Association (OR (95% CI)) between annual average air pollution concentrations and asthma outcomes for California Health Interview Survey 2001 respondents residing in the San Joaquin Valley, California (all ages)
| Daily/weekly symptoms* | Emergency department visits/hospitalisation | ||||
| Crude | Adjusted† | Crude | Adjusted† | ||
| Ozone | (193 yes, 559 no) | (78 yes, 681 no) | |||
| Continuous (per 10 ppb) | 1.13 (0.88 1.46) | 1.23 (0.94 to 1.60) | 1.47 (1.05 to 2.07) | 1.49 (1.05 to 2.11) | |
| Quartile | |||||
| <27.0 | 1.00 | 1.00 | 1.00 | 1.00 | |
| 27.1 to 30.2 | 1.68 (1.01 to 2.79) | 1.54 (0.91 to 2.61) | 2.44 (1.18 to 5.07) | 2.35 (1.12 to 4.95) | |
| 30.3 to 33.9 | 1.97 (1.19 to 3.26) | 2.18 (1.30 to 3.68) | 1.75 (0.81 to 3.79) | 1.80 (0.82 to 3.95) | |
| 34.0+ | 1.44 (0.86 to 2.42) | 1.62 (0.95 to 2.61) | 2.63 (1.27 to 5.43) | 2.65 (1.26 to 5.57) | |
| PM10 | (198 yes, 569 no) | (79 yes, 695 no) | |||
| Continuous (per 10 μg/m3) | 1.31 (1.08 to 1.60) | 1.29 (1.05 to 1.57) | 1.32 (1.01 to 1.73) | 1.29 (0.99 to 1.69) | |
| Quartile | |||||
| <31.71 | 1.00 | 1.00 | 1.00 | 1.00 | |
| 31.72 to 42.66 | 1.68 (0.99 to 2.85) | 1.73 (1.00 to 2.98) | 1.78 (0.87 to 3.67) | 2.00 (0.95 to 4.20) | |
| 42.67 to 44.33 | 1.96 (1.17 to 3.30) | 1.89 (1.11 to 3.22) | 1.42 (0.67 to 3.01) | 1.45 (0.67 to 3.11) | |
| 44.34+ | 2.64 (1.60 to 4.37) | 2.51 (1.49 to 4.21) | 2.17 (1.08 to 4.36) | 2.03 (1.00 to 4.13) | |
| PM2.5 | (152 yes, 459 no) | (58 yes, 559 no) | |||
| Continuous (per 10 μg/m3) | 1.86 (1.15 to 2.99) | 1.82 (1.11 to 2.98) | 1.42 (0.74 to 2.71) | 1.47 (0.76 to 2.84) | |
| Quartile | |||||
| <17.89 | 1.00 | 1.00 | 1.00 | 1.00 | |
| 17.90 to 21.39 | 1.39 (0.76 to 2.51) | 1.53 (0.83 to 2.84) | 2.03 (0.85 to 4.86) | 2.15 (0.87 to 5.29) | |
| 21.40 to 23.49 | 2.03 (1.14 to 3.60) | 1.82 (1.01 to 3.29) | 2.53 (1.08 to 5.95) | 2.33 (0.97 to 5.58) | |
| 23.50+ | 2.39 (1.36 to 4.20) | 2.46 (1.38 to 4.41) | 2.23 (0.94 to 5.31) | 2.30 (0.95 to 5.56) | |
↵* Participants were asked in a single question to report the frequency of asthma symptoms, such as coughing, wheezing, shortness of breath, chest tightness, and phlegm production.
↵† Adjusted for age, gender, race/ethnicity, poverty and insurance status.
O3, ozone; PM2.5, particulate matter less than 2.5 μm in aerodynamic diameter; PM10, particulate matter less than 10 μm in aerodynamic diameter.