A conversation with Iain Finlay of Aurora Sustainability Ltd who is one of the primary organisers of the Climathon event in Edinburgh.
In this episode we partner with Leeds Climathon organisers and look at the issue they have chosen for this year’s Climathon which is Air Pollution.
Keywords: Priestly International Centre for Climate; Leeds Climate Commission; Clean Air Zones; indoor air pollution; mould and damp; Primary and Secondary pollutants; Ozone; Volatile Organic Compounds; Nitrous Oxide; Persistent Organic Compounds; Particulate matter; Hydrocarbons; Noxious gases; Dispersed; Atmospheric deposition; Acid rain; Smog; Black smoke.
Traduzione in Italiano – not yet available
Hi everyone, today’s episode is presented with colleagues in Leeds, who are co-ordinating this year’s Climathon event there. The theme is Air Pollution, which is also being explored in Warsaw, Ahvaz and Berlin. In this episode we will explore the types and causes of air pollution and some of the negative effects of this. Listeners might like to refer back to Episode 23 in this series on Greenhouse Gases. I am delighted to be joined by Kate Lock who is part of the co-ordinating team for the event this year. She will explain the context for the event.
Thanks Victor. I work for the Priestley International Centre for Climate at the University of Leeds and we are hosting our Climathon with the newly formed Leeds Climate Commission.
Here in Leeds, air pollution is a really big problem, which is why it’s our Climathon challenge. Leeds is the third worst polluted city in the UK, and it’s in breach of legal levels of air pollution which will incur massive fines if it’s not brought into line.
We know air pollution is making people sick and the figures for Leeds are staggering: almost 700 people will die this year from illnesses related to it. Mitigating climate change and protecting our health is interlinked – which is why tackling the causes of it brings benefits for all.
The UK government has chosen Leeds to become one of five Clean Air Zones by 2020, so that is the theme of our challenge – how do we do that, in time, and make Leeds a better city for everyone?
Thank you Kate – air pollution is a real problem for many regions and particularly cities around the globe. Air pollution is caused by anything that upsets the natural balance of the gases that make up our atmosphere. The two most common gases in the atmosphere are Nitrogen at 78% and Oxygen at 21% and then some much smaller amounts of Carbon Dioxide and Argon. Nature has spent billions of years getting the balance just right and working within the boundaries of the planet. Yes, there are occasional natural causes of imbalance such as volcanoes, forest fires, sandstorms and other disturbances which can cause local pollution but generally the system is in balance.
Why is air pollution a problem? Well, there are two main concerns – the associated health risks and climate change. Many of the gases that create air pollution are also ‘greenhouse’ gases and so are part of the problem causing climate change. Often, the damage to our health caused by poor quality air is not immediate but happens over a long time so can go unnoticed in the short term.
The World Health Organisation believes that air pollution is now the single largest cause of environmental health risks worldwide. Furthermore, it estimates that 92% of the world’s population live in areas that do not meet air quality guideline levels. The negative health problems include lung diseases like asthma or emphysema and also cardiovascular problems with the heart and circulation. There is also a greater risk of developing cancers with long term exposure to air pollution. Some recent studies make a link also between dementia and air pollution.
It is important to say that a very significant cause of health problems is the indoor air pollution caused by very poor quality cooking stoves used in many countries. This has an adverse affect on the lives of women and young children particularly. In the UK and similar countries the problems of poor quality housing can give rise to mould and damp which create health problems. Of course, humans are not the only victims of this and air pollution affects plants and animals and so can damage crop yields and impact on bio-diversity.
It is important to distinguish between Primary and Secondary pollutants. Primary pollutants enter the atmosphere directly from a process such as burning fuel in a vehicle. Secondary pollutants form when primary pollutants react with something else to form other compounds. So the chemicals emitted from cars as exhaust react together with sunlight to form Ozone – a molecule of oxygen which at ground level is harmful. The term Volatile Organic Compounds (VOC’s) is used to refer to a group of chemicals that react in the atmosphere with Nitrous Oxide and heat and sunlight to form Ozone. Exhaust gases from vehicles and oil-based paints are examples of VOC’s. There are also Persistent Organic Compounds (POP’s) which are organic compounds that do not break down in natural conditions. These are mainly the by-product of industrial chemicals, pesticides, solvents and pharmaceuticals and can cause damage to both health and the environment.
Another form of air pollution is Particulate Matter, which is defined as solid or liquid particles that remain suspended in the air. It can be produced by natural sources, such as windblown dust or volcanoes, or by human activities, such as burning biomass or vehicle exhaust. Particle size is measured in micrometers (μm), or one millionth of a meter. Particles that are ten micrometer or less (<10μm) can be inhaled freely into the lungs and cause respiratory diseases, lung damage, or even cancer. Particulate matter of this size is referred to as PM 10. The concentration of pollutants in a volume of air is often referred to as the Parts per Million or Parts per Billion. Though this may sound like a very small amount these are very relevant figures when measuring pollution of any sort.
There are 500 million cars and vehicles in use today globally. These produce exhaust gases or fumes of Hydrocarbons –which are molecules of hydrogen and carbon. Other exhaust particulates include carbon monoxide, nitrogen oxides and lead. We often use the term Noxious gases to refer to any gas that is harmful or bad for one’s health. Local geography and climate can combine to make matters worse in specific situations and trap the polluted air from being blown elsewhere. Cities such as Leeds, Santiago in Chile and Mexico City are examples of this. A current topic of debate is whether or not Diesel fuel is a more environmentally friendly alternative to petrol. Diesel fuel is known to emit about 10-15% less carbon monoxide and hydrocarbons and also requires less refining than petrol. However, diesel engines emit significantly higher levels of nitrogen oxides, particulate matter, and soot. In recent years there has been an increase in the sale of diesel engines aimed at reducing short and medium term emissions. The scandal of the falsified diesel engine test results by some manufacturers has placed a huge question mark over these vehicle emissions and the associated environmental pollution. Air pollution studies are showing quite varied local findings between and even within cities. This has led to a lot of confusion amongst experts and laymen alike.
When pollution or emissions are blown away from the source over a wider geographic area they are said to be Dispersed. This means that some areas can suffer from pollution that is produced elsewhere. Sometimes, pollution in the higher atmosphere is brought back down to earth in rain or snow falls thus polluting the ground and the water. This is known as Atmospheric deposition and the most commonly known form is called Acid rain. Other causes of air pollution are power plants, factories and some agricultural practices.
The word Smog is often used to describe the air pollution in cities sometimes visible as a brown haze in photographs. Originally the term was formed from the words smoke and fog but now just refers to air pollution. Smoke refers to foreign particles in the air caused by combustion whilst fog is a thick cloud of water vapour which hangs low in the atmosphere and can restrict visibility. With the traffic congestion and exhaust fumes in modern cities the word smog is more correctly termed petrochemical smog which is the result of sunlight on the nitrous oxides and volatile organic compounds that form ground level ozone and volatile organic compounds. The word soot is sometimes used and this refers to black dust or flakes caused by incomplete burning of organic matter such as wood or coal etc. The term Black Smoke is used to refer to the black exhaust fumes often seen as heavy vehicle engine are under pressure climbing a hill for instance. It is caused by the incomplete burning of the diesel fuel and is one of the reasons diesel engines have such a bad name environmentally speaking.
Air pollution is something that generally builds over a period of time through consistent behaviour that causes emissions. We are all responsible for contributing to this through our lifestyles and purchasing habits. We can and must make behaviour change to help reduce the root causes of this pollution. Climathon is a chance to join with others to develop and work on solutions to these problems.
That concludes this episode in the series and we hope you have found this useful and informative. My thanks to Kate and her colleagues in Leeds for their help and support with putting this episode together. Good luck to all those working to make the Climathon event happen. We look forward to you joining us for further episodes in the series.