Table 2 Pollutant levels and climatologically data in the studied zones during all seasons; Salamanca, Guanajuato, 2004 - 2005

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