Plastic can enter the human food chain

Researchers from the University of Eastern Finland have found that small pieces of plastic called nanoplastics can travel up the human food web, through plants, insects and even fish.

About New study:

• The team of researchers developed a new, metallic fingerprint-based method to detect and measure the amount of nanoplastics in organisms.
• The experiment:
• For the study, researchers applied the technique to a model food chain that contains three trophic levels (trophic level is the position an organism occupies in the food chain) — lettuce, which was the primary producer, black soldier fly larvae, the primary consumer, and insectivorous fish (roach) as the secondary consumer.
• The researchers exposed lettuce plants to nanoplastics from commonly found plastic waste in the environment — polystyrene (PS) and polyvinyl chloride (PVC) nanoplastics — through contaminated soil for 14 days.
• They were then harvested and fed to black soldier fly larvae, insects that are used as a source of protein in many countries, and are also used as feed for chickens and cattle.
• After five days of feeding them the lettuce, the insects were then fed to the fish (roach) for five days. The roach, (Rutilus rutilus) is widely found in fresh and brackish water and is sometimes eaten and used as bait.

What is plastic?

• Plastic is a polymer or a long, long chain of monomers.
• In nature, polymers exist everywhere. But it is also possible to create them from crude oil or petroleum.
• These are known as synthetic polymers and plastic is one of them. Synthetic polymers have extraordinary traits. They are lightweight, durable and can be given any colour and molded into almost any shape.

What makes plastic non-biodegradable?

• Strong bond: The atomic structure of plastic or the monomer is essentially made up of carbon and hydrogen that has a strong bond and is hard to break. This bond make plastic non-biodegradable and causing plastic pollution.
• Unfortunately, no plant/animal/bacteria exists has the ability to break down the bonds between carbon and hydrogen atoms of the monomer of plastic.
• In exposure to ultra violet rays of sunlight, plastic breaks down into very small pieces known as micro plastics.

Why plastic is a threat?

• Adding toxics to atmosphere:The used plastic is unsuitable for recycling and is burnt, which further releases toxic chemicals into the atmosphere. 
• Contamination:In case, the plastic is not burnt, it ends up in a landfill, potentially contaminating soil, land and water sources.
• Adding threats to marine life:Plastic bags threats marine life such as fishes, turtles which unknowingly consume plastic that is dumped into the water bodies. Ocean plastic is estimated to kill millions of marine animals every year. 
• Uncollected waste:Since there is no adequate capacity of recycling of plastic waste, a huge quantity of plastic waste remains uncollected causing substantial damage to soil and water bodies.