Plastic pollution, a little-recognized health threat

Plastic pollution is a still largely unrecognized threat to human health, warns an international group of experts in The Lancet . Its impact, they emphasize, extends from childhood to old age, particularly affecting the poorest populations. The warning comes just ahead of the final negotiations of the Global Plastics Treaty , taking place in Geneva from August 5 to 14, which seek a legally binding international agreement to curb this environmental crisis.

One of the biggest risks comes from microplastics, tiny particles invisible to the naked eye that are found virtually everywhere: from oceans and food to the air in our own homes and cars. Research from the University of Toulouse , published last week in the journal Plos One , revealed that we can inhale up to 68,000 microplastics a day in indoor spaces, a figure 100 times higher than previous estimates.

The team, led by researcher Nadiia Yakovenko, used Raman spectroscopy to analyze 16 samples of domestic and vehicle air, finding concentrations of up to 2,238 particles per cubic meter inside cars and 528 in homes. Ninety-four percent of these particles were smaller than 10 micrometers, allowing them to penetrate deep into the respiratory system. "We were surprised to find so many microplastics in places we usually consider safe, like our own homes or cars," Yakovenko said.

These particles are not harmless. They release toxic additives such as bisphenol A and phthalates, which can enter the bloodstream and are linked to respiratory problems, hormonal disorders, infertility, neurological disorders, and some types of cancer. Recent studies have even detected microplastics in human reproductive fluids, opening up new lines of research into their potential impact on fertility.

Anna Sanchez-Vidal, a professor at the University of Barcelona and a member of the Scientists' Coalition for an Effective Plastics Treaty , points out that global plastic production could triple between 2019 and 2060 if urgent measures are not taken. "The associated damage is not inevitable. It can be mitigated with evidence-based laws and policies, with transparent monitoring and adequate funding," she tells the Science Media Centre.

However, some scientists, such as Roberto Rosal, a professor at the University of Alcalá, urge caution in the face of certain excessively alarmist messages: " There is no general evidence that plastics cause direct illness and death , nor that the production projections of 1,200 megatonnes by 2060 are realistic. Even so, plastic waste pollution is a real and serious problem that requires effective solutions."

The new Lancet Countdown on Health and Plastics project will monitor the health and environmental impacts of plastics throughout their life cycle. Its first report will be published in 2026, with the aim of providing scientific data to guide public policy, in parallel with the implementation of the Global Plastics Treaty.

Meanwhile, evidence about the risks of inhaling microplastics continues to grow. As Yakovenko warns: "We spend 90% of our time indoors and are constantly exposed to these pollutants without realizing it."