WHO reviews risk to humans of microplastics found in bottled water

Scientists have found more than 90 per cent of bottled water tested in a recent study was contaminated with microplastics, prompting the World Health Organisation (WHO) to review the risk to human health of drinking water with plastic particles.

Credit: Tarasyuk Igor/Shutterstock

Scientists at State University of New York tested 259 bottles of water from 11 brands bought from nine countries including the US, and found 93 per cent of the bottled water had microplastics.

As much as 10,000 tiny pieces of plastic were found in a litre of water. Twice as much plastic was found in branded bottles of water, than the amount found in tap water.

The findings have led the WHO to launch a review to consider the impact of microplastics in drinking water and whether a lifetime of drinking or eating particles of plastic could threaten people’s health.

Separate study: microplastics altered fishes’ brains

While no data is available to link microplastics to human health conditions such as dementia, in a separate study scientists discovered it can be absorbed into fishes’ brains, changing their behaviour in potentially harmful ways.

According to a peer-reviewed paper published in September 2017 by Scientific Reports, the tiniest bits of marine plastic pollution – called nanoplastic – were found to move up the aquatic food chain and reach predators’ brains, affecting their ability to hunt.

Researchers fed bits of nanoplastic (undetectable by the naked eye) to daphnia, a type of freshwater zooplankton.

When some of the plastic-contaminated daphnia was then fed to freshwater carp, researchers monitored the hunting behaviour of the fish by video recording them and found the fish began exhibiting unusual behaviours.

Bits of polystyrene were found in the brains of the carp which were fed with the nanoplastic-contaminated daphnia. (The nanoplastic did not appear in the brains of carp given ‘untainted’ daphnia). Scientists said the nanoplastic inside the daphnia was absorbed by the body tissues of predators and passed into the brain, where it affected their behaviour.

“A change in a fish’s hunting behavior may cause reduced growth and a decrease in their ability to avoid predators,” said Karin Mattsson, an author of the study and postdoc at the University of Gothenberg.

'Anxiety-like' behaviours in fish later in life

Neel Aluru, a biologist at Woods Hole Oceanographic Institution, has studied how early-life exposure to toxic chemicals in zebrafish may lead to developmental disabilities.

He has looked at how chemicals added to plastics during production (polychlorinated biphenyls (PCBs) affect behaviour in zebrafish and discovered fish exposed to PCB-contaminated water exhibit anxiety-like behaviors later in life.

The brains of these fish also show molecular variation, suggesting changes in their genetic code.

Plastics production rose to more than 300 million tons in 2014, according to PlasticsEurope (2015). The amount of plastics entering the ocean in 2015 was estimated to be as much as 12.7 million tons.

Referring to his zebrafish research, Mr Aluru told News Deeply: “Future research should look at how nanoplastic particles reach the brain.

“Where are they in the brain and how do they affect behaviour? I don’t doubt that plastic particles are toxic but it is important to show all the results clearly.”

To read the bottled water study by State University of New York organised by Orbmedia visit: https://orbmedia.org/sites/default/files/FinalBottledWaterReport.pdf

To read the peer-reviewed paper on daphnia and carp fish published by Scientific Reports visit: www.nature.com/articles/s41598-017-10813-0