What if I told you that you possibly consume approximately 5 grams of plastic every week? And drinking water is the largest source of microplastic in our diet – 82.4 per cent of Indian tap water is contaminated. It’s in our salt, fish, beer, honey, and sugar.
Our life is plasticised. Microplastics have invaded our air, ocean, drinking water and food. Although humans are not at risk from microplastic contamination yet, some intervention must be made to avoid future health hazards.
Microplastics are plastic particles sized from 1 nanometre to 5 millimetres that are increasingly contaminating not only ocean life but also food and water, according to latest research.
In 2020, researchers from University of Newcastle, Australia, and World Wide Fund for Nature took a closer look to find out what plastic contamination means for human nutrition. They did a comprehensive review of 52 studies and reported that the average consumption of plastic fibres (0-1 millimetre) from common food and beverages like seafood, beer, salt, drinking water ranges from 0.1 grams to 5 grams per person per week.
Microplastic in water
All sources of drinking water including groundwater, surface water, tap and bottled, are the largest supplier of microplastics in our daily diet. A 2019 WWF report revealed an average person consumes about 1,769 microplastic particles each week.
This report cited a Plos One study that provided insight on regional variation of average percentage of tap water sample containing plastic fibres and number of fibres per 500 ml of water. Results revealed, 94 per cent of tap water in the US and 72 per cent in Europe were microplastic-contaminated. In India, 82.4 per cent of tap water contained plastic fibre, with the presence of 4 fibres per 500 ml. The report also showed that an average person ingests 5,800 particles of synthetic fibre annually, 88 per cent of which comes from tap water.
A 2018 Orb Media study by Sherri Mason and colleagues analysed microplastic content of 259 bottled water of 11 brands purchased across nine different countries, including India. The study found microplastics like polypropylene, nylon in 93 per cent of bottled water. Per gallon, 40 plastic fragments were found, each larger than the width of a human hair. Popular packaged water brand Bisleri from India had the second-highest number of microplastic fibres. A Statista chart shows different brands and microplastic content in each of them.
Microplastic in foods
In recent years, a slew of research has added to our understanding of the prevalence, distribution, and origin of microplastic. However, the existing body of knowledge doesn’t provide a clear picture of how microplastic contamination works. They are biodegrading-resistance and exist for long periods of time in our environment. Common things we eat are already showing high contamination levels.
Microplastics were identified in common fruits and vegetables, according to a 2020 study published in Environmental Research. The results showed apples had the highest microplastic count of 195,500 particles per gram followed by broccoli and carrots with more than 100,000 particles per gram. Lettuce was the least contaminated vegetable of all.
In 2014, researcher Gerd Liebezeit and colleagues analysed 24 German beer brands for microplastic fibres, fragments, and granular material. Researchers found contamination in all brands. The results varied widely between individual samples and dates of production.
Nineteen samples of honey from Germany, France, Italy, Spain, and Mexico, were analysed for non-pollen particulates. Coloured fibres from 40/kg to 660/kg honey were found in all the samples investigated. Authors identified the environment as the source of these fibres. This study also included five commercial sugars and found transparent, coloured fibres and fragments in all of them.
Plastic-polluted oceans produce sea fish and seafood with higher concentration of microplastic in their respiratory and digestive system. A 2020 study, revealed microplastic accumulation in the muscles of marine fishes. A 2015 article reported one-third of the marine fish sample collected from Makassar, Indonesia and California, US markets had plastic garbage and textile fibres in their intestines.
Microplastic harmful to human health?
Long-term effects of plastic consumption on human health are not yet clear, but studies are underway. However, fisheries and aquaculture research have already demonstrated the deleterious effect of plastic consumption. Food and Agriculture Organization of United States reported excess accumulation of microplastic in digestive and respiratory system of marine fishes was associated with higher mortality rate in aquatic organisms.
A detailed 2020 review attempted to study “potential effects of microplastics and additives of concern on human health” and suggested the effect of microplastic on human health will depend on multiple factors including the concentration, chemical properties of the plastic, point of entry or exposure, size or shape of the particle, etc. No concrete evidence is available at this stage to draw conclusions.
In a strategic report, the European Food Safety Authority (EFSA) mentioned the digestive tract of marine animals contain the highest amount of microplastic, which is eliminated during consumption. For animals that are consumed whole, such as a portion of 225 g mussels that contains 7 micrograms, plastics might have negligible effect on human health. EFSA encouraged more research to understand human health implications of microplastics.
How to reduce microplastic consumption
It is impossible to live a plastic-free life. There are few steps that can reduce our plastic footprint.
· Both tap and bottled water contain microplastics. To avoid double sources of contamination, use tap water over bottled water. The best possible way is to use a suitable water purifier.
· Never microwave food in plastic utensils. Use glass cookware to heat your foods.
· Store your foods in glass or steel containers, wrap them in aluminium foil or use plastics that are labelled as ‘recyclable’, ‘biodegradable’ or ‘environment friendly’.
· Eat fresh, home-cooked meals as much as possible. Avoid plastic-wrapped and packaged foods.
· Be responsible and don’t discard plastic here and there. Keep your beaches, drains, water bodies clean. Whenever possible, support your community, city, state, and country to keep your environment clean.
Dr Subhasree Ray is Doctoral Scholar (Ketogenic Diet), certified diabetes educator, and a clinical and public health nutritionist. She tweets @DrSubhasree. Views are personal.
(Edited by Neera Majumdar)