Tel Aviv University researchers have found that in a marine environment, microplastics absorb and concentrate toxic organic substances and thus increase their toxicity tenfold, which may lead to a severe impact on human health if ingested.
The new study, which is the first to show the complete "life cycle" of microplastics, was recently published in the journal Chemosphere.
The novel research on microplastics, which are plastic materials that appear in a configuration of particles and microscopic fibers the size of tens of microns up to a few millimeters, examined the entire process that the microplastic undergoes, from the interactions it has with environmental pollutants to the release of the pollutants and the creation of increased toxicity.
The researchers discovered that adsorption of those organic pollutants to the microplastics increases toxicity by a factor of 10 and may also cause severe impact on humans who are exposed to contaminated food and drink.
Researcher Dr. Ines Zucker explained: "In this study we showed that even very low concentrations of environmental pollutants, which are non-toxic to humans, once adsorb to the microplastic result in significant increase in toxicity. This is because microplastics are a kind of 'magnet' for environmental pollutants, concentrating them on its surfaces, 'ferrying' them through our digestive tract, and releasing them in a concentrated form in certain areas -- thus causing increased toxicity."
Zucker added: "We have found that the adsorption capacity of an oxidized microplastic particle (the configuration of the microplastic after undergoing environmental weathering) is significantly higher than a non-oxidized particle.
"After the environmental pollutants adsorb to the microplastic, the pre-loaded particle may reach the digestive tract through the ingestion of contaminated food and water where it releases the toxins in close proximity to the cells of the digestive tract, thus increasing the toxicity of these substances, Zucker said.
"This is another painful reminder of the dire consequences of polluting the marine and terrestrial environment with hazardous industrial waste, which has unfortunately been saturated with plastic in recent decades," the doctor said. "The dangers are not theoretical but are more tangible than ever. Although there is a great deal of awareness of this problem, the preventive measures in the field are still far from imprinting a significant mark."