Do you need to go undercover to check air quality?

The answer appears to be 'yes' when it's a cigar show where you are checking for air quality. I still can't figure out why the researchers were afraid of hostile treatment at the cigar show, but anyways, here are the results [you'll have to go to the article for the fun bits]:

Under Environmental Protection Agency guidelines, air with fewer than 15 micrograms per cubic meter is considered good quality; air with more than 251 micrograms per cubic meter is hazardous.

Mr. Kennedy’s preliminary findings showed that the average level of particulate matter in the hotel [the venue for the cigar show] the day before the event was 8 micrograms per cubic meter, 40 micrograms where he was waiting to get in line for the event and 1,193 micrograms inside the ballroom.

Thanks to Olive Ridley for the pointer.