Microplastic contamination is no longer just an environmental issue; it has become a direct concern for human health. While research previously focused on the degradation of plastic in our oceans, attention is now shifting toward how these microscopic fragments infiltrate our bodies through everyday consumer products. As synthetic materials become standard in food preparation, we are beginning to realize that our reliance on plastic may be leading to significant levels of direct ingestion.

​Infants are particularly at risk, as their developing systems are highly sensitive to chemical and physical pollutants. Ironically, the heat-based sterilization methods recommended for baby bottles—typically made of polypropylene—may be the primary cause of this exposure. New evidence suggests that high temperatures trigger the release of millions of microparticles, forcing a critical re-evaluation of the safety of standard infant feeding practices.

Plastic infant feeding bottles can release up to 16 million pieces of microplastic during each use. Such bottles are routinely exposed to hot water and vigorous shaking when parents are making formula for babies. The researchers at Trinity College Dublin estimated the daily exposure of an infant up to 12-months-old ranged from 14,600 to 4.5 million microparticles. Although microplastics are found elsewhere, such as bottled water, their levels reported have been in the thousands per liter only. This means babies could be consuming doses thousands of times higher than adults.

The team assessed 10 different baby feeding bottles made from polypropylene. These are typically exposed to temperatures of up to 100°C in a cleaning procedure advised by the World Health Organization. For one product, the number of microparticles increased from around one to 55 million particles per liter, when the temperature was increased to 95°C. ‘Although it is too early to make a policy based on this single study, the results ring an alarm, according to an ecotoxicologist at the University of Southern Denmark.

The study will be ‘pretty concerning’ for parents. However, frustratingly, scientists also do not know what this means toxicologically, because there are so few studies on the health impacts of microplastics. Still, the scientists offer advice for parents. Formula should be prepared with hot water that is at 70°C or higher in a non-plastic container. When it has cooled, the formula can be transferred to the plastic bottles.

Adapted from www.chemistryworld.com