Background
Methods
Data on emergency department visits
Environmental data
Year | Month | Week |
---|---|---|
2014 | September | 1st (Sep. 1–7), 2nd (8–14), 3rd (15–21), 4th (22–28) |
October | 1st (Oct. 15–21), 2nd (22–28) | |
November | 1st (Oct. 31–Nov. 6), 2nd (7–13), 3rd (14–20), 4th (21–27) | |
December | 1st (Dec. 1–7), 2nd (8–14), 3rd (15–21), 4th (22–28) | |
2015 | January | 1st (Jan. 6–12), 2nd (13–19), 3rd (20–26) |
February | 1st (Feb. 2–8), 2nd (9–15), 3rd (16–22), 4th (Feb. 23–Mar. 1) | |
March | 1st (Mar. 2–8), 2nd (9–15), 3rd (16–22), 4th (23–29) | |
April | 1st (Apr. 2–8), 2nd (9–15), 3rd (16–22), 4th (23–29) | |
May | 1st (May 7–13), 2nd (15–21th), 3rd (22nd–28th) | |
June | 1st (Jun. 1–7), 2nd (8–14), 3rd (15–21), 4th (22–28) | |
July | 1st (Jul. 3–9), 2nd (10–16), 3rd (17–23), 4th (24–30) | |
August | 1st (Aug. 3–9), 2nd (10–16), 3rd (17–23), 4th (24–30) | |
September | 1st (Sep. 4–10), 2nd (11–17), 3rd (Sep. 25–Oct. 1) | |
October | 1st (Oct. 2–8), 2nd (9–15), 3rd (16–22), 4th (23–29) | |
November | 1st (Nov. 4–10), 2nd (11–17), 3rd (18–24), 4th (Nov. 25–Dec. 1) | |
December | 1st (Dec. 2–8), 2nd (9–15), 3rd (16–22) | |
2016 | January | 1st (Jan. 6–12), 2nd (13–19), 3rd (20–26), 4th (Jan. 27–Feb. 2) |
February | 1st (Feb. 3–9), 2nd (10–16), 3rd (17–23), 4th (Feb. 24–Mar. 1) | |
March | 1st (Mar. 3–9), 2nd (10–16), 3rd (17–23), 4th (24–30) | |
April | 1st (Apr. 1–7), 2nd (8–14), 3rd (15–21), 4th (22–28) | |
May | 1st (May 9–15), 2nd (16–22), 3rd (23–29) |
Statistical analyses
Results
Emergency room visits for asthma
Weekly levels of air pollutants, temperature, relative humidity, wind speed, and air pressure
Fine particle | Coarse particle | Temperature(°C) | Relative humidity (%) | Wind speed (m/s) | Air pressure (hPa) | |||||
---|---|---|---|---|---|---|---|---|---|---|
Particles (μg/m3) | Protein (μg/m3) | Endotoxin (EU/m3) | Particles (μg/m3) | Protein (μg/m3) | Endotoxin (EU/m3) | |||||
Whole | 14.4 (5.2) | 1.42 (0.84) | 0.0019 (0.0022) | 7.6 (3.3) | 0.12 (0.08) | 0.0052 (0.0052) | 15.1 (7.7) | 65.5 (6.4) | 2.1 (0.3) | 1010.2 (4.9) |
Autumn 1 | 12.2 (2.1) | 1.83 (0.74) | 0.0031 (0.0035) | 7.7 (1.1) | 0.17 (0.11) | 0.0098 (0.0089) | 18.0 (5.2) | 65.9 (5.0) | 1.9 (0.26) | 1010.7 (4.15) |
Winter 1 | 13.2 (4.4) | 1.26 (0.34) | 0.0007 (0.0006) | 7.1 (5.8) | 0.07 (0.04) | 0.0014 (0.0007) | 5.6 (1.3) | 69.2 (3.5) | 2.0 (0.3) | 1012.6 (2.7) |
Spring 1 | 18.7 (7.4) | 1.96 (0.70) | 0.0020 (0.0022) | 8.5 (3.3) | 0.16 (0.05) | 0.0039 (0.0026) | 14.6 (5.6) | 61.5 (9.2) | 2.2 (0.2) | 1010.0 (4.5) |
Summer | 12.7 (4.3) | 0.79 (0.33) | 0.0008 (0.0009) | 8.1 (2.0) | 0.19 (0.07) | 0.0076 (0.0047) | 26.1 (3.1) | 68.6 (5.1) | 2.2 (0.4) | 1002.9 (1.8) |
