2026年天津（第二次） Passage D

In a groundbreaking new study, researchers discovered bottled water sold in stores can contain 10 to 100 times more bits of plastic than previously estimated — nanoplastics (纳米塑料) are so tiny that they cannot be seen under a microscope.

Nanoplastics are just 1/1000th the width of an average human hair — so tiny that experts say they can migrate through the tissues of the digestive tract (消化道) or lungs into the bloodstream, distributing potentially harmful artificial chemicals throughout the body and into cells.

One liter of water — equal to two standard- size bottled waters — contained an average of 240,000 plastic particles (粒子) from seven types of plastics, of which 90% were identified as nanoplastics and the rest were microplastics, according to the new study.

Microplastics are polymer fragments that can range from less than 0.2 inch (5 millimeters) down to 1/20000th of an inch (1 micrometer) . Anything smaller is a nanoplastic that must be measured in billionths of a meter.

In the new study, published Monday in the journal Proceedings of the National Academy of Sciences, researchers from Columbia University presented a new technology that can see, count and analyze the chemical structure of nanoparticles in bottled water.

Instead of 300 per liter, the team behind the latest study found the actual number of plastic bits in three popular brands of water sold in the United States to be in between 110,000 and 370,000, not higher.

“The innovative techniques presented in the study open the door for further research to better understand the potential risks to human health.” said Jane Houlihan, research director for Healthy Babies, Bright Futures — a nonprofit committed to reducing babies’ exposures to neurotoxic (毒害神经的) chemicals, who was not involved in the study.

“Infants and young children may face the greatest risks, as their developing brains and bodies are often more vulnerable to impacts from toxic exposures.” said Houlihan in an email.

Nanoplastics are the most worrisome type of plastic pollution for human health, experts say. That’s because the particles can invade individual cells and tissues in major organs, potentially interrupting cellular processes and depositing harmful chemicals such as bisphenols, phthalates, PFAS, and heavy metals.

There are things people can do to reduce their exposure to plastics, said Houlihan. “We can avoid consuming foods and drinks in plastic containers. We can wear clothing made from natural fabrics and buy consumer products made from natural materials,” Houlihan said. “We can simply assess the plastic in our daily lives and find alternatives whenever possible.”