A recent study has probed the presence of microplastics in the samples of water collected from 11 different locations across the coastal state of Goa and has concluded that the plastic impurity is significantly present in all of them.

The study titled ‘Clean Drinking Water: A pipe dream? — Assessment of Microplastics In Tap Water from Different Water Sources in Goa’ was conducted by Toxics Link — a Delhi-based non-profit in February this year. The testing of the samples was carried out by the Goa-based National Institute of Oceanography (NIO). 

“The size of microplastics ranged from < 20 µm (less than 20 micrometers; 1 millimeter =1000  µm) to 1000 µm, while microplastics smaller than 100 µm were dominant. Fibre was the most dominant category found in both tap water and treatment plant samples, ” Mahua Saha, the lead researcher from NIO was quoted.

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For the study, a total of 11 water samples were collected from different locations across Goa. Out of 11 water samples, five tap water samples were collected from residential areas of Margao, Panjim, Mapusa, Marcel and Canacona. The remaining six samples were collected from three different water treatment plants (WTPs), Assonora, Opa and Salaulim, both pre-treated and post-treated. 

“Samples from WTPs were taken to understand the level of pollution of MPs in the water source and also if the treatment resulted in some change. The source of the tap water sample for Mapusa is from Assonora WTP, Panjim and the Marcel tap water source is from Opa WTP and Margao tap water source is from Salaulim WTP. However, WTP related to Canacona tap water samples could not be collected and analyzed,” the report stated.

What exactly are microplastics?

Particles of plastics of sizes less than five millimeters are termed as microplastics.  They are highly persistent in the environment and are, therefore, accumulating in different marine ecosystems at increasing rates. 

“As a new type of pollutant, microplastics have received some attention in recent years and have been recognized as emerging marine pollutants of significant concern, due to their persistence, ubiquity and toxic potential,” the study noted.

What did the study find?

The study found that every sample (both from tap water sources and water treatment plants) had an ‘abundance’ of microplastics present in it. 

“Shockingly, MPs (microplastics) collected from different WTPs. Though their number varied, their presence, especially in tap water samples, raises serious concern about microplastic exposure for the residents,” the study highlighted.

Primary microplastics, secondary microplastics

Microplastics can be classified as primary and secondary microplastics. The primary microplastics are produced by the unintentional release of intermediate plastic feedstock (such as pellets, nurdles or microbeads from personal care products). Examples of primary microplastics include microbeads found in personal care products, plastic pellets (or nurdles) used in industrial manufacturing and plastic fibres used in synthetic textiles. 

Secondary microplastics are defined as fragments of larger plastic items that suffer fragmentation, found both in marine and terrestrial habitat. Weathering also causes the breakdown of large plastic into tiny fragments. Another process that causes breakdown of large plastic pieces into smaller pieces is ‘photodegradation’ by ultraviolet radiation from sunlight.

Is there a link between consuming microplastics and human health?

The study mentioned that once ingested through tap water, there is the potential for exposure to chemical contaminants absorbed to the microplastics and any additives in microplastics.

“Therefore, microplastics may cause toxicity in the human body, and microplastics in tap water should not be overlooked. Although the water treatment process may reduce a portion of the microplastics, some microplastics still remain in tap water,” it stated.

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However, the study also mentioned that there is no documented evidence till date that ingesting microplastics can directly harm human health but it underlined that the potential threat of microplastics cannot be ignored. 

What does the study recommend?

The study highlighted that there is dearth of enough research on the subject of microplastics and made following recommendations:

• Plastic-packaged drinking water bottles, packed food and beverages should be studied further for the presence of microplastics and smaller nanoplastics. 

• The occurrence of microplastics pollution in different commercial products such as flavored coffee drinks and vitamin water still requires additional research.

• The presence of microplastics in the body or in scuba divers or water sports trainers needs to be researched.

• Investigating MPs removal by distinct treatment steps at DWTPs (drinking water treatment plants) working under ordinary conditions is required.

• Possible water enrichment of MPs during the conventional treatment processes at DWTPs needs further investigation

• Optimising current treatment technologies or inventing new processes aimed at the removal of MPs or their problematic fractions that would remain in treated water after passing through an unaltered process ought to be looked at.