Indoor Air Pollution

Most of us are aware of the impact of air pollution and many of us will be impacted by the proposed clean air zone which may be introduced in Bath city centre over the coming years.

There is probably less awareness of indoor air pollution although it is something which has, to an extent, featured in our home Surveys for a number of years.

Most Surveyors are very much aware of the risks of carbon monoxide and hence the essential advice to have all gas appliances checked and maintained by qualified contractors and to install a good quality mains-wired carbon monoxide alarm in all rooms with a gas or solid fuel appliance. Twice this week we have identified gas leaks and on one occasion we arranged for a repair to be carried out whilst the Survey was being completed.

We check the radon maps when undertaking a Survey and we identify signs of mould and condensation when carrying out a Survey inspection. Mould is normally related to condensation but condensation can occur when the temperature has been lowered by, for example, a roof leak and dampness in a wall.

There are a number of other health and safety matters which we are constantly looking out for including defective flues, lead water pipes, flues close to windows, unsafe electrical fittings, slippery decking, unprotected retaining walls and compromised escape routes.

There are many materials which may contain asbestos and again this is something we would always try to highlight in a RICS HomeBuyer Report or a Building Survey.

Many of the solutions to alleviate indoor air pollution can be undertaken through good building maintenance. Normally our recommendations in a Survey report are prioritised with health and safety related matters being at the very top of the list followed by maintenance to protect the fabric of a building and then by repairs which may be considered to be of a more cosmetic nature.

The information below was obtained from the US Environmental Protection Agency but it is all equally relevant to those of us living in the southwest.


Radon is a radioactive gas that is formed in the soil. It can enter indoors through cracks and openings in floors and walls that are in contact with the ground.

  • Radon is the leading cause of lung cancer among nonsmokers, and the second leading cause of lung cancer overall.


Secondhand Smoke

Secondhand smoke comes from burning tobacco products. It can cause cancer and serious respiratory illnesses.

  • Children are especially vulnerable to secondhand smoke. It can cause or worsen asthma symptoms and is linked to increased risks of ear infections and Sudden Infant Death Syndrome (SIDS).


Combustion Pollutants

Combustion Pollutants are gases or particles that come from burning materials. In homes, the major source of combustion pollutants are improperly vented or unvented fuel-burning appliances such as:

  • space heaters
  • woodstoves
  • gas stoves
  • water heaters
  • dryers
  • fireplaces


Volatile Organic Compounds (VOCs)

VOCs are emitted by a wide array of products used in homes including:

  • paints and lacquers
  • paint strippers
  • cleaning supplies
  • varnishes and waxes
  • pesticides
  • building materials and furnishings
  • office equipment
  • moth repellents
  • air fresheners
  • dry-cleaned clothing

VOCs evaporate into the air when these products are used or sometimes even when they are stored.

  • Volatile organic compounds irritate the eyes, nose and throat, and cause headaches, nausea, and damage to the liver, kidneys and central nervous system. Some of them can cause cancer.


Asthma Triggers

Asthma triggers are commonly found in homes, schools and offices and include mold, dust mites, secondhand smoke and pet dander. A home may have mold growing on a shower curtain, dust mites, pilllows, blankets or stuffed animals, secondhand smoke;in the air, and cat and dog hairs;on the carpet or floors. Other common asthma triggers include some foods and pollutants in the air.

  • Asthma triggers cause symptoms including coughing, chest tightness, wheezing and breathing problems. An asthma attack occurs when symptoms keep getting worse or are suddenly very severe. Asthma attacks can be life threatening. However, asthma is controllable with the right medicines and by reducing asthma triggers.



Moulds are living things that produce spores. Moulds produce spores that float in the air, land on damp surfaces and grow.

  • Inhaling or touching moulds can cause hay fever-type symptoms such as sneezing, runny nose, red eyes and skin rashes. Molds can also trigger asthma attacks.


Improving Your Indoor Air

Take steps to help improve your air quality and reduce your IAQ-related health risks at little or no cost by:

Controlling the sources of pollution:Usually the most effective way to improve indoor air is to eliminate individual sources or reduce their emissions.

