Table 1.

Second-hand smoke exposure characterization

Parameters	Controls (AIR)	In utero 3R4F SHS
Mass concentration (mg/m3)a	–	11.70 ± 2.93
Number concentration (#/cm3)b, c	–	972 231
Mean geometric diameter (nm)b, c	–	29.2 ± 2.7
Geometric standard deviationb, c	–	2.9 ± 0.1
Temperature (°C)	23.7 ± 1.5	24.4 ± 1.7
Relative humidity (%)	41.7 ± 11.4	40.0 ± 13.9

Abbreviations: SD standard deviation

^aAverage mass concentration determined gravimetrically

^bMeasurements made with a scanning mobility particle sizer (SMPS)

^cValues reported are averages from samples taken over 9 days