Previous Year Question
Why is there a great concern about the ‘microbeads’ that are released into environment?
They are considered harmful to marine ecosystems.
They are considered to cause skin cancer in children.
They are small enough to be absorbed by crop plants in irrigated fields.
They are often found to be used as food adulterants.
Correct Answer: A
Detailed Solution
Microbeads are extremely small, solid and intentionally manufactured plastic particles. They are generally smaller than 5 millimetres.
Microbeads are considered primary microplastics because they are manufactured in a microscopic size from the beginning.
In contrast, small particles formed by the breaking and fragmentation of larger plastic objects are called secondary microplastics.
Microbeads have been used in certain cosmetics, face washes, scrubs, toothpaste and industrial cleaning products.
They are commonly made from polyethylene, polypropylene, polystyrene and other synthetic polymers.
Due to their extremely small size, they can pass through the filtration systems of wastewater treatment plants and reach rivers, lakes and oceans.
They do not readily dissolve or biodegrade in water and can therefore persist in the marine environment for long periods.
Plankton, fish, shellfish, turtles and seabirds may mistake them for food and ingest them.
Their ingestion may cause digestive obstruction, internal injuries, reduced feeding ability and adverse effects on growth and reproduction.
Certain toxic chemicals and persistent organic pollutants can adhere to the surface of microbeads. Chemical additives present in plastics may also be released into the environment.
These particles and associated pollutants can be transferred through aquatic organisms into the food chain.
Option (b) is incorrect: Causing skin cancer in children is not the principal established environmental concern associated with microbeads.
Option (c) is incorrect: Their absorption by crop plants is not the primary basis of the broad concern expressed in this question.
Option (d) is incorrect: Microbeads are not ordinarily used for adulterating food products.
Therefore, the principal concern about microbeads is that they are harmful to marine ecosystems.