Autumn 2 | 11.3 (4.2) | 0.95 (0.42) | 0.0026 (0.0021) | 7.4 (2.9) | 0.05 (0.02) | 0.0074 (0.0050) | 18.1 (4.0) | 67.1 (6.2) | 1.9 (0.3) | 1011.2 (4.2) |
Winter 2 | 12.3 (3.1) | 1.20 (0.71) | 0.0010 (0.0005) | 5.5 (2.1) | 0.05 (0.03) | 0.0017 (0.0004) | 6.9 (2.6) | 65.1 (4.4) | 2.1 (0.3) | 1014.4 (3.0) |
Spring 2 | 17.8 (5.0) | 2.05 (1.32) | 0.0032 (0.0025) | 8.6 (3.6) | 0.12 (0.05) | 0.0049 (0.0031) | 15.5 (5.04) | 61.0 (5.3) | 2.2 (0.2) | 1010.1 (3.7) |
Fine particles | Protein (fine particles) | Endotoxin (fine particles) | Coarse particles | Protein (coarse particles) | Endotoxin (coarse particles) | Temperature | Relative humidity | Wind speed | Air pressure | |
---|---|---|---|---|---|---|---|---|---|---|
Fine particles | 1.00 | |||||||||
Protein (fine particles) | 0.654 (< 0.001) | 1.00 | ||||||||
Endotoxin (fine particles) | 0.212 (0.064) | 0.331 (0.003) | 1.00 | |||||||
Coarse particles | 0.551 (< 0.001) | 0.175 (0.128) | 0.134 (0.246) | 1.00 | ||||||
Protein (coarse particles) | 0.233 (0.041) | 0.169 (0.142) | 0.045 (0.695) | 0.357 (0.001) | 1.00 | |||||
Endotoxin (coarse particles) | − 0.104 (0.367) | − 0.085 (0.465) | 0.474 (< 0.001) | 0.187 (0.103) | 0.498 (< 0.001) | 1.00 | ||||
Temperature | 0.015 (0.897) | − 0.045 (0.698) | 0.218 (0.057) | 0.244 (0.032) | 0.592 (< 0.001) | 0.633 (< 0.001) | 1.00 | |||
Relative humidity | − 0.548 (< 0.001) | − 0.516 (< 0.001) | − 0.523 (< 0.001) | − 0.187 (0.103) | 0.015 (0.897) | − 0.006 (0.960) | − 0.033 (0.779) | 1.00 | ||
Wind speed | 0.026 (0.822) | 0.037 (0.750) | 0.088 (0.445) | 0.020 (0.860) | 0.104 (0.366) | 0.081 (0.485) | 0.082 (0.476) | − 0.367 (0.001) | 1.00 | |
Air pressure | 0.043 (0.709) | 0.176 (0.126) | − 0.102 (0.378) | − 0.135 (0.240) | − 0.567 (< 0.001) | − 0.463 (< 0.001) | − 0.511 (< 0.001) | 0.008 (0.944) | − 0.294 (0.009) | 1.00 |
Association of environmental factor levels with emergency department visits for asthma
Variables | Coef | SE | p value |
---|---|---|---|
Fine particles | − 0.009 | 0.011 | 0.414 |
Intercept | − 16.799 | 16.449 | 0.307 |
Temperature | 0.046 | 0.010 | < 0.001 |
Relative humidity | − 0.009 | 0.009 | 0.322 |
Wind speed | − 0.213 | 0.174 | 0.222 |
Air pressure | 0.019 | 0.016 | 0.235 |
Protein (fine particles) | 0.032 | 0.062 | 0.609 |
Intercept | − 16.566 | 16.538 | 0.317 |
Temperature | 0.046 | 0.010 | < 0.001 |
Relative humidity | − 0.002 | 0.009 | 0.823 |
Wind speed | − 0.170 | 0.172 | 0.324 |
Air pressure | 0.018 | 0.016 | 0.264 |
Endotoxin (fine particles) | 59.792 | 20.907 | 0.004 |
Intercept | − 18.420 | 16.674 | 0.269 |
