in englischer Sprache
Montag, 2. Mai 2022, 20-21h
Sprecher: Prof. Dr. Lukas Kenner, MedUni Wien
Five grams of plastic particles on average enter the human gastrointestinal tract per person per week. This is roughly equivalent to the weight of a credit card. Whether ingested micro- and nanoplastics (MNPs) pose a health risk is being investigated in numerous studies but is largely unknown to date.
MNPs enter the food chain from packaging waste, among other sources. The plastic particles are not only trafficked into the body via food such as marine life or sea salt in particular, drinking also plays a part. According to a study, anyone who drinks the recommended 1.5 to two liters of water a day from plastic bottles ingests around 90,000 plastic particles per year in this way alone. However, those who choose tap water can, depending on their geographical location, reduce the amount ingested to 4,000 plastic particles. Researchers also demonstrated widespread contamination of mineral water with xenohormones leached from PET (polyethylene terephthalate) bottles. Xenohormones are known to exhibit oestrogenic activity which can act carcinogenic in the body.
Medical research on the topic centers on the digestive system where MNPs can be found in tissue. Experimental studies indicate that ingested MNPs passing through the gastrointestinal tract lead to changes in the composition of the gut microbiome. Such changes are associated with the development of metabolic diseases such as diabetes, obesity or chronic liver disease. In addition to the effects on the gut microbiome, scientists also described specific molecular mechanisms that facilitate the uptake of MNPs into gut tissue. Using specific analyses, it was shown that MNPs in the gastrointestinal tract could increasingly be taken up into tissue under certain physicochemical conditions and activate mechanisms involved in local inflammatory and immune responses. Nanoplastics in particular are associated with biochemical processes that are crucially involved in carcinogenesis.