Table 2.

Concentrations and proportions of measured pollutants and pollution surrogates.

Pollutant/Mixture		Proportion < LOD (%)
1. Monitored pollutants
Formaldehyde (µg/m3) *	2.81 (LOD–17.33)	23.3
Nitrogen Dioxide(µg/m3) *	0.76 (LOD–70.57)	46.6
BTEX (ppb) *	3.00 (LOD–145.00)	19.4
2. Pollution surrogates
CHCE #	16.85 (0–33)
ETS (% exposed)	22.8%
Distance to road
<50 m	3.5%
51–100 m	5.4%
>100 m	91.2%

* Median (range); ^# Mean (range); LOD—Limit of Detection; CHCE—Combined Household Chemical Exposure; ETS—Environmental Tobacco Smoke.