Microplastics and nanoplastics are ubiquitous. They are found in air, water and various foods. Even in-and not just around-fruit and vegetables. In apples and carrots especially. The sad finding comes from an Italian study, ‘Micro- and nano-plastics in edible fruits and vegetables. The first diet risks assessment for the general population‘, published in Environmental Research. (1)
The study
Researchers from the Food and Environmental Hygiene Laboratory at the University of Catania in collaboration with the Laboratoire de Biochimie et Toxicologie Environnementale in Sousse, Tunisia, analyzed 36 products including fruits (apples and pears) and vegetables (carrots, lettuces, broccoli and potatoes). Samples were collected from six outlets in Catania (3 greengrocers, one supermarket and two zero-mile stores) in as many areas of the city.
After washing fruits and vegetables, the researchers peeled and centrifuged the individual samples. Using an innovative technique (patented by the Etna laboratory, directed by Professor Margherita Ferrante) they finally measured the size and amount of microplastics in the food.
The results
The examinations found the presence of microplastics ranging in size from a minimum of 1.51 μm (in carrots) to 2.52 μm (in lettuces). A form that easily penetrates the cells of seeds, roots, leaves and fruits. (2)
The contamination, expressed in particles per gram (ppg) of vegetable, averages 223 thousand ppg (52,600-307,750) in fruits and 97,800 ppg (72,175-130,500) in vegetables.
The higher levels of microplastics in fruits should be attributed to several factors, according to the researchers. The very high vascularization of the fruit pulp, the greater size and complexity of the root system. The age of the tree may also promote accumulations to which vegetables are less susceptible, having a shorter life cycle.
Carrots (whose development cycle is 60 to 75 days) were found to be the most contaminated vegetable. Presumably because of the small hairs around its central root, which can facilitate access to smaller microplastics.
The daily dose of microplastics
The Catania University study also cross-referenced microplastic contamination levels with Estimated Daily Intakes of fruits and vegetables for adults and children. (3) This results in the first ever calculated estimate of exposure to microplastics smaller than 10 microns in the general population through consumption of such foods.
Children, as the table shows, are far more exposed to contaminants than adults. Exposure to these as well as other substances of potential toxicity is in fact measured in relation to body weight, which in toddlers is substantially lower.
‘Although the abundant presence of microplastics in the vegetables investigated is of considerable concern, exposure through ingestion of these foods is lower than consumption of PET bottled mineral water,’ the researchers comment. (4)
Marta Strinati
Notes
1) Gea Oliveri Conti Ph, Margherita Ferrante, Mohamed Banni, Claudia Favara, Ilenia Nicolosi, Antonio Cristaldi Ph, Maria Fiore Ph, Pietro Zuccarello Ph. Micro- and nano-plastics in edible fruits and vegetables. The first diet risks assessment for the general population. Environmental Research, Volume 187, August 2020, 109677. https://doi.org/10.1016/j.envres.2020.109677
2) V. Karl-Josef Dietz, Simone Herth, Plant nanotoxicology, Trends in Plant Science, Volume 16, Issue 11, 2011, https://doi.org/10.1016/j.tplants.2011.08.003
3) The calculation is based on separate daily consumption for adults and children as follows: apples and pears 165.3 and 115.7 g for adults and children respectively, lettuce and broccoli 53.0 and 24.2 g, potatoes 78.5 and 65.0 g, carrots 20.3 and 18 g. The average body weight considered is 70 kg for adults and 16 kg for children
4) The estimated daily intake (EDI) of microplastics by consumption of PET bottled mineral water is 40.1 μg/kg/body weight/day for adults and 87.8 μg/kg/body weight/day for children. V. P. Zuccarello, M. Ferrante, A. Cristaldi, C. Copat, A. Grasso, D. Sangregorio, M. Fiore, G. Oliveri Conti, Exposure to microplastics (<10 μm) associated with plastic bottles mineral water consumption: The first quantitative study, Water Research, 2019, https://doi.org/10.1016/j.watres.2019.03.091
Professional journalist since January 1995, he has worked for newspapers (Il Messaggero, Paese Sera, La Stampa) and periodicals (NumeroUno, Il Salvagente). She is the author of journalistic surveys on food, she has published the book "Reading labels to know what we eat".