For millions, a warm cup of tea is the perfect way to start the day. But recent research might prompt a second thought before brewing your next pot.

Scientists from Universitat Autònoma de Barcelona have discovered that a single tea bag can release billions of microplastics into your drink. Alarmingly, these tiny plastic particles are not just passing through the body; some are absorbed by mucus-producing cells in the intestine, and a few can even penetrate the cell nucleus, which houses our genetic material.

While the long-term effects of ingesting microplastics remain uncertain, researchers are growing increasingly concerned. "The potential health implications of environmental micro/nanoplastics (MNPLs) are increasingly concerning," the team stated in their findings, published in the journal Chemosphere. They also noted that food packaging, including tea bags, may be a significant source of these contaminants.

Microplastics in tea bags: a closer look

To explore the extent of the issue, the researchers analyzed three common types of tea bags:

- Nylon tea bags ordered from Amazon

- Polypropylene tea bags from AliExpress

- Supermarket tea bags with an unknown filter polymer.

Each tea bag type was steeped in near-boiling water (95°C) to mimic real-world brewing conditions. The results were shocking: all three released vast quantities of nano-sized plastic particles into the water.

Polypropylene tea bags were the worst offenders, releasing around 1.2 billion particles per milliliter, with an average size of 136.7 nanometers.

Nylon tea bags released 8.18 million particles per milliliter, averaging 13.8 nanometers in size.

The impact on human cells

To understand the potential risks, the researchers stained the microplastics and exposed them to various types of human intestinal cells. The mucus-producing cells showed the highest uptake of these particles. More worryingly, some microplastics managed to infiltrate the cell nucleus, potentially disrupting cellular functions.

Microplastics have previously been linked to health risks, including early-onset cancer. Earlier studies showed that gut cancer cells proliferate faster after exposure to these particles. However, much remains unknown about how chronic exposure to microplastics affects human health, particularly in vulnerable groups like children.

 Calls for action

The findings add to a growing body of evidence suggesting that plastic pollution poses a significant threat to human health. Maria Westerbos, co-founder of the Plastic Health Council, emphasized the urgency of addressing the issue:
"Time and time again, scientists reveal the dangerous effects of plastics on health. Policymakers must stop ignoring the evidence and act before it’s too late."

With the final negotiations for a Global Plastics Treaty approaching, researchers are urging immediate action to reduce plastic use in food packaging and tea bags. They also call for further research to fully understand the health risks posed by microplastics.

"As the use of plastics in food packaging continues to rise, scientific research and policymaking must address the challenges posed by MNPL contamination to ensure food safety and consumer well-being," the researchers concluded.

This study serves as a stark reminder of the hidden dangers in everyday items and underscores the need for urgent solutions to curb plastic pollution. For tea lovers, it might be time to consider alternatives like loose-leaf tea or biodegradable tea bags.