|Characteristics of each casino visited in the present study and dates of count visits|
|Casinoa||Square Footageb||Total Number of Slot Machines Countedc||Total Number of Table Games Countedc||Number of Tables in Poker Areac||Number of High Stakes Slot Machinesc||NS Area Typec,d||Dates of Count Visitsf|
aCasino names have been replaced with anonymous identifiers.
bData on square footage for each casino was obtained from the 500 Nations Website .
cCounts of slots and tables were determined from the on-site (firsthand) observations made in each casino for the present study in both nonsmoking (NS) and smoking (S) areas. The type of nonsmoking area for each casino was also observed firsthand for the present study.
d“Enclosed” nonsmoking (NS) areas were defined as being in a different room that had enclosing walls limiting direct air flow from smoking (S) areas; “Partial” (partially separate) nonsmoking areas were in a different room but had no barriers to air flow from the smoking areas; “Open” nonsmoking areas were in the same room and not physically separated from the main casino smoking areas. See Table 5 for further notes on the type of nonsmoking area observed in each casino.
eSquare footage values for Casinos B and I were not available on 500 Nations Website  and were obtained from other online sources including casino-specific websites (not cited here to avoid casino disclosure).
fDate of casino visits where counts of patrons were made, two per casino, in MM/DD format. All visits were made on Friday or Saturday evenings or early the next morning (from 6 pm to 3 am) in 2008. The time difference between the two visits ranged from 1 day to 7 days. See Table 5 for the dates on which we made PM2.5 measurements.
Klepeis et al.
Klepeis et al. BMC Public Health 2012 12:819 doi:10.1186/1471-2458-12-819