UK Smog Levels Lowest Since Records Began

LONDON, United Kingdom, January 15, 2001 (ENS) - UK Government figures released Friday show urban air quality in 2000 was the best since records began.

In urban areas last year, there were 17 days of moderate or higher air pollution on average per site, compared to 30 days in 1999 and 23 in 1998. The main causes of moderate or higher air pollution at urban sites are ozone, particulate matter and sulphur dioxide.


Vehicle emissions contribute significantly to ground level ozone production. (Photo courtesy
Ozone occurs naturally in the atmosphere and plays a critical function in the stratosphere by protecting life on Earth from the sun's harmful ultraviolet rays.

But in the lower troposphere and in the presence of sunlight, ozone reacts with nitrogen oxide (NOx), sulphur dioxide (SOx) and volatile organic compounds to become a pollutant, commonly known as smog.

NOx and SOx are produced by natural sources such as forest fires and by motor vehicles' exhaust and industrial emissions.

The UK established National Air Quality Standards in 1993. The standards represent defined levels which avoid significant risks to health. As levels increase above the standard, the likelihood of effects on health increases.

Levels of ozone in the high band may cause coughing and discomfort on deep breathing during exercise in some people. In some North American cities, the problem has been attributed to premature deaths.

In Toronto, for example, 1,000 people died and another 5,500 were hospitalized last year because of air pollution, according to the Toronto Board of Health.

The UK's air quality headline indicator measures the average number of days per site on which pollution levels are above National Air Quality Standards. Friday's figures show a downward trend in the number of bad air days.


Environment Minister Michael Meacher. (Photo courtesy Department of Environment, Transport and the Regions)
"These figures show that the steps being taken at national and local level to reduce emissions from all sectors are maintaining the overall improvement in air quality and helping to reduce the impact of air pollution on our health," said Environment Minister Michael Meacher.

Meacher announced consultative proposals to improve the way that information about levels of air pollution is provided to the public and the launch of a web site showing progress by local authorities towards improving local air quality.

"It's important people have instant access to the most up to date information on air quality as quickly as possible," said Meacher. "It will mean vulnerable people can better assess the impact of current air pollution on their health, and when pollution levels are high, everyone needs to play their part by considering what action they can take to reduce pollution."

Last week's figures showed that in the UK's rural areas, there were 25 days of moderate or higher air pollution on average per site. This compares with 48 days in 1999 and 29 days in 1998.

According to the UK government, ozone is the main form of pollution in rural areas and much of it comes from mainland Europe. Though ozone levels were down in rural areas in 2000, the indicator shows no clear trend over the last seven years.

Far from the source of ozone, rural areas experience varying levels of air pollution because of the weather's role in spreading pollutants from mainland Europe.