Measurement techniques of exposure to nanomaterials in the workplace for low- and medium-income countries: A systematic review

Nanotechnology offers many opportunities but there is still considerable uncertainty about the health risks and how to assess these.In the field of risk analysis for workers potentially exposed to nano-objects and their agglomerates and aggregates (NOAA) different methodological approaches to measure airborne NOAA have been proposed.This study proposes a systematic review of scientific literature on occupational exposure to NOAA in the workplace with the aim to identify techniques of exposure measurement to be recommended in low- and medium-income countries.We gathered scientific papers reporting techniques of NOAA exposure measurements in the workplace, we summarized the data for each eligible technique according to PRISMA guidelines, and we rated the quality of evidence following an adapted GRADE approach.We found 69 eligible studies to be included in qualitative synthesis: the majority of studies reported a moderate quality and only two studies demonstrated the use of a high quality exposure measurement technique.The review demonstrates that a basic exposure measurement, i.e. evidence for the presence or absence of NOAA in the workplace air, can be achieved with moderate (40 techniques) to high (2 techniques) quality; comprehensive exposure measurement, that allow the quantification of NOAA in the workplace, can be achieved with moderate (11 techniques) to high (2 techniques) quality.The findings of the study also allowed to finalize a list of requirements that must be fulfilled by an effective measurement technique (either basic or comprehensive) and to highlight the main weaknesses that need to be tackled for an effective affordability evaluation of measurement techniques to be recommended in low- and medium-income countries.