Contribution of smoking and air pollution exposure in urban areas to social differences in respiratory health

BMC Public Health

Table 2 Respiratory health risk factors by SES (educational level)

Respiratory health risk factors	SES: all grades		<10 years		= 10 years of school education		>10 years		P-value¹ of linear trend effect of SES
	N	%	N	%	N	%	N	%
Occupational exposure ²	1251	14.2	318	16.4	637	15.1	296	10.1	0.0296
Current smoker		17.5		20.3		17.9		13.9	0.0368
Non-smoker with ETS	1243	36.6	315	38.4	632	37.3	296	33.1	0.1780
Non-smoker without ETS		45.9		41.3		44.8		53.0	0.0038
Distance to major road with >10.000 cars/day 0–100 m	1216	22.1	304	26.0	624	19.9	288	22.9	0.3490
	N	AM	N	AM	N	AM	N	AM
		SD		SD		SD		SD
PM ₁₀ 5-years mean	1254	49.4	318	50.0	637	49.7	296	48.2	<0.0001
		4.6		4.3		4.4		5.2
NO ₂ 5-years mean	1254	49.2	318	49.1	637	49.3	296	49.4	0.3941
		4.3		4.6		4.1		4.2

¹ p-value of the logistic regression
² Dust, gases, vapours, wet conditions or extreme temperature
Abbreviations:
NO_2: Nitrogen dioxide; PM₁₀: Particulate matter with aerodynamic diameter of ≤ 10 μm, calculated as PM₁₀ = 0.71*TSP; TSP: Total suspended particles; AM: Arithmetic mean; SD: Standard deviation

ISSN: 1471-2458