Scientists from Nanjing University and the University of Massachusetts Amherst in China discovered that steam disinfection of siliconerubber baby bottles nipples exposes children and the environment to microplastic and nanoplastic particles.
These very fine particles pose health and environmental risks. However, microplastic pollution has become a growing global concern. This new source of microplastic pollution was discovered by the researchers.
Baoshan Xing is a professor of environmental and soil chemistry at the UMass Amherst Stockbridge School of Agriculture. He was also co-author of the research published in the journal. Nature Nanotechnology.Conventional techniques cannot detect these tiny particles. The more small the particles, the greater the physiological effect.
Xing worked with Yu Su, the lead author, and Rong Ji, the co-corresponding author. They are both environmental scientists at Nanjing University’s School of the Environment.
Su says that silicone rubber was once considered a thermally stable polymeric substance. However, it has undergone aging after repeated moist heat sterilizations. “The environment is a major source for microplastics due to the aging and decomposition plastics. We proposed and confirmed that silicone rubber can be decomposed by moist heating to microplastics, even nanoplastics (< 1 µm)."
Previous research by Xing (who has been named to an annually updated list of the most cited researchers each year since 2014) and colleagues in China revealed that nanoplastics are both internalized and reduced in lipid digestion in a simulated human gastrointestinal tract.
Traditional techniques cannot detect particles smaller that 20 micrometers. This is approximately half the thickness of a human hair. Nanjing University researchers examined rubber nipples with optical photothermal imaging (O-PTIR), microspectroscopy. This is a new technique that can analyze a material’s composition, morphology, and other aspects.
The microspectroscope showed numerous flake- and oil-film-shaped microplastics in the wash water of the steam-disinfected rubber nibles. The technique also showed submicrometer-resolved steam etching on and chemical modification of the nipple surface.
“The results indicated that by the age of one year, a baby could ingest >0.66 million elastomer-derived micro-sized plastics (MPs)… Global MP emission from teat disinfection may be as high as 5.2 × 1013 The research paper says that particles are produced every year.
Xing and colleagues point out that similar silicone-rubbed-based consumer products, including bakeware and sealing rings in cups and cooking appliances, are also likely to produce micro- and nanoplastic particles when heated at or above 100 degrees C. They will continue their research into the release of particles into the environment from various plastic objects.
Xing states, “We have identified a significant new source for microplastics in the environment.” Some plastics end up in the sewer systems. They end up in the water and land fills. Because they don’t readily decompose, they have a very long life expectancy in the environment.
Rong Ji from Nanjing University says, “The behavior of these silicon rubber-derived nano- and microplastics within the environment are unclear.” Further research is needed in order to understand their potential dangers to the environment and humans.