Lane Cove Tunnel Investigation

Current CAR investigators involved: CI Marks and Jalaludin, AIs Smith and Brunekreef

The opening of a dual stack ventilated road tunnel in inner north-western Sydney in early 2007 provided a unique opportunity to assess the impact of road-traffic intervention on air quality exposures and health in the local community. The tunnel was designed to divert traffic off a heavily congested surface road. The main aim of the study was to establish whether changes in air quality occurring after the tunnel opened affected the health of the local community.

Data collection and primary analysis have been completed. Principal findings were the absence of consistent changes in regional air quality related to the tunnel intervention despite a substantial reduction in NO2 exposure in the vicinity of the main bypassed road. These local improvements in air quality were not associated with improvements in respiratory symptoms or lung function. Manuscripts reporting the findings in relation to air quality changes and clinical outcomes are being submitted for publication and to NSW Health. Although the primary analysis has been completed, a number of important questions remain to be answered.

Traffic-related air pollution, including NO2 and other oxides of nitrogen, are increasingly recognised as a key source of pollutant exposure in urban environments. Intervention studies in this field are extremely rare and offer a unique opportunity to assess the impact of changes in air pollution, unconfounded by meteorological events that are usually responsible for natural changes.