The effects of plastic pollution on the environment and human health are causing considerable worry, particularly now that it is breaking down into tiny particles that are accumulating in the environment. Now, scientists at the University of Eastern Finland have discovered that tiny plastic particles known as nano plastics can pass through plants, insects, and even fish on their way up the human food chain. Nanoplastics are minute pieces of plastic waste that are less than 1,000 nanometers in size (1 nm is equal to one billionth of a metre).
What does the study find about plastics?
According to research results that were revealed on September 12 in the journal Nano Today, a group of scientists created a brand-new metallic fingerprint-based technique to locate and quantify the presence of nano plastics in organisms.
In order to conduct their research, they used a model food chain with three trophic levels, including lettuce as the primary producer, black army fly larvae as the major consumer, and insectivorous fish (roach) as the secondary consumer.
For the study, polystyrene (PS) and polyvinyl chloride (PVC) nano plastics, which are frequently found in environmental plastic debris, were used to expose lettuce plants to nano plastics for a period of 14 days through contaminated soil. Then, they were gathered and given to the larvae of black army flies, which are fed to poultry and cattle as well as being utilized as a source of protein in many nations.
The fish (roaches) were fed the insects for five days after receiving the lettuce for five days. The roach (Rutilus rutilus), which may be found in both fresh and brackish water, is frequently eaten and occasionally used as bait.
How can it travel up the food chain?
The researchers analyzed the dissected fish, insect larvae, and plants using scanning microscopy. Images demonstrated how the nano plastics from the soil were absorbed by plant roots and accumulated in leaves. In turn, the tainted lettuce gave the insects access to the nano plastics. Despite enabling them to empty their intestines for 24 hours, imaging of the black army fly’s digestive system revealed that both PS and PVC nano plastics were discovered in the mouth and gut. However, compared to the PVC nano plastics, the lettuce and insects both contained fewer PS particles.
Particles were found in the gills, liver, and gut tissues of fish that had consumed the contaminated insects. The study concluded that the liver is the major target tissue for nano plastics entering vertebrates since it has the highest concentration of nano plastics.
