EESA10H3 Lecture Notes - Indoor Air Quality, Smog, Mechanistic Organic Photochemistry

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28 Jul 2011
Human Health and the Environment
Lecture 2: Airborne Hazards and Human Health
The final is going to be cumulative. Professor does not yet know of the midterm date. She
will post it on the intranet as soon as she gets information on it. The midterm examination
will most likely be after the reading week but not 100% guaranteed. The professors new
office hours are 4PM-6PM Wednesday before lecture in SW410.
Change in Teaching Assistant
Wing-Shun Wu for P-Z online lecture (LEC 60)
Office Hours Friday 12PM-2PM
Announcement on Readings
Book and presentations are enough for the exams
Only the topics that the professor covers in class look through the text, otherwise there
is nothing additional
Airborne Hazards
Today we will discuss two types of air pollutants
1)Outdoor air pollution
2)Indoor air pollution
What are the major sources of air pollution? They are natural and manufactured
Natural include forest fires, volcanoes most of them that we cannot avoid
Manufactured has different kinds of industry and the burning of fossil fuels
Outdoor Air Pollution
Listed are 6 common air pollutants
They are regulated by the U.S. Act it is called the Clean Air Act of U.S.A.
A strict threshold is placed on these six pollutants
Discuss pollutants that are not regulated in Canada or U.S. as they still represent a
hazard to human health
Is a chemical gas that has three oxygen atoms combined
There are two different types of ozone
One is good ozone ozone layer in stratosphere protects us from harmful ultraviolet
(UV) radiation
There are ozone holes and problems with the pollution (is the good ozone) and this ozone
is not formed on ground level
It is formed in the upper level of atmosphere
What is the subject of concern is the ground level of ozone ozone formed just a little bit
above the ground and how this ozone is formed
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Volatile Organic Compounds (VOC) react with Nitric Oxides (NOx) and with some effect
of heat and sunlight (this is actually photochemical reaction)
Photochemical Reaction is any chemical reaction that is triggered by light, sunlight
When heat and sunlight has effect on the formation of ozone we can discuss where is the
higher risk of being poisoned or having adverse effect of human health on these gas
Hot, warm, sunny climates are a big problem for these types of photochemicals,
photochemical oxidants i.e. Mexico City
We all know that Mexico City receives a lot of sunshine because of its warmer climate
In Los Angeles there is also a big problem with photochemical smog
In cold climates the problem is not that, it is less significant
In the morning and in the evening the concentration is lower
In the middle of the day especially around rush hour when traffic is heavy heat is higher
and sunshine is combined with pollution thus the concentration of ozone increases
Ozone is a summertime pollutant even in Toronto or in Canada contamination and
pollution with the ozone is much higher during the summer
Ozone is transported over very long distances it doesnt matter where it is formed (can
be formed in Asia or Europe but can affect us here in North America)
What does the ozone do to our health, to our bodies? It causes lung damage (we call it
lung disease) affect small airways which means in the lower levels of our lungs some
changes and some problems can be seen
This results in shortness of breath, chest tightness (pressure on the chest), awful cough,
nausea and can irritate and damage eyes, nose, sinuses, throat
But we believe that if we go outside if you exercise you will get healthy and probably
more resistant and not be such a burner about todays chemical
Scientists and experts found something very interesting that people that exercise
outside a lot are more vulnerable
It is logical because many urban people exercise on the street together with the
emissions and gases and they breathe deeper, take in much more air in their lungs
Particulate matter (PM)
What is the particulate matter in air? Particles found in the air
Particles can be solid particles or can be liquid particles aerosols
These particles vary significantly in size from really large with black soot (sticky tack
material) i.e. smoke that is somewhat very visible to very tiny particles of liquid
That is why we often find in literature particles and PM10 and PM2.5 What does this
PM 2.5 - particles smaller than 2.5 microns in diameter
Experts believe that these particles are small enough to be transported in lower level
part of your lungs in the narrower airways because they are so small they can hurt your
lungs on very small alveolis
Bigger particles will stay in upper level - nose, a little bit in the mouth (in the upper
level of the respiratory system)
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Major source of particles (particulate matter) are vehicles, vehicle exhaust, factories,
different types of industry, construction sites (demolition, reconstruction), stone
crashing, or burning emit soot and smoke
But not all particle matter is emitted as some is formed in the air
Serious health effects, why? These particulate matter can be associated with acidic
material acids as these acids damage the lungs a lot (very dangerous to our lungs)
Carbon Monoxide
Why does carbon monoxide need more discussion and attention?
You are exposed and it is very hard to know that you are poisoned but it is also a very
common pollutant
It is everywhere in outside pollution, outside air, also indoor big problem indoor
Both critical for indoor pollution as well as for outdoor pollution
Odourless, colourless gas emitted during the burning process but incomplete burning,
burning of fossil fuels anything that has carbon as a content and if it is partially
burned process is not finished until end when emits carbon monoxide
Couple of examples include heaters indoor, woodstoves, gas stoves, fireplaces (poorly
ventilated thus carbon monoxide can spread), water heaters, automobile exhaust,
tobacco smoke
1,000 people die each year in U.S. as a result of CO poisoning
If someone is exposed to the lower dosage of carbon monoxide not something very visible
right away
For a longer time especially for a fireplace that is not ventilated you want experience for
an significantly adverse amount of time but what might happen is you might have
symptoms similar to the flu or similar to food poisoning (vomiting, dizziness, nausea
something like that)
Many physicians get confused as it is hard for them to determine/detect what is going on
if you dont give them some clue (usually you dont know)
Some people are even more vulnerable infants, elderly, and people that already have
problems such as heart and respiratory illnesses before that
They experience adverse effects in much lower concentrations than other healthy people
are at a higher risk
Health effects of Carbon Monoxide
What does carbon monoxide actually do and why do we experience that adverse affect?
Carbon monoxide interferes with delivery of oxygen because carbon monoxide has a
much higher affinity for hemoglobin (part of our blood, red in colour)
About two hundred or even more than two hundred times higher affinity for hemoglobin
than oxygen
As a result of this we can experience some health problems problems include fatigue,
detected or undetected (that we do not know reason for) headaches, some weaknesses
When a concentration increases in the air then symptoms get worse as there is
confusion, disorientation i.e. we usually dont know that we are poisoned and when we
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