A woman drinking bottled water after a workout.
Ever since bottled water became popular in the 1990s, there has been a vigorous debate over whether it's healthier to drink bottled water or tap water. Bottled-water aficionados often claim it's purer than tap water because it's traditionally marketed as being "from the source" or having come from an untouched stream. That has to be cleaner than water that reaches your home after traveling from God-knows-where through city pipes, right?
What many people don't realize is that bottled water isn't regulated as stringently as tap water. Tap water is overseen by the Environmental Protection Agency (EPA), which requires more frequent testing and stricter disinfection standards. Bottled water is regulated by the Food and Drug Administration (FDA) as a food product.
Tap water found to have fewer microplastics than bottled water
A recent study from The Ohio State University (OSU) delivered another big victory for Team Tap, finding that after testing six brands of bottled water against tap water from four water treatment plants, bottled water contained more than three times as many microplastics as tap water. The big problem is that plastic bottles can shed tiny plastic particles, smaller than a speck of dust, into the water when temperatures change, the cap is removed, or the bottle tumbles around in a purse or the back seat of a car.
A boy drinking from the kitchen sink.via Canva/Photos
The tests revealed that the amount of microplastics in bottled water ranged from 2.6 to 11.5 million particles per liter, while tap water ranged from 1.6 to 2.6 million particles per liter. In the best-case scenario, tap water contains similar levels of microplastics, but in the worst-case scenario, bottled water contains more than seven times as many.
The researchers were surprised by their findings because nanoplastics are so small that they've been hard to quantify in the past.
"This lack of knowledge primarily reflects limitations in the methods to isolate and analyze the nanoplastics," said Megan Jamison Hart, a PhD candidate at OSU and the study's lead researcher. "In this study, we developed and validated a novel method for isolating MNPs [micro- and nanoplastics], allowing for the determination of their concentrations using scanning electron microscopy and identification using optical photothermal infrared spectroscopy (OPTIR)."
Are microplastics harmful to humans?
Much more research on microplastics is needed to determine their potential harm to humans. Studies have linked microplastics to impaired immune function, increased inflammation, and cellular damage in animals. Researchers believe that larger nanoplastics pass through the digestive tract and are eventually excreted. Smaller nanoplastics, however, may move into human tissues and even enter the brain.
"While we don't really fully understand the human health risks associated with nanoplastic exposure, it's still better to try and mitigate that risk because evidence indicates that they do cause problems, even if we're not fully aware of what those are yet," said Hart.
A woman drinking out of a plastic water bottle. via Canva/Photos
Given that scientists have yet to determine the harm that micro- and nanoplastics can cause in our bodies, they believe it's best to avoid them as much as possible.
"We can make educated choices to try and reduce our daily exposure to these harmful chemicals," said Hart. "For the average person who is thirsty and wants a drink, the best way to do that would be drinking it straight out of the tap rather than grabbing pre-bottled water."
Hart told StudyFinds that the best thing to do is ditch bottled water and instead drink filtered tap water from a reusable metal bottle.
"This has definitely changed my own drinking habits," she said. "I was primarily a tap water drinker before, knowing that disposable bottles were bad for the environment, but this is something I am even more adamant about now, and I swapped my reusable plastic bottle for a reusable metal one."