Background
Methods
Statistical analysis
Results
Population and Exposure to Contaminants
School 1 n = 239 | School 2 n = 225 | p | |
---|---|---|---|
Gender (female/male) | 118/121 | 117/108 | 0.60 |
Age (years) | 9.0 ± 1.6 | 9.2 ± 1.5 | 0.11 |
Weight (k) | 34.8 ± 11.4 | 36.4 ± 11.6 | 0.13 |
Height (cm) | 134.0 ± 10.8 | 135.5 ± 10.6 | 0.08 |
BMI | 19.1 ± 3.7 | 19.1 ± 3.6 | 0.75 |
Previous diseases and symptoms n (%) | |||
Bronchitis | 29 (12.1) | 24 (10.6) | 0.74 |
Pneumonia | 17 (7.1) | 9 (4.0) | 0.14 |
Cough | 219 (91.6) | 207 (86.6) | 0.16 |
Acute asthma | 3 (1.2) | 0 (0.0) | 0.34 |
Acute respiratory tract infections | 221 (92.4) | 178 (79.1) | 0.001 |
Hospitalization for asthma | 2 (0.8) | 0 (0.0) | 0.60 |
Hospitalization for acute respiratory tract infections | 13 (5.4) | 5 (2.0) | 0.07 |
FEV1 (%p)* | 102.5 ± 21.1 | 101.5 ± 14.4 | 0.55 |
FVC (%p)* | 109.3 ± 23.7 | 109.2 ± 18.0 | 0.95 |
FEV1/FVC (c) | 92.6 ± 9.8 | 91.6 ± 10.0 | 0.24 |
PEFR (%p) | 106.5 ± 26.7 | 107.1 ± 24.3 | 0.81 |
Variables |
Spring
|
Summer
|
Fall
|
Winter
| |
---|---|---|---|---|---|
O3 (μg/m3) | School 1 | 28.7 ± 2.7 | 28.1 ± 0.7 | 15.4 ± 0.1 | 20.2 ± 0.7 |
School 2 | 17.6 ± 0.3 | 23.6 ± 1.6 | 39.8 ± 1.3 | 33.2 ± 1.9 | |
p*
| 0.001 | 0.001 | 0.001 | 0.001 | |
SO2 (μg/m3) | School 1 | 31.2 ± 1.1 | 32.1 ± 0.7 | 27.2 ± 0.7 | 25.8 ± 0.4 |
School 2 | 23.9 ± 1.1 | 23.0 ± 1.4 | 26.8 ± 1.6 | 35.6 ± 1.9 | |
p*
| 0.002 | 0.001 | 0.01 | 0.001 | |
CO (ppm) | School 1 | 0.84 ± 0.09 | 0.37 ± 0.07 | 0.26 ± 0.01 | 0.81 ± 0.09 |
School 2 | 1.4 ± 0.4 | 1.9 ± 0.9 | 2.4 ± 1.4 | 5.8 ± 0.9 | |
p*
| 0.001 | 0.001 | 0.001 | 0.001 | |
NO (μg/m3) | School 1 | 18.4 ± 1.9 | 11.1 ± 0.4 | 4.7 ± 1.9 | 15.6 ± 1.3 |
School 2 | 18.5 ± 1.7 | 6.6 ± 1.1 | 126.0 ± 7.7 | 65.4 ± 15.1 | |
p*
| 0.75 | 0.015 | 0.001 | 0.001 | |
NO2 (μg/m3) | School 1 | 66.4 ± 4.2 | 12.4 ± 0.2 | 7.4 ± 0.2 | 14.9 ± 1.9 |
School 2 | 6.3 ± 1.5 | 2.6 ± 0.6 | 51.6 ± 17.1 | 28.7 ± 3.0 | |
p*
| 0.001 | 0.024 | 0.001 | 0.002 | |
NOx (μg/m3) | School 1 | 81.6 ± 6.9 | 19.6 ± 0.5 | 11.5 ± 0.2 | 27.8 ± 2.0 |
School 2 | 24.6 ± 2.5 | 6.9 ± 1.3 | 156.1 ± 9.3 | 92.2 ± 21.4 | |
p*
| 0.001 | 0.018 | 0.001 | 0.001 | |
PM10 (μg/m3) | School 1 | 77.9 ± 2.9 | 60.7 ± 1.4 | 41.7 ± 1.0 | 60.8 ± 3.3 |
School 2 | 53.1 ± 24.4 | 11.3 ± 3.2 | 7.4 ± 0.7 | 77.9 ± 2.9 | |
p*
| 0.001 | 0.001 | 0.013 | 0.001 | |
Temperature (°C) | School 1 | 19.3 ± 0.1 | 20.9 ± 0.1 | 20.2 ± 0.4 | 16.2 ± 0.7 |
