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Earth Day 2024: Are You Drinking Too Much Plastic?

Every year, 12 million tonnes of plastic find its way into our oceans. A large amount of this is filtered out, but there is still a small percentage of microplastics that make their way into our drinking water.

This Earth Day, the theme is Planet vs. Plastics and the impact plastic pollution is having on our planet. For decades we have known that over production of plastic waste is harming our environment, but in recent years we have also learned the damage this could be doing to our bodies.

What are microplastics?

Microplastics are extremely small pieces of waste plastic, less than 5mm in size, that are created from the disposal and breakdown of consumer products and industrial waste. Despite their size, microplastics have a colossal impact on our ecosystems, infiltrating our oceans, drinking water and even the air that we breathe.

Recent studies have shown that a small percentage of microplastics are making their way into our drinking water, as they are able to bypass conventional filtration processes. However, very little is known about the effect microplastics are having on the human body, if any at all.

What kind of microplastics are being found?

Within drinking water, fragments and fibres were predominant particle shapes and polyethylene terephthalate and polypropylene were the polymers most detected. Polyethylene terephthalate (PET) and polypropylene are both mainly used in applications of packaging and textile production.

Who is contributing to the growing totals of microplastics in our drinking water?

The World Health Organisation attributes the ever-increasing amount of microplastics found in our water to a number of factors including “surface run-off (e.g. after a rain event), wastewater effluent (both treated and untreated), combined sewer overflows, industrial effluent, degraded plastic waste and atmospheric deposition”.

There is also the possibility that plastic bottles and caps could also be contributing to microplastics entering the contained water inside and therefore being consumed.

What are the potential hazards of consuming microplastics?

Microplastics may present potential hazards from chemical exposure, particle impacts and potential microbial threats within biofilms. Particle characteristics such as size, surface area, and shape will influence their impact on the body, however due to the lack of human studies carried out, the full extent of the risks associated with consumption are fully understood.

While plastic polymers are generally deemed low in toxicity, they can harbour unbound monomers and additives. Additionally, hydrophobic chemicals, including persistent organic pollutants, may adhere to plastic particles and make their way into the body.

Biofilms, which are formed by microorganisms in drinking-water systems, predominantly consist of non-pathogenic species, yet some can harbour harmful pathogens like pseudomonas aeruginosa and legionella, both of which can lead to pneumonia and other serious health conditions.

It is important to keep in mind that without enough human trials carried out with satisfactory quality control, studies associated with microplastics cannot be deemed fully reliable and any results should be interpreted with caution.

What can be done to reduce the amount of microplastics in water?

Treatment systems are highly effective in removing similar particles from drinking water and wastewater, with drinking water filtration methods proving that they can remove similar particles of much smaller sizes and at higher concentrations than those of microplastics. These methods will continue to advance and evolve as our knowledge on the existence and effects of microplastics grows.

Water suppliers and regulators should continue to priories the removal of any microorganisms and chemicals that pose a concern to public health and ensure that water treatment processes are optimised and used efficiently.

What can I do?

The WHO have also advised that routine monitoring of microplastics in drinking water is not currently recommended, as there is no evidence to indicate a human health concern. However, there is work that can be done to reduce the amount of single use plastic products currently in production and turn to more sustainable options.

Choosing to invest in reusable metal straws and cups rather than single use plastic options is just one of the small ways you can contribute to removing the need for overproduction of plastic goods ending up in our oceans.