Indoor air pollutants (including nitrogen dioxide, mould spores, particulate matter and volatile organic compounds) can trigger or exacerbate asthma, other respiratory conditions or cardiovascular conditions. People who are particularly sensitive include babies and young children, pregnant women, older people, and those with existing respiratory conditions or cardiovascular conditions. However, the effect of pollutants on an individual depends on several factors including the concentration of the pollutant, whether the pollutant is present continuously or intermittently, the duration of exposure, how many different pollutants are present and the susceptibility of the individual. More research into air quality and exposure to a range of pollutants in different types of indoor environments is needed to fully understand the impacts of indoor air pollution on health.
Activities that create moisture in the home such as air-drying clothes indoors and having a bath/ shower
How does it contribute to poor indoor air quality?
Moisture indoors creates conditions for damp and encourages growth of dust mites and microbes such as moulds and bacteria. These then pollute the air by producing spores, volatile compounds and toxins that are associated with allergies, asthma and respiratory disease.
How can this be prevented or reduced?
- Avoid air-drying clothes indoors if possible, or increase the ventilation if this cannot be avoided.
- If you use a tumble dryer, vent it outside (unless it is the self-condensing type).
- Use the bathroom extractor fan if present, or open windows where possible and safe to provide temporary increased ventilation.
- Close the bathroom door when this room is in use to help stop moisture reaching other rooms.
- Repair sources of water damage and ensure that any residual moisture is removed.
- Ensure damp and mould problems are fixed promptly. Information on assistance with home maintenance and improvements can be found on the housing pages on the council website.
- In rented properties, if ventilation is inadequate or repairs are not undertaken by the landlord, you can make a complaint about this to the council.
- Avoid exposure to dust mites by using mattress and pillow covers, washing bedding regularly and avoiding using second hand mattresses if possible.
- Further advice on damp and mould prevention from the council.
How does it contribute to poor indoor air quality?
Tobacco smoke is a source of various pollutants including carbon monoxide (CO), carbon dioxide (CO2), oxides of nitrogen (NOX), volatile organic compounds (VOCs), formaldehyde, ammonia (NH3) and polycyclic aromatic hydrocarbons (PAHs). Second hand smoke is a known carcinogen and can contain more than 7,000 substances.
Components of tobacco smoke are deposited onto surfaces, and then are slowly released back into the room as vapour.
Vaping using E-cigarettes is a source of ultrafine particulate matter.
How can this be prevented or reduced?
- Avoid smoking indoors – advice on quitting smoking is available from the council's stop smoking service.
Using open solid-fuel fireplaces and appliances, for example wood burning/ multi-fuel stoves
How does it contribute to poor indoor air quality?
The most significant indoor air pollutants created from the use of solid fuels are particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs).
Other pollutants which may also be released indoors include gases such as carbon monoxide (CO), carbon dioxide (CO2), oxides of nitrogen (NOX) and volatile organic compounds (VOCs).
Using an open fireplace is much more polluting than an enclosed solid fuel appliance. However, increases in particulate matter (PM) levels are associated with solid fuel appliances when the door is opened for refuelling and removing ash.
How can this be prevented or reduced?
- Try to avoid or reduce the amount of solid fuel burning if it is not your main source of heating.
- Follow the product instructions when using appliances to minimise exposure to pollutants.
- Always use the correct fuel and look for the 'Ready to Burn' logo.
- Consider upgrading to an Ecodesign enclosed solid fuel burning appliance.
- Solid fuel appliances must have local authority building control consent to be installed, or installed by a member of a Competent Persons Scheme, for example HETAS.
- The chimney must be swept at least once per year by a professional and/or registered chimney sweep.
- Install a carbon monoxide monitor in the same room to alert you to dangerous fumes.
- Keep your home well ventilated if using a solid fuel fire or appliance by using background ventilation (such as trickle vents), mechanical ventilation or opening windows if possible and safe.
- Further information can be found from the Clean Air Greater Manchester ‘Air Pollution from domestic burning’ leaflet, the City Council website smoke page and the DEFRA ‘Burn better’ campaign.
Using free-standing bottled gas or paraffin heaters indoors
How does it contribute to poor indoor air quality?
Burning gas or paraffin in freestanding (unflued) heaters releases pollutants such as nitrogen oxides (NOX), carbon monoxide (CO) and particulate matter (PM) into the indoor environment.
These heaters also put a lot of moisture into the air – when burnt, one gallon of gas or paraffin produces about a gallon of water. Therefore there is a risk of creating damp conditions that could encourage the growth of dust mites and microbes such as moulds and bacteria.
How can this be prevented or reduced?
- Avoid using freestanding (unflued) bottled gas or paraffin heaters indoors – try to use an alternative form of heating.
- Follow the manufacturers instructions and keep the heater well maintained and serviced.
- Use a carbon monoxide monitor in the same room to alert you to dangerous fumes.
- Keep your home ventilated if using free standing gas or paraffin heaters by using background ventilation (such as trickle vents), mechanical ventilation or opening windows if possible and safe.
