Table II.
Distribution of ambient air pollutant levels; the LIFE Study (2005–2009).
| Unit | IQR | Min | 25% | Median | 75% | Max | |
|---|---|---|---|---|---|---|---|
| Cycle average for first observed cycle (n = 500)a | |||||||
| Criteria pollutants | |||||||
| Sulfur dioxide (SO2) | ppb | 0.98 | 0.082 | 0.96 | 1.37 | 1.94 | 6.22 |
| Ozone (O3) | ppb | 9.14 | 9.97 | 23.54 | 27.85 | 32.68 | 40.54 |
| Nitrogen oxides (NOX) | ppb | 9.20 | 0.63 | 7.53 | 10.83 | 16.73 | 51.31 |
| Nitrogen dioxide (NO2) | ppb | 4.97 | 0.56 | 4.98 | 7.03 | 9.95 | 24.98 |
| Carbon monoxide (CO) | ppb | 123.70 | 75.8 | 184.0 | 250.0 | 307.7 | 500.6 |
| Particulate matter (PM10) | μg/m3 | 12.26 | 5.68 | 16.01 | 23.91 | 28.27 | 40.45 |
| Fine particular matter (PM2.5) | μg/m3 | 3.19 | 5.42 | 10.15 | 11.82 | 13.34 | 19.18 |
| Particulate constituents | |||||||
| Elemental carbon (AEC) | μg/m3 | 0.31 | 0.004 | 0.12 | 0.26 | 0.42 | 1.26 |
| Ammonium (ANH4) | μg/m3 | 0.47 | 0.38 | 0.95 | 1.16 | 1.42 | 2.53 |
| Nitrate (ANO3) | μg/m3 | 0.69 | 0.001 | 0.54 | 0.77 | 1.23 | 5.62 |
| Organic compounds (AOC) | μg/m3 | 1.10 | 0.38 | 1.44 | 1.86 | 2.54 | 6.18 |
| Sulfate (ASO4) | μg/m3 | 1.29 | 1.25 | 2.44 | 2.99 | 3.73 | 5.75 |
| Day average 5 days prior to ovulation in first observed cycle (n = 440)b | |||||||
| Criteria pollutants | |||||||
| Sulfur dioxide (SO2) | ppb | 1.47 | 0 | 0.50 | 1.05 | 1.97 | 11.80 |
| Ozone (O3) | ppb | 14.40 | 3.34 | 19.80 | 26.78 | 34.20 | 66.09 |
| Nitrogen oxides (NOX) | ppb | 10.49 | 0.19 | 5.12 | 9.24 | 15.61 | 171.02 |
| Nitrogen dioxide (NO2) | ppb | 6.62 | 0.11 | 3.73 | 6.64 | 10.35 | 47.50 |
| Carbon monoxide (CO) | ppb | 133.76 | 51.6 | 157.1 | 218.7 | 290.9 | 1250.3 |
| Particular matter (PM10) | μg/m3 | 16.57 | 0.29 | 12.76 | 21.43 | 29.33 | 64.53 |
| Fine particulate matter (PM2.5) | μg/m3 | 6.89 | 0.56 | 8.00 | 10.88 | 14.89 | 32.00 |
| Particulate constituents | |||||||
| Elemental carbon (AEC) | μg/m3 | 0.36 | 0 | 0.05 | 0.21 | 0.41 | 2.23 |
| Ammonium (ANH4) | μg/m3 | 0.92 | 0 | 0.64 | 0.99 | 1.56 | 5.54 |
| Nitrate (ANO3) | μg/m3 | 0.72 | 0 | 0.36 | 0.58 | 1.08 | 9.26 |
| Organic compounds (AOC) | μg/m3 | 1.63 | 0.01 | 0.98 | 1.71 | 2.61 | 6.99 |
| Sulfate (ASO4) | μg/m3 | 2.08 | 0 | 1.96 | 2.85 | 4.04 | 10.97 |
aExcludes one participant who could not be geocoded.
bAdditionally excludes 60 participants who achieved pregnancy or were censored at the end of the entry cycle (ovulation date not assessed).