Temperature | 0.043 | 0.010 | < 0.001 |
Relative humidity | 0.009 | 0.009 | 0.333 |
Wind speed | − 0.100 | 0.170 | 0.556 |
Air pressure | 0.019 | 0.016 | 0.242 |
Coarse particles | 0.044 | 0.013 | 0.001 |
Intercept | − 17.309 | 16.523 | 0.295 |
Temperature | 0.042 | 0.010 | < 0.001 |
Relative humidity | − 0.001 | 0.008 | 0.944 |
Wind speed | − 0.172 | 0.171 | 0.314 |
Air pressure | 0.018 | 0.016 | 0.251 |
Protein (coarse particles) | − 1.011 | 0.702 | 0.150 |
Intercept | − 12.459 | 16.738 | 0.457 |
Temperature | 0.049 | 0.010 | < 0.001 |
Relative humidity | − 0.004 | 0.007 | 0.588 |
Wind speed | − 0.186 | 0.168 | 0.270 |
Air pressure | 0.014 | 0.016 | 0.383 |
Endotoxin (coarse particles) | 29.637 | 9.044 | 0.001 |
Intercept | − 13.346 | 16.850 | 0.428 |
Temperature | 0.030 | 0.011 | 0.007 |
Relative humidity | − 0.007 | 0.008 | 0.343 |
Wind speed | − 0.210 | 0.174 | 0.226 |
Air pressure | 0.015 | 0.016 | 0.349 |
Variables | Spring | Summer | Autumn | Winter | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Coef | SE | p value | Coef | SE | p value | Coef | SE | p value | Coef | SE | p value | |
Fine particles | 0.024 | 0.018 | 0.199 | − 0.082 | 0.055 | 0.131 | 0.052 | 0.032 | 0.107 | 0.003 | 0.032 | 0.931 |
Intercept | − 29.035 | 37.402 | 0.438 | − 22.254 | 77.335 | 0.774 | 9.183 | 34.969 | 0.793 | 45.921 | 42.385 | 0.279 |
Temperature | 0.088 | 0.033 | 0.007 | 0.040 | 0.045 | 0.375 | 0.038 | 0.032 | 0.239 | 0.107 | 0.052 | 0.039 |
Relative humidity | 0.016 | 0.016 | 0.311 | − 0.021 | 0.043 | 0.621 | 0.016 | 0.019 | 0.419 | 0.036 | 0.029 | 0.214 |
Wind speed | 0.898 | 0.567 | 0.113 | − 0.608 | 0.453 | 0.180 | 0.537 | 0.403 | 0.183 | 0.411 | 0.500 | 0.411 |
Air pressure | 0.026 | 0.036 | 0.477 | 0.027 | 0.079 | 0.736 | − 0.010 | 0.034 | 0.763 | − 0.048 | 0.041 | 0.245 |
Protein (fine particles) | − 0.128 | 0.121 | 0.291 | − 1.039 | 0.521 | 0.046 | 0.098 | 0.129 | 0.449 | 0.048 | 0.233 | 0.837 |
Intercept | − 48.966 | 38.962 | 0.209 | − 53.432 | 80.320 | 0.506 | 11.460 | 34.557 | 0.740 | 49.651 | 46.418 | 0.285 |
Temperature | 0.119 | 0.039 | 0.002 | 0.011 | 0.047 | 0.822 | 0.038 | 0.034 | 0.252 | 0.107 | 0.051 | 0.035 |
Relative humidity | < 0.001 | 0.015 | 0.974 | 0.001 | 0.030 | 0.977 | − 0.001 | 0.015 | 0.966 | 0.035 | 0.028 | 0.221 |
Wind speed | 0.632 | 0.544 | 0.246 | − 0.505 | 0.394 | 0.200 | 0.262 | 0.359 | 0.465 | 0.367 | 0.502 | 0.465 |
Air pressure | 0.047 | 0.038 | 0.210 | 0.057 | 0.082 | 0.488 | − 0.010 | 0.034 | 0.756 | − 0.051 | 0.045 | 0.254 |
Endotoxin (fine particles) | 22.987 | 43.993 | 0.601 | 28.411 | 181.928 | 0.876 | 23.465 | 34.868 | 0.501 | 97.331 | 399.535 | 0.808 |
