Table 2 Association between mean annual exposure of the home address to locally generated primary PM₁₀ and prevalence of respiratory symptoms in young children.

	Unadjusted			Adjusted*
	OR†	95% CI	n‡	OR†	95% CI	n‡
Cough without a cold
1998	1.22	1.10 to 1.36	2567	1.21	1.07 to 1.38	2164
2001	1.46	1.27 to 1.68	2301	1.56	1.32 to 1.84	1756
Night time cough
1998	1.11	1.01 to 1.23	2579	1.06	0.94 to 1.19	2174
2001	1.25	1.09 to 1.43	2318	1.25	1.06 to 1.47	1771
Current wheeze
1998	0.99	0.89 to 1.10	2584	0.99	0.88 to 1.12	2175
2001	1.09	0.93 to 1.30	2331	1.28	1.04 to 1.58	1774

OR, odds ratio; CI, confidence interval.

*Adjusted for confounding variables in table 1.

†Per μg/m³ increase in locally generated primary PM₁₀.

‡Number of responses.