Inhalable microplastics and plastic additives in the indoor air of chemical laboratories

While recognition of airborne microplastics is increasing, there are still limited data on the microplastics within the aerosol size fractions most relevant to human inhalation (PM₁₀ and PM_2.5). Additionally, there are concerns that many of the additives used in plastic formulations have endocrine-disrupting properties, which could increase the hazards associated with microplastic exposure.

To better understand the toxicological risks associated with airborne microplastics, more data are urgently needed on the mass concentrations of both microplastics and the related chemical additives in the air we breathe. Inhalation exposure to plastic-related species is currently uncertain in chemical laboratory workplaces.

Using a Pyrolysis Gas Chromatography Mass Spectrometry (Pyr-GC/MS) based method, the airborne mass concentrations of both polymeric material and small molecule plastic additives were determined in inhalable air from two indoor locations. This method represents a fast, direct technique that can be used to better standardize airborne microplastic measurements.

The PM_2.5 and PM₁₀ concentrations of seven different polymers were determined, with average plastic concentrations of 0.51 μg m^-3 for the PM_2.5 samples and 1.14 µg m^-3 for the PM₁₀ samples. Polycarbonate, polyvinylchloride, and polyethylene had the highest airborne concentrations in the inhalable fraction of air. Simultaneously, the airborne concentrations of plastic additives were determined, with phthalate-based plasticizers having an average concentration of 334 ng m^-3 across all air samples.

Both microplastics and their chemical additives were quantified within the inhalable fraction of indoor air (PM₁₀), using a straight forward mass spectrometry technique with minimal sample preparation. This information furthers knowledge on the hazards associated with indoor air exposure, and it presents a useful methodology for the mass quantification of plastic-related airborne pollutants.