Study on the accumulation characteristics of nanoplastics in SD rats under inhalation exposure route

To explore the accumulation of respiratory nanoplastics in tissues out of respiratory system, the 100 nm polystyrene nanoplastics were used to perform a 2h-short term uptake exposure to SD rats, and the polystyrene concentrations in liver, kidney, heart, and brain of rats were determined with pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The results showed that the concentrations in the kidney, heart, and liver of the exposure group (0.416±0.143), (0.633±0.278), and (0.617±0.179) g/g were significantly higher than those of the control group (0.249±0.020), (0.070±0.096), and (0.101±0.140) g/g (P<0.05), but no significant correlation were found among different tissues (P>0.05), and polystyrene was not detected in the brain of both the control and exposure groups. The results show that the nanoplastics can enter the blood circulation of rats through the alveoli and deposit in tissues such as liver, kidney, and heart shortly after 2 h of inhalation exposure of 100 nm polystyrene nanoplastics. The study preliminarily explored the accumulation characteristics of nanoplastics in organisms, and could provide data support for further research on the potential impacts of respiratory nanoplastics on human health.