Putting air pollution on the map

While the nature of air pollution may have changed in recent decades, it still has a significant impact on our health and wellbeing across the world, especially for those with underlying respiratory conditions. Arne Berndt, owner / adviser at SoundPLAN GmbH and SoundPLAN International LLC looks at the problems causes by air pollution and how mapping software can help alleviate its worst affects.

The World Health Organisation (WHO) reports that air pollution is the world’s largest single environmental health risk. It says that in 2012 one in eight of total global deaths (around 7 million people) was the result of air pollution exposure. Reducing air pollution and people’s exposure to it could therefore save millions of lives.

Air pollution’s link to respiratory diseases, including acute respiratory infections and chronic obstructive pulmonary diseases is well established. There is also a lesser known, but strong correlation between exposure to air pollution and cardiovascular diseases, such as strokes, ischaemic heart disease and cancer. At the other end of the scale air pollution can cause temporary ailments such as headaches and skin rashes.

Air pollution sources

Air pollution comes from a variety of sources including chemical use (in the home as well as industrial processes), any form of combustion, or any process that produces large amounts of dust, including natural phenomena such as volcanic eruptions and forest fires.

Occurrences of heavy smog have declined, thanks to various initiatives around the world to reduce pollutants, including smoke and sulphur dioxide emissions, such as the ‘Clean Air for Europe Act’ and the USA’s ‘Clean Air Act’. However, at the end of November 2015, authorities in Beijing, China issued their highest smog warning of the year to date as pollution monitoring equipment showed levels 17 times above those considered safe by the WHO, in parts of the city. The pollution is caused largely by the Chinese coal-burning power industry.

Globally, it is however, traffic that is now the largest single contributor to air pollution around the world, although power plants and factories also make an important contribution. Although modern vehicles are more environmentally friendly than earlier models, the sheer volume of them means that pollution from vehicles has increased dramatically and is a significant risk to health.

Mapping air pollution

To combat this global health menace, many countries’ planning processes require calculations for the dispersal of air pollution, when developing new buildings and infrastructure. Mapping software is used to bridge the gap between the science needed to understand it and engineering being planned to mitigate it. ‘Dispersal’ refers to what happens to the pollution during and after its introduction into the atmosphere. Understanding this can help people identify and control it.

Air pollution dispersal has become the focus for environmental conservationists and governmental environmental protection agencies (local, state, province and national) in many countries as a means of air pollution control.

Air pollution is measured at monitoring stations in a number of locations, but terrain and weather factors mean that levels can vary greatly even in small areas, making wide-scale accurate measurements difficult.

Therefore instead of relying on measurements a number of models are available to map air pollution dispersal. These range from ‘simple’ Gauss models up to complex prognostic models. The model selection depends strongly on the task and the available data.

Air pollution models are highly dependent on the meteorological situation for the dispersal calculation, requiring multiple meteorological scenarios. In order to correctly assess the pollution load for average and various percentiles, it is paramount to simulate the dispersal of the pollutants for a wide variety of wind directions and scenarios. An added variant is that the air pollutants are often reactive gases which change over time under the presence of UV light.

Robust and reliable

The results of air pollution models are often critical in planning processes and need to be robust enough to withstand the scrutiny of the court system. It is essential that they can be validated and have well-defined boundary conditions, are supported by a team of experts and used by well-trained people.

The management of meteorological conditions and the control of different scenarios are a constant focus for developers and software improvements regularly mean what was impossible yesterday might be possible today. Measured meteorological data must be assessed profoundly and modified very cautiously, especially if the reference meteorological station is outside the investigation area. Developers continually add tools to assess, complete and modify data.

Consequently, the air pollution mapping software has become a powerful tool to save time and avoid nasty surprises when inspecting calculation results. Some software includes diagrams to analyse background pollution measurement and to deliver supporting arguments to why the background concentrations need to be adjusted.

If poor measurements cannot be rectified, this software helps visualise data problems and supplies good arguments for better data.

Mitigating air pollution

The ideal situation would be to reduce air pollution and eventually eliminate man-made sources. While progress is being made in this direction, there would need to be a major scientific breakthrough or global change in lifestyle to significantly alter current levels. Transport and power are such integral parts of modern life that air pollution is here to stay for the foreseeable future. Therefore it is vitally important that we monitor, map and disperse as much air pollution as possible to lessen the impact on health across the world. Mapping software plays a key role in that task and with developments happening all the time, anyone involved in air pollution monitoring or dispersal should speak to an expert to get the latest information.

http://www.soundplan.eu/english/soundplan-air-pollution/

Published in PECM – January 2016