Many years down the line when the history of our time is written, it will most probably be called the plastic age. Plastic has become an inseparable part of our lives. So much so that even the food we are eating, the air we are breathing and the water we are drinking has plastic in them. In 2019, researchers from Medical university of Vienna, Austria published a paper. In that study, they looked at the stool samples of people from different countries and found that all of them had plastic particles. 9 different types of plastics were identified and at least 20 plastic particles were present per 10 g of sample. In another study in France, scientists discovered tiny pieces of plastic raining down from the sky. They recorded a daily rate of 365 plastic particles per square meter.
Plastic is a material formed by inter linking long chains of molecules made of carbon and hydrogen. Because they are light, durable, and can be moulded into any shape, plastic has become ubiquitous in our lives. About 300 million tonnes (300000000000 Kg) of plastic is produced in a year. According to one report, an average Indian uses about 11 Kg of plastic products in various forms in a year. Almost 50% of this is single use plastic. From polythene shopping bags, to brushes, toothpaste tubes, to food storage boxes to our shoes and clothes almost everything we use has plastic in one way or the other. Only about 10% or less of the plastic is recycled. About 8 million tonnes is dumped into the oceans every year and a lot more is dumped into landfills. As you may have heard before, the plastic takes thousands of years to break down. But once in water or the soil, it can break up into smaller sized pieces. The plastic fragments that are smaller than 5mm are called the microplastics. Though a 5mm upper limit is used as a definition, microplastics usually tend to be in the micrometer size range which is below the detection limit of the naked eye (a micrometer is 1000 times smaller than a millimeter).
Microplastics are classified into primary and secondary microplastics. Primary microplastics are those that are intentionally synthesized for use in cosmetic and personal care products. Examples of primary microplastics include the plastic microbeads that are added to facial cleansers, scrubs, shampoos, laundry detergent, toothpastes etc. Secondary microplastics on the other hand are formed by the disintegration of larger plastic products like bottles, fishing nets, bags, etc. According to one study, there could be anywhere between 15-51 trillion microplastic particles floating around in the oceans. Because of their small size, the fish mistake microplastics for food. These plastic fragments are then absorbed into the circulation and become embedded in the tissue. Till now microplastics have been found in more than 114 species of fish and other marine organisms.
Microplastics in ocean are also consumed by birds that depend on the marine ecosystem. From the oceans, microplastics make their way to our dinner tables via these fish and birds. Microplastics have also been found in other food products such as table salt, sea weed, etc. According to one research report from Australia, people consume about 5 grams of microplastic per week, that is as much plastics as in one credit card.
Another way in which microplastic enters our body is through the air we breath. It has been found that workers in textile and PVC industries are prone to inhaling these from their surroundings. Another example is the study from France where microplastics were collected from rain water.
Microplastics are also present in the water we drink. It is now well known that chemicals in plastic slowly leech into the water stored in plastic bottles. Additionally, the primary microplastics included in cleansers, shampoos or detergents are washed off and enter water sources. These are small enough to escape treatment processes. As per a report published by World Health Organization, microplastics of different sizes, shapes and composition are widely found in both surface and drinking water sources. As many as 1000 to 10,000 microplastic particles were found in a liter of water, including in bottled water.
There is no research as yet suggesting that consuming microplastics can directly impact human health. The world is only just waking up to the reality of microplastics filling our oceans. Studies in mouse, however, have shown that microplastics accumulate in kidney, liver and gut and cause disturbance in the metabolism. Tissue damage due to microplastics has also been reported in marine organisms. It has also been reported that microplastic ingestion reduces appetite thereby leaving less energy for other life functions such as reproduction and physical growth of fish. This is relevant not only to human health but also to economy as it can have a profound impact on the livelihood of fishing folk. Microplastics have also been found to be especially effective in adsorbing harmful chemicals and pathogenic microbes found in their environment. Once inside the human body, these could cause illness.
There are many steps that can help reduce our exposure, and that of our future generations, microplastics. Minimize the use of plastic in your day to day life as much as possible. Do not heat or cook food with plastic utensils or in plastic containers and avoid food with plastic packaging. Reduce household dust that can carry microplastics. If you are in the habit of using tea bags, watch out for the plastic used to make the packs or as a sealant that can melt off in hot water. Avoid using cleansers, shampoos, or toothpaste that contain microbeads. You can check the composition of the product for ingredients like polyethylene, polyethylene terephthalate, nylon, polypropylene and polymethyl methacrylate which are generally used in the preparation of microbeads. Instead consider using products with natural ingredients like almond shells. If you are going shopping, carry a cloth or jute bag instead of asking for single use polyethene bags. Most importantly, when using plastics keep in mind the 3R rule – reduce, reuse, recycle.