Unlike industrial chimney stacks pumping out thick furls of black smoke, unless an engine is burning oil, we don’t often see what comes out from vehicle exhausts.
However, just because it’s not very visible, doesn’t mean to say there are no consequences – because the effect of traffic emissions can be far-reaching, for both the planet and our health.
What Emissions Does Traffic Produce?
Vehicles emit a lethal cocktail of pollutants which adversely affect the ambient air quality and our health. The main components are the following:
- Benzene – a volatile organic compound (VOC) which is a known carcinogen and the major constituent of petrol.
- Carbon Monoxide – a very common air pollutant, this is a toxic gas which impairs the ability of the blood to transport oxygen around the body. It can cause lack of concentration, dizziness, headaches, nausea, and carbon monoxide poisoning with very high exposure causing death.
- Nitrogen Dioxide – formed via combustion and irritating to the eyes and respiratory system.
- Ozone – a secondary pollutant formed by a photochemical reaction in the presence of ultraviolet light, hydrocarbons and nitrogen dioxide. Exposure on sunny days, when ground-level ozone is high, can cause inflammation of the airways and respiratory problems.
- Particulate Matter – small particles suspended in the air which are easily inhaled. Of particular danger are particles measuring less than 10 micrometers in diameter. The smallest particulates can lodge deep in the lungs and find their way into the blood stream. Particulates are found mainly in diesel and studies show that in areas where there is high diesel use (for instance in inner city areas by buses and taxis), health effects are pronounced.
- Polynuclear Aromatic Hydrocarbons (PAH’s) – a group of organic compounds of which prolonged or long-term exposure may lead to some lung cancers.
- Sulphur Dioxide – a sharp-smelling, acidic gas which combines with water to produce acid rain. Its presence in traffic emissions is thought to trigger asthma attacks and bronchial conditions.
The health effects of traffic emissions can be severe and in particular are associated with breathing difficulties such as wheezing, coughing, bronchitis, pneumonia, pulmonary diseases and asthma. However it is now also believed that traffic fumes may interfere with lung growth and performance and shorten life expectancy because of it.
A study published in medical journal ‘The Lancet’ in 2007, reported that children who live within 500 metres from a motorway suffer from significantly impaired lung function compared to those who lived further away. This was the first study of its kind to connect shortened life expectancy to traffic emissions and has prompted environmental campaigners to lobby government for more stringent measures to be put in place which will curb vehicle emissions and particularly diesel.
Sulphur dioxide from traffic emissions combines with water vapour to produce acid rain. However, if conditions are dry, then it may travel many hundreds of miles before doing so. Therefore acid rain is not just a local problem; sulphur dioxide which has been produced here, may fall as acid rain as far away as Canada.
Effects are detrimental to soils, plants, and vegetation. It can also upset the delicate chemical balance in waterways, damaging the eco-culture and killing marine life.
Although total acid rain levels in the UK have fallen, due to an improvement in some industries where the use of sulphur has been restricted, it is still very much a problem with traffic emissions.
Cut Down On Vehicle Use
Using a car is one of the most polluting acts most individuals will do. Despite improvements in technology to manufacture cars which are kinder to the environment and produce less damaging emissions, our dependence of driving continues unabated, with the amount of traffic on the roads – and the harmful emissions it produces – continuing to climb.
For the effect of traffic emissions to fall, we need to learn to leave the car at home.