Combatting Airborne Microplastics in the Workplace – January 31, 2022 – Jed Thomas Environmental Science News Articles
They’re with you on every trip you take, every surface you clean, every outfit you try on. Like the tagline of a bad horror movie, you can’t run and you can’t hide from microplastics.
In particular, for those of us who work indoors, there is no escape from plastic-based textile fibres. Each year, European households consume around 60 million tonnes of plastic, representing around 16% of global plastic production.1 In fact, it is estimated that around 60% of the clothes we wear and 70% of our tea towels, quilts, curtains and cushions are plastic-based.2
And production is growing – by about 6% every year.
What are microplastics?
To be specific, microplastics are solid synthetic particles or variable-shaped polymer matrices that measure between 1 mm and 1 μm, all of which are insoluble in water.3 Sometimes microplastics are produced deliberately, as in microbeads that are ubiquitous in cosmetics. some products. Otherwise, they’re the result of more plastic degradation – and that’s what experts worry the most about.
For example, a study of dust deposited in households revealed
that carpeted houses had more than double the
fibrous polyethylene, polyamide and polyacrylic airborne than non-carpeted areas. Yet worryingly, while they could be spared these particular microplastics, the long-term degradation
of coating applied to most hard floor coverings ensures that these
homes have a higher concentration of polyvinyl fibers than their carpeted counterparts.4
As for plastics, this is what is added to the compound –
to give it extra strength, some smell, less flammability, etc. – which is disturbing. Most additives leach from the surfaces of microplastics once ingested because they are not bound to the plastic polymers. In particular, the additives of concern are phthalates and bisphenol A (BPA), all of which disrupt the human endocrine system.
Take benzyl butyl phthalate, or BBP, a plasticizer used in everything from food containers and electrical wires to flooring and paints. Due to their endocrine effects, most phthalates are linked to insulin resistance and are classified as xenoestrogens.5 All of this also applies to bisphenol A (BPA), which has been hardening plastics since 1957.6
The disturbing fact is that we inhale BBP and BPA treated plastics at a higher rate when we are indoors – current concentrations range from 1.6 to 12.6 microplastic particles per m3.7
By far, synthetic textile fibers – particularly polyamine, nylon and polyester fibers – are the most abundant microplastics in indoor air. Most of the clothes that we all wear in the office will be made from synthetic materials, from which thousands of tiny fibers tear easily during a day. But all sorts of everyday tasks, from opening plastic packaging to using a printer, spew other microplastics, like degraded polypropylene and polyethersulfone, into the office air.8
Of course, there are simple protective measures that can be put in place immediately, such as increased ventilation – in fact, many workplaces are already taking similar precautions for COVID-19.9 And other measures, such as the redistribution of office space to allow for greater distance between workstations, may be more expensive, but as we all continue to split our time between home and office, this might not even require additional square footage, just a little extra planning.
But, in the interests of health and safety, it is important to characterize and quantify airborne microplastics – especially those that are 2.5 μm in diameter or less, because at this size, they can cross the pulmonary barrier and enter the bloodstream.
Measure airborne microplastics
When you go below 500 μm, however, background interference from organic compounds will sabotage the analysis of untreated samples. There are a few chemicals that can neutralize these interferences, but the current fashion is to treat samples with sodium hydrochloride or 30% hydrogen peroxide.10 Usually, after treatment, a zinc chloride solution, with a density between 1.6 and 1.7 g/cm3, is used to separate components, including microplastics of different types.11
In order to identify the particles, it is usual to follow a two-step process. First, using a stereomicroscope with imaging analysis software, study the shape of the microplastics in the sample, which should provide a cursory understanding of their origin. If you observe fine fibers, the culprits are clothing and furniture; if you can see fragments, it’s the degraders of larger plastics like food containers, trash bags, and electrical appliances.
Second, an analysis of the polymer composition of your microplastics, which will help identify toxicological hazards, is commonly performed using Fourier Transform Infrared (FTIR) spectroscopy. Using infrared light, this non-destructive spectroscopic method transforms the absorption rates of components into a spectrum, according to the Fourier transform function, and numerical cross-references to identify polymers. Although FTIR instruments are relatively expensive and require skilled technicians, the method produces reliable results with small samples.
Another popular choice is a combination of Raman spectroscopy and spectral imaging equipment, in which a uniform wavelength laser is reflected, scattered, and absorbed by a sample, producing a unique fingerprint for each component. Although this method has the unique ability to detect microplastics down to 1 μm, it suffers from a fair amount of interference (in particular, high background fluorescence) and instrument libraries are currently underdeveloped.
Nevertheless, information on how to measure airborne microplastics is still very limited, but the dangers of overexposure are, as we have seen, much less limited. More research is needed to set standards for methodology and exposure in the workplace, to understand the exact behavior and nature of airborne microplastics, to understand their toxicological profile – and it is needed. quickly.
Now is not the time to breathe.
1: Gasperi, Johnny et al. “Microplastics in the Air: Are We Breathing It?” Current Opinion in Environmental Science and Health, 1 (2018).
2: Manshoven, Saskia et al. Plastic in textiles: Potentials for circularity and reduction of environmental and climate impact. European Topic Center on Waste and Materials in a Green Economy, 2021.
3: Frias, JPGL and Nash, Róisín. “Microplastics: finding consensus on the definition.” Marine Pollution Bulletin. 138 (2019).
4: Soltani, Neda Sharifi et al. “Quantification and assessment of exposure to microplastics in Australian indoor house dust.” Environmental Pollution, 283 (2021).
5: Zang, Miao et al. “Association between phthalate exposure and insulin resistance: a systematic review and meta-analysis update.” Environmental Science and Pollution Research, 28 (2021).
6: Rubin, Beverly. “Bisphenol A: An endocrine disruptor with widespread exposure and multiple effects. The Journal of Steroid Biochemistry and Molecular Biology, 2 (2011).
7: Gasperi, Johnny et al. “First Look at Microplastics in Indoor and Outdoor Air.” 15th EuCheMS International Conference on Chemistry and the Environment, September 2015, Leipzig, Germany. Main speech; Chen article again or first.
8: Torres, María Agulló Asunción et al. “Overview of the Occurrence of Airborne Microplastics and the Implications of Using Face Masks During the COVID-19 Pandemic.” Total Environmental Science, 800 (2021).
9: Prata, Joana Correia. “Airborne microplastics: consequences for human health?” Environmental Pollution, 234 (2018).
10: Chen, Guanglong et al. “An Overview of Analytical Methods to Detect Microplastics in the Atmosphere.” TrAC Trends in Analytical Chemistry, 130 (2020).
11: Dris, Rachid et al. “Fibers in atmospheric fallout: a source
microplastics in the environment? » Marine Pollution Bulletin, 104 (2016).