Data from two new studies published this month showed microplastic contamination in tap water and sea salt, prompting calls for large-scale, global research on the ramifications for human health.
The tiny particles were found in sea salt in the UK, France, Spain, China and the US, according to reports in UK newspaper The Guardian on 9 September.
A few days before, Orb Media published the findings of tests on tap water carried out in 14 countries: microplastics were present in 72% of samples taken in European countries including the UK, Germany and France. In Europe, a 500 ml glass of water contains 1.9 fibres on average; in the US, where contamination levels are 94%, the figure is 4.8.
Previous studies have shown microplastics in fish bound for human consumption, as well as beer, sugar and honey. Microplastics have also been shown to absorb toxic chemicals from the marine environment, and then release them when consumed by fish and mammals. What this all means for human health is far from clear, though.
“The first studies into the health effects of microscopic plastics on humans are only just now beginning; there’s no telling if or when governments might establish a ‘safe’ threshold for plastic in water and food,” the authors wrote Orb Media’s new report, Invisibles: the plastic inside us. “Even farther away are studies of human exposure to nano-scale plastic particles, plastic measured in the millionths of a millimetre.”
Indeed, whilst researchers are building a picture of the presence of plastics in the environment and the food chain, very little is known about how ingestion impacts humans. In part, this is because it’s proving almost impossible to find a control group that have not been exposed to the particles.
Small particles; major problem
A growing number of experts insist that more research is urgently needed. In an interview with FoodNavigator last year, Professor Tamara Galloway, an ecotoxiciologist at the University of Exeter in the UK, said exposure science, ecology, epidemiology and particle toxicity fields provide “ample evidence” for the plausibility of a risk to public health.
Dr Colin Janssen, who led research at the University of Ghent, Belgium, showing that Europeans currently consume up to 11,000 pieces of plastic in their food every year, is another who has said questions need to be asked and answers found.
“Are [these microplastics] encapsulated by tissue and forgotten about by the body, or are they causing inflammation or doing other things?” he mused in an interview with Sky News in January this year. “Are chemicals leaching out of these plastics and then causing toxicity? We don’t know and actually we do need to know.”
Given so little is known about their impact, there is currently no legislation for microplastics and nanoplastics as contaminants in food. Regulators have been keen to play down fears.
In a statement sent to FoodNavigator, an EFSA spokeswoman suggested the latest research and calls for action are unlikely to see any changes in the short-term. There is “nothing planned in the near future in this area from EFSA’s side, but in our 2016 statement we clearly indicated the areas were further research should be carried out”, she explained.
In June last year, EFSA noted that the presence of microplastics and nanoparticles in food was an “emerging issue”. It proposed further studies on “the occurrence of microplastics and especially nanoplastics in food, their fate in the gastrointestinal tract, and their toxicity. Knowledge on the toxicity of nanoplastics is particularly needed because these particles may penetrate all kinds of tissues and eventually end up in cells,” EFSA added.
The authority’s expert panel said at the time that it was “too early to say” whether the particles are harmful to consumers, but it seemed “unlikely”, according to Dr Peter Hollman, who helped draft the statement.
Microplastics come from a range of sources, including pre-production plastic pellets, microbeads used in cosmetics and large items that break down in the environment, like food packaging and plastic bottles.