Air quality data

We monitor air pollution and compare the data against the national air quality targets to identify long-term trends.

You can view graphs of air quality data measurements from the Harrow automatic monitoring sites, over the last month. These graphs are up dated every month:

Mean Daily NO2 (ppb) concentrations from Harrow 1 and Harrow 2
PM10 (ug M-3) mean concentrations and 24 hour running mean for Harrow 1 and Harrow 2
SO2 (ppb) mean concentration and 15 minute mean for Harrow 1

The latest air quality data is available in the downloads section.

An archive of pervious air quality from the Harrow monitoring sites are available.

Longer-term Air Quality Monitoring

Two types of Diffusion tubes are located around the borough sampling for Nitrogen Dioxide and Benzene.

This form of monitoring uses a passive method, this means they do not use a pump to pull air through the sampler, instead air 'diffuses' into the sampler over the sampling period. The tubes are then collected and sent to a laboratory for analysis. Diffusion tubes are a simple way of monitoring air pollution and allow a greater number of sites to be monitored. As they do not require a power source or large amount of space for use they can be employed a greater number of sites than the continuous monitoring stations.

To view a list of sites for Nitrogen Dioxide and Benzene diffusion tubes click here.

The annual monthly mean concentrations for NO₂ and Benzene click here