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 pollutants

1. Carbon Monoxide

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 Dioxide

Symptoms: Carbon monoxide causes symptoms of headache, dizziness, disorientation, nausea and fatigue and has very bad effects on health.    

3. Radon

Symptoms: Cancer, lung tissue decay, coughing, heavy breath, infections like pneumonia and bronchitis, fatigue, fever, sore throat, nausea, vomiting, depression.

4. Ozone (O3)

Symptoms: It causes irritation to throat, lungs, and tightness in chest, chest pain and difficulty in breathing and coughing. 

5. Sulfur Dioxide (SO2)

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 Fibers

Symptoms: Lung cancer, respiratory problems, high risk of breathlessness and asthma.

7. Molds, Bacteria and Termite

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 carefully

• 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.