Indoor Air Quality
Are you breathing fresh air in your home? Unhygienic air in and around your home causes harm to your body and mind and may create risks to your lives. Polluted indoor air weakens our immune system and makes us feel sick. This write up tells you various causes, sources and solutions to indoor pollution.
What causes indoor air pollution?
- Chemicals, particulate matters or biological materials create air pollution which causes harm to human beings and other living organisms and destroys natural environment.
- Molds, termite, bacteria, gases such as carbon monoxide, carbon dioxide, radon, volatile organic compounds, particulates, harmful particles and energy stressor induce adverse effects on health and affect indoor air quality also.
- High temperature and humidity levels can increase pollutants in indoor air. Therefore, indoor air is increasingly becoming health hazard as compared to outdoor air.
Several indoor air pollutantsMajor sources of indoor air pollution are the burning of wood, charcoal, dung, crop residue, heating, cooking, and smoking, use of chemicals, dampness, and improper drainage. Dust collection can create pollution in indoor air also. Certain building materials such as asbestos fibers, particle boards etc. also affect indoor air. Some air pollutants are following.
1. Carbon MonoxideCarbon monoxide, CO is colorless and odorless gas which is produced from burning of kerosene oil, coal, wood, room heater, gas water heater, fire places, generators and automobile exhausts from attached garages in the house. Burning tobacco, room heater and heating furnaces etc. also produce carbon monoxide gas.
Symptoms: Carbon monoxide causes symptoms of headache, dizziness, disorientation, nausea and fatigue. High level of CO can kill people living in the house.
2. Carbon DioxideCO2 is colorless gas and gives burning smell. This gas being light in weight remains at higher level than the level of oxygen. It is less harmful than carbon monoxide. The burning of wood, oils, coals and cooking, heating smoking produce carbon dioxide which has bad effects on health. When carbon monoxide generated from burning woods, oils etc mixes with oxygen, it changes into carbon dioxide.
Symptoms: Carbon monoxide causes symptoms of headache, dizziness, disorientation, nausea and fatigue and has very bad effects on health.
3. RadonIt is radioactive invisible atomic gas which may be found in rock formation under buildings or in some building materials. It is one of the most dangerous gases and tends to accumulate at floor level being heavy gas.
Symptoms: Cancer, lung tissue decay, coughing, heavy breath, infections like pneumonia and bronchitis, fatigue, fever, sore throat, nausea, vomiting, depression.
4. Ozone (O3)Ozone is odorless and colorless gas. At ground level ozone is air pollutant, commonly called smog. It is formed when nitrogen oxide from cars, power plants and industries is combined with hydro carbons. Sunlight reacts with these pollutants and forms ozone gas due to chemical reactions. Smog/ pollution levels are higher in the months from May to September.
Symptoms: It causes irritation to throat, lungs, and tightness in chest, chest pain and difficulty in breathing and coughing.
5. Sulfur Dioxide (SO2)This gas is a chemical compound produced by volcanoes. It is also found in various industrial processes such as manufacturing units, electricity production etc. Coal and petroleum often contain sulfur compounds and their combustion generates sulfur dioxide. Oxidation of SO2 usually holds the presence of nitrogen oxide which forms H2SO4. SO2 produced from fuels is used to generate power and spoils the environment.
Symptoms: Respiratory problems for asthmatic children and adults, wheezing, chest tightness and shortness of breath, alterations in lungs, increase in existing cardiovascular disease.
6. Asbestos FibersAsbestos fibers are produced from silicate minerals such as thermal insulation, fire proofing and other building materials like floor tiles, ceiling tiles, pipe wrap etc. Asbestos itself is not dangerous but affects only when asbestos fibers are released at the time of cutting, rubbing, drilling or building remodeling. The fibers enter the lings through air and have adverse effects on the health. These fiber particles are too small to visualize with necked eyes and are inhaled and accumulated in lungs.
Symptoms: Lung cancer, respiratory problems, high risk of breathlessness and asthma.
7. Molds, Bacteria and TermiteMolds, fungus and insects can not be seen with necked eyes. Molds or bacteria and fungi can grow almost on any substance where moisture is present inside and outside the house. Mold can grow on wet floors, leakage from roof, leaking around water pipe and improper drainage also. They grow very fast on organic substances, moisture where oxygen is present. The presence of mold can be found on unused furniture, below carpets, behind wall papers, or paneling.
Symptoms: Molds or bacteria and fungi can create health hazard to human beings potentially causing allergic reaction and respiratory problems.
8. HVAC (Heating Ventilating and Air Conditioning)
The green design movement in commercial and residential HVAC industry emphasizes on indoor air quality. While designing HVAC system, it is necessary to see moisture and humidity control which optimizes the conservation of energy.
In this system outside air is forced to enter the house and the same air forces inner pollutant air and moisture to exit through vent. Don’t use this process when there is high humidity in outside air. If it is done, it is harmful and causes mold growth. Dust and other particles deposited in building create indoor air pollution. Lacquers, pesticides, some paints, lead etc. create pollution in indoor air also.
Symptoms: Respiratory infections; asthma and allergies; skin, eye, nose and throat irritations; headaches, damage to central nervous system; and cancer.
How to improve indoor air quality?
1. Design your house carefullyThe architect must keep in mind indoor air quality to protect house from indoor air pollution. He should design the house in such a way that it is environment friendly. The following are some important tips to improve indoor environment quality.
- Keep construction in proper direction
The building outside the house should not be made at 90 degrees towards the direction of wind. Try to take maximum benefit of wind outside the building by constructing building ranging from 0 Degree to 30 Degree. When the wind prevails in east or west direction, keep in mind the effect of solar heat taken at the time of orientation of building.