School 2 | 15.4 ± 0.5 | 16.8 ± 0.1 | 16.5 ± 0.1 | 12.1 ± 0.5 | |
p*
| 0.001 | 0.028 | 0.007 | 0.001 | |
Relative humidity (%) | School 1 | 54.0 ± 0.9 | 52.9 ± 0.7 | 74.6 ± 0.1 | 65.7 ± 0.6 |
School 2 | 50.9 ± 1.2 | 50.4 ± 2.3 | 74.0 ± 0.8 | 66.4 ± 2.5 | |
p*
| 0.02 | 0.078 | 0.129 | 0.001 |
Allergic Diseases and Respiratory Symptoms
Variables | Spring | Summer | Fall | Winter | |
---|---|---|---|---|---|
Wheezing n (%) | School 1 | 50 (20.9) | 25 (10.4) | 25 (10.4) | 220 (92.0) |
School 2 | 22 (9.7) | 12 (5.3) | 16 (7.1) | 216 (96.0) | |
p*
| 0.0001 | 0.04 | 0.20 | 0.61 | |
Rhinorrhea n (%) | School 1 | 139 (58.1) | 82 (34.3) | 84 (35.1) | 74 (30.9) |
School 2 | 88 (39.1) | 66 (29.3) | 67 (29.7) | 61 (27.1) | |
p*
| 0.0001 | 0.25 | 0.03 | 0.36 | |
Eczema n (%) | School 1 | 12 (5.0) | 18 (7.5) | 6 (2.3) | 31 (12.9) |
School 2 | 11 (4.8) | 11 (4.8) | 11 (4.8) | 10 (4.4) | |
p*
| 0.94 | 0.40 | 0.17 | 0.001 | |
Acute respiratory tract infection n (%) | School 1 | 78 (32.6) | 54 (22.5) | 38 (15.8) | 206 (86.1) |
School 2 | 57 (25.3) | 43 (19.1) | 77 (34.2) | 178 (79.1) | |
p*
| 0.50 | 0.35 | 0.001 | 0.04 | |
Dyspnea n (%) | School 1 | 44 (18.4) | 26 (10.8) | 17 (7.1) | 36 (15.0) |
School 2 | 25 (11.1) | 20 (8.8) | 21 (9.3) | 26 (11.5) | |
p*
| 0.02 | 0.47 | 0.38 | 0.26 | |
Hospitalization for ARTI n (%) | School 1 | 2 (0.8) | 2 (0.8) | 2 (0.8) | 17 (7.1) |
School 2 | 1 (0.4) | 1 1 (0.4) | 1 1 (0.4) | 5 (2.2) | |
p*
| 0.59 | 0.59 | 0.59 | 0.01 |
Respiratory symptoms | ||||||
---|---|---|---|---|---|---|
Wheezing OR† (95%CI) | Rhinorrhea OR† (95%CI) | Eczema OR† (95%CI) | ARTI OR† (95%CI) | Dyspnea OR † (95%CI) | Hospitalization by ARTI OR† (95%CI) | |
O
3
(
μg/m
3
)
| 1.0464 (1.0160, 1.0777)* | 1.0429 (1.0000, 1.0881)* | 0.9973 (0.9770, 1.0181) | 1.0820 (1.0405, 1.1251)* | 1.0313 (1.0025, 1.0609)* | 1.0008 (0.9893, 1.0123) |
SO
2
(
μg/m
3
)
| 1.0213 (1.0018, 1.0413)* | 0.9929 (0.9675, 1.0209) | 0.9969 (0.9835, 1.0105) | 1.0521 (1.0254, 1.0794)* | 1.0082 (0.9893, 1.0271) | 0.9985 (0.9910, 1.0061) |
NO
2
(
μg/m
3
)
| 0.8432 (0.7630, 1.0318) | 0.8443 (0.7312, 1.0748) | 1.0714 (0.9990, 1.1490) | 0.8942 (0.7832, 1.0208) | 0.9236 (0.8394, 1.0167) | 1.0378 (0.9982, 1.0791) |
PM
10
(
μg/m
3
)
| 1.0478 (1.0329, 1.0630)* | 1.0318 (1.0107, 1.0534)* | 0.9974 (0.9875, 1.0075) | 1.0977 (1.0771, 1.1188)* | 1.0184 (1.0044, 1.0378)* | 0.9991 (0.9935, 1.0047) |
