A new study reported in BMJ Global Health is highlighting the significant cost of bottled water. The study has estimated that about one million bottles of water are sold around the planet every minute, with demand expected to increase. Although many people need bottled water because they cannot access it regularly at their homes, others in wealthier countries often simply purchase bottled water for the sake of convenience. Many bottled water consumers also think, mistakenly, that bottled water is significantly healthier than (filtered) tap water.
But studies have shown that most bottled water contains microplastics, although estimates have indicated that anywhere from ten percent to 78 percent of bottled water brands contain microplastics.
A recent study in the Proceedings of the National Academy of Sciences showed that bottled water carries anywhere from 110,000 to 370,000 tiny plastic particles per liter, with ninety percent of those particles being made up of nanoplastics and ten percent being microplastics. Nanoplastics are smaller than one micrometer.
The plastics included polyethylene terephthalate (PET), bisphenol A (BPA), a type of nylon called polyamide, and other known chemicals, but many nanoplastics were unknown chemicals; there could be anything contaminating our bodies and environment. This study also emphasized that bottled water contains much higher levels of microplastics than tap water.
The health impacts of microplastics are still being investigated, but they have been found everywhere from plants, to the air, to the human placenta, and common sense would suggest that it probably isn't having a positive impact. Plastic is also known to contain chemicals like BPA, which can mimic natural hormones called endocrines. BPA exposure has been associated with a variety of negative health impacts.
The plastic bottles are also a major problem for the environment. The relatively recent invention of plastic means most of it has been generated in the past few decades. But it now accounts for about ten percent of total global waste.
The study authors noted that our increasing reliance on and consumption of bottled water is detrimentally affecting our health and the environment; they suggested that people and governments should start to prioritize tap water consumption.
Another recent study in PLOS Water examined the various levels of different chemicals in bottled and tap water in the San Francisco Bay Area.
The researchers assessed many samples of three types of water: 100 samples of bottled water, 603 samples of tap water, and 111 samples of Brita-filtered tap water. The study showed that almost all the water samples that were tested met health standards for drinking water that are set by the US government.
The work also found that when it came to other chemical contaminants of water, the bottled water and Brita-filtered tap water were about comparable. However, unfiltered tap water did carry significantly higher levels of trihalomethanes, which are generated when water is disinfected with chlorine, a common method in water systems. These chemicals were also still found in all of the water types that were tested, including bottled water, at varying levels.
The study authors were not setting out to cause alarm, they noted. They simply are suggesting that tap water is probably improved with a filter like Brita, or something comparable. The work also shows that filtered tap water is basically just as good as bottled water, so people don't have to keep buying it if they think it carries lower levels of certain chemicals.
Sources: BMJ Global Health, Proceedings of the National Academy of Sciences, PLOS Water