Do you know what is in car exhaust?

Car exhaust is a really unpleasant mixture of gases, compounds and chemicals. We all breathe this in to a greater or lesser extent depending on our daily activities, so it might be a good idea to find out what is actually in exhaust fumes, and the effects that breathing this in could have on our health. Many of us exercise near high levels of pollution from car exhaust, without thinking about the risks that we run by doing so.


Most vehicles need oil and gas to power their engines, with mechanical and chemical reactions occurring to run the vehicle. Combustion of the fuel releases a mixture of gases and suspended particles which are referred to as exhaust gas.


Car exhaust contains a mix of gases like sulphur dioxide and ozone, nitrogen dioxide, carbon monoxide as well as compounds such as benzene and toluene in addition to thousands of chemicals.


Carbon monoxide is the commonest single cause of poisoning in industry as well as in the home- as it is colourless, tasteless and odourless, and it binds to the haemoglobin in our blood, causing suffocation in large enough quantities.


The other compounds and chemicals in exhaust gas can cause heart disease, lung disease and cancer. There is no safe level of these pollutants – even small amounts at concentrations lower than recommended air quality standards can cause illness.


In addition to the gases and chemicals, car exhaust also contains small particles which are less than 0.1 micrometre in size, which easily get into the smallest sacs in the lungs and are just as easily absorbed into your circulatory system. Note that diesel fuel emissions are the worst from a health perspective – diesel exhaust is regarded by the World health Organisation as a Group 1 carcinogen – carcinogenic to humans.


Just breathing exhaust fumes in, is dangerous to your health – but when you exercise your breathing rate increases. Moderate exercise near a source of car exhaust can result in you absorbing as much as five times as much fine particulate matter than if you were at rest.


Most at risk will be the frail or elderly, and people with conditions such as asthma, diabetes or heart disease.


So – protect your health by limiting the amount of exposure that you have to car exhaust fumes, and if you exercise on busy roads, rather choose quieter roads, a park or other recreation area, early in the morning before the build up of traffic. Later in the day there are more pollutants, and the heat causes pollutants like ozone to form.