Temperature (°C)
| 0.6520 (0.5407, 0.7863)* | 0.8914 (0.6810, 1.1668) | 1.0457 (0.9174, 1.0192) | 0.3842 (0.2998, 2.0312) | 0.8669 (0.7242, 1.0378) | 0.9975 (0.9273, 1.0730) |
School
| 1.6696 (1.2966, 2.499)* | 1.5749 (1.0955, 2.2645)* | 0.8596 (0.7206, 1.0253) | 1.5218 (1.0897, 2.1252)* | 1.2422 (0.9745, 1.5834) | 0.9386 (0.8508, 1.0355) |
Atopy
| 1.0535 (0.9735, 1.1400) | 1.1192 (1.0102, 1.2399)* | 1.0493 (1.0018, 1.0991)* | 1.0873 (0.9973, 1.1855) | 1.0631 (0.9901, 1.1415) | 1.0257 (0.9996, 1.0525) |
Allergen
| 1.0127 (0.9719, 1.0552) | 0.9620 (0.9120, 1.0147) | 1.0078 (0.9838, 1.0324) | 1.0097 (0.9653, 1.0562) | 0.9715 (0.9362, 1.0081) | 0.9961 (0.9828, 1.0096) |
Fossil fuels
| 1.0084 (0.9683, 1.0503) | 1.0537 (0.999, 1.1108) | 1.0015 (0.9779, 1.0256) | 0.9940 (0.9507, 1.0393) | 1.0007 (0.9648, 1.0381) | 0.9993 (0.9861, 1.0127) |
Passive smoking
| 1.0259 (0.9826, 1.0711) | 1.0010 (0.9465, 1.0586) | 1.0159 (0.9905, 1.0419) | 1.0432 (0.9951, 1.0937) | 1.0253 (0.9862, 1.0659) | 1.0086 (0.9945, 1.0230) |
Pulmonary Function
Lung function | ||||
---|---|---|---|---|
FVC β† (95%CI) | FEV1 β† (95%CI) | PEF β† (95%CI) | FEV1/FVC β† (95%CI) | |
O3 (μg/m
3) | -0.0746 (-0.1018, -0.0474)* | -0.0046 (-0.0064, -0028)* | -0.0160 (-0.0219, -0.0101)* | 0.0578 (-0.0048, 0.1205) |
SO2 (μg/m
3) | -0.0248 (-0.0426, -0.0069)* | -0.0029 (-0.004, -0.0017)* | -0.0103 (-0.0142, -0.0064)* | -0.0278 (-0.069, 0.0133) |
NO2 (μg/m
3) | 0.1572 (0.0648, 0.2496)* | 0.0132 (0.0070, 0.0193)* | 0.0484 (0.2840, 0.6869)* | 0.0284 (-0.1845, 0.2414) |
PM10 (μg/m
3) | -0.0142 (-0.0274, -0.0009)* | -0.0028 (-0.0036, -0.0019)* | -0.1519 (-0.1807, -0.1230)* | -0.0691 (-0.0996, -0.0385)* |
Temperature (°C) | 0.3220 (0.0148, 0.4959)* | 0.0263 (0.0147, 0.0379)* | 1.1837 (0.805, 1.5623)* | 0.03621 (-0.3635, 0.4359) |
School | -0.3019 (-0.5400, -0.0638)* | -0.2800 (-0.1163, 0.0759) | -1.2844 (-1.8012, -0.7675)* | -1.8346 (-7.2676, 3.5982) |
Atopy | -0.0252 (-0.1440, 0.0936) | -0.0201 (-0.1163, 0.0759) | 0.0021 (-0.2371, 0.2415) | -0.4488 (-2.6628, 1.7640) |
Allergen | 0.0068 (-0.0550, 0.0686) | -0.0165 (-0.0665, 0.0335) | -0.0306 (-0.1552, 0.0939) | -0.4686 (-1.6205, 0.6832) |
Fossil fuels | -0.0186 (-0.0798, 0.0425) | -0.0142 (-0.0637, 0.0352) | -0.1179 (-0.2412, 0.0052) | 0.1946 (-0.9447, 1.339) |