Ventilating: Increasing the amount of fresh air brought indoors helps reduce pollutants inside. When weather permits, open windows and doors, or run an air conditioner with the vent control open. Bathroom and kitchen fans that exhaust to the outdoors also increase ventilation and help remove pollutants.

Always ventilate and follow manufacturers’ instructions when you use products or appliances that may release pollutants into the indoor air.

Changing filters regularly: Central heaters and air conditioners have filters to trap dust and other pollutants in the air. Make sure to change or clean the filters regularly, following the instructions on the package.

Adjusting humidity:The humidity inside can affect the concentrations of some indoor air pollutants. For example, high humidity keeps the air moist and increases the likelihood of mold.

Keep indoor humidity between 30 and 50 percent. Use a moisture or humidity gauge, available at most hardware stores, to see if the humidity in your home is at a good level. To increase humidity, use a vaporizer or humidifier. To decrease humidity, open the windows if it is not humid outdoors. If it is warm, turn on the air conditioner or adjust the humidity setting on the humidifier.

Take Action to Improve Air Quality in Every Room

Important tips that will help control indoor pollutants

  • Test for radon and fix if there is a problem.
  • Reduce asthma triggers such as mould and dust mites.
  • Do not let people smoke indoors.
  • Keep all areas clean and dry. Clean up any mould and get rid of excess water or moisture.
  • Always ventilate when using products that can release pollutants into the air; if products must be stored following use, make sure to close tightly.
  • Inspect fuel-burning appliances regularly for leaks, and make repairs when necessary.
  • Consider installing a carbon monoxide alarm.



Radon is the second leading cause of lung cancer.

Radon gas enters your home through cracks and openings in floors and walls in contact with the ground.

Test your home with a do-it-yourself radon kit. If the test result indicates you should fix, call a qualified radon mitigation specialist.
Ask your builder about including radon-reducing features in your new home at the time of construction.


Asthma is a serious, sometimes life-threatening respiratory disease that affects the quality of life for many people.

Environmental asthma triggers: are found around the home and can be eliminated with these simple steps:

  • Don’t allow smoking in your home or car.
  • Dust and clean your home regularly.
  • Clean up mould and fix water leaks.
  • Wash sheets and blankets weekly in hot water.
  • Use allergen-proof mattress and pillow covers.
  • Keep pets out of the bedroom and off soft furniture.
  • Control pests—close up cracks and crevices and seal leaks; don’t leave food out.


Secondhand Smoke

Secondhand smoke: smoke comes from burning tobacco products such as cigarettes, pipes and cigars.

  • To help protect children from secondhand smoke, do not smoke or allow others to smoke inside your home or car.



Mould can lead to allergic reactions, asthma and other respiratory ailments.

Mould: can grow anywhere there is moisture in a house.

  • The key to mold control is moisture control.
  • If mold is a problem in your home, you should clean up the mold promptly and fix the water problem.
  • It is important to dry water-damaged areas and items within 24-48 hours to prevent mold growth.


Volatile Organic Compounds (VOCs)

VOCs cause eye, nose and throat irritation, headaches, nausea, and can damage the liver, kidney, and central nervous system.

Volatile organic compounds (VOCs): are chemicals that evaporate at room temperature. VOCs are released from products into the home both during use and while stored.

  • Read and follow all directions and warnings on common household products.
  • Make sure there is plenty of fresh air and ventilation (e.g., opening windows and using extra fans) when painting, remodeling or using other products that may release VOCs.
  • Never mix products, such as household cleaners, unless directed to do so on the label.
  • Store household products that contain chemicals according to manufacturers’ instructions.
  • Keep all products away from children!


Combustion Pollutants

Carbon monoxide causes headaches, dizziness, disorientation, nausea and fatigue, and high levels can be fatal.

Nitrogen dioxide causes eyes, nose and throat irritation, impairs lung function, and increases respiratory infections.

Sources include:

  • Gas stoves.
  • Unvented kerosene and gas space heaters.
  • Leaking chimneys.
  • Tobacco products.


It is important to:

  • Ventilate rooms where fuel-burning appliances are used.
  • Use appliances that vent to the outside whenever possible.
  • Ensure that all fuel-burning appliances are properly installed, used, adjusted and maintained.