Plastic has permeated every aspect of modern day life, from the microchips in your computer to the bags you carry your shopping in. Plastic, which is derived from the Greek word Plastikos, is typically an organic polymer of high molecular mass which is derived from petrochemicals and often contain other chemicals, such as ethylene oxide, xylene, and benzene, and additives such as phthalates, adipates, and alkylphenols. Vinyl chloride used in the manufacturing of PVC pipes is a carcinogen. Thus, this innocuous piece of trash, discarded most mindlessly, is the most harmful to the environment.
Plastic is not easily bio-degradable, so it becomes a long-term problem. Its breakdown in the environment requires hundreds to thousands of years, though we may never know its actual degradation time, as this material has been in use only since World War 2. While plastic water bottles may take 450 years, polystyrene foam may ‘live’ for over 5000 years. The degradation process depends on the type of polymer present in discarded plastic.
Over 400 million tonnes of plastic are produced globally each year. It is estimated that one third of all plastic waste ends up in soil or freshwater. Most of this plastic disintegrates into particles smaller than 5 mm, referred to as microplastics, and breaks down further into nanoparticles, which are less than 0.1 micrometer in size. It is estimated that terrestrial microplastic / microfiber pollution is much higher than marine one – an estimate of four to 23 times more, depending on the environment.
We are living in a plastic planet, so what does it mean for our health? Drinking from a plastic bottle ingests microplastic particles, some of it may end up lodged in the gut, or traveling through the lymphatic system, according to European Food Safety Authority. According to research published in Tropical Journal of Pharmaceutical Research, researchers from Saudi Arabia found higher concentration of endocrine disruptor Bisphenol-A (7.5 ng/L) in plastic water bottles under higher temperature conditions.
A study carried out on more than 250 water bottles sourced from 11 brands in nine different countries, by researchers at the State University of New York, have found an average of 10.4 microplastic fibres per liter in portable water. Plastics in water are known to carry microbes and non-native species.
Scores of tap water samples from more than a dozen nations were analysed by scientists for an investigation. Overall, 83% of the samples were contaminated with plastic fibers. The US had the highest contamination rate at 94%, with plastic fibers found in tap water sampled at sites including Congress buildings, the US Environmental Protection Agency’s headquarters, and Trump Tower in New York. Lebanon and India had the next highest rates. European nations had the lowest contamination rate at 72%. The average number of plastic fibers found in each 500ml sample ranged from 4.8 in the US to 1.9 in Europe.
Microplastics aren’t poisonous as such, but it is the fragments and toxins released during photo-decomposition that pollute our soil and water. They are known to absorb hormone disruptors and heavy metals. According to research carried out at Lund University, microplastic particles laced with toxic chemicals like mercury, mercury and lead taken in by filter-feeding organisms in aquatic environment. When tiny plankton ingests plastic, animals (including Homo sapiens) up the food chain can bioaccumulate these in larger quantities.
When microplastic particles laced with organic pollutants such as polychlorinated biphenyls are inadvertently eaten by fish or other terrestrial animals often mistaking for food, the acidic and enzyme-rich conditions in the stomach could accelerate how quickly these toxins are released into the body, affecting the behaviour of the animals concerned.
Organisms can be negatively affected by plastic nanoparticles. According to the results published in Environmental Science and Technology, these particles slow the growth of algae, cause deformities in water fleas and impede communication between small organisms and fish.
A research paper published in the Proceedings of the National Academy of Sciences estimates that 90% of seabirds carry around 10% of their body weight in plastics – a similar proportion to airline hand luggage allowance for humans. Many marine animals also die through entanglement with marine litter such as discarded nylon ropes and nets which are constitute synthetic polymers. Plastic debris accumulating on beaches during high tides is also a major concern for tourism worldwide.
The abundance of plastic production in the past 40 years has created a host of landfill problems worldwide. Burning plastics is not a viable alternative as it generates harmful toxins and recycling efforts often do not match the demand of plastics for consumers. As a result, plastics continue to accumulate on Earth creating pervasive environmental problems.
The ban imposed by most Indian states on use of plastic bags is a positive step towards minimizing plastic pollution. On March 15, 2018, Maharashtra became the 18th state in India to ban the manufacture, sale, import, storage and use of all plastic carry bags and a range of other plastic products. While most citizens have welcomed the ban and happily moved to eco-friendly alternatives, some are still struggling to find the best way to get rid of plastic and plastic products.
(Dr Alvarinho Luis is a senior climate change
scientist at a reputed
Institute based in South Goa).
