What size are microplastics?
TogÂeÂther with Covid-19, theÂre is one more topic domiÂnaÂting public media. No, we are not talÂking about cliÂmaÂte chanÂge — we are talÂking about microÂplaÂsÂtics. How often did you hear about microÂplaÂsÂtic polÂluÂtiÂon? Sounds famiÂliÂar? Well, then think about how often did someone explain to you what microÂplaÂsÂtic sources are, what size theÂse parÂticÂles have, and how it is defined?
If you expeÂriÂenÂced it as we did, you proÂbaÂbÂly have heard of this microÂplaÂsÂtic proÂblem a lot, witÂhout realÂly getÂting a clue of what exactÂly everÂyoÂne is talÂking about. In geneÂral, microÂplaÂsÂtics are basiÂcalÂly plaÂsÂtic parÂticÂles of a size smalÂler than 5 mm.
HoweÂver, we are much more famiÂliÂar with theÂse synÂtheÂtic mateÂriÂals in bigÂger sizes — nameÂly macroÂplaÂsÂtic. The latest parÂcel from AmaÂzon, our food packÂaÂging, the chair your sitÂting in right now: all very likely conÂtain plaÂsÂtics. The reason for that is quick to be found. This synÂtheÂtic mateÂriÂal is fleÂxiÂble, proÂcessaÂble, unbreÂakaÂble, and (very important) cheap.
HoweÂver, theÂre is always a downÂsiÂde and plaÂsÂtic is no excepÂtiÂon. Apart from its appeÂalÂing chaÂracÂteÂristics, it is bad for the enviÂronÂment. EspeÂciÂalÂly sinÂce it is not realÂly degraÂdaÂble and theÂrÂeÂfoÂre perÂsists for uncounÂtaÂble years. Your greÂat-greÂat-greÂat-greÂat-greÂat-greÂat-greÂat-greÂat grandÂson or grandÂdÂaughÂter may very likely find the plaÂsÂtic bag you bury today (don’t you dare to try that out!).
Microplastic sources
Let’s talk about the sources of microÂplaÂsÂtic polÂluÂtiÂon. Like alreÂaÂdy menÂtioÂned, plaÂsÂtic is surÂrounÂding us everÂyÂwheÂre. TheÂrÂeÂfoÂre, it is not surÂpriÂsing, that human actiÂviÂties are the main cauÂse for the polÂluÂtiÂon of the enviÂronÂment with microÂplaÂsÂtic. Tire wear parÂticÂles, synÂtheÂtic clotÂhing, parÂtiÂcuÂlaÂtes, and cosÂmeÂtic proÂducts are just some exampÂles of anthroÂpoÂgeÂnic microÂplaÂsÂtic sources. While theÂse polÂlutÂants are geneÂralÂly conÂsideÂred priÂmaÂry microÂplaÂsÂtic, seconÂdaÂry plaÂsÂtic shouldÂn’t be negleÂcÂted. TheÂse emerÂge through conÂstant abraÂsiÂon of macroÂplaÂsÂtic (like plaÂsÂtic bags) that has found its way into the environment.
PriÂmaÂry and seconÂdaÂry microÂplaÂsÂtics have two things in comÂmon. 1. they are perÂsisÂtent. 2. they are cauÂsed by our actions. HoweÂver, we should keep in mind that taking care of plaÂsÂtic bags and our trash will not solÂve the proÂblem. The bigÂgest and most undeÂreÂstiÂmaÂted microÂplaÂsÂtic source from ashore are… cars! The fishing indusÂtry is also an undervaÂlued source for plaÂsÂtic polÂluÂtiÂon, with its fishing nets of synÂtheÂtic fibers being a masÂsiÂve polÂlutant in seas and oceans.
Plastic waste — the ugly truth
Thanks to the AnthroÂpoÂceÂne, microÂplaÂsÂtics are everywhere.
