Background
Lancaster University (LU) union representatives raised concerns about poor air quality in an Underpass at the Bailrigg campus. LU contacted DustScanAQ seeking assistance on rectifying the problem.
Issue
Conditions in the Underpass were a perfect storm for poor air quality: no mechanical ventilation, unrestricted private vehicle traffic, over 300 idling buses and thousands of students per day waiting at the kerbside.
Solution
DustScanAQ undertook a six-month survey at the Underpass, monitoring the key pollutants associated with traffic emissions. A low-cost automatic monitor was recommended, which provided accurate results but also fit in with LU’s budgetary constraints. A series of six-monthly reports were produced by DustScanAQ which documented the fluctuations in pollutant concentrations over the monitoring period. The results of the monitoring informed the mitigation measures, which were discussed with LU and then implemented at the end of September.
Outcome
The first four months (June – September) of monitoring recorded 14 exceedances of the NO2 one-hour mean objective: it looked certain that the 18 allowable exceedances per calendar year would be surpassed. Following discussions with LU, several mitigation measures were implemented in September. These included widening the footpath, upgrading over 30% of the bus fleet to Euro VI engines and introducing a one-way system for buses only. The graph below shows the average hourly fluctuation of NO2 concentrations in the Underpass over the six-month monitoring period.
The final two months (October and November) of monitoring saw improvements in concentrations related to the mitigation implemented by Lancaster University in September. This resulted in zero exceedances of the one-hour being recorded in these final two months, as well as a reduction in PM10 and PM2.5 concentrations. DustScanAQ will continue monitoring at the Underpass for a further six months, starting from the beginning of 2020. This monitoring survey will be used to inform continued mitigation measures to further improve air quality in the Underpass.