Swab each nostril with moistened cotton-tipped swab. Use only one swab per nostril.
Survey swabs for the amount of radioactivity present.
Radioactivity measured from survey swabs is one way to estimate pulmonary contamination. Pulmonary contamination usually requires decorporation treatment.
Lung contamination is estimated to be about 5% of total radioactivity measured in both nares.
Caveats:
Data supporting accuracy of the 5% estimate is uncertain.
Delays in swab collection may influence reliability of the estimate.
Swab collection should occur before nasal decontamination, sneezing, nasal trauma, etc.
Presence of radioactivity in only one nostril suggests non-respiratory source of contamination.
Presence of alpha-emitting radioisotopes will be masked by the water on the cotton swab. Swabs must therefore be allowed to dry fully when surveying for alpha emitters.
Conclusion: During a mass casualty event, there will NOT be time to obtain or perform this type of analysis; alternate methods of estimating levels of internal contamination via the respiratory route will then need to be employed.