- Keep adequate opening area towards the wind
The openings in building should be located towards the direction of wind. Keep opening area, 20 to 30% of floor area of the house. Where air or wind is quit constant, the area of opening should be 30 to 50% of the floor area. Living room window should be in open space.
- Where there is problem of open space, provide courtyard to solve the problem of space. Where the wind flow is low, provide open space around the house to get maximum natural air and light.
- The area of opening should be at least 20 to 30% of floor area of the house. Outlet opening/ exhaust should be located on lee ward direction (opposite to air direction). The level of outlet opening is at the ceiling level to remove pollutant air from house. Keep the sill of windows at 2 feet to 2 feet 9 inches for taking maximum benefit of air moment. The windows should be fixed at occupancy level (the level of sitting).
- Keep adequate slope in floors and on roof
The roof of house has sealed corners and adequate slope to drain rain water to avoid leakage causing dampness. Especially the floors of bathroom and kitchen should have proper slope to drain out waste water.
- Fix chimney and keep minimum offsets
Chimney should be fixed on over gas stove, cooking range etc. to remove air pollutants. There should be minimum offsets inside the building to avoid dust collection.
- Avoid pattern ceiling by doing plaster finish
Do plaster finish to avoid pattern ceiling (un-plastered ceiling) and face work brick wall that keeps dust.
- Install doors, windows and exhaust fans
Fix wire gauge door and window shutters to avoid entry of bacteria to the house. Install exhaust fan in kitchen, toilet, bathroom, store etc. to air out polluted air.
2. Make arrangements for proper ventilation
Proper ventilation is a primary method to improve indoor air quality in a building. It helps in reducing in the level of CO in the house. Natural and mechanical ventilation draws air inside the house and removes it out. You can enjoy proper ventilation by using following ways.
- Install low level windows to get maximum air
Low level windows should be provided towards the flow of wind. The position of windows should be according the use of various rooms, components of building. Windows’ opening should be so arranged that they give maximum light in occupancy area (the area of sitting). Outlet openings should be at high level and be located on lee ward direction (opposite to wind direction). Maximum air flows are achieved if both inlet and outlet area are at equal level. The height of windows sill should be 2’ to 2-1/2’ from floor level to get maximum natural air. Fix two windows instead of one single into the rooms having only exposed wall. The buildings where persons are working or sitting on floor, the sill height of windows should be 1-1/2’ from floor level.
- Fix mechanical devices
Mechanical devices such as exhaust fans etc. can help in removing polluted air from house. Use exhaust fan while cooking, using toilets, bathroom, washroom etc. Also make use of air purifier to remove pollutants from the house.
- Install outside openings to remove polluted air
Outdoor air enters the house through doors, windows, ventilation, openings etc. and removes polluted air out through vents in the house. The windows and openings should be at occupancy level, in the direction of flow of air. Ventilator should be at higher level towards opposite direction of air flow.
3. Utilize hygienic building material/ goods
- Avoid materials releasing adhesives/urea: Avoid use of porous building material. Don’t make use of particle board or medium density fiber board for kitchen cabinets etc. to avoid adhesives releasing urea formaldehyde. You can use pressed wood products (obtained from timber). Purchase quality products according to required quantity.
- Don’t use VOC products: Avoid paints and floor finishes which have adhesive and sealants emitting unhealthy volatile organic compounds (VOC) as these organic compounds spread harmful chemicals in indoor environment. Refer to manual instruction with container of the product.
- Opt for hardwood flooring: Install flooring of hard material such as bamboo, wood, marble stone or concrete flooring. Avoid tiles and asbestos floors; which contain harmful fibers. Use solid wood products such as flush door to avoid dust collection. Don’t use wall paper, paneling on walls to avoid the growth of molds. Don’t use from wall to wall carpets to avoid growth of molds.
- Use pesticide in low quantity: Try to use minimum quantity of pesticides. Remove all indoor air pollutants and if not possible keep them with proper sealant (cover). Integrated pest management technique should be used to reduce the need of pesticides.
4. Maintain your house properly
- Clean your house regularly: Dust, molds/termite, bacteria and other harmful particles should be cleaned at regular interval and remove these harmful particles away from home. Chimney, flues (Gas Stoves), exhausts should be cleaned regularly. Also clean wastewater drains etc. regularly. Make use of damping or mopping rather than sweeping. Carpet must be cleaned regularly to avoid growth of molds and to prevent allergy due to dust. Get periodic inspection done by experts in treatment of cleaning/molds.
- Repair leakage in rain water pipes and water supply pipes
Ensure that there is no hole in rain water pipes to avoid leakage or dampness during rain. The joints of rain water pipes are tight to avoid any leakage. Water supply pipes should also be checked to avoid leakage. Sewer line should have adequate slope to drain out waste water immediately. Plinth protection should be made around building to avoid the entry of rain water to the foundation and to prevent growth of bacteria etc.
- Utilize household products carefully: Use domestic products as per instruction of the manufacturer. Make sure that there is plenty of fresh air while working with domestic products. Don’t keep empty containers in the house. Never mix household care products unless directed on labels. Keep out the entire pest and other cleaning agents out of reach of children.
- Maintain burning equipment: Always make sure that burning equipments, gas appliances are maintained and adjusted properly. Keep windows, ventilators and glass shutters open during cooking time. Utilize vented space heater instead of un-vented heater. Flue and chimney should be cleaned regularly. Always keep flue of chimney open.