Objective To explore the presence of microplastics in sputum and nasal lavage fluid collected from couriers and to describe the level and characteristics of the microplastics.
Methods Nine male couriers were randomly recruited in Shenyang city, Liaoning province and sputum samples (> 3 ml) and nasal lavage fluid samples (by nasal irrigation with 20 ml ultra pure water ) were collected among the couriers. The number, length, width and shape of the suspected microplastics in the samples were observed with a polarizing microscope.
Results There were microplastics fibers in the samples of sputum and nasal lavage fluid collected from all of the couriers, with the average abundance of 105.4 and 0.8 per gram, respectively. The observed microplastics were mainly fibrous with the length ranging from 20.5 μm to 2476.8 μm in the sputum samples and 50.8 μm to 6200.0 μm in the nasal lavage fluid samples. The width of the microplastics was in the range from < 1.0 to 61.9 μm for those in the sputum samples and from 5.0 μm to 46.4 μm in nasal lavage fluid samples.
Conclusion Suspected microplastics were observed in sputum and nasal lavage fluid samples collected from couriers. Further qualitative and quantitative study on the characteristics of the microplastics in the samples may assess the exposure load of microplastics in human respiratory tract simply and rapidly.