EspeÂciÂalÂly oceÂans are heaÂviÂly impacÂted as reporÂted by seveÂral sciÂenÂtiÂfic stuÂdies. Even earths most remoÂte regiÂon — the antÂarÂcÂtic — is no safe-heaÂven as microÂplaÂsÂtic alreÂaÂdy enteÂred the respecÂtiÂve food chain (1). Reports from all over the world report of plaÂsÂtic polÂluÂtiÂon in soils, freshwaÂter, and even precipitation!
While we often feel priÂviÂleÂged, and perÂhaps even innoÂcent, as we belieÂve most of the plaÂsÂtic we use gets upcyÂcled — the truth is much more inconÂveÂniÂent. Many countÂries (incluÂding the EU) ship conÂtaiÂners of plaÂsÂtic trash to emerÂging countÂries (e.g. 70 % of the US plaÂsÂtic trash is shipÂped to countÂries like BanÂglaÂdesh, Laos, EthioÂpia, and SeneÂgal). TheÂse countÂries’ low capaÂciÂty of proÂcesÂsing all the wasÂte does lead to heaÂvy plaÂsÂtic pollution.
HoweÂver, things are even worse than they seem. Not only are microÂplaÂsÂtic parÂticÂles a proÂblem themÂselÂves, as many plaÂsÂtics conÂtain (enviÂronÂmenÂtal) conÂtaÂmiÂnants in high conÂcenÂtraÂtiÂons. Apart from potenÂtiÂalÂly toxic subÂsÂtances, some of theÂse conÂtaÂmiÂnants on microÂplaÂsÂtics are microÂorÂgaÂnisms. The bioÂfilm-proÂmoÂting proÂperÂties of microÂplaÂsÂtics are reporÂtedÂly enhanÂcing the emerÂgence and spread of antiÂbioÂtic resistance.2
Why action against microplastic pollution is required now!
SinÂce we ansÂweÂred the quesÂtiÂon on the sources of microÂplaÂsÂtics, we still need to disÂcuss why it is necesÂsaÂry for our enviÂronÂment and us to stop this polÂluÂtiÂon. Apart from picÂtures of sea dwelÂlers dying in agoÂny becauÂse of plaÂsÂtic polÂlutÂants, the folÂloÂwing numÂbers may be kind of a motiÂvaÂtiÂon for everÂyoÂne. By breathing air, 68 415 microÂplaÂsÂtic parÂticÂles are inhaÂled every year by a sinÂgle perÂson. Add 90 000 parÂticÂles of plaÂsÂtic to this if you’Âre drinÂking out of plaÂsÂtic botÂtÂles, and 4 000 if you are lucky enough to have access to drinÂking water from the tap. Things don’t stop here, and we can only estiÂmaÂte how many addiÂtioÂnal parÂticÂles a sinÂgle indiÂviÂduÂal takes up through the conÂsumpÂtiÂon of groÂceÂries like honey, beer, musÂsels, (sea-)salt, and so on… you are what you eat!
HoweÂver, sciÂenÂtists calÂcuÂlaÂted that an averaÂge human eats as much as a whoÂle creÂdit card — a week (2)!
Well…
RefeÂrenÂces
(1) E. BergaÂmi, C. ManÂno, S. CapÂpelÂlo, M.L. VanÂnucÂciÂni, I. CorÂsi, NanoÂplaÂsÂtics affect moulÂting and faecal pelÂlet sinÂking in AntÂarÂcÂtic krill (EuphauÂsia superÂba) juveÂniÂles, EnviÂronÂment InterÂnaÂtioÂnal, VoluÂme 143, 2020, 105999, ISSN 0160–4120, https://doi.org/10.1016/j.envint.2020.105999.
(2) GruÂber, E.S., StadlÂbauÂer, V., PichÂler, V. et al. To WasÂte or Not to WasÂte: QuesÂtioÂning PotenÂtiÂal Health Risks of Micro- and NanoÂplaÂsÂtics with a Focus on Their IngesÂtiÂon and PotenÂtiÂal CarÂciÂnoÂgeÂniÂciÂty. Expo Health 15, 33–51 (2023). https://doi.org/10.1007/s12403-022–00470‑8