Table 6.

Characteristics of on-site sampling studies of polymer NMP air pollution.

Study	Setting	Participants & sample size	Intervention	Methodology	Outcomes
Akhtar et al. [41]	10 clinics, 5 private + 5 private teaching hospitals	Number of patients not reported	Ordinary patient care, including RBC restorative care	Dust collected from surfaces, treated and extracted for microplastics using sieving, oxidative extraction, density separation, filtration, visual observation and polymer identification by digital microscope and ATR-FTIR spectroscopy	NMP count concentration (n/g dust)) NMP inhalation intake (n/g dust/day and year) NMP morphologies NMP morphologies: chemical compounds
Tang et al. [40]	1 hospital clinic, multiple units	Number of patients not reported	Ordinary patient care, including RBC restorative care	NanoTracer, every 10 s. real-time concentration of NMPs within the range of 10–300 nm. Also, information that may influence the concentration of NMP, including the number of patients and the dental procedures	NMP count concentration (n/cm³)
Rafiee et al. [39]	1 clinic, 6 units, open-area concept	10 patients receiving either orthodontic bonding or debonding and denture adjustment)	Different treatment procedures, of which 3 included RBC. 20 min preprocedural ->40 min during procedure ->20 min postprocedural	Optical NMP sizer + mass concentration measured with a DustTrack laser photometer + personal sampler fixed to the clinician faceshield for microbial analysis	NMP count concentration (not reported) NMP mass concentration (not reported) NMP size distribution, 13 sizes (0.3–10 μm)
Lahdentausta et al. [38]	1 clinic, public	84 regular adult patients undergoing 253 procedures	Ordinary patient care, including RBC restorative care	Optical NMP sizer measuring NMPs 0.3 to 10 μm, 50 cm away from patient mouth. NMP mass concentrations were calculated by converting volume size distributions to mass size distributions, assuming an NMP density of 1 g/cm³.	NMP count concentration (n/cm³) NMP mass concentration (μg/m³) NMP size distribution (<1, 1–5, >0.5 μm)
Field et al. [37]	1 hospital, operating theatre + adjoining anaesthetic room	Number of patients not reported	Standard cardiothoracic surgery, including coronary artery bypass grafts, lobectomies, and surgical tracheostomies.	Glass sampling beakers size 1 L with a known base surface area. 8 a.m.–8 p.m.–8 a.m. repeated x7. Beakers were rinsed, filtered onto 0.02 μm membranes and analysed using micro-Fourier-transform infra-red spectroscopy.	NMP count n/m²/day Mean (SD) – maximum NMP size (μm) Prevailing NMP morphology: Prevailing compounds:
Polednik [36]	1 clinic	Number of patients not reported	Ordinary patient care, including RBC restorative care	Ultrafine NMP counters, optical spectrometers, NanoTracer, aerosol monitors, inductively coupled plasma optical emission spectrometry, carbon analyser, and passive sampling using Petri plates.	NMP count concentration (n/cm³) NMP mass concentration (μg/m³) NMP size distribution (<0.5 and >0.5 μm)
Sotiriou et al. [35]	1 clinic	Number of patients not reported	Ordinary patient care, including RBC restorative care	Continuous NMP measurements taken every minute using Climet, PTRAK, and DustTrak Integrated NMP samples were collected for about 5 h on each of five sampling days using PM2.5 and PM10 samplers	NMP count concentration (n/cm³) NMP mass concentration (μg/m³) NMP size distribution (<0.5 and >0.5 μm)
Henriks-Eckerman et al. [34]	6 clinics, 3 private + 3 public, 1-7 units	Number of patients not reported	Ordinary patient care, including RBC restorative care	Thermal desorption tubes containing Tenax TA, above the patient’s mouth, at the nurse’s breathing zone, gas chromatograph (DL < 0.5 ng/m³)	Monomer concentration above the patients’ mouth, at the nurse’s breathing zone and in the sampling area (mg/m³)

ATR-FTIR attenuated total reflectance fourier transform infra-red spectroscopy, DL detection limit, NMP nano-microsize particle, RBC resin-based composite.