What Is the UK's DAQI?

Although we might associate polluted air with major cities in China, India and other developing parts of the world, the reality is that over 90% of the global population is exposed to air quality that is not deemed safe for humans by the World Health Organisation (WHO). To combat the problem and equip their citizens with the data they need to make informed decisions, governments around the globe have introduced Air Quality Indexes (AQI), which are sophisticated monitoring and reporting systems.

In the UK, this system is known as the Daily Air Quality Index (DAQI) and it provides up-to-the-minute information on a variety of pollutants across the country. This article will provide a brief introduction into how the system works, but for those interested in learning more about the topic in greater detail, an event later this year may be beneficial. Scheduled to take place in Telford in the UK this October, the Air Quality Emissions (AQE) Show will examine the subject from all angles.

How does DAQI work?

After a strategic review of the UK’s air monitoring networks in 2011, the DAQI was launched on January 1^st, 2012.  The system is created via the accumulation of data from air quality sensing equipment across the country, which is supplemented by satellite imaging data. In this way, the DAQI is capable of measuring the real-time concentrations of the pollutants which are considered most dangerous to humans.

These are, in no particular order, particulate matter 2.5 (PM2.5), particulate matter 10 (PM10), nitrogen dioxide (NO2), sulphur dioxide (SO2) and ground-level ozone (O3). This means that the monitoring system is almost identical to that of the USA, except that measurements of carbon monoxide (CO) are no longer included. The numeric values and corresponding categorisation of air quality are based upon the concentrations of these pollutants.

What are the different levels of air quality as defined by DAQI?

After assimilating all of the latest data, the DAQI then assesses it and produces an air quality value from 1 to 10, with 1 signifying clean air and 10 indicating dangerously polluted air. Where elevated levels of more than one contaminant are detected in a specific area, the pollutant with the higher concentration will determine the area’s DAQI value. After being assigned a numeric value of 1 to 10, a region is then given a greater categorisation from one of four levels.

The first, labelled “Low”, refers to values of between 1 and 3 and poses no risk to anyone. The second, accounting for levels of 4 to 6 is named “Moderate” and while no specific action is prescribed for the general population, those suffering from health conditions are asked to consider reducing strenuous physical activity outdoors. The “High” category refers to level 7 to 9 and advises vulnerable groups to reduce their activity, while the general population should consider a reduction too. In the top level, labelled “Very High” and denoting a value of 10, vulnerable groups are told to avoid physical activity altogether, while the general population are asked to reduce it.