymer (plastic) was invented to reduce the use of natural resources to some extent, as plastic does not contain a single natural molecule. Originally meaning "pliable and easily shaped," plastic has enabled the creation of versatile, affordable products. However, the global reliance on plastic has resulted in significant pollution, as plastic materials are not biodegradable and, in some cases, have been linked with carcinogenesis. Plastic can persist for centuries—plastic bottles, for example, take around 450 years to decompose. Today, an estimated 8,300 million metric tons of plastic litter our planet’s surface, impacting land, waterways, and air quality and putting the ecosystem's health at risk.
The environmental toll is severe. Plastic pollution affects biodiversity and is found across land and marine ecosystems, posing plant and animal life risks. Marine animals, including sea turtles and seabirds, often ingest plastic, leading to entanglement, digestive issues, and, ultimately, death from starvation or suffocation. Studies reveal that approximately 267 species are affected by plastic ingestion and entanglement, with nearly 400,000 marine mammals dying each year due to plastic pollution. Coral reefs, vital marine ecosystems, are also damaged by plastic debris settling on the seabed.
Plastics contribute around 10% to global waste, with chlorinated plastics releasing toxic chemicals that can leak into soil, and the groundwater, and other water bodies along with natural rainwater, contaminating water resources and causing diseases in plants, animals, and humans. In landfills, there are so many different kinds of bacteria that speed up the degradation of plastic in landfills. Some bacteria are like pseudomonas, nylon-eating bacteria, etc. The breakdown of nylon takes place by an enzyme called nylonase and methane, released by the action of this enzyme, which is a very powerful greenhouse gas and expressively endorses global warming. Plastic can also encourage endocrine disturbance in humans and animals. Humans are exposed to this through the mouth, nose, and skin. BPA is an additive used in the manufacturing of plastic, and it has the potential to impair the level of sex hormones. It also disturbs the metabolism and catabolism of the human and animal bodies.
Additionally, the accumulation of plastic in animal food chains, notably in sea turtles and seabirds, disrupts biodiversity and affects human food sources. Studies on sea turtles reveal large quantities of plastic in their stomachs, which can be fatal. Researchers have documented that at least 267 species have suffered due to plastic ingestion or entanglement, leading to severe physical harm and death.
In response, governments worldwide are adopting measures to curb plastic use and promote alternatives. Countries like the USA, Australia, Canada, and the UK have banned BPA from household items and children’s products. In India, several states have restricted plastic use, encouraging natural fiber bags as replacements. Approximately 60% of medical plastics are now incinerated instead of ending up in landfills. The United Nations Environmental Assembly (UNEA) adopted a resolution in March 2022, aiming to develop a legally binding treaty addressing global plastic pollution by 2024.
Plastic is almost used in every single product found in human life. After its discovery in the 1950s, plastic became one of the fundamental materials due to its benefits, low price, light weight, flexibility, and transparency. While convenient, single-use plastics have an overwhelming environmental impact. These plastics, often used for only a few minutes, can take forever to decompose, leading to significant pollution in oceans and lands along with water resources. They break down into microplastics, which infiltrate natural ecology, ecosystems, and food chains, posing serious risks to animals, birds, other wildlife, and human health. The need for sustainable alternatives is urgent and constantly growing. Besides, studies on the screening of effective microbial strains and other improved removal strategies are urgently required to reduce the hazards generated by plastic threats in the natural environment to an acceptable level.
References
Thompson, R.C.; Olsen, Y.; Mitchell, R.P.; Davis, A.; Rowland, S.J.; John, A.W.G.; McGonigle, D.; Russell, A.E. Lost at Sea: Where Is All the Plastic? Science. 304, 838. (2004).
Forever Toxic: The science on health threats from plastic recycling. Greenpeace, 24th May (2023).
Hazardous Chemicals in plastic products and food chain in Kenya. CEJAD, IPEN, Arnika, 2nd May (2023).
Further reading
Potential risks of food packaging plastic waste on human health and the environment
Impact of Microplastics on Soil Health and Crop Yield
How plastic pollution can affect agriculture and rural communities