The next time you reach out for your salt cellar, pause for a moment. The salt may contain microplastics — potentially harmful particles that, many fear, may adversely affect your health.

Doctors have already found plastic in human poop. A study by a team in the Medical University of Vienna has just confirmed that people are ingesting plastics. It found microplastics — small plastic particles less than 5mm long — in human excreta.

Microplastics have pervaded the ecosystem and consequently the body. Researchers in India have found it in sea salt and cosmetics, and also in water bodies. International studies have detected microplastics in tap and bottled water (including water samples from India), in honey and even in beer.

These are potentially harmful. Though research worldwide is nascent on the subject, similar studies on fish and other marine population have shown damage to the digestive, hormonal and respiratory systems caused by microplastics.

The findings of the Austrian team led by Dr Philip Schawbl of the university’s Gastroenterology and Hepatology division and the Environment Agency of Austria are among the first to establish that people have started to ingest plastic. The researchers found microplastics in every stool sample they collected from eight participants across the world.

“Now that we have evidence that microplastics are ingested by humans, several questions pop up,” says Schawbl. Schawbl’s team presented the findings at a conference of the United European Gastroenterology in October in Vienna after testing stool samples from Finland, Austria, UK, Russia, Poland, Italy, Japan and the Netherlands.

But not much is known — yet — about the main sources of microplastics in people and how they may harm the body, says Schawbl in an e-mail interview to BL ink . “Personally, I was astonished that we found microplastic particles in all samples. But what really surprised me was the fact that we found up to nine different plastic types — indicating that several sources might be involved,” he adds.

Worldwide, research on microplastic and human health has concentrated on the digestive system. However, Joana Correia Prata of Portugal’s University Fernando Pessoa, in her paper Airborne microplastics: Consequences to human health? published in Environmental Pollution last year, states that airborne microplastics accumulating in lungs can impact the health of workers in the synthetic textile and PVC industries, causing ailments such as asthma, pneumonia and acute lung distress.

“As environmental concentrations are lower than occupational exposure, inflammatory diseases will be less severe,” she writes, but warns that they could still be a cause of asthma and cardiac diseases.

The past two years have witnessed a surge in discussion and research on microplastics. “A key problem with plastics is that they are essentially indestructible; rather than being biodegraded, they break down into smaller and smaller pieces, eventually becoming microscopic fragments,” an article in Lancet Planetary Health said in October 2017. “We should no longer just be concerned with large plastic items clogging up oceans and waterways, but also more attention needs to be paid to these tiny fragments and their effects on planetary health,” it says. As of 2015, 6,300 million tonnes of plastic waste had been generated in the world, it adds. Around 79 per cent ended up in landfills or the environment (nine per cent was recycled and 12 per cent incinerated).

India has much to be worried about. India and the rest of South Asia are the worst culprits, releasing 274 kilo tonnes of primary microplastics into the oceans, says the International Union for Conservation of Nature in its study Primary Microplastics in the Oceans: a Global Evaluation of Sources , released last year.

Not much research has been done on microplastics in India, but a new study from the Centre for Environmental Science and Engineering in Indian Institute of Technology (IIT) Bombay establishes that Indian sea salts are contaminated with microplastics. Researchers Chandan Krishna Seth and Amritanshu Shriwastav, both from IIT Bombay, tested eight brands of sea salts and found traces of microplastics in all. Since India is one of the world’s largest exporters of salt, the findings may have widespread repercussions.

“These results are in line with similar studies across the world, which imply the widespread contamination of seas across the globe with plastic debris,” says Shriwastav. The study was published in Environmental Science and Pollution Research in August. Though the researchers found microplastic particles in sea salt, they are unsure of its impact. Often, simple filtration methods can sieve out the microplastics from salt. “At present we do not know if such a level would pose any effect. Also there are many additional pathways for microplastics exposure. A more comprehensive exposure and risk assessment is required before we can conclude anything,” he adds.

Schawbl draws attention to the impact of microplastics on animals where the ingested material locates itself in blood, lymph or liver. “These particles are foreign bodies and thus may cause immunoreactions. However, we don’t know if the same is true for humans,” he says. Further, microplastics are laced with additives and chemicals, which can cause harm.

Underneath the placid calm of the Vembanad lake on which hundreds of houseboats glide by, microplastics are working up a storm. Professor EV Ramasamy’s team of researchers studied the lake over the past two years and found microplastics in the sediments. The findings of the research were published in the international journal Environmental Pollution in 2017 by Ramasamy and S Sruthy, both from the School of Environmental Science at Mahatma Gandhi University, Kottayam.

