Volatile Organic Compounds (VOCs) contain carbon and hydrogen and are found in a thousands of products used everyday, for instance, air fresheners, vehicle exhaust and building materials like paint, varnish, glue and cigarette smoke and office supplies like permanent markers.

These chemicals can harm both the environment and pose a serious health risk to humans. In this article I will explain more about the sources of these pollutants, how they affect us and how we can limit their exposure to us and the environment.

VOCs are produced directly through the use of fossil fuels like gasoline or by the by-products like vehicle emissions. Also some VOCs can combine with other chemicals to form new compounds thus adding to the amount of pollutants in the environment, for example, VOCs like limonene and styrene can react with nitrogen oxides or ozone to produce secondary aerosols.

However, the main source of synthetic VOCs is solvents used in paints such as ethyl acetate, glycol ethers and acetone. However, because of the cost and concern of environmental effects, more companies are using aqueous based solvents.

But not all VOCs are synthesized; there are some that are naturally produced. The main source of naturally produced VOCs is from plants, the amount produced by plants; however this varies due to many factors including, temperature which will affect the rate at which these compounds enter the atmosphere.

Another important factor is sunlight which affects the rate of biosynthesis which occurs in the cells of living organisms, where substances are converted into more complex compounds, the process of which is catalysed by enzymes.

When it comes to the environment, VOCs are important to the environment as they contribute to ozone formation. Ground-level ozone has serious effects on plants and ecosystems, for instance, it can cause damage to leaves of trees and other plants. It can also interfere with the ability to produce and store food in sensitive plants; therefore it affects their ability to fight diseases, pests, exposure to pollutants and their ability to compete with other species. It also reduces the yields of crops and growth of forests which impacts our ecosystems as well as food source.

VOCs can affect both the environment as well as the health of humans. However, in enclosed areas the concentrations of these chemicals can build up to the level where they pose a health risk.

The concentrations of VOCs indoors can be approximately ten times higher than outdoors. The effects of this type of pollutant are not quick to recognize as usually the concentrations of these compounds are low so that symptoms develop slowly.

Some health effects caused by VOCs are nausea, headaches, irritation of eyes, nose and throat, which are usually the first indication that VOCs are present. Some serious health effects include damage to the central nervous system and to the kidneys while other VOCs like those that contain benzene can cause cancer. Of course the severity of the health effects will depend on the concentration the individual has been exposed to as well as the nature of the VOCs in the area of exposure.

There are many simple ways which one could use to lessen the effects or fix the problem of VOCs, such as, opening windows to increase ventilation when using chemicals like paints or varnishes or glues and adhesives when inside. However when possible it is best to carry the objects outside for painting or varnishing or to apply adhesives.

An alternative would be to use paints and varnishes that are labelled as "low emissions" meaning that they have fewer VOCs than regular products.

Other measures one can take to lessen exposure to VOCs include not mixing household cleaning products unless the manufacturer's label indicates that it is safe to do so. Also if products containing VOCs have not been used in a long time or after opening they are seldom used, they should be discarded.

This is because gases can leak from closed containers. Of course to avoid wastage we should buy in quantities that can be used soon.

Of course prevention is a better cure, so that avoiding the use of products with VOCs can improve the quality of air in your home and lessen your exposure to such pollutants.

Therefore it can be seen that we are surrounded by volatile organic compounds which are produced naturally by plants and are found in thousands of items we use or encounter everyday. These chemicals can generate ozone which can affect the ability of plants to fight diseases, pests, resist the effects of pollutants and their ability to compete with other species for resources.

When this happens to crops it affects our food supply and security. VOCs can also cause serious health problems in humans. However, lessening one's exposure to VOCs is simple once the source of the compounds has been identified.