The Atlantic Ocean contains 12-21 million tonnes of microplastics — about 10 times higher than previously determined — according to new research published in Nature Communications.

Highlights of the report

• In the study, scientists studied pollution of the Atlantic Ocean caused by three types of plastics: polyethylene, polypropylene, and polystyrene, which were suspended in the top 200 metres of the ocean.
• These three types of plastic are most commonly used for packaging.
• Scientists say that pollution caused by microplastics has been “severely” underestimated in previous assessments.
• They also estimate that based on plastic waste generation trends from 1950-2015 and considering that the Atlantic Ocean has received 0.3-0.8 per cent of the global plastic waste for 65 years.
• To date, a key uncertainty has been the magnitude of contamination of the ocean and our findings demonstrate that this is much higher in terms of mass than has been estimated previously.

Try this PYQ:

Q. Why is there a great concern about the ‘microbeads’ that are released into the environment? (CSP 2019)

(a) They are considered harmful to marine ecosystems.

(b) They are considered to cause skin cancer in children.

(c) They are small enough to be absorbed by crop plants in irrigated fields.

(d) They are often found to be used as food adulterants.

What are Microplastics?

• Microplastics are plastic debris smaller than 5mm in length, or about the size of a sesame seed.
• While they come from a variety of sources, one of them is when larger pieces of plastic degrade into smaller pieces, which are difficult to detect.

How does plastic reach the oceans?

• There are multiple pathways for them to reach the oceans.
• For instance, riverine and atmospheric transport from coastal and inland areas, illegal dumping activities and direct-at-sea littering from shipping, fishing and aquaculture activities, scientists have said.
• According to the IUCN, at least 8 million tonnes of plastic end up in the oceans every year and makes up about 80 per cent of all marine debris from surface waters to deep-sea sediments.

Why is plastic pollution especially harmful?

• Plastic can take hundreds to thousands of years to decompose depending on the type of plastic and where it has been dumped.
• Some marine species such as zooplanktons show preferential ingestion of smaller particles, making them easier to enter the food chain and their conversion to fast-sinking faecal pellets.
• Over the past few years, various news reports have shown that marine animals such as whales, seabirds and turtles unknowingly ingest plastic and often suffocate to death.
• While all sorts of marine species are prone to get impacted by plastic pollution, typically, bigger marine species tend to get more attention because of the amounts of debris they can hold up.

Impact on humans

• For humans, too, marine plastic pollution is harmful if it reaches the food chain. For instance, microplastics have been found in tap water, beer and even salt.
• One of the first studies to estimate plastic pollution in human ingestion that was published in June 2019 said that an average person eats at least 50,000 particles of microplastic each year.
• Consumption of plastic by humans is harmful since several chemicals that are used to produce plastics can be carcinogenic.
• Even so, since microplastics are an emerging field of study, its exact risks on the environment and human health are not clearly known.

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