LAQN presents 2016 London air quality findings

London is continuing to struggle to meet some of its air quality objectives, a researcher in the field has confirmed.

Louise Mittal, a senior air quality analyst at King’s College London’s environmental research group made the comments at the 2017 London Air Quality (LAQN) Conference in the capital yesterday morning (14 July).

London experienced a series of winter smogs during colder months

Presenting the findings of the LAQN’s 2016 report — which summarises the recordings taken from the Network’s 100 monitoring stations around the capital — she confirmed that a number of areas around the city were found to be in breach of legal limits during the year.

Monitoring

Among the findings, Ms Mittal revealed that fewer than half the sites achieved the annual 40 µg/m3 NO2 mean objective, with 11 sites having recorded an annual mean twice the legal limit or above.

For particulate matter — PM10 — all sites met the 40 µg/m3 annual mean objective for 2016, but many were recorded to still be above the 20 μg/m³ World Health Organisation objective.

For finer particles — PM 2.5 — all of the monitoring sites were found to be in compliance with the yearly mean target of 25 µg/m3, but only one site achieved the 10 μg/m³ World Health Organisation target.

Commenting on the findings, she said: “London is still struggling with meeting some objectives despite vehicle improvements. There are some promising signs in pollution trends but there is still a long way to go.”

Full findings from the LAQN report are available on the Network’s website having been published last month.

Momentum

Despite slow progress towards air quality objectives, Professor Frank Kelly, director of the Environmental Research Group which runs the LAQN, expressed some optimism that momentum is gathering in efforts to tackle air pollution.

In his opening address to the Conference, he said: “The last 12 months have been pretty exciting if you work in the air quality area, an awful lot seems to be happening.

“In London we have had a lot of activity done by the mayor, with the ULEZ [Ultra Low Emission Zone] coming in and the T-Charge, as well as action on electric single decker buses. With the coming of the electric taxi too, it is an exciting time, much more so than 12 or 24 months ago.

“At a national level we have the consultation around air quality plans and the World Health Organisation is opening its guideline expert group again. So there is an awful lot happening. That is good because there is a lot to do to improve air quality and that is the focus of our meeting today.”

Winter smog

The Conference also heard research of two pollution episodes witnessed during the winter, presented by air quality analyst Dr Anna Font.

Alerts were displayed on the day before and during high air pollution levels in the winter

Winter smogs are formed when a thin layer of the atmosphere near the earth becomes cooler than that above it — this is known as temperature inversion. When this happens pollutants are trapped at ground level until there is a change in the weather.

Dr Font explained that in mid-January the UK experienced it most significant PM 2.5 episode since 2012. Cold temperatures and still conditions are thought to have contributed to the episode. A winter smog was also felt between 29 November and 6 December, which led to pollution alerts having been issued by the Mayor of London (see airqualitynews.com story).