What are microplastics?
Microplastic is any fragment of plastic that is between 1 nanometer and 5 millimetres wide.
Microplastics are very common in our environment. They are found in water, soil and the air. According to one estimate, 2.7 million tonnes of microplastics seeped into the environment in 2020, an estimate expected to double by 2040. It’s probably safe to say that microplastics are just about everywhere.
Microplastics occur in the environment as a consequence of plastic pollution. Microplastics are present in a variety of products, from cosmetics to synthetic clothing to plastic bags and bottles.
What are the sources of microplastics?
There are two main sources of microplastics:
Some plastics are made to be small. These are known as primary microplastics, like the microbeads intentionally added to face washes and other personal care products.
But most microplastics come from the slow disintegration of larger plastic products, including plastic wrap, takeaway containers, polyester clothes, tires, paint and artificial turf. These are known as secondary microplastics.
What are the chemicals present in microplastics?
Microplastics consist of carbon and hydrogen atoms bound together in polymer chains. Other chemicals, such as phthalates, polybrominated diphenyl ethers (PBDEs), and tetrabromobisphenol A (TBBPA), are typically also present in microplastics, and many of these chemical additives leach out of the plastics after entering the environment.
How do microplastics enter into the environment?
There are several ways.
Primary microplastics enter the environment directly through any of various channels—for example, product use (e.g., personal care products being washed into wastewater systems from households), unintentional loss from spills during manufacturing or transport, or abrasion during washing (e.g., laundering of clothing made with synthetic textiles).
Over time discarded plastic products – like water bottles and cling wrap – can break down into microplastics.
However, microplastics find their way into the environment, once they’re there, they get around. Research has shown that particles can move through the food web, as well as through soil, water, ice – even the air.
How microplastics are damaging the plants, animals and the environment?
Microplastics are not biodegradable. Thus, once in the environment, primary and secondary microplastics accumulate and persist.
Microplastics have been found in a variety of environments, including oceans and freshwater ecosystems. Microplastics also are a source of air pollution, occurring in dust and airborne fibrous particles.
Microplastics have been found lodged in the digestive tracts and tissues of various invertebrate sea animals, including crustaceans such as crabs.
Fish and birds are likely to ingest microplastics floating on the water surface, mistaking the plastic bits for food. The ingestion of microplastics can cause aquatic species to consume less food and therefore to have less energy to carry out life functions, and it can result in neurological and reproductive toxicity.
Microplastics are suspected of working their way up the marine food chains, from zooplankton and small fish to large marine predators.
One study found they can slow the growth of a microscopic marine algae known as phytoplankton, the base of several aquatic food webs. Another report found microplastics can make soil less fertile, hampering harvests.
Microplastics may speed the melting of snow and ice in places like the Arctic, limiting the planet’s ability to reflect sunlight and speeding global warming, one study suggested.
How do microplastics enter human body?
Microplastics can enter the human body through ingestion and inhalation. It remains to be confirmed if nanoplastics – which are less than 1 micrometer across – may even slip through the skin, as some research suggests.
How can microplastics pose problems for humans?
Microplastics have been detected throughout the human body, including in the blood, saliva, liver, kidneys, and placenta. Microplastics smaller than 1 micrometer, known as nanoplastics, can infiltrate cells.
Microplastics can cause oxidative damage, DNA damage, and changes in gene activity, known risks for cancer development.
Microplastics may have adverse impact on reproduction such as reduced sperm count and quality, ovarian scarring, and metabolic disorders in offspring.
Findings in models show inflammation, cell death, lung and liver effects, changes in the gut microbiome, and altered lipid and hormone metabolism.
Microplastics’ physical properties are one source of potential hazards. In humans, researchers point to illnesses caused by particulate air pollution, which contains microplastics, and by workplace exposure to plastic dust.
Other threats arise from chemicals in and on microplastic particles, including plastic components — such as BPA, phthalates, and heavy metals — that are known or suspected to cause disruption to nervous, reproductive, and other systems.
One 2019 study found some adults could potentially be consuming between 39,000 to 52,000 microplastics particles a year on average, depending on their location and what they do.
How can we reduce the amount of microplastics in the environment?
A first step is for companies to stop adding unnecessary microplastics to products.
Also important is redesigning products so they contain less plastic and shed fewer plastic fibres but also are not released to the environment at end of life.
Bolstering waste collection and recycling systems would help prevent plastic products from escaping into the environment, where they break down into microplastics.
Educational campaigns aimed at raising awareness of plastics pollution and encouraging reuse and recycling of plastics.
Placing bans on microbeads.
Remediation of microplastics already in the environment is another key component of reducing microplastics pollution.
A number of bacterial and fungal species possess biodegradation capabilities, breaking down chemicals such as polystyrene, polyester polyurethane, and polyethylene. Such microorganisms potentially can be applied to sewage wastewater and other contaminated environments.
PRACTICE QUESTIONS
QUES . Consider the following: UPSC PRELIMS 2025
I. Cigarette butts
II. Eyeglass lenses
III. Car tyres
How many of them contain plastic?
(a) Only one
(b) Only two
(c) All the three
(d) None
Answer – (c) EXPLANATION: Cigarette filters are made of cellulose acetate which is a plastic and therefore contribute significantly to plastic pollution. Cellulose acetate breaks up into microplastics when it ends up in the environment. Glasses materials for lenses come in four types of plastic: polyethylene, Trivex, polycarbonate, high-index polymers, and glass. Tyre particles are a significant but often-overlooked contributor to microplastic pollution. They account for 28% of microplastics entering the environment globally. Despite the scale of the issue, tyre particles have flown under the radar.