Intercept | − 38.240 | 37.175 | 0.304 | 33.846 | 70.257 | 0.630 | 6.580 | 34.906 | 0.850 | 49.851 | 45.574 | 0.274 |
Temperature | 0.096 | 0.032 | 0.003 | 0.049 | 0.049 | 0.309 | 0.028 | 0.032 | 0.390 | 0.103 | 0.051 | 0.042 |
Relative humidity | 0.010 | 0.015 | 0.517 | 0.035 | 0.028 | 0.210 | 0.004 | 0.020 | 0.835 | 0.044 | 0.046 | 0.336 |
Wind speed | 0.732 | 0.552 | 0.185 | − 0.163 | 0.412 | 0.692 | 0.333 | 0.382 | 0.382 | 0.361 | 0.501 | 0.471 |
Air pressure | 0.036 | 0.036 | 0.317 | − 0.035 | 0.071 | 0.618 | − 0.006 | 0.034 | 0.864 | − 0.052 | 0.045 | 0.248 |
Coarse particles | 0.065 | 0.026 | 0.013 | 0.048 | 0.071 | 0.496 | 0.087 | 0.036 | 0.017 | 0.037 | 0.020 | 0.058 |
Intercept | − 40.870 | 37.408 | 0.275 | 42.374 | 70.477 | 0.548 | − 2.956 | 35.372 | 0.933 | 34.113 | 42.135 | 0.418 |
Temperature | 0.103 | 0.034 | 0.003 | 0.035 | 0.051 | 0.500 | 0.042 | 0.033 | 0.212 | 0.096 | 0.052 | 0.066 |
Relative humidity | 0.014 | 0.015 | 0.349 | 0.033 | 0.028 | 0.227 | 0.007 | 0.015 | 0.647 | 0.042 | 0.029 | 0.146 |
Wind speed | 0.909 | 0.555 | 0.101 | − 0.155 | 0.330 | 0.640 | 0.185 | 0.358 | 0.606 | 0.631 | 0.496 | 0.203 |
Air pressure | 0.037 | 0.036 | 0.299 | − 0.044 | 0.071 | 0.537 | 0.003 | 0.034 | 0.933 | − 0.037 | 0.041 | 0.361 |
Protein (coarse particles) | − 4.194 | 2.563 | 0.102 | − 0.635 | 2.404 | 0.792 | − 1.318 | 0.909 | 0.147 | 5.056 | 2.264 | 0.026 |
Intercept | − 6.415 | 42.314 | 0.879 | 29.896 | 71.928 | 0.678 | 13.038 | 33.558 | 0.698 | 41.434 | 41.091 | 0.313 |
Temperature | 0.106 | 0.033 | 0.001 | 0.052 | 0.049 | 0.295 | 0.044 | 0.033 | 0.185 | 0.114 | 0.052 | 0.028 |
Relative humidity | 0.002 | 0.014 | 0.867 | 0.038 | 0.030 | 0.216 | < 0.001 | 0.015 | 0.983 | 0.036 | 0.028 | 0.205 |
Wind speed | 0.609 | 0.551 | 0.269 | − 0.165 | 0.359 | 0.646 | 0.256 | 0.355 | 0.471 | 0.361 | 0.467 | 0.440 |
Air pressure | 0.006 | 0.041 | 0.892 | − 0.031 | 0.072 | 0.663 | − 0.012 | 0.033 | 0.716 | − 0.044 | 0.040 | 0.272 |
Endotoxin (coarse particles) | 9.069 | 32.095 | 0.778 | 45.832 | 26.900 | 0.088 | 10.432 | 15.789 | 0.509 | 311.199 | 208.761 | 0.136 |
Intercept | − 34.800 | 38.148 | 0.362 | 18.278 | 70.654 | 0.796 | 9.706 | 34.671 | 0.780 | 56.880 | 44.515 | 0.201 |
Temperature | 0.094 | 0.035 | 0.007 | 0.019 | 0.049 | 0.706 | 0.018 | 0.037 | 0.619 | 0.059 | 0.058 | 0.314 |
Relative humidity | 0.006 | 0.014 | 0.677 | 0.022 | 0.028 | 0.434 | − 0.005 | 0.015 | 0.731 | 0.046 | 0.029 | 0.112 |
Wind speed | 0.657 | 0.545 | 0.228 | − 0.315 | 0.362 | 0.384 | 0.243 | 0.359 | 0.498 | 0.254 | 0.485 | 0.600 |
Air pressure | 0.033 | 0.037 | 0.370 | − 0.018 | 0.071 | 0.799 | − 0.008 | 0.034 | 0.813 | − 0.059 | 0.043 | 0.171 |