Air Quality
According to the EIS report carried out by the National Children’s Hospital, Construction dust has the potential to cause local impacts through dust nuisance at the nearest sensitive receptors (including hospital buildings).
In addition to construction dust, there is the potential for Aspergillus impacts to occur. Construction activities such as excavation, earth moving and backfilling may generate quantities of dust, particularly in dry and windy weather conditions. While dust from construction activities tends to be deposited within 200 m of a construction site, the majority of the deposition occurs within the first 50 m
The extent of any dust generation depends on the nature of the dust (soils, peat, sands, gravels, silts etc.) and the nature of the construction activity. In addition, the potential for dust dispersion and deposition depends on local meteorological factors such as rainfall, wind speed and wind direction. Vehicles transporting material to and from the site also have the potential to cause dust generation along the selected haul routes from the construction areas
Operational Phase – Air Quality
There is the potential for a number of emissions to the atmosphere during the operational phase of the development. In particular, the traffic-related air emissions may generate quantities of air pollutants such as NO2, CO, benzene and PM10. The energy requirements of the site from boilers and generators may also give rise to some air emissions.
Climate
There is the potential for a number of greenhouse gas emissions to atmosphere during the operational phase of the development. Road traffic and space heating of buildings may give rise to CO2 and N2O emissions. There is the potential for a number of greenhouse gas emissions to atmosphere during the construction of the development. Construction vehicles, generators etc., may give rise to CO.
Vehicles (including HGV’s and LGV’s) travelling to and from the site during the construction phase have the potential to cause dust nuisance at nearby sensitive receptors. The receptors modelled represent the worst-case locations close to the proposed development and were chosen due to their close proximity (within 200 m) to the road links which will be impacted by the addition of construction traffic during the construction phase of the proposed development.
The traffic data used in this assessment was provided by Arup Consulting Engineers. Worst case speeds i.e. peak hour speeds were applied to the applicable road links.
PM10 concentrations are well within the annual limit value at all worst-case receptors. In addition, the 24-hour PM10 concentration of 50 μg/m3 , which can only be exceeded 35 times per year within the limit, is found to be in compliance at all receptors. The greatest number of exceedances are predicted to be 2 days per year at each receptor. Annual average PM10 concentrations are at most, 46% of the limit value, at the worst-case receptor. PM2.5 concentrations at all worst-case receptors are well below the limit value of 25 μg/m3 . The annual average PM2.5 concentration peaks at most, 48% of the limit value, at the worst-case receptor.