Lung-deposited surface area concentration measurements in selected occupational and non-occupational environments

Previous experimental and epidemiologic studies suggested that exposure to ultrafine particles (UFP) may result in adverse health effects. Metrics such as the number-concentration and especially the surface-area or lung-deposited surface area (LDSA) appear to be appropriate metrics of dose for predicting pulmonary inflammation of insoluble and poorly soluble ultrafine particles. Currently not much data including LDSA concentrations is available. The aim of this study was therefore to measure LDSA concentrations in a variety of occupational and non-occupational environments as well as in chamber tests. To this end, novel handheld online-monitors were deployed and evaluated for their suitability to be used in a variety of micro-environments and under different conditions. Chamber emissions tests included incense and candle burning, 3D printing and cigarette/e-cigarette smoking. The LDSA concentration was measured in occupational environments such as a canteen kitchen, a welding workshop and in a car. Measurements were also conducted in a private house with a wood-burning stove and with ongoing parallel cooking activities. Depending on the type of micro-environment, the ongoing activities or the material investigated in the chamber-tests, large differences were observed in terms of measured LDSA concentrations, some exceeding up to 1000 times that of the baseline concentration detected before activities initiated. In some of the investigated environments LDSA concentrations were measured for the first time. The data might therefore serve as reference for future studies. The handheld instrument used to measure this data worked well both for stationary measurements as well as for personal monitoring and proved to be an alternative to bulkier benchtop instruments.