“The lake receives water from five to six rivers and a bund blocks the water for half the year. Hence whatever the rivers bring into the lake remains there for considerable time. Our study on its sediments found, on an average, 266 microplastic particles every square metre,” says Ramasamy.

The team is now testing the water, and the preliminary findings are staggering. “Microplastics are much more abundant in the waters than in the sediments,” Ramasamy says. They have also come across microbeads — small plastic particles used in cosmetics — which they didn’t find in the sediments.

The team is studying the impact of microplastics in the Vembanad lake area. They have examined common salt and bottled water and found contamination. “Every 250g of salt has about 30-40 plastic particles in it, and even the local bottled water has about 5-10 particles per five litre. The work is still on,” he says, adding that the university is trying to tie up with specialised government bodies for more extensive research.

“It is imperative to study the organisms in the lake — fish and clam — which are staple food in the region. We discard the head and remove the intestine of the fish; clams, on the other hand, are consumed whole. These organisms ingest microplastics and they get into our system when we consume them. By consuming plastic we are simultaneously consuming a cocktail of chemicals. That is the real danger,” he says.

Agrees Priti Mahesh, chief coordinator of the Delhi-based NGO Toxics Link. “Plastic attracts a lot of other chemicals, some of which are endocrine disrupters,” says Mahesh. Endocrine disruptors are chemicals that can interfere with endocrine systems and cause tumours and other disorders.

Microplastics, clearly, are forcing people to look at plastics in a different way. “For long, plastics have just been considered litter. The fact that they will eventually break down and impact human body was not perceived. Plastic takes a long time to break down, hence studies too have taken time to get there,” adds Mahesh.


Eating poison: Studies on fish and other organisms have shown that microplastic ingestion damages the digestive, hormonal and respiratory systems of marine life


Earlier this year, Toxics Link tested 18 products from 16 major cosmetic brands for microplastics. Among them were rinse-off products such as face washes, face masks and face scrubs and leave-on lotions such as sunscreens and baby lotions. Nine out of the 18 products — all rinse-off items — tested positive for microplastics. The microbeads — small particles which mostly function as exfoliating agents and are found in face washes and some toothpastes — are a particular cause of alarm. “When you rinse off the face wash, the microbeads go down the drain and directly get into the water system and into large water bodies,” says Mahesh. The findings are a call to greater governmental and corporate participation in tackling the issue. Many countries the world over, including the UK and France, have banned microbeads.

The NGO is now taking up a study to find if microplastics have invaded the tap water systems. “We will test the water from eight cities including Delhi both before and after water treatment to find if the filtration systems of the water boards are able to capture and reduce the amount of microplastics,” Mahesh says. The testing requires a lot of instrumentation which is not easily available, she adds.

All of this makes the next phase of research — the impact of microplastics on human body — complicated. Though the World Health Organization (WHO) in India has not taken up research on the direct impact of microplastics on human health, globally it is putting together a roadmap to review the risks.

“There is limited information to make an informed risk assessment or to say with certainty whether or not exposure to microplastics in the environment poses a long-term risk to human health,” says a WHO spokesperson. Of late, the organisation has had to constantly engage with questions on toxicity of ingested micro and nano plastics. “Microplastics may carry microbial pathogens or adsorb chemical contaminants. The microplastics themselves may be manufactured with toxic additives. Concerns have been raised relating to whether the small size of the plastics may theoretically penetrate the gut and distribute in body,” adds the spokesperson. All of this has prompted the WHO to review the evidence on microplastics and make risk assessments.

Microplastics are just beginning to make a noise in the Indian medical fraternity. “The IMA (Indian Medical Association) has not done any study on this, but we are consumed by the idea of it being a health hazard,” says IMA honorary finance secretary VK Monga. “We don’t know the magnitude of the microplastic in our body or the health hazard it can pose. Hypothetically, it can harm the intestinal lining, it can attack the useful bacteria in the body, it can harm the cardiac, neurological and hormonal systems,” says Monga.

While he admits that the IMA needs to dig deeper into the issue, the key, he adds, is heightened awareness about plastic use. “Bans and doling out challans (fines) can only work if these are coupled with individual commitments to reducing plastic use,” he says. Ramasamy seconds the idea: We cannot do without plastic now. But we can restrict its use, he stresses.