pubhlth 264 - week 1: ambient air pollution & health effects study guide

what are the two major air pollution problems at global level?

1) ozone depletion: CFCs & halogen compounds destroying the ozone layer (stratospheric ozone). UV radiation breaks apart CFC molecules & release chlorine atoms which in turn reacts with ozone & destroys it

2) climate change: carbon dioxide & methane emission levels are harder to treat than just having a substitute for ozone layer

what are the two major air pollution problems at regional level?

1) acid rain: pollutants (oxides of sulfur & nitrogen) produce acid aerosols that can travel long distances

2) photochemical smog: "smoke" + "fog" industrial smog & photochemical smog (triggered by UV rxn with pollutants)

what are the major air pollution problems at local level?

1) nitrogen dioxide (NO2): high levels indoors than outdoors, gas products of combustion from stationary sources and motor vehicles

2) sulfur dioxide & acid aerosols: SO2 emitted by fossil fuel combustion (coal, oil)

3) particulate matter (PM): fine particles getting inhaled and penetrated

4) volatile organic compounds (VOCs): volatile and readily inhalable (ex: butane, propane, octane) emitted naturally by decomposition and industrial activities, precursors of smog

5) carbon monoxide (CO): reacts with blood hemoglobin

in which atmospheric region does the ozone layer occur & what would be the human health consequences of ozone layer destruction?

• ozone layer occurs in the stratosphere and can be destroyed by man-made chemicals

• human health consequences: sunburn, skin cancer, eye damage, cataracts, suppresses immune system, DNA mutation

on an overcast or cloudy day, would you expect any O3 buildup due to smog? why?

• no, would not expect any O3 buildup due to smog

• photochemical smog relies on UV radiation in order to be created

what international treaty went into effect in 1987, aiming to protect the ozone layer? what is the did it do?

• montreal treaty

• made a first agreement to restrict CFCs

• protected the ozone layer by phasing out the chemicals which deplete it

which geographical area in the U.S. has the most significant acid rain problem & what are the environmental/human health effects of acid rain?

• northeastern U.S. has the most significant acid rain problem

• due to large number of cities, the dense population, the concentration of power, & industrial plants

• impaired forest growth reduced ecosystem productivity

• increase in acidity for lakes & rivers

• death of fish & wildlife

• weathering of monuments & buildings

• health impacts for those prone to respiratory ailments

what are the differences b/w industrial smog & photochemical smog?

1) industrial smog:

• burning sulfur rich oil or coal creates SO2, SO 3, sulfuric acid, ammonium sulfate

• carbon leads to CO2 & CO

• days w/ stagnant air, usually winter.

2) photochemical smog:

• smog from reaction of sunlight w/ pollutants

• the kind that blankets so many American cities today

• brown air smog"

• contains tropospheric ozone, NO2, VOCs, 100 more...

• hot sunny days in urban areas create perfect conditions

why is O3 presence in the troposphere a paradox to O3 in the stratosphere?

• good up high, bad nearby

• up at the stratospheric level ozone forms a protective layer that serves a vital function: it absorbs the wavelength of solar radiation known as ultraviolet-B thus protect lives from sunburn, skin cancer, eye damage, & cataracts. this can suppress immune system and cause DNA mutation

• at ground level, ozone is a health hazard. the tropospheric ozone is created through the interactions of man-made emissions of VOC & nitrogen oxides in the presence of heat & sunlight.

what does VOC stand for? what is the role of VOC in smog formation?

• volatile organic compounds

• readily inhalable (butane, propane, & octane)

• VOCs are happens before photochemical smog & react w/ nitrogen oxides emitted from vehicles, power plants & industrial activities to form ozone, which in turn helps the formation of fine particulates

cite two ways in which hazardous air pollutants (HAPs) differ from criteria pollutants.

• the 6 criteria pollutants have primary & secondary standards + uses NAAQS

• the 188 HAPs have no primary or secondary standards that limit pollutant concentrations in the air, but have maximum achievable control technology standards (MACT)

particulate matter (PM) air pollution is sometimes categorized as PM10, PM2.5, or ultrafine particles. why is particle size an important factor determining the adverse human health effects?

• size of the particles is related to their potential to cause health problems

• small particles, less than 10 micrometers, are the biggest problem b/c they can penetrate deep into the lungs, and some can even enter the bloodstream.

• UFP can also penetrate cell walls & the blood brain barrier & can be absorbed into vital organs.

why is air pollution still a public health problem worldwide?

• air pollution is the world's fourth leading mortality risk factor, and air quality is deteriorating in the metropolitan areas of many growing developing countries.

why could air pollution affect COVID-19 susceptibility?

• SARS-CoV-2 is respiratory virus that can affect the lungs, blood vessels, & many other parts of body.

• air pollution can affect the body's immune defense, making an individual more susceptible to respiratory infections

• many health conditions are associated w/ increased vulnerability to COVID-19 are also cause by long-term exposure to air pollution

• a study, examining the association b/w air pollution and Covid-19 incidence & mortality, showed that chronic exposure to nitrogen dioxide has a significant impact on the incidence & mortality of Covid-19 disease.