1st Occupational, Environment and Human Health Conference, Hamad Medical Corporation,

6- 7 December 201,5 Doha, Qatar

Dr. Latif

What’s indoor air pollution?

Indoor air pollution refers to chemical, biological and physical contamination of indoor air. (1)

It is the amount of contaminants in the air inside a building from sources such as cigarette smoking, fuel combustion, as well as the geology of the area (radon in soil or rocks beneath the structure). 

Why it is important?

Why should you be concerned about the quality of air that you breath?
•    Time indoor - most people spend more time indoors than outdoors
•    Children at higher risk of health damage due to indoor pollution.
•    Some pollutants have higher concentration indoor than outdoor.
•    The contaminant indoor air could damage people’s health

From outdoor to indoor

Early humans spent most of their times indoor, however modern people spend almost 90% of their times indoor. (2)

History of Indoor Air Quality

•    Greek philosophers in 500 BC, concerned with air quality in mines
•    The Roman choler, Pliny the Elder, advised masks for stonecutters
•    Early 1800s, first ventilation standards to control odor.
•    In 1858, Florence Nightingale, the mother of modern nursing, recommended air exchange rate to avoid re-infection in hospitals. (3)

•    As a result of the energy crises in the1970’s, the energy conservation awareness has led to more isolation and less ventilation.

Facts on Indoor Air Pollution

These are some important numbers:
    1.4 million buildings in the US have indoor  problems
    Indoor radon exposure -the second leading cause of lung cancer, Elevated levels of radon gas, is found in nearly one out of every 15 homes in the United States according to the U.S. Environmental Protection Agency (EPA). (4)
    Second hand smoking causes 3,000 lung cancer deaths and 35,000 to 50,000 heart disease deaths in non-smokers
    Legionnaires Disease strikes 25,000 people
30% of all commercial buildings have significant indoor Air Quality
(IAQ) problems

Sources of Pollutants

•    People and pets generate carbon dioxide, moisture and microbes
•    Combustion appliances such as wood stoves and gas stoves
•    Use of consumer products such as detergents and air fresheners
•     Cigarette smoking
•    Soil under and around buildings – radioactive elements
•    Appliances such as humidifiers, air conditioners

Health effects due to indoor air pollutants

    Neurological effects: fatigue, nausea, headache
    Respiratory infections
    Asthma
    Humidifier fever
    Legionnaire’s disease
    Lung cancer

Most Common Pollutants

•    Household cleaning products.
•    Radon - radioactive
•    Combustion -  food preparing
•    Moisture molds


Household cleaning products

Volatile Organic Compounds (VOCs)
(VOCs) are a large group of carbon-based chemicals that easily evaporate at room temperature.
Products containing VOCs can include:
    Air fresheners
    Chlorine bleach
    Detergent and dishwashing liquid
    Dry cleaning chemicals
    Furniture and floor polish
    Oven cleaners

What are the health effects of VOC exposure?

    Short-Term (Acute) to high levels of VOCs
    Eye, nose and throat irritation
    Headaches and Dizziness
    Nausea / Vomiting
    Worsening of asthma symptoms
Long-Term (Chronic) to high levels of VOCs
    Cancer
    Liver damage
    Kidney damage
    Central Nervous System damage

Radon - Radioactive pollution

Radon It is a radioactive, colorless, odorless, noble gas
It is formed as one intermediate step in the normal radioactive decay chains through which uranium slowly decay into lead.
 Where does radon come from?
    Natural source:
    Earth and rock beneath home;
    Well water;
    Outdoor air;
    Artificial source:
    Daily life materials: leather; low density plastic (like plastic bags) paints
    Building materials: gypsum board, concrete block and wood paneling

Why it is a serious issue

Radon is a gas, so it is easily inhaled, - Unlike all the other intermediate elements in the decay chains, radon is gaseous and easily inhaled
    Available in all construction materials, every where!
    Higher considerations indoor; more than outdoor .
the average indoor radon level is about 1.3 picocuries (pCi/L) in the United States. The average outdoor level is about 0.4 pCi/L.(5)

Should you test for radon?

    Testing is the only way to know your home's radon levels.
     There are no immediate symptoms that will alert you to the presence of radon.
    The US EPA, Surgeon General, American Lung Association, and National Safety Council recommend testing your home for radon.

How to Lower the Radon Level

    The most effective way to lower the radon level is set a vent pipe system and fan, which pulls radon from beneath the house and vents it to the outside.

Household cooking- Food preparing

Cooking Up Indoor : Emissions from Stoves

It is very common in developing countries to use biomass in cooking (wood, charcoal, animal dung and agriculture residues)this produce gaseous pollutants such as CO, CO2 and O3.
Emissions from biomass combustion are a major source of air pollution, and are estimated to cause millions of premature deaths worldwide annually.
 Around 3 billion people cook and heat their homes using open fires and simple stoves burning biomass (wood, animal dung and crop waste) and coal.
Over 4 million people die from illness linked to the household air pollution from cooking with solid fuels.

Specific sources in the middle east

Cooking Up Indoor: Emissions from Stoves

    In general modern stoves are sued universally, however, Cooking meats with charcoal grills is a common activity in the middle east, usually outdoor, occasional indoor.

Indoor : Emissions from ACs

Cooling equipments are more required than  heating,

Indoor Molds

What are molds?
    Molds are fungi that can be found both indoors and outdoors.
    Molds grow best in warm, damp, and humid conditions,
    Grow on food and other surfaces that contain sufficient moisture.

Health effects of molds

    Coughing or wheezing, eye irritation, or skin irritation.
    People with mold allergies may have asthma attacks.
    Immune-compromised people and people with chronic lung illnesses, may get serious infections in their lungs when they are exposed to mold.

What is Sick Building Syndrome (SBS)?

    Condition of a building in which more than 20% of the occupants are suffering from adverse health effects but with no clinically diagnosable disease present

    It is a condition of a building ; not of the occupants

    It takes place due to long term exposure to low levels of contaminants


these are some strategies to help people improve indoor air quality
     - Pollutant Source Control
     - Increased Ventilation
     -  Dehumidification
     -  Use of Air Cleaners
     -  Dust collectors
     -  Filters


1-Glossary of Environment Statistics, Studies in Methods, Series F, No. 67, United Nations, New York, 1997.
2-WORLD FUTURE FUND, INDOOR AIR, HUMAN HEALTH AND CHEMICALS, from: http://www.worldfuturefund.org/wffmaster/Reports/wff-indoorair.html 

3-Professor Alan Hedge, Cornell University, VENTILATION AND INDOOR AIR QUALITY  from: http://ergo.human.cornell.edu/studentdownloads/DEA3500pdfs/iaqresp.pdf
4-American Lung Association, Radon,  from: http://www.lung.org/our-initiatives/healthy-air/indoor/indoor-air-pollutants/radon.html

5-Air check, Radon Fact Sheet, from: http://www.radon.com/radon/radon_facts.html