Hospital admissions for asthma and chronic obstructive airways disease in east London hospitals and proximity of residence to main roads.

We describe a matched case-control study investigating the association between respiratory illness and proximity of residence to main roads. The study was carried out in response to previously inconsistent reports on this question; the null hypothesis was of no association of traYc related air pollution to respiratory illness, hospital admissions for asthma and chronic obstructive airways disease. The study focused on Tower Hamlets, East London where hospital admissions for asthma are 80% above national rates. 2