MICROPLASTICS, AN EMERGING ENVIRONMENTAL THREAT

Plastic has been playing a very significant role in our lives and has made our lives better in so many different ways. It is cheap, flexible, durable, non-corrosive and inert.

By Ayesha Khaliq1, Zahoor Ahmad1* and Orooj Surriya2

However, majority of plastic polymers synthesized are not biodegradable and while degrading into fragments they are converted into microplastics and nanoplastics. The amount of plastic polymers that are recycled or burned at waste-to-energy conversion facilities are quite less as compared to landfills, where large amounts of plastics are dumped thus taking thousands of years to decay and resulting in the release of potentially harmful materials. Thus plastic waste has been acknowledged as an environmental threat, leading to the formation of microplastics and nanoplastics which find a way from landfills into the aquatic and terrestrial ecosystems; thus endangering and entering various food chains.

Microplastics are an emerging environmental threat. Researchers believe that we are not only using but rather we are eating, drinking and even breathing microplastics, which may disrupt human health if not controlled. Recently, a lot of media coverage has been given to the enormous amounts of plastic floating about in the oceans; which may originate from primary and secondary sources of plastics resulting in the formation of microplastics. Thus causing threat to aquatic life. According to estimates, the amount of microplastic contamination on land is 4 to 23 times more than that in the ocean, depending on the habitat. Plastic fragments are nearly everywhere in the environment, and they can have a variety of negative impacts. According to the report, a quarter of all plastic garbage is lost to soil or waterways. The majority of this plastic degrades into microplastics (particles smaller than 5mm) and these further degrade into nanoparticles (less than 0.1 mm in size). Researchers have spent years establishing reliable spectroscopic methods that are of the highest caliber, but they are still looking for effective and uncomplicated approaches for the examination of microplastics but still have not found a workable answer. Scattered plastics have been accepted and given names in terms of size, point of origin and disintegration technique as a result of the rapid expansion of plastic materials and polymers i.e. cosmetics, electrical appliances, plastic containers, sachets, glassware, wrapping for consumer product and many other items are common producers of microplastics. These deteriorated polymers are so minuscule that they have been discovered in a variety of animals; including human brains, blood, gastrointestinal tract, mouth, muscles (meat) and reproductive systems. However, it may be argued that the harm posed by microplastics pollution to land-based plants, animals and people is greater.

Micro plastics pieces have been discovered in the environment and present a serious issue in a number of ecological areas. Other research revealed that microplastics have been detected from the bottom of the ocean to the highest point on Earth (Mount Everest). Less than 20% of microplastics came from the ocean, whereas about 80% came from land. In terrestrial ecosystems, microplastics are more likely to interact with the biota, which may have an impact on the geochemistry and biophysical environment thus causing environmental toxicity. Microplastics may be a stressor of climate change in terrestrial systems, particularly in soil and air settings. One of the consequences of microplastics on the environment is the death and harm of aquatic birds, fish, mammals and reptiles brought on by the aggregation and digestion of microplastic fibers.

Micro plastics are present in soils all over the world, particularly in agricultural soils. They may penetrate the irrigation soils through a variety of channels including irrigation, wastewater sludge, dumping and air deposition. By changing their biophysical surroundings, microplastics may interact with soil fauna which impacts both the soil’s function and fitness. Naturally, as they build up in the soil, they may be absorbed by plants and move up the food chain. The link between microbial activity and water-stable aggregates is impacted by microplastics, as they carry the bulk density and water holding capacity. Additionally, soil microbes and earthworms may readily swallow microplastics, which then build up in casts in the colon. As the foundation of several food chains, burrows may have long-term ecological repercussions on not just their own species but also other types of creatures.

A significant contributor for spreading microplastics is sewage. According to the study, about 80% and 90% of the microplastics are found in sewage, such as those from clothing fibers survive in the sludge. Several thousand tons of micro plastics enter our soils each year as a result of the frequent use of sewage sludge as fertilizer in agricultural areas. Even tap water has been discovered to contain microplastics due to the sewage water leakages. In addition, microplastics could harbor pathogens and serve as an environmental disease vector. The health of soil fauna and the functionality of the soil can both be impacted by microplastics interactions with them. The loss of species that dwell underneath the ground such as mites, larvae and other microscopic organisms that keep the soil fertile, is a result of terrestrial microplastic contamination. In general, when plastic particles degrade, they acquire new physical and chemical characteristics, raising the possibility that they will be more harmful to surrounding life in an ecosystem. Additionally, the likelihood of harmful consequence increases with the number of potentially impacted species.

Our clothes are one of the primary suppliers for microplastic fibers. Every time we wash our clothing; tiny strands of acrylic, nylon, spandex and polyester shed. These microplastic fibers are taken to wastewater treatment facilities or released into the environment. More than 700,000 microplastic fibers might be emitted into the environment throughout each cycle of a clothes washer, according to recent research quoted by Water World in 2016. Although hand washing, which is more widespread in underdeveloped countries, has not yet been researched but the implications might be substantial. Globally, 1.5 million trillion microfibers were thought to be present in the waters in the year 2019.

The majority of marine plastic debris roughly 70% floats on the surface of the waters, 15% floats in coastal regions and the remaining floats in sediments. Because they are so small, microplastics can mistakenly be consumed by fish, mussels, zooplankton, sea birds and other marine animals. Studies have reported that some aquatic animals may easily consume microplastics and their smaller components, nanoparticles. They frequently develop liver toxicity, neurotoxicity, reproductive toxicity and gastrointestinal toxicity. Researchers are concerned about the impact of microplastics on humans and small vertebrates since they have seen several epidemic situations in which microplastics are present in the organisms and have an impact on their survival. A limited number of studies have already made a significant contribution by demonstrating that microplastics are readily deposited in various bodily regions (from tiny to big), but also that microplastic particles are accessible for absorption into human circulation and the accompanying dangers i.e. Asthma-like clinical symptoms and increased chronic bronchial constriction have also been linked to microplastics.

Microplastics have the potential to be exposed to human beings via soil, water, food and are globally dispersed in every ecosystem. Currently researchers are working on potential risks of microplastics in public health and the environment. Alternatives to plastics have been the subject of numerous studies, but none have been proven effective. To lessen the negative impacts of microplastics thin plastic shopping bags with fewer than 40 microns should be banned while implementing an efficient recycling system for plastic bags. Plastic litter is already dumped in non-manageable ways thus disposal through waste-to-energy will be crucial in minimizing the environmental impact of plastics. Also raising awareness through schools, colleges, universities, various governmental and non-governmental organizations, and networks regarding the chronic effects of microplastics pollution through programs and campaigns and educating individuals responsibility to minimize plastic by choosing to reject, reduce, reuse and recycle plastics will help attenuate the microplastics pollution.

Ayesha Khaliq1, Zahoor Ahmad1* and Orooj Surriya2

1Department of Botany, Constituent College of University of Central Punjab Bahawalpur 63100, Pakistan

2Department of Zoology, Constituent College of University of Central Punjab Bahawalpur 63100, Pakistan