Vapour intrusion is an environmental health concern that can have an impact on the indoor air within your home or place of work. It can have seriously negative effects on your short term and long term health. But what exactly is vapour intrusion and how is it detected?
An Introduction to Vapour Intrusion
Vapour intrusion refers to when chemicals in the soil or ground water get into the indoor air. This happens because the chemicals have spilled onto the ground, perhaps from a factory or an underground storage tank. The chemicals will find their way into the groundwater and also travel through the soil as vapours.
These vapours can slowly seep through the foundation of a house through the cracks, which can then allow them to contaminate the indoor air. These chemical vapours include Volatile Organic Compounds, otherwise known as VOCs. These chemical compounds are dangerous to human health and they can have serious long term health effects. Because many people spend a lot of their time indoors, the long term exposure to these VOCs will have a negative effect on their health. Studies have shown that exposure to VOCs increases the risk of cancers such as lymphoma and leukemia.
So we know that these chemicals are harmful to the human body and have an effect on long term health, but how can we detect them? How do you know if your home or workplace is being affected by vapour intrusion?
How is Vapour Intrusion Detected?
Since we cannot see the dangerous vapours, how can we detect that they are there? There are, in fact, a number of ways of detecting vapour intrusion. Vapour intrusion is detected by collecting soil, groundwater and gas samples from near the contamination site or from near the property in question. These environmental data resources are much more effective than sampling the indoor air, because the quality of the air can vary from day to day.
It is also possible to detect the problem by taking samples from underneath the home’s foundation – which are called sub-slab samples. This is to see if the vapours in the soil have reached the home. Usually, a sub-slab sample will be more reliable than an indoor air sample, because it is not as affected by the other chemical sources in the indoor environment.
What if I Live in an Area Where Vapour Intrusion is a Concern?
If you live within an area where vapour intrusion is a problem, there are certain concerns that you should be aware of. If your home or business is under threat of vapour intrusion, this probably means that there is a dry cleaner or a gas station where chemicals or petroleum have contaminated the groundwater or the soil. If this is the case, the potential for vapour intrusion is probably already being investigated.
In this situation, you might be contacted by the site owner for clean-up or by others who are working on the project. You will need to give your consent before any sampling or testing is performed on your property.
If it is discovered that there is a problem with vapour intrusion in your home, the solution will be to install a Radon Mitigation System. This system is designed to prevent the gases that are present in the soil from entering your home. It works by applying a low amount of suction below the foundation of your house, so that the vapours can be vented to the outside. This type of system is quite efficient and you will not notice it making a large difference in your heating and cooling efficiency.
If the contamination of the groundwater has been caused by a factory or other commercial enterprise, they will usually be responsible for cleaning up the contamination and also paying for the installation of this system in your house. Once the original contamination has been cleaned up, you will usually not need the system. However, in some situations it is recommended that the system stays in place for the long term.
It is important to be aware of vapour intrusion and the risks that it brings, because this environmental concern can have serious effects on health.