In a surprising twist to growing concerns over plastic pollution, drinks stored in glass bottles may actually contain more microplastics than those in plastic containers, according to a new study by France’s food safety agency ANSES.
Researchers found that beverages like soda, iced tea, beer, and lemonade packaged in glass bottles had up to 100 microplastic particles per liter — significantly higher than the levels found in plastic bottles or metal cans, which ranged five to fifty times lower.
“We expected the opposite result,” Iseline Chaib, a PhD student who helped lead the research, said in an AFP report. The team discovered that the plastic particles in glass bottle samples closely matched the color and composition of the paint used on the caps. Microscopic scratches caused by friction between bottle caps during storage may be responsible for releasing these particles.
Guillaume Duflos, research director at ANSES, noted that the aim was to examine how packaging materials influence microplastic contamination in drinks sold in France. While the study revealed a notable presence of microplastics, especially in glass containers, ANSES emphasized that no threshold has been established to define what might be harmful to health.
Water and wine showed relatively low microplastic levels across all types of packaging, with sparkling and still water in plastic bottles having as little as 1.6 particles per liter. Interestingly, even wine in glass bottles had minimal contamination, though researchers could not yet explain why.
As a preventive measure, ANSES tested a method to clean bottle caps using air and alcohol, which successfully reduced microplastic levels by about 60%.
The findings were published last month in the Journal of Food Composition and Analysis, underscoring the need for continued research into the health implications of microplastic exposure and urging manufacturers to take practical steps in reducing contamination.
