You may think that drinking bottled water is a healthier choice than tap water, but a new study has found that you may be swallowing more than just water. According to the study, published in the journal Proceedings of the National Academy of Sciences, the average liter of bottled water contains about 240,000 plastic particles, most of them invisible to the naked eye.
These particles, known as microplastics, are smaller than one micrometer, or one millionth of a meter, and can pass through the intestine and lungs into the bloodstream and organs.
The study, led by scientists from Columbia University and Rutgers University, used a newly developed laser technology to detect and categorize the microplastics in three popular brands of bottled water (the brands were not named). They found that about 90% of the particles were nanoplastics, which are even smaller than microplastics and can cross the blood-brain barrier and the placenta. The most common types of plastics found in the bottled water were polyethylene terephthalate (PET), which is used to make the bottles, and nylon, which may come from the filters used to purify the water.
The researchers compared the levels of microplastics in bottled water with those in tap water, seafood, and table salt, and found that bottled water had the highest concentration of microplastics among these sources. They also found that the shape of the microplastics mattered: irregularly shaped particles caused more cell death than spherical ones, suggesting that they may be more harmful to human health.
The health effects of microplastics on humans are still unclear, as there is not enough evidence to link them to any specific diseases or disorders. However, some studies have suggested that microplastics may interfere with hormone function, cause inflammation, trigger allergic reactions, and act as endocrine disruptors. Some experts have also raised concerns about the chemicals that may leach from the plastics, or the bacteria and viruses that may attach to them.
The authors of the study said that their findings were not alarming, but rather a cause for concern. They said that more research is needed to understand how microplastics affect the human body, and how long they stay in the body before being excreted. They also said that the best way to prevent microplastic exposure is to reduce plastic waste and improve recycling. In the meantime, they said that they have cut back on their own consumption of bottled water.