Chapter 15 Questions
Under natural conditions the pH of rainfall is closest to
5.6
The greatest emission of sulfur dioxide comes from
Electricity generation (power plants)
The least amount of nitrogen oxide emissions comes from
Fires- the most comes from vehicles
A pungent reddish-brown gas often associated with photochemical smog
NO2
Based on the National Ambient Air Quality Standards (NAAQS), the 2008 standard for ozone states that the average ozone levels are not to exceed 0.075 ppm (75 ppb) in any 8- hour period. Is Pittsburgh in compliance with this standard? Discuss how this NAAQS may not truly reflect the overall air quality.
Pittsburgh seems to be in compliance since the NAAQS standard is an average and all of the monthly average ozone levels are below the 75 ppb standard. Since the NAAQS standard is an average, it is possible for the ozone levels to exceed the standard and still be in compliance, as evidenced by the monthly maximum ozone levels where the standard 75 ppb is exceeded five times.
Explain how the same ozone that is harmful in the troposphere is beneficial in the stratosphere.
Possible explanatory statements: • Tropospheric and stratospheric ozone are chemically identical; at ground level, it is a respiratory irritant. • In the stratosphere, ozone is still a respiratory irritant but there are no humans exposed at this level. In the stratosphere, ozone is the only substance that absorbs the energy from UV-B radiation and prevents most of it from reaching the surface of the Earth. • Harmful effects of UV-B radiation include a reduction in photosynthetic activity, reduction in ecosystem productivity, increase in skin cancer, and increase in cataracts and other eye problems.
Ozone is classified as a secondary pollutant. Identify the primary pollutants necessary for its formation and describe how tropospheric ozone is formed.
Primary Pollutants necessary for the formation of ozone: NOx VOC (Volatile Organic Compounds) NO2 + sunlight = NO + O NO + O + VOC = photochemical oxidants + O3
A corrosive gas from burning coal often associated with industrial smog
SO2
Two major factors involved in the conversion of primary pollutants into secondary pollutants are
Sunlight and water
According to the article, what is the cause of sick building syndrome and what are the advantages of this cure?
The cause of Sick Building Syndrome, according to the article, is "the increasing use of air conditioning in modern offices. Bacteria can build up in the ventilation system and leave office workers suffering from a range of problems, such as breathing difficulties, headaches, sore throats, stuffy noses and itchy eyes." Advantages of the cure: • 20% reduction in all symptoms • 40% reduction in complaints of respiratory problems • 30% reduction in complaints of stuffy noses • 50% reduction in muscular complaints • Killed bacteria and mold in ventilation systems • System is relatively cheap • Reduced worker absences due to building related illnesses • Cost effective
A dangerous indoor air pollutant
CO
The EPA identifies all of the following as reasons for sick building syndrome except
High levels of radon in the basement
A thermal inversion
Occurs when a warm air layer overlies a cooler layer.
The pollutant least likely to be emitted from a smokestack would be
Ozone- because it's secondary...
The World Health Organization estimates that over half of the deaths worldwide due to indoor air pollution occur among
Children less than 5yrs old
The effects of acid deposition include all of the following except
Increased numbers of salamanders in ponds and streams- usually cause a decrease in populations
What other sources of indoor pollution contribute to sick building syndrome? Will the ultraviolet light be effective against these sources? Suggest one additional control measure that would be effective against SBS.
Other sources of indoor pollution that contribute to Sick Building Syndrome: • Chemical contamination from indoor sources such as glues, carpeting, furniture, cleaning agents, and copy machines • Chemical contamination in the building from outdoor sources such as vehicle exhaust located near the air intakes of the building • Long-term effects could come from asbestos in older buildings Ultraviolet light will NOT be effective against these additional sources. Additional control measures: • Increased ventilation • Filters in a ventilating system (must be properly maintained) • Houseplants (low-light) can reduce contaminant levels • Ban smoking Sealing cracks in the basement (radon) • Removal of asbestos by qualified asbestos abatement personnel
Emitted from both diesel and burning wood
PM10
Identify two relationships between the data presented. Apply these relationships to your answer in (b) to explain the pattern of ozone levels in Pittsburgh.
Possible relationships between data: • The higher the monthly average solar radiation, the higher the monthly ozone level (either maximum or average). Or the converse - The lower the monthly average solar radiation, the lower the monthly ozone level (either maximum or average). • The higher the monthly maximum ozone level, the higher the monthly average ozone level. Or the converse - The lower the monthly maximum ozone level, the lower the monthly average ozone level. • The monthly average solar radiation is lower in the fall and winter months and higher in the spring and summer months. • The ozone levels (either maximum or average) are lower in the fall and winter months and higher in the spring and summer months. Since the source of energy for this photochemical reaction is sunlight, the greater the amount of solar radiation (or the greater the duration of the solar radiation as indicated by seasonally longer or shorter days) the greater the amount of ozone produced. The data seems to indicate that ozone levels fluctuate seasonally in Pittsburgh.
Which statement regarding the decreased levels of stratospheric ozone is correct?
The largest decrease in the level of stratospheric ozone over the Arctic region occurs between January and April - in winter, cold weather & low sun promotes Cl2 formation
All of