Passive smoking | -0.0219 (-0.0868, 0.0493) | -0.0276 (-0.0801, 0.0248) | -0.0966 (-0.2272, 0.0340) | -0.3535 (-1.5614, 0.8544) |
FVC (%) | FEV1(%) | PEF (%) | FEV1/FVC | |
---|---|---|---|---|
Models#
| Percent change (95%CI) | Percent change (95%CI) | Percent Change (95%CI) | % (95%CI) |
Girls | ||||
One-pollutant model
| ||||
O3 8 hr-average &
| -0.21 (-0.84, 0.45) | -0.34 (-1.21, 0.57) | -0.27 (-1.55, 0.98) | 0.24 (0.11, 0.37)* |
PM10 24 hr-average §
| -0.23 (-1.26, 0.82) | -0.37 (-0.56, -0.13) * | -0.29 (-0.45, -0.14) * | 0.11 (0.04, 0.18)* |
SO2 24 hr-average ¶
| -0.09 (-0.33, 0.18) | -0.11 (-0.61, 0.42) | -0.04 (-0.76, 0.65) | 0.15 (0.03, 0.28)* |
Two-pollutant models
| ||||
O3 8 hr-average &
| -0.12 (-0.46, 0.25) | -0.14 (-0.37, 0.07) | -0.11 (-0.45, 0.29) | 0.19 (0.11, 0.27)* |
PM10 24 hr-average §
| -0.23 (-0.75, 0.29) | -0.27 (-0.48, -0.06)* | -0.22 (-0.75, 0.31) | 0.09 (-0.01, 0.19) |
O3 8 hr-average &
| -0.18 (-0.62, 0.27) | -0.23 (-0.42, -0.03) * | -0.17 (-0.33, -0.02)* | 0.23 (0.12, 0.34)* |
SO2 24 hr-average ¶
| -0.04 (-0.23, 0.14) | 0.11 (-0.25, 0.45) | -0.06 (-0.47, 0.33) | 0.10 (0.03, 0.18)* |
PM10 24 hr-average §
| -0.37 (-0.69, -0.01) * | -0.13 (-0.44, 0.20) | -0.25 (-0.47, -0.03) * | 0.05 (-0.03, 0.14) |
SO2 24 hr-average ¶
| -0.07 (-0.58, 0.44) | 0.06 (-0.48, 0.61) | 0.03 (-0.65, 0.69) | 0.18 (0.10, 0.26)* |
Boys | ||||
One-pollutant model
| ||||
O3 8-hr average &
| -0.11 (-0.64, 0.42) | -0.36 (-0.61, -0.12)* | -0.22 (-0.66, 0.21) | 0.21 (0.09, 0.33)* |
PM10 24-hr average §
| -0.24 (-0.53, 0.07) | -0.43 (-0.76, -0.11)* | -0.36 (-0.68, -0.04)* | 0.02 (-0.05, 0.13) |
SO2 24 hr-average ¶
| 0.17 (-0.41, 0.76) | 0.08 (-0.26, 0.42) | -0.05 (-0.37, 0.28) | 0.13 (0.02, 0.24)* |
Two-pollutant models
| ||||
O3 8 hr-average &
| -0.06 (-0.50, 0.38) | -0.15 (-0.43, 0.13) | -0.22 (-0.77, 0.34) | 0.14 (0.05, 0.23)* |
PM10 24 hr-average §
| -0.20 (-0.59, 0.21) | -0.66 (-1.08, -0.24)* | -0.57 (-1.01, -0.14) * | -0.003 (-0.05, 0.045) |
O3 8 hr-average &
| -0.32 (-0.60, -0.04)* | -0.41 (-0.78, -0.05) * | -0.33 (-0.52, -0.15)* | 0.16 (0.09, 0.24)* |
SO2 24 hr-average ¶
| 0.14 (-0.43, 0.72) | 0.09 (-0.31, 0.50) | -0.12 (-0.58, 0.34) | 0.09 (0.02, 0.17)* |
PM10 24 hr-average §
| -0.34 (-0.60, -0.10)* | -0.29 (-0.72, -0.15)* | -0.28 (-0.51, -0.06)* | 0.03 (-0.08, 0.14) |
SO2 24 hr-average ¶
| 0.05 (-0.61, 0.72) | 0.06 (-0.63, 0.74) | 0.03 (-0.87, 0.93) | 0.14 (0.04, 0.25)* |