Associations of livestock farm exposures and chronic obstructive pulmonary disease (COPD), current asthma and nasal allergies in 12 117 questionnaire responders
| COPD | Current asthma | Nasal allergies | |
| Prevalence n (%) | 553 (4.6) | 1365 (11.3) | 2778 (23.2) |
| Covariates | |||
| Age increase per 10 years | 1.56 (1.44–1.70) | 1.06 (1.02–1.12) | 0.84 (0.81–0.87) |
| Sex (reference is male) | 1.05 (0.88–1.25) | 1.15 (1.03–1.29) | 1.10 (1.00–1.20) |
| Ex-smoker | 1.63 (1.32–2.01) | 1.16 (1.01–1.31) | 0.82 (0.74–0.90) |
| Current smoker | 2.30 (1.78–2.90) | 1.18 (1.00–1.39) | 0.62 (0.54–0.71) |
| Exposure | |||
| Presence of livestock farms (yes or no) | |||
| Within 100 m | 0.47 (0.24–0.91) | 0.65 (0.45–0.93) | 0.78 (0.61–1.00) |
| Within 500 m | 0.91 (0.77–1.09) | 0.96 (0.85–1.07) | 0.99 (0.91–1.08) |
| Within 1000 m | 0.71 (0.51–0.98) | 0.84 (0.67–1.06) | 0.92 (0.76–1.10) |
| Presence of farm animals in 500 m (yes or no) | |||
| Pigs | 1.01 (0.80–1.26) | 0.84 (0.72–0.97) | 1.02 (0.91–1.13) |
| Poultry | 1.04 (0.80–1.35) | 1.17 (0.99–1.38) | 1.01 (0.89–1.14) |
| Cattle | 0.91 (0.76–1.11) | 0.98 (0.87–1.11) | 0.93 (0.85–1.02) |
| Goats | 1.07 (0.51–2.26) | 0.90 (0.54–1.48) | 1.10 (0.77–1.57) |
| Mink | 0.59 (0.24–1.45) | 0.68 (0.39–1.18) | 1.34 (0.96–1.88) |
| Presence of farm animals in 1000 m (yes or no) | |||
| Pigs | 0.97 (0.77–1.21) | 0.94 (0.81–1.09) | 1.03 (0.92–1.15) |
| Poultry | 0.87 (0.72–1.05) | 1.02 (0.90–1.15) | 0.94 (0.85–1.03) |
| Cattle | 1.01 (0.75–1.37) | 1.03 (0.84–1.26) | 0.94 (0.81–1.10) |
| Goats | 0.96 (0.69–1.32) | 0.79 (0.64–0.98) | 0.95 (0.82–1.11) |
| Mink | 0.95 (0.66–1.36) | 0.99 (0.78–1.25) | 0.90 (0.75–1.08) |
| Distance to the nearest farm (quartiles) | |||
| >640 m | 1 | 1 | 1 |
| 450–640 m | 0.76 (0.60–0.97) | 0.87 (0.75–1.03) | 1.03 (0.91–1.17) |
| 290–450 m | 0.92 (0.73–1.16) | 0.86 (0.73–1.00) | 1.02 (0.91–1.15) |
| <290 m | 0.71 (0.56–0.91) | 0.83 (0.71–0.98) | 0.87 (0.77–0.98) |
| Test for trend | 0.03 | 0.03 | 0.03 |
| Number of livestock farms in 1000 m (quartiles) | |||
| <4 | 1 | 1 | 1 |
| 4–7 | 0.96 (0.76–1.21) | 1.02 (0.87–1.19) | 0.97 (0.87–1.10) |
| 7–11 | 0.91 (0.72–1.15) | 0.97 (0.83–1.13) | 0.94 (0.84–1.06) |
| >11 | 0.89 (0.69–1.15) | 0.95 (0.80–1.12) | 0.93 (0.82–1.05) |
| Test for trend | 0.33 | 0.45 | 0.19 |
| Modelled fine dust emission from farms | |||
| Log-weighted fine dust emission from farms within 500 m# | 0.92 (0.78–1.09) | 0.96 (0.86–1.07) | 0.98 (0.91–1.07) |
| Log-weighted fine dust emission from farms within 1000 m# | 0.93 (0.85–1.01) | 0.96 (0.90–1.02) | 0.98 (0.93–1.02) |
Data are presented as OR (95% CI), unless otherwise stated. All responders with complete exposure data were included, who did not live or work on a farm and who had lived in their home for >1 year (n=12 117; fig. 1). All OR (95% CI) were adjusted for age, sex and smoking habits. The presence of a type of farm animal was adjusted for the presence of other types of farm animals. Bold type indicates statistical significance (p<0.05). Analyses of the influence of covariates on COPD, current asthma and nasal allergies were mutually adjusted. #: OR (95% CI) for an interquartile range (IQR) increase in log-transformed exposure, IQR for ln (fine dust) for farms within 500 m 7.54 g·year−1·m−2, corresponding to a 1881-fold increase (exposure 7.54) for nontransformed values and IQR for ln (fine dust) for farms within 1000 m 3.08 g·year−1·m−2, corresponding to a 22-fold increase for nontransformed values.