Table 1 Characteristics of the study population according to self-reported traffic, distance from high traffic roads (HTRs), metres of HTRs within 200 m from home, particulate matter (PM) emissions, and estimated nitrogen dioxide (NO2) from the land-use regression model
n%Self-reported intense traffic (%)Distance from HTR, mean (SD)Metres of HTR within 200 m from home, mean (SD)PM emissions (kg/m2), mean (SD)Estimated NO2 (μg/m3), mean (SD)
Gender
    Males449147.315.0464 (531)684 (474)0.120 (0.081)45.3 (8)
    Females499752.715.0463 (536)684 (466)0.120 (0.081)45.5 (8)
    p Value0.8910.8700.9580.4480.043
Age (years)
    25–34172218.212.2598 (610)677 (411)0.098 (0.080)43.2 (8)
    35–44553958.415.2452 (535)668 (470)0.121 (0.080)45.4 (8)
    45+222823.516.4389 (438)723 (491)0.136 (0.082)47.0 (8)
    p0.003<0.0010.037<0.001<0.001
Education (years)
    <9428245.111.6559 (623)688 (462)0.106 (0.079)43.6 (8)
    9–13369038.917.2414 (453)699 (477)0.126 (0.082)46.2 (8)
    >13135614.319.5292 (328)641 (463)0.148 (0.076)49.1 (7)
    p trend<0.001<0.0010.153<0.001<0.001
Occupation
    Managerial/professional111211.718.2349 (395)628 (454)0.132 (0.079)47.3 (8)
    Other non-manual378539.916.9418 (484)700 (482)0.130 (0.082)46.4 (8)
    Manual labour124813.213.3543 (594)690 (466)0.109 (0.079)44.1 (8)
    Other or unemployed114712.112.2498 (547)650 (434)0.111 (0.080)44.3 (8)
    Housewife209122.012.2534 (605)702 (471)0.108 (0.081)43.9 (8)
    p trend*<0.001<0.0010.750<0.001<0.001
Area-based SEP
    High169817.919.6272 (261)649 (495)0.157 (0.076)50.3 (6)
    Medium high168817.821.0310 (361)748 (512)0.147 (0.081)48.2 (8)
    Intermediate165717.519.9398 (483)689 (459)0.136 (0.082)46.4 (8)
    Medium low182419.211.4511 (549)683 (414)0.098 (0.076)42.4 (8)
    Low243225.67.1709 (669)589 (388)0.083 (0.066)41.6 (7)
    p trend<0.001<0.0010.144<0.001<0.001
Smoking habit
    Non-smoker297731.414.8440 (504)688 (474)0.121 (0.083)45.4 (8)
    Ex-smoker264127.815.8462 (548)683 (465)0.120 (0.080)45.7 (8)
    Current smoker382240.314.2481 (545)682 (469)0.119 (0.081)45.2 (8)
    p trend0.4780.0060.7840.2510.194
Humidity or moulds
    No901095.015.0460 (530)684 (468)0.121 (0.081)45.5 (8)
    Yes4114.313.1551 (581)698 (511)0.100 (0.079)43.0 (8)
    p Value0.4510.0230.820<0.0010.936
Chronic bronchitis or emphysema
    No909195.814.9463 (535)683 (470)0.120 (0.081)45.4 (8)
    Yes3974.217.5466 (492)712 (468)0.119 (0.077)45.3 (8)
    p Value0.1830.9190.4910.8580.818
Asthma
    No901695.014.8465 (537)685 (469)0.120 (0.081)45.4 (8)
    Yes4725.019.1442 (463)659 (472)0.121 (0.081)45.7 (8)
    p Value0.0160.3470.4900.8660.379
Rhinitis
    No826187.114.7468 (539)681 (465)0.119 (0.081)45.3 (8)
    Yes122712.917.3431 (495)701 (499)0.127 (0.081)46.4 (8)
    p Value0.0180.0150.4340.001<0.001
  • SEP, socioeconomic position.Totals may vary because of missing information.

  • p for testing homogeneity.

  • *Housewives are excluded.