Bottled water exposed to sunlight releases harmful compounds, according to recent research.
Volatile Organic Compounds (VOCs) are chemicals that easily evaporate at room temperature and can be found in many products such as fuels, solvents, paints, and cleaning products. They are also present in plastics, including plastic bottles and food packaging. While many types are harmless, some can negatively impact health over the long term.
Drinking bottled water under sunlight – (Photo: Shutterstock).
In a recent study, scientists in China exposed six types of plastic bottles to ultraviolet A (UVA) rays and sunlight. All plastic bottles were made from polyethylene terephthalate (PET) – one of the most common plastics – but there were significant differences in the composition and concentration of volatile organic compounds among the bottles.
The team found that these bottles released a complex mixture of VOCs, including alkanes, alkenes, alcohols, aldehydes, and acids. This may be due to photodegradation, where the plastic structure breaks down due to exposure to sunlight.
They also found evidence of VOCs with “high toxicity,” including carcinogens such as n-hexadecane.
According to IFLScience on June 24, the risk of toxicity from drinking a sip of water is extremely low; however, prolonged exposure could lead to health risks.
“Our findings provide compelling evidence that plastic bottles exposed to sunlight can release toxic compounds that pose health risks. Consumers need to be aware of these risks, especially in environments where bottled water is exposed to sunlight for extended periods,” said Dr. Huase Ou, the lead researcher from the University of Tainan (China).
Sunlight is not the only factor to consider when using plastic bottles for drinking water. Previous studies have shown that just leaving water in a plastic bottle for one day can cause hundreds of chemicals to leach into the beverage. Some of these substances are believed to be harmful to health, including carcinogens or endocrine disruptors.
Additionally, heating plastic bottles can have serious consequences. According to a study from 2020, approximately 1.3 to 16.2 million microplastic particles per liter were released into baby formula bottles during sterilization.
The study was published in the journal Eco-Environment & Health.
