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Table 3 Spearman’s rank correlation coefficients for exposure variables from the 5-minute time period

From: Traffic-related air pollution exposures and changes in heart rate variability in Mexico City: A panel study

 

PM2.5

Ozone

CO

CO2

Formaldehyde

NO2

NOx

PM2.5 (n = 3314)

1.0

      

Ozone (n = 4406)

0.33

1.0

     

CO (n = 4353)

0.24

−0.07

1.0

    

CO2 (n = 4371)

0.27

−0.06

0.78

1.0

   

Formaldehyde (n = 1784)

0.56

0.36

0.79

0.77

1.0

  

NO2 (n = 4406)

0.21

−0.007

0.84

0.72

0.60

1.0

 

NOx (n = 4406)

−0.13

−0.34

0.79

0.70

0.52

0.81

1.0

  1. Sample sizes are the total number of repeated observations across all 16 subjects.
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Environmental Health

ISSN: 1476-069X