The Elevation of the Mass Concentration Ratio of PM ₁₀ to PM ₁ in Printing Shop Was Associated With Small Airway Impairment

Currently, there is a substantial amount of research on the impact of long‐term exposure to printing shop particles (PSPs) on worker health. However, the effects of short‐term exposure to PSPs on consumer health and the appropriate exposure metric for assessing the health risks of PSPs remain unclear. In this study, a two‐stage crossover experiment was conducted, in which 20 healthy adults were randomly exposed to different size distributions of PSPs during two separate experimental periods. Lung function of the participants was tested before and after PSP exposure, and blood samples were collected for analysis. The results indicated that, compared to traditional particle exposure metrics such as mass and number concentration, the ratio of PM 10 to PM 1 mass concentration (PMC 10 /PMC 1 ) was a more suitable metric for evaluating PSP exposure risks. After exposure to PSPs, participants showed a decline in lung function. As the PMC 10 /PMC 1 ratio increased in two experimental periods, lung function indicators associated with small airways, such as forced expiratory volume in 1 s (FEV 1 ), FEV 3 , forced expiratory flow at 25% of FVC exhaled (FEF 25 ), FEF 75 , and FEF 25-75% , significantly decreased. Blood biochemical test results revealed an increase in potassium levels in the serum of participants, potentially related to small airway damage caused by PSPs. In summary, this study proposes a more suitable exposure metric to evaluate the health impact of PSPs and other nanoparticles, offering epidemiological evidence on the health effects of short‐term exposure to these substances.