To ask the Secretary of State for Environment, Food and Rural Affairs, what comparative estimate he has made of the proportion of (a) PM 10 and (b) PM 2.5 particulate matter emissions in the vicinity of an incinerator that come from the incinerator and those that exist independently in the vicinity of an incinerator.
Estimates of total particulate matter from incinerators compared to a local environment are made at the point of permitting using dispersion modelling techniques. The modelling estimates the total particulate released from an incinerator and combines this data with site specific information on the ambient air quality in the local environment to establish the contributory impact.
Dispersion modelling is undertaken at the individual incinerator location taking into account the rate of particulate release, the height of stack, the temperature of the plume and the local topography. This modelling shows the impact on the local area of the installation. By incorporating local metrological conditions and background particulate levels (established by local authority testing stations) it is possible to gauge the relative impacts of the incinerators.