Experts warn against drinking from plastic water bottles

There’s a never-ending stream of fresh warnings about how everyday items are ruining our health, and now plastic water bottles are on the list of things to avoid.

Before we go any further, this isn’t a warning against drinking water. You absolutely should drink the recommended minimum of two litres of water per day, and you’ll need to drink more if you’re physically active to avoid getting dehydrated.

Dehydration has a host of nasty consequences in the short and long terms, so drink up!

But maybe don’t do that from a plastic bottle.

You may already have swapped to a reusable, metal water bottle as a way to cut down on your personal plastic waste, but now there’s the added benefit of protecting your own health.

A 2024 study by Columbia University found that as many as 240,000 nanoplastic particles are found in the average litre of bottled water.

By comparison, there are 5.5 of these per litre of tap water.

Nanoplastics have been linked to cancer, birth defects and fertility issues, and they’re smaller than the microplastics we often hear about in the news.

The trouble with nanoplastics over their micro cousins is that they’re small enough to directly enter blood cells and the brain.

Researchers discovered these nanoplastics by analysing samples from three popular bottled water brands in the US.

The plastics used to make water bottles typically contain phthalates, and those have been linked to 100,000 annual premature deaths in the US.

Photo by Matthew Horwood/Getty Images

The US’s National Institute of Environmental Health Sciences said that phthalates are”'linked with developmental, reproductive, brain, immune, and other problems”.

Researchers were confident they would find these nanoplastics before beginning the research, owing to these bottles’ use of phthalates.

"This was not surprising, since that is what many water bottles are made of,” said study co-author Beizhan Yan, an environmental chemist at Columbia University’s Lamont-Doherty Earth Observatory.

"PET is also used for bottled sodas, sports drinks, and products such as ketchup and mayonnaise.

"It probably gets into the water as bits slough off when the bottle is squeezed or gets exposed to heat."

Another type of plastic particle found in the same was polyamide, a type of nylon, with those particles outnumbering those from polyethylene terephthalate (PET).

"Ironically, this probably comes from plastic filters used to supposedly purify the water before it is bottled," Yan added.

“Previously this was just a dark area, uncharted. Toxicity studies were just guessing what’s in there.

"This opens a window where we can look into a world that was not exposed to us before."

Naixin Qian, a Columbia graduate student in chemistry and the study’s lead author, said: “People developed methods to see nano particles, but they didn’t know what they were looking at.”

The researchers have since expanded their research beyond water bottles.

Bastiaan Slabbers/NurPhoto via Getty Images

“There is a huge world of nanoplastics to be studied,” said one of the researchers. “By mass, nanoplastics comprise far less than microplastics.”

However: “it’s not size that matters. It’s the numbers, because the smaller things are, the more easily they can get inside us."

So, how can you avoid ingesting these nefarious little plastics?

Simplex Health says “the only guaranteed way to get pure water is through steam distillation by using a water distiller”.

It added: "Distilled water is 99.8 percent pure, which means it is purer that any bottled or tap water and purer than using any other type of filtration or purification method. Water is gently boiled to kill off viruses and bacteria.

"The steam produced is captured in a stainless steel coil where it cools to form pure water.