Microplastics have been discovered in apples, carrots, pears, broccoli and lettuce, studies have revealed. Root vegetables including radishes, turnips and parsnips could also be contaminated with the man-made waste, prompting fears over the health impact.
– The tiny pollutants are thought to have been sucked into plants roots with water, and then travelled up the stem into the leaves and, where possible, fruits.
– Scientists have argued for decades that this was ‘impossible’, claiming they were ‘too large’ to fit through the pores in the roots.
– Microplastics have previously been identified in meats including chicken, canned fish and shellfish.
According to the first peer-reviewed study by University of Catania scientist Margherita Ferrante, apples are the most contaminated fruit while carrots are the vegetables most affected. Published this week in the journal Environmental Research, the report calls for an urgent review of the effects of microplastics on human health.
A second peer-reviewed study out this week will reveal plastic is being sucked up with water through the root systems of food crops. The study was performed jointly by Dr. Lianzhen Li of the Yanthai Institute of Coastal Zone Research in China and Professor Willie Peijnenburg from Leiden University in the Netherlands and is to be published in the journal Nature Sustainability.
Professor Peijnenburg found microplastics are penetrating the roots of lettuce and wheat plants, after which they are transported to the edible above-ground plant parts. For decades scientists have believed that plastic particles are too large to pass through the physical barriers of intact plant tissue. But this new research casts doubts on this – with root vegetables such as carrots, radishes, turnips, and leafy vegetables like lettuce found to be most at risk of microplastic contamination. Campaigners believe these new findings cast serious doubts over the safety of the food we eat.
The study, published in the journal of Nature Nanotechnology this week, also said plants can absorb tiny pieces of plastic through their roots, which slows their growth, possibly impacting the income for farmers. Experts from the US and China undertook the study, and found that plants exposed to nanoplastics took up those that were both positively and negatively charged.
‘Our experiments have given us evidence of nanoplastic uptake and accumulation in plants in the laboratory at the tissue and molecular level,’ said environmental scientist Baoshan Xing of the University of Massachusetts Amherst.
We have demonstrated this from root to shoot. Nanoplastics reduced the total biomass of model plants. They were smaller and the roots were much shorter.
If you reduce the biomass, it’s not good for the plant – the yield is down and the nutritional value of crops may be compromised.
We don’t know exactly why, but it’s likely that the positively charged nanoplastics interact more with water, nutrients and roots, and triggered different sets of gene expressions.’
Both studies have been shared with the Plastic Health Coalition ahead of a key summit looking into the relationship between plastic and health held in Amsterdam in April 2021. The Summit is being organised by the Plastic Soup Foundation.
Founder of Plastic Soup Foundation Maria Westerbos said:
“For years we have known about plastic in crustaceans and fish, but this is the first time we have known about plastic getting into vegetables.
“If it is getting into vegetables, it is getting into everything that eats vegetables as well which means it is in our meat and dairy as well.
“What we need to find out now is what this is doing to us. This is unchartered territory. Does plastic make us sick?”
Which fruits and vegetables were most contaminated?
Below are fruits and vegetables tested ranked in order from most to least contaminated with microplastics.
The results are from a study published today in the journal Environmental Research.
1. Apples (M. domestica). As much as 195,500 micro- and nano-plastic particles were found.
2. Pears (P. communis). 189,550 micro- and nano-plastics were found.
3. Broccoli (B. oleracea italica). 126,150 micro- and nano-plastic particles were found.
4. Lettuce (L. sativa). 50,550 micro- and nano-plastic particles were found.
5. Carrots (D. carota). 101,950 micro- and nano-plastic particles were found.
In the study scientists purchased six fruits or vegetables of each type from six different places, shops or supermarkets. The mixture was then dehydrated and analysed with an electron microscope to identify the microplastics.
‘Based on the results obtained, it is urgently important to perform toxicological and epidemiological studies to investigate for the possible effects of microplastics on human health,’ the authors conclude. Scientists involved in the research were based in the University of Catania, and Sousse University and Monastir University in Tunisia.
‘Most microplastics are emitted either directly or via degradation of plastics, to the terrestrial environment and accumulate in large amounts in soils, thus representing a potential threat to terrestrial ecosystems,’ the researchers said.
‘The plastic particles (after entering the plants) were subsequently transported from the roots to the shoots. Higher transpiration rates enhanced uptake of plastic particles, showing that the transpirational pull was the main driving force for their movement.’
The scientists analysed whether the pollutants were absorbed by placing fluorescent microplastics in treated wastewater.
Sian Sutherland, co-founder of environmental campaign group A Plastic Planet, said:
“We’ve known for years that plastics are in our air, ocean and soil. And now finally we have the proof plastics are in the fruit and vegetables we feed to our children.
“But a five-a-day diet of toxic microplastics and chemicals is not what the doctor ordered.
“Today I’m calling for an urgent investigation into what these toxins are doing to our health. Now more than ever we must listen to the scientists not the plastic lobbyists”
Approximately 330 million tons of plastic were produced across the globe in 2015 alone, with large amounts likely ending up in the oceans and the world’s water systems.