- Further information about using portable heaters is available from the Greater Manchester Fire and Rescue Service.
Using cleaning products, plug in air fresheners, household sprays/ aerosols and paints
How does it contribute to poor indoor air quality?
Household products can be a source of a range of pollutants including volatile organic compounds (VOCs), ammonia, formaldehyde and hydrochloric acid.
How can this be prevented or reduced?
- Try to use the minimum amount of product.
- Try to use non-spray alternatives.
- Switch to using to lower VOC alternatives, such as unperfumed cleaning products or low VOC/ water based paint. Look out for product labels on paint containers - paints labelled ‘low-VOC’ should contain fewer than 50 grams per litre of VOC.
- Follow the product instructions when using products to minimise exposure to pollutants.
- Keep your home well ventilated when using products by using background ventilation (such as trickle vents), mechanical ventilation or opening windows if possible and safe.
Using new building materials and home furnishings
How does it contribute to poor indoor air quality?
Chemical emissions of volatile organic compounds (VOCs) and formaldehyde may be released over significant periods of time from new building materials and home furnishings into the indoor environment. The amount will depend on factors such as how much material is present, the temperature and how the room is ventilated.
How can this be prevented or reduced?
- Choose low-emission materials (for example, products with a low VOC or formaldehyde content and emissions) if furniture or flooring needs replacing – look out for product labels such as Ecolabel.
- Keep your home ventilated by using background ventilation (such as trickle vents), mechanical ventilation or opening windows if possible and safe.
Using candles and incense sticks
How does it contribute to poor indoor air quality?
Burning candles releases pollutants such as nitrogen oxides (NOX), carbon monoxide (CO), smoke, particulate matter (PM), volatile organic compounds (VOCs) and formaldehyde into the indoor environment.
How can this be prevented or reduced?
- Try to avoid or reduce candle burning indoors - consider using electric candles instead.
- Follow the product instructions when using candles to minimise exposure to pollutants.
- Keep your home well ventilated if burning candles or incense sticks by using background ventilation (such as trickle vents), mechanical ventilation or opening windows if possible and safe.
How does it contribute to poor indoor air quality?
Gas and solid/ liquid fuel cookers are a source of indoor pollutants such as carbon monoxide (CO), nitrogen oxides (NOX) and particulate matter (PM).
Regardless of the source of heat, cooking processes can be a source of other pollutants such as VOCs, particulate matter and polycyclic aromatic hydrocarbons (PAHs).
Cooking can also put a lot of moisture into the air. Therefore there is a risk of creating damp conditions that could encourage the growth of dust mites and microbes such as moulds and bacteria.
How can this be prevented or reduced?
- Cooking food by boiling or steaming is generally less polluting than frying and grilling.
- Use the cooker extractor fan if present.
- Put a lid on saucepans to keep the steam inside and don’t leave kettles boiling.
- If possible, close the kitchen door when this room is in use to help stop moisture reaching other rooms.
- Gas cookers should not be used to heat a room.
- Cookers must be correctly installed and tested.
- Keep your home well ventilated when cooking by using background ventilation (such as trickle vents), mechanical ventilation or opening windows if possible and safe.
Using gas appliances, for example boilers
How does it contribute to poor indoor air quality?
Badly fitted and poorly serviced gas appliances can cause leaks and a build up of poisonous carbon monoxide (CO).
How can this be prevented or reduced?
- Gas appliances should be serviced regularly.
- Always use a Gas Safe registered engineer to fit, fix or service your gas appliances.
- Use a carbon monoxide monitor in the same room to alert you to dangerous fumes.
- Further advice about gas safety for property owners and tenants is available from the council.
Radon is a colourless, odourless radioactive gas that is formed naturally in the ground that has links to causing lung cancer. Radon can enter buildings from the ground beneath or from the materials they are built from, and levels can build up indoors. However, for most homes the risk to health is low. The UK Health Security Agency (UKHSA) is the UK’s primary expert on radon and radiation protection. Their UKradon website has more information about radon, including:
Asbestos can be found in any building built before the year 2000. When materials that contain asbestos are disturbed or damaged, fibres are released into the air. When these fibres are inhaled, they can cause a range of serious lung diseases which often take a long time to develop.
Lead is a toxic metal and has long been recognised as a harmful environmental pollutant. It was once regularly used in the manufacturing of common household products and petroleum. Lead is particularly dangerous to young children because their growing bodies absorb more lead than adults do, and their brains and nervous systems are more sensitive to its damaging effects.
Lead in paintwork is the most significant source of lead exposure. If left untouched and in good condition, lead-based paint may not pose a significant hazard to health. However, chipped or deteriorating paint can create dust, chips and suspended particles that can be inhaled. Methods to remove paint such as dry scraping, sanding, or open-flame burning can increase airborne lead levels. Further advice on lead paint in homes is available from the UK Department for Environment, Food and Rural Affairs.
Lead exposure can also be caused by dust being brought in from outside from sources such as contaminated soil, clothing or equipment. Other activities that can increase indoor lead concentrations are soldering and stained-glass making.