Exhaled breath condensate (EBC) is an emerging and noninvasive specimen allowing the study of lung processes. EBC could be an ideal biological matrix, as it could provide information about the deposited dose. The purpose of this study is to examine whether exhaled UFP in EBC could be correlated with exposure levels or surrogate of nanoparticle exposure.Methods
18 TiO2-exposed nanomaterial workers and 23 non-exposed controls were recruited from nanotechnology factories. A questionnaire was used to collect personal information. EBC was collected by an ECoScreen turbo (Viasys GmbH, Höchberg, Germany) and stored at −80°C until analysis. The particle size-number distribution of ultrafine particles (PM0.1) were assessed in the EBC samples with the NanoSight LM10 HS system (Nanosight Ltd., Salisbury, UK) using the Nanoparticle Tracking Analysis (NTA) method. The results were expressed as average size(nm) mode size(nm) concentration ((x108 #particles/mL), % of UFP and particles number of UFP).Result
The average size of particles (nm) in TiO2 exposed worker was smaller than non-exposed workers. The concentration of particles (x108 #particles/mL) in TiO2 exposed worker was higher than non-exposed workers. However, there was no significant difference between TiO2 exposed and controls in the average size(nm), mode size(nm), concentration (x108 #particles/mL), % of UFP and particles number of UFP. But we found that the particles number of UFP in females was significantly higher than in males.Discussion
The possible reason for no association between nanomaterial exposure and particle concentration in EBC may be due to the storage of EBC in −80°C refrigerator for a period of time which may induce aggregation or agglomeration of nanoparticles. Further study is required to clarify the use of exhaled UFP in fresh EBC as exposure matrix.