MICROPLASTICS
I have been reading an article in Toxicological Sciences, Microplastic presence in dog and human testis and its potential association with sperm count and weights of testis and epididymis Get access Arrow saying that microplastics are finding their way into the testicles of dogs and human beings. If true this is alarming.
Some of the microplastics found in the environment are coming from tyres and man-made fibres, and recycling can also be a source of microplastics, but most of the microplastics found in the environment are caused by the fragmentation of ordinary plastic when exposed to sunlight.
These fragments are very persistent because their molecular weight is too high for microbes to consume them. The consequence of this is that they persist in the environment for a very long time, getting smaller and smaller until they are small enough to get into our food and into our bodies.
It will be a very long time before we succeed in keeping plastics out of the open environment, even in the developed world, so the only way to prevent plastic in the environment from accumulating there for decades is to make the plastic products with a d2w masterbatch, at little or no extra cost. The molecular weight will rapidly reduce, and they will then biodegrade and be removed by bacteria and fungi. https://www.symphonyenvironmental.com/why-biodegradable/
There is another article in Chemosphere, Vol. 353 (Apr 2024) 141463 saying that microplastics affect cell-migration and distribution during cancer-cell division.
It seems to me that it is really urgent now to start making all short-life plastic products with a d2w masterbatch. There is no time to lose.
OXO-DEGRADABLE and OXO-BIODEGRADABLE
“Oxo-degradation” is defined by CEN (the European Standards authority) in TR15351 as “degradation resulting from oxidative cleavage of macromolecules.” This describes ordinary plastic, (which does not contain an intentionally-added prodegradant catalyst). It will abiotically degrade by oxidation in the open environment and create microplastics, but does not become biodegradable except over a very long period of time. It is well known that fragmentation is accelerated by colorants and other additives, but they do not cause biodegradation.
By contrast, “oxo-biodegradation is defined by CEN as “degradation resulting from oxidative and cell-mediated phenomena, either simultaneously or successively”. This means that the plastic (which does contain a prodegradant catalyst) degrades rapidly by oxidation until its molecular weight is low enough to be accessible to bacteria and fungi, who then recycle it back into nature.
MICROPLASTICS FROM PLA and PP.
I have been reading the report of a scientific study in “Ecotoxicology and Environmental Safety” Volume 271, February 2024, showing that 76-day UV radiation induced the fragmentation of plastic items and microplastics formation, from both PP and PLA items.
“Bio-based plastics may have a slower release of fragmented particles under UV radiation compared to conventional polymer types, but they still have the potential to act as a source of microplastics in the marine environment, with particles being available to biota within ingestible size fractions.”
Again, the better option would be PP made with a d2w masterbatch, so that the microplastics would quickly biodegrade. D2w is not used with PLA.
Michael Stephen
Michael Stephen is a lawyer and was a member of the United Kingdom Parliament, where he served on the Environment Select Committee. When he left Parliament Symphony Environmental Technologies Plc. attracted his attention because of his interest in the environment. He is now Deputy Chairman of Symphony, which is listed on the AIM market of the London Stock Exchange, and is the founder and Chairman of the Biodegradable Plastics Association.
Earlier Postings in this Column
All articles from Michael Stephen
Interview with Michael Stephen
Questions and Answers on OXO-Biodegradability
Disclaimer
The opinions expressed here by Michael Stephen and other columnists are their own, not those of Bioplasticsnews.com