Textbook Notes (280,000)
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EESA10H3 (100)
Chapter 2

Textbook notes on Chapter 2


Department
Environmental Science
Course Code
EESA10H3
Professor
Jovan Stefanovic
Chapter
2

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Human Health and Environment Chapter 2 (Textbook reading): Air Pollution
recognition of the relationship b/w nonworkplace (community) air pollution and respiratory
disease dates back to the first use of coal as a combustion source
air pollutants caused serious illness & deaths among people w/ cardiopulmonary disease
oCardiopulmonary disease: a disease that involves both heart and lungs
oOccurred in Meuse Valley of Belgium in 1930/ Donora Pennsylvania in 1948/ London in
1952 (in London, reached 4000+. Mortality mostly due to bronchitis, pneumonia and
acute exacerbation of underlying cardiac and respiratory diseases)
air pollution crisis worldwide
1. Air pollution has no boundaries/national borders b/c:
atmosphere is dynamic and always changing
contaminants are transported (over thousands of miles), diluted, precipitated &
transformed
2. primary emissions of sulphur oxides, nitrogen oxides, carbon monoxides, respirable
particulates and metals (lead and cadmiums) in populated cities in Asia, Africa, Latin
America and Eastern Europe due to uncontrolled industrial expansion, increasing motor
vehicle numbers & congestion & pollution caused by fuels used for cooking & heating
There is a relationship b/w air pollution and wealth. Countries that have lots of
poor people tend to have lots of air pollution (high levels of total suspended
particulates because they rely heavily on coal) vs. wealthy people
e.g. particulate levels in Beijing can reach over 1200mg/m 3 whereas US
has only 150mg/m 3
3. nations that have reduced the primary emissions from heavy industry, power plants, and
autos, new problems have arisen from pollution by newer industries and from air
pollution caused by secondary formation of acids and ozone
high air pollution contributes heavily to the high mortality rates due to acute respiratory disease in
kids under age of 5 or 28% of deaths in this age group (however air pollution also affects kids in
developed countries too)
Specific Air Pollutants Associated w/ Adverse Respiratory Effects
Pollutant SourcesHealth effects
Sulphur oxides, particulatesCoal & oil power plants
Bronchoconstriction, chronic
bronchitis, chronic obstructive
pulmonary disease (COPD)
Carbon dioxide Motor vehicle emissions,
fossil-fuel burning
Asphyxia leading to heart and
nervous system damage, death
Oxides of nitrogenAuto emissions, fossil fuel
power plants, oil refineries
Airway injury, pulmonary
edema, impaired lung defences
Ozone Auto emissions, ozone
generators, aircraft cabins
Same as oxides of nitrogen
Polycyclic aromatic
hydrocarbons
Diesel exhaust, cigarette
smoke, stove smoke,
Lung cancer
Radon NaturalLung cancer
Asbestos Asbestos mines and mills,
insulation, building materials
Mesothelioma, lung cancer,
asbestosis
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ArsenicCopper smelters, cigarette
smoke
Lung cancer
Allergens Pollen, animal dander, house
dust
Asthma, rhinitis
Sulphur Dioxide and Acidic Aerosols
Sulphur dioxide (SO2) is produced by the combustion of sulphur contained in fossil fuels (e.g.
coal and crude oil).
oTherefore, major sources of environmental pollution w/ sulphur dioxide are electric power
generating plants, oil refineries and smelters
oSoft coal contains lots of sulphur dioxide
Sulphur dioxide is a clear highly water-soluble gas so it is effectively absorbed by the mucous
membranes of the upper airways w/ a much small proportion reaching the lung
Sulphur dioxide released in the atmosphere undergoes chemical reaction w/ water, metals and
other pollutants to form aerosols
oAerosol: a system of colloidal particles dispersed in a gas; smoke or fog
oMost common pollutants resulting from atmospheric reaction are sulphuric acid, metallic
acids and ammonium sulphates
Smog= smoke + fog (visible cloudy combo of the two)
oIncreases asthmatic responses in children and adults
Higher particle acidity (nmol/m3) was significantly associated w/ an increase in risk of bronchitis
while higher levels of gaseous acids were significantly associated w/ risk of asthma
o+vly assoc. w/ wheeze attacks, chronic wheezing, and any asthmatic symptoms
oConnection b/w acidic aerosols and mortality; increased death in people w/ underlying
chronic heart and lung disease
Inhalation of high concentrations of sulphur dioxide has been shown to increase airway resistance
(bronchoconstriction)
Bronchoconstriction is the constriction of the airways in the lungs due to the tightening of
surrounding smooth muscle, with consequent coughing, wheezing, and shortness of breath.
Bronchoconstriction can also be due to an accumulation of thick mucus.
oIts removed in the upper airways during rest (b/c its highly water soluble) but exercising
will increase SO2 in the lower airways
Particulates
Particulate air pollution closely related to S02 and aerosols
Particulates are particles suspended in the air after various forms of combustion or industrial
activity
Air pollution is characterized by high levels of particulates, sulphur dioxide and moisture
Particles <2.5 microns in diameter PM2.5 (a.k.a. fine particles)
Small particles can penetrate deeply into the lung (causes respiratory problems) while larger
particles would be trapped in the upper airway
Relationship of particulate levels w/ subtle changes in heart rate variability (HRV)
oLimitation to the research found on the relationship is: conducted research on older
people (dont know if it occurs in younger people too)
Heart rate variability: a measure of the cyclic variations of beat to beat intervals and of the
instantaneous heart rate
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