Lecture 9: Air Pollution Flashcards
T/F: Globally, air pollution is the #1 cause of early
death compared to any other toxicant group
true!!
T/F: There was rapid and relatively
unregulated industrial
expansion and the burning of
fossil fuels (especially coal)
until ~1950s
true!!
what was the “great smog”?
happened in London 1959, lasted 5 days because of cold weather with a temperature inversion (kept everything trapped in the lower atmosphere)
During that time, 1,000 tons of smoke particles,
2,000 tons of carbon dioxide, 140 tons of
hydrochloric acid, 14 tons of fluorine compounds
and 370 tons of sulfur dioxide was released into the
air.
* Contributed to the deaths of between 4000-12000
people (mostly elderly and children)
what led to the creation of air pollution control legislation?
the great smog, and other smog events across NA
______ is now the largest contributor to air pollution in
North American cities
Automobile exhaust
T/F: Globalization has led to the
outsourcing of manufacturing to
other countries… Which contributes
to air pollution elsewhere
true!
_____ is comprised of four main
air pollutants:
- particulate matter
- ozone (O3)
- nitric oxides (e.g., NO2)
- sulfur oxides (e.g., SO2)
Smog
what happens with acute lung injury? (4)
oxidative damage
airway reactivity
pulmonary edema
cell proliferation
______ in acute lung injury: Ozone, NO2, tobacco smoke and lung
immune system cells can all generate ROS
oxidative damage
______ in acute lung injury: Air pollutants can trigger
bronchoconstriction, limiting oxygen uptake.
* Problematic with asthma sufferers
airway reactivity
______ in acute lung injury: Extensive cellular damage causes leaking
of fluid into alveolar spaces.
* Less gas exchange
pulmonary edema
______ in acute lung injury: Epithelial cells proliferate, excessive cell
division can lead to an increased potential
for mutations
cell proliferation
what happens with chronic lung injury?
COPD
fibrosis
asthma
cancer
______ in chronic lung injury: Emphysema = destruction of the alveolar sacs.
* Bronchitis = constant inflammation of bronchi +
excessive mucous deposition.
* Increase in lung infections
COPD, chronic obstructive pulmonary disorder
______ in chronic lung injury: Inflammation response leading to increased
deposition of collagen in damaged lungs.
* Makes lungs less elastic, decreasing gas
exchange.
fibrosis
______ in chronic lung injury: Recurrent bronchoconstriction
asthma
______ in chronic lung injury: Direct DNA mutations from oxidative damage.
* Indirect DNA mutations from excessive cell
division to replace damaged cells
cancer
_________ is a large mixed class of
compounds (i.e., anything that’s small, for example
dust and soot)
Particulate matter
what are the four classifications of particulate matter?
PM100 = dust = particles >100 µm.
PM10 = coarse = particles 2.5-10 µm.
PM2.5 = fine = particles 0.1-2.5 µm.
PM0.1 = ultrafine = nanoparticles = <0.1 µm
T/F: Other toxicants can absorb onto the surface of
particles (metals, gasses, pesticide residue, etc.)
exacerbating the PM effects
true!
T/F: worldwide estimates suggest that particulate matter can cause
up to 25% of lung cancer deaths, 8% of COPD deaths, and
about 15% of heart disease and stroke
true!!
______ is heterogeneous and usually associated with other types of pollution,
so it is difficult to assess a direct mechanism of toxicity.
PM, particulate matter
what are the five possible mechanisms that PM uses to be toxic?
- Leads to lung irritation which
leads to increase permeability
in lung tissue; - Increases susceptibility to
viral and bacterial pathogens
leading to pneumonia in
vulnerable persons who are
unable to clear these infections; - Aggravates the severity of
chronic lung diseases
causing decreased lung
function - Causes inflammation of
lung tissue, resulting in the
release of chemicals that
impact heart function; - Causes changes in blood
chemistry that can
contribute to heart attacks
T/F: Estimates that reducing PM to WHO
recommended levels would prevent 15% of air
quality related deaths
true!!!!
Fine particulate matter (PM2.5)
10 μg/m3 annual mean
25 μg/m3 24-hour mean
Coarse particulate matter (PM10)
20 μg/m3 annual mean
50 μg/m3 24-hour mean
these are guidelines from which organization?
WHO, air quality guidelines
where does majority of PM from human activities in Canada come from?
home firewood burning!
Most nitrogen dioxide (NO2) is created by _______. In urban areas, NO2
fluctuates during the day based on ________.
automobile exhaust
traffic patterns
NO2 is a lung irritant (especially terminal bronchioles). In the lung, NO2 can be
converted to ______ and _______, which can then cause chemical
pneumonitis and pulmonary edema
nitrous (HNO2) and nitric (HNO3) acid
T/F: Acute damage fro Nitrogen Dioxide begins at exposures of 75 to 100 ppm. Urban air rarely get above this
true!! thank goodness
where does majority of NO2 from human activities in Canada come from?
transportation and mobile equipement!
what do gas stoves leak, and what does it contain?
gas, containing benzene (known carcinogen!!)
T/F: cooking in general can create fine particulates that are known irritants that can cause/exacerbate respiratory problems
true!! 2.5 microns or less
_______ is the most acutely toxic of
common air pollutants
Ozone (O3)
Large quantities of NO2 lead to the
_______ of NO2 creating large quantities
of ozone
photolysis
T/F: Ozone (O3) can oxidize cellular components
true!!! not good!!
what direct effects does ozone have on birds?
Damage to respiratory systems
- Increase physical stress
- Reduce immune function
- Mortality
what indirect effects does ozone have on birds?
Decreases plant quality and growth rate
- Reduce number of insects
- Reduced access to high-quality habitat
T/F: Regulations to protect human health have also
stemmed the decline in bird abundance due to O3
true!!
______: Emitted from vehicles using high sulfur fuels
and from coal combustion
sulfur dioxide (SO2)
In the
lungs, SO2 can be converted into ________, which causes
bronchoconstriction and reduced airway
flow.
sulfurous
acid (H2SO3)
SO2 absorbed primarily in _______ and _________
* Acute exposure (>250 ppm) causes
direct cellular damage in lungs.
* Long term exposure less than 1 ppm
leads to bronchoconstriction, bronchitis
and higher susceptibility to infections
nasal passages
and bronchi
Industrial activity in the ‘rust-belt’ of made a lot of SO2. In the atmosphere, this was converted into sulfuric acid, which then precipitated as ‘_______’. Some rain had a pH of 4!
acid rain
normal rain is usually ~5.6
Excessive decrease of pH in many lakes killed a lot of the organisms, what caused this rapid decline?
acid rain!
how did we reduce the prevalence of acid rain?
Heavy regulation of SO2 emissions in the 1980’s
_____ was where a lot of our
understanding of acid rain on
boreal/shield lakes came from.
Smelting plants built in the late
1800’s. Still a bit of an issue
Sudbury
T/F: 98% of all electricity in Manitoba generated is from hydro (Nelson River project alone
generates 81%)
true!!
where is the fossil fuel generating plant (natural gas) in manitoba?
Brandon
Selkirk was decomissioned in 2020
where were the two major mining smelters in Manitoba? when were they shutdown?
Ni in Thompson (2019)
Cu in Flin Flon (2010)
what are the two main human sources of sulfur oxides?
ore and mineral industries
electric power generation
The Canadian Council of Ministers of the Environment
(CCME) organization has come up with the _________, to help with air quality
Canadian Ambient Air Quality Standards (CAAQS)
this is extremely recent!
