Table 1.
Summary of the sampling parameters, and meteorology parameters within the sampling duration.
| N (homes) | n (samples) | Mean ± SD | Median | Min | Max | |
|---|---|---|---|---|---|---|
| Indoor PM2.5 (μg/m3) | 60 | 810 | 10.2 ±15.8 | 6.8 | 0.11 | 289.0 |
| Outdoor PM2.5 (μg/m3)* | 10.9 ±4.7 | 10.3 | 3.2 | 60.5 | ||
| Indoor sulfur (μg/m3) | 60 | 810 | 0.3 ± 0.2 | 0.2 | 0.02 | 1.1 |
| Outdoor sulfur (μg/m3)* | 0.4 ±0.2 | 0.4 | 0.04 | 1.3 | ||
| Indoor-outdoor particle infiltration ratio (i.e. sulfur ratio) | ||||||
| All (HVAC=mixed) | 60 | 810 | 0.74 ±0.39 | 0.68 | 0.00 | 3.64 |
| HVAC=0 | 42 | 271 | 0.79 ±0.30 | 0.77 | 0.16 | 1.91 |
| HVAC=1 | 58 | 539 | 0.72 ± 0.44 | 0.64 | 0.00 | 3.64 |
| Meteorology^ | ||||||
| Ambient Temperature (°C) | 18.4 ±7.5 | 18.3 | −1.1 | 31.1 | ||
| Indoor Temperature (°C) | 60 | 769 | 22.2 ±2.4 | 22.1 | 14.5 | 28.0 |
| Relative humidity (%) | 62.3 ±13.8 | 62.0 | 0.0 | 97.0 | ||
| Indoor Relative humidity (%) | 60 | 769 | 51.2 ±9.4 | 51.2 | 18.6 | 75.1 |
| Wind speed (m/s) | 3.8 ±1.5 | 3.6 | 0.9 | 9.8 | ||
| Precipitation (inch/day) | 0.1 ±0.4 | 0.0 | 0.0 | 4.3 |
*
Measurements of outdoor PM2.5 and sulfur concentrations were conducted at the Jefferson Street center monitoring site
^
Meteorology data for the homes in our study cohorts, including ambient temperature, relative humidity, wind speed, and precipitation, were obtained from the North American Regional Reanalysis (NARR) database. Indoor temperature and relative humidity were measured using HOBO Temperature/Relative Humidity 3.5% Data Logger.