PHAR 303 Lecture Notes - Lecture 13: Sulfur Dioxide, Nasal Cavity, Sewage Treatment
11 May 2018
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Lecture 13 (Feb 22) Respiratory Toxicants & Air Pollution
• Household air pollution and second hand smoke, ambient particulate matter pollution
• Sometimes its voluntary (tobacco) and sometimes it is not.
• Deaths from outdoor air pollution – mostly in Russia. In Canada, very low bc big country spread out.
~3000 deaths per year due to acute smog & 21 000 due to chronic smog
• The smog alert was 21st one this season, capping the previous record of 19 smog alerts issued in 2005.
• 2009 – Ban of new fireplaces & wood stoves
• Smog especially affects asthmatic children and people with respiratory ailments or heart disease. It is therefore
recommended that these individuals avoid intense physical activity outdoors until the smog warning is lifted.
• Environment Canada says that wood heating in Quebec is the largest source of fine particles that contribute to
smog in the winter months. Wood heating generates more particles than industrial activities and transportation.
• Worse city in Canada for air pollution is Winsor Ontario – major border cross between Canada & USA
• In Canada, smog kills more Canadian than Car accidents
The Respiratory System
• Nasal cavity → Trachea → 1◦ , 2◦ 3◦ Bronchi → Terminal bronchi Alveoli
• Surface area is ~ size of tennis court
• Bronchus: Epithelium layer, Muscle, Cartilage & Cilliary cells
• Ciliated cells secrete mucus at top of cilia
• Bronchiole – contains clara cells high in CYP P450s
• Alveolus containing capillaries – seize of erythrocyte.
• Defense against pollution is largely ciliated cells. Muscus secreted & transported out of lungs until you swallow it.
• Alveoli filled with lots of macrophages that remove very tiny particles by endocytosis. Macrophages get into
mucociliary transport system and are removed from lungs. Mucociliary system transports particles.
• Particles of different sizes will reach different depths in the lungs.
o Particles < 10 u will be retained in terminal bronchiole
o Particles < 2.5u can be transported all the way down to distal alveoli
• Where do we get particles in the air? Some of them are generated naturally by dust storms or people choose to
smoke tobacco and be exposed to air pollutants or not.
• Babies are more susceptible to infections bc lungs more vulnerable & absorb more dust, CO2 etc.
• Multiple effects – damage to lungs: lungs are designed so well for gas exchange so they can absorb any gas.
According to image, you can have brain damage, liver and foot.
• Air pollution – we tend to think about it that’s caused by someone else & industries. London air pollution due to
coal burning. London fog killed more than >4 000 in 1952. Couldn’t see at all, couldn’t drive. Sulphur Dioxide in
the air. They end up by banning coal & installed clean air laws. As the city became more dense, trucks and cars
were more used so there is still a big pollution. One of the first countries that regulates cars number in downtown.
• Air pollution is moving. There’s more than 1 source of pollution: Natural sources from volcanoes, fires.
Manufactured air pollutions.
• Farms are a major source of air pollution.
o Transportations/ Mobile : airplanes, ground transportations, buses, motorcycles, cars, trucks
o Stationary : industry, power plants, sewage treatment
o Area: Livestock, farming
o Density populated cities
o Natural : lightning, volcanoes, wildfires, forests
• Indoor and outdoor exposures more in developing countries
Categories of Indoor Air Pollutants
• Pathogenic Microorganisms – molds, bacteria, viruses
• Allergenic Microorganisms – molds, bacteria
• Respirable Particules – smoke, dust, pet hairs, dust mites
• Volatile Organic Compounds – formaldehyde, cooking products, hair sprays, pesticides
• Radon & Radon Decay Products – radioactive decay from uranium
• Average: there’s about 1 air change per hour. Air comes into house from a lot of different sources.
• Indoor air pollution : fireplaces, cleaning agents, gas stoves, tobacco, mould (immune reaction), trichloroethylene
(immunosuppression).
• How radon enters a house? Could cause small fraction of lung cancer. It’s in the soil.
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Lecture 13 (feb 22) respiratory toxicants & air pollution: household air pollution and second hand smoke, ambient particulate matter pollution, sometimes its voluntary (tobacco) and sometimes it is not, deaths from outdoor air pollution mostly in russia. In canada, very low bc big country spread out. Wood heating generates more particles than industrial activities and transportation: worse city in canada for air pollution is winsor ontario major border cross between canada & usa. In canada, smog kills more canadian than car accidents. Muscus secreted & transported out of lungs until you swallow it: alveoli filled with lots of macrophages that remove very tiny particles by endocytosis. Macrophages get into mucociliary transport system and are removed from lungs. According to image, you can have brain damage, liver and foot: air pollution we tend to think about it that"s caused by someone else & industries. London fog killed more than >4 000 in 1952.
