GGR203H1 Lecture Notes - Circulatory System, House Dust Mite, Indoor Air Quality
EESA Notes Lecture 2
Nitrogen Oxides and Sulfur Oxides
contributes a great amount in formation of ground ozones combined with volatile organic
compounds and the help of the heat and sunlight
form in any type of combustion process
When in air, can easily form acids (acids aerosols), therefore, nitrogen contributes in formation
of acid rain acidifies soils and open water
Can form nitrate particles when reacting with solid particles (salts) and can stay in the air or
come back to the soil surface through rain and contaminate soil.
Regardless of source of nitrogen oxides, nitrogen oxides can travel very far like ozone.
A major affect they have on our bodies is harm to our lungs and other breathing organs. The
intensity and location of damage to our body depends on the forms of the nitrogen oxides.
o If it is water soluble, it causes damage to upper areas of our respiratory system (e.g.
nose, bronchioles, throat)
o If it is not water soluble, it will reach lower areas of our lungs and affect small airways.
Nitrogen oxide gases are harmful to those who already have respiratory problems (e.g. Asthma
– most common) or weak immune system. Children are more vulnerable to such a negative
How are Sulfuric Oxides produced: usually during the burning of coal (soft coal) and oil and as
well from the extract of metals from ores.
Sulfur Dioxides are very soluble and can dissolve in water vapour or water molecules in air and
forms acid rain (similar to nitrogen dioxide).
Sulfur oxide gases can react with other solids and form solid sulfates.
Major reason lead is found in air (especially in urban areas) is b/c gasoline was leaded (not
Young children are particularly sensitive to the aversive effects of lead.
Lead in air can slowly deposit on soil and water surfaces (can enter our food chain).
Some may accidentally ingest lead contaminated soil
INDOOR AIR POLLUTION
Recently science realized that indoor air pollution can contain 2-5 times higher concentrations of
hazardous pollutants than outdoor air. Why? One reason is because modern buildings are built
very air tight to conserve energy but resulted in very little ventilation and contaminated air stays
in the buildings and accumulates. As well, most people spend about 90% of our time indoors
(e.g. children, elderly, pregnant women and those with chronic illness).
Sources of pollutants:
o building materials and furnishing (e.g. wall, paints)
o asbestos insulation (not in use as much)
o wet or damp carpet (e.g. chemicals on new carpets)
o furniture made of certain pressed wood products (e.g. almost all wood is treated and
pressed with glue which can evaporate)
o cleaning products and air fresheners (e.g. Lysol)
o personal care and hobbies (e.g. hairspray)
o Other sources can be from cooking and insecticides.
o Heating (e.g. any type of combustion in developing countries)
o Outdoor air pollution (all contaminants found outside can be found inside)
What is the problem then?
o Most people won’t know that we are exposed to pollutants because they are
indetectable through our senses.
o The symptoms we get if exposed and harmed are not specific and may be mistaken for
flu or a cold.
o Regular concentrations and exposure is required before symptoms develop
o Symptoms of aversive effects to regular exposure: tiredness, dizziness, nausea, irritation
of the nose (e.g. itchy)
o Symptoms of aversive effects to high concentration exposure over many years: cancer,
It is a fibrous material (group of six different minerals – natural minerals) which is separable,
long, strong and flexible heating resistant fibers.
o Building materials
o Paper products
o Automobile industry
o Special packaging and coatings
Can’t be dissolved in water, cannot evaporate into the air, or even break down into elements (it
remains solid throughout) therefore, cannot reduce its toxic effects
If it deposited on the soil surface, it remains on the soil surface and cannot move through the
How might you be exposed to asbestos?
o We are all exposed to asbestos but at very low levels and so we aren’t harmed much
o However those working in some industries are exposed more than others and those
who live near such industries are effected through emission
o Asbestos used for insulation is spread during demolition of old buildings or remodelling
o From drinking water (natural contamination)
o Contaminated cement pipes leading to contaminated drinking water.
Human Health Affect: affects the lungs and the membranes surrounding the lungs
Asbestosis: a scar like tissue forming inside the lungs and are not common (found in those
exposed to high concentration).
Symptoms: difficulty breathing; heart enlargement; disability and may lead to death, increase
the risk of attaining cancer.
If someone is smoking in the presence of asbestos increases their chances of getting affected
and harmed by asbestos.
However, asbestos are not related to birth defects.
How will one know that someone is continuously exposed to asbestos? Can be measured in
urine and mucus. By measuring the level, doctors can assess the potential risk.
Volatile organic compound (easily evaporates at room temperature)
Colorless but has a strong scent (e.g. the smell of new furniture or carpeting)
Glue is formaldehyde and can evaporate; can be found in cigarettes and automobiles, paints and
permanent press fabrics (e.g. drapes)
o Water Eyes
o Nausea, Coughing
o Chest tightness
o Asthmatic reactions
o Skin rashes
o Allergic reactions
o Cancer (not so common)
Some people are very sensitive to formaldehyde
Most physicians are not trained to identify the symptoms of the effects of formaldehydes
Mold, Moisture and Indoor Air Quality
Requires moisture (but not necessarily standing water) but needs high relative air humidity; cold
air is favourable for mold growth.
Where can mold be found?
o Bathrooms and kitchens
o Gym areas
o Locker rooms
o Leaky areas
o Damp basements
To control indoor mold growth one should regulate the relative humidity between 30 and 60
percent; however they are often undiscovered.
Molds produce tiny spores and can cause discoloration and odour problems.
The mold health effects:
o Major source of indoor allergens
o Trigger asthma
o Produces toxins
o Produces irritants
Can be more harmful than first hand smoking
Smoking is a choice but being exposed to second hand smoke is not a choice
Has about 4 000 different compounds and 40 of them are carcinogens
About 3 000 lung cancers case are discovered in non smoking people (in the U.S.)
Can affect the cardiovascular system, cause asthma and pneumonia, and can increase the risk of
bronchitis in children, ear infection and reduce immune system effectiveness
Air Dust and Indoor Air Quality
Heating and cooling systems can circulate air contaminants such as dust mite, mold, pollen,
bacterium through forced air in the systems.
Duct cleaners provide services to remove these air contaminants but one must also have to
consider if these companies use chemicals and what kinds because some may harm more than
Cleaning and ventilating the house is helpful in reducing dust.