Microplastics and nanoplastics are ubiquitous. They are in the air, in water e in various foods. Also inside - and not just around - the fruit and vegetables. Especially in apples and carrots. The sad discovery comes from an Italian study, 'Micro- and nano-plastics in edible fruit and vegetables. The first diet risks assessment for the general population', Published on Environmental Research. (1)
A systematic review
I ricercators of the laboratory of environmental and food hygiene of the University of Catania in collaboration with the Laboratoire de Biochimie et Toxicologie Environnementale of Sousse (Tunisia) analyzed 36 products including fruit (apples and pears) and vegetables (carrots, lettuce, broccoli and potatoes). The samples were collected in six points of sale in Catania (3 greengrocers, a supermarket and two zero km shops), 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 quantity of the microplastics contained in the food.
Exams detected the presence of microplastics of sizes ranging 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)
Contamination, expressed in particles per gram (ppg) of vegetable, amounts on average to 223 thousand ppg (52.600-307.750) in fruit and 97.800 ppg (72.175-130.500) in vegetables.
The highest levels of microplastics in fruit can be attributed to several factors, according to the researchers. The very high vascularity of the fruit pulp, the greater size and complexity of the root system. The age of the tree can also favor accumulations to which the vegetables are less exposed, having a shorter life cycle.
The carrot (whose development cycle is 60–75 days) was found to be the most contaminated vegetable. Presumably due to the small hairs around its central root, which can facilitate access to the smaller sized microplastics.
The daily dose of microplastics
A systematic review The University of Catania also crossed the levels of contamination from microplastics with Estimated Daily Intakes (Estimated daily intakes) of fruit and vegetables for adults and children. (3) Hence the first ever calculated estimate of exposure to microplastics smaller than 10 microns of the general population through the consumption of such foods.
Children, as the table shows, they are much more exposed to contaminants than adults. Exposure to these as well as to other potentially toxic substances is measured in relation to body weight, which is substantially lower in children.
'Despite the abundant presence of microplastics in the vegetables investigated is of considerable concern, exposure through the ingestion of these foods is lower than the consumption of mineral water in PET bottles', comment the researchers. (4)
Footnotes to the story
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 fruit 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) See 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 a separate daily consumption for adults and children as follows: apples and pears 165,3 and 115,7 g respectively for adults and children, lettuce and broccoli 53,0 and 24,2 g, potatoes 78,5, 65,0 and 20,3 g, carrots 18 and 70 g. The average body weight considered is 16 kg for adults and XNUMX kg for children
4) The estimated daily intake (EDI) of microplastics by consuming mineral water bottled in PET is 40,1 μg / kg / bw / day for adults and 87,8 μg / kg / bw / day for the children. VP Zuccarello, M. Ferrante, A. Cristaldi, C. Copat, A. Grasso, D. Sangregorio, M. Fiore, G. Oliveri Conti, Exposure to microplastics (<10 μm) associated to 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".