Annual mean levels of air pollutants at residential address, by year and averaged across study period, μg/m³.

<p>Values are mean ± SD (range);</p><p>* air pollution data were not available for two participants (one in each of Years 1 and 2 of the study) because their residential addresses were outside the Greater London area</p><p>Annual mean levels of air pollutants at residential address, by year and averaged across study period, μg/m³.</p

Odds ratios for associations of potentially confounding variables with prevalence of lifetime (ever having had) asthma, hay fever and eczema.

<p>Data shown as odds ratio (OR) for unit increase in variable unless otherwise stated, with 95% confidence intervals in brackets; ORs adjusted for all variables shown in table; ETS exposure = positive urinary cotinine:creatinine ratio (CCR ≥ 30ng/mg);</p><p>* p<0.05</p><p>**p<0.01</p><p>Odds ratios for associations of potentially confounding variables with prevalence of lifetime (ever having had) asthma, hay fever and eczema.</p

Odds ratios for associations of potentially confounding variables with prevalence of current respiratory/allergic symptoms.

<p>Data shown as odds ratio (OR) for unit increase in variable unless otherwise stated, with 95% confidence intervals in brackets; ORs adjusted for all variables shown in table; ETS exposure = positive urinary cotinine:creatinine ratio (CCR ≥ 30ng/mg);</p><p>* p<0.05</p><p>**p<0.01</p><p>Odds ratios for associations of potentially confounding variables with prevalence of current respiratory/allergic symptoms.</p

Prevalence of current respiratory/allergic symptoms among all children, and by sex and ethnicity.

<p>Percentages are for rows, except for first column which reads vertically (e.g. 49.9% of all respondents were male; 14.1% of males have current wheeze); percentages may not add to 100.0 due to rounding</p><p>Prevalence of current respiratory/allergic symptoms among all children, and by sex and ethnicity.</p

Exposure to air pollution as a risk factor for current and lifetime respiratory/allergic symptoms.

<p>Adjusted associations between air pollutants and the prevalence of current and lifetime respiratory/allergic symptoms. Odds ratios adjusted for age, sex, BMI, socio-economic deprivation (IMD score), ETS exposure and year of study, with a random effect for school. Single-pollutant models were calculated for each air pollutant. Odds ratios are for unit increase in pollutant, in μg/m³. Current symptoms defined as within the last 12 months; lifetime conditions defined as ‘having ever had’ asthma, hay fever or eczema. Vertical dotted line indicates null (OR = 1). Horizontal lines indicate 95% confidence intervals of odds ratios. * p<0.05, **p<0.01</p