The pulmonary deposition and retention of indium-111 labeled ultrafine carbon particles in healthy individuals.
BACKGROUND
Particulate air pollution, for example, from ultrafine (UF) particles, has negative health effects. However, there is still limited knowledge regarding the fate of inhaled particles in the human body.


OBJECTIVE
To describe the normal lung deposition and 1 week particle retention of indium-111 labeled UF carbon particles in healthy subjects. Additionally, the possibility to extend the follow-up period to 4 weeks was also investigated for one of the subjects.


RESULTS
The cumulative pulmonary particle clearance 1 week post-administration, corrected for activity leaching and mucocilliary transport of activity deposited in the central airways, was 4.3 ± 8.5% (average ± standard deviation at group level), with marginal translocation of particles from lungs to blood, 0.3%. There was no observable elimination of particles from the body via urine. Seven days after exposure, the cumulated activity leaching was 3% (group level), which indicates a stable bonding between the particles and Indium-111. The volunteer followed for a total of 4 weeks, showed a cumulative decrease of activity retention in the lungs of 10.5%. After correction for activity leaching and clearance from central airway deposition, the estimated particle clearance was about 2%.


CONCLUSIONS
No evidence for particle translocation from the lungs could be proven 7 days after exposure. It is possible to follow-up Indium-111 labeled UF carbon particles at least 1 month post-administration without increasing the administered activity.
Department of Public Health Sciences, Division of Occupational and Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
Anna
A
Klepczyńska-Nyström
Alejandro
A
Sanchez-Crespo
Martin
M
Andersson
Rolf
R
Falk
Anders
A
Lundin
Britt-Marie
BM
Larsson
Magnus
M
Svartengren
D000328:Adult; D000336:Aerosols; D000465:Algorithms; D001692:Biological Transport; D002244:Carbon / Q000737:chemistry; D055598:Chemical Phenomena; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007205:Indium Radioisotopes; D019570:Inhalation Exposure; D008168:Lung / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics*; D011877:Radionuclide Imaging; D020545:Respiratory Mucosa / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism*; D014018:Tissue Distribution; D055815:Young Adult
D000336:Aerosols; D007205:Indium Radioisotopes; D052638:Particulate Matter; D002244:Carbon