Q: When we talk about air quality what do we mean?
A: Air is a mixture of gases and compounds, some of which are good and some of which are bad. Many of the bad gases and microscopic particles are the products of human activity – fumes and smoke from factories, burning fossil fuels and, most importantly, in modern urban areas like Tyne and Wear, from vehicle exhaust fumes. So good air quality is air that isn’t over-contaminated with harmful gases and compounds caused mainly by human activity.

Q: And for chemists out there, what sort of gases and compounds are we talking about?
A: Mainly Nitrous Oxides (NOx) and Sulphur Dioxide (SO2). Nitrogen dioxide is the worst culprit for poor air quality and is produced by burning petrol or diesel in vehicles. Over the past few years, despite engines getting cleaner, NOx emissions have been rising because there are more vehicles on the road. Sulphur dioxide (SO2) emissions have actually been declining because they are mainly produced in manufacturing processes in factories and from power stations. However we can’t be too careful: because most of our electricity comes from fossil fuel burning power stations, SO2 emissions are still a concern. We can all help reduce these by reducing the amount of electricity we use by turning appliances off in the home when we don’t need them.

Q: You mentioned compounds as well?
Yes, besides the gases there are also fine dust particles which are suspended in the air and they reduce air quality too. Particulate matter is made up of microscopic small solid and liquid particles present in the atmosphere. The main source of particulate matter in the UK is road traffic emissions, particularly from diesel vehicles. Particulates are also released as a result of industrial processes and have natural sources such as dust storms and volcanoes. Ultra fine particles, know as PM10, refers to fine particles with a diameter of less than 10 micrometres (µm). These particles are of particular concern for health as they can be carried deep into the lungs where they can cause inflammation and worsening of lung and heart conditions. Particulates may also carry surface-absorbed carcinogenic (cancer-causing) compounds into the lungs.There are also volatile organic compounds, known as VOCs. These are found in quite small quantities and are the result of manufacturing processes like paint production.

Q. And what sort of impact do these have on our health.
It’s difficult to say, but they do have a very big impact on everybody’s health and quality of life. Earlier this year there was a Government report that said poor air quality causes 50,000 premature deaths a year, which is a huge number. Poor air quality has been linked to increased levels of heart and lung disease. And children living on streets with heavy traffic have been shown to have higher levels of respiratory problems like asthma.
Day to day, some people really suffer when air quality is bad – mainly in the summer. For example people who already have asthma or bronchitis might find it gets worse when the air quality is particularly bad. Bad air quality is also responsible for eye irritation and coughing.

Q: So what’s the best way to improve air quality?
A: Urban air quality in the North East is mainly affected by private vehicle use. The more people walk, cycle or use public transport to get about and use their cars less, the better our air quality will become and this will mean we all feel much better and more healthy when we are out and about outside.