Table 1.

Relative risks (RR) per 10 μgm⁻³ with associated 95% confidence intervals (CI) from fitting models with different lags of exposure and the average of the previous three days. Data from Greater London, 2002–2005

Lag	Exposure	RR	95% CI
0	Xt	1.017	1.001 – 1.034
1	Xt−1	1.021	1.005 – 1.038
2	Xt−2	1.020	1.004 – 1.036
3	Xt−3	1.013	0.997 – 1.029
avg. 1–3	${\sum }_{i=l}^3{X}_{t-l}/3$	1.030	1.010 – 1.050