Table 4.

Comparisons of percent changes in FEV₁ during and post-exposure in the transport hub and the park

Time points	Transport hub		Park		P value
	Mean	95 % CI	Mean	95 % CI
During exposure 1 h	−3.48	−4.43, −2.53	−0.32	−1.28, 0.64	0.01*
During exposure 2 h	−4.43	−5.47, −3.39	−1.59	−2.68, −0.50	0.04*
Post-exposure 5 h	−2.53	−3.93, −1.13	−2.28	−3.90, −0.66	0.13
Post-exposure 7 h	−2.22	−3.56, −0.88	−1.96	−3.68, −0.24	0.37
Post-exposure 9 h	−1.11	−2.41, 0.21	−1.28	−2.85, 0.29	0.67
Post-exposure 22 h	−2.21	−4.25, −0.17	−1.64	−3.55, 0.27	0.21

95 % CI 95 % confidence intervals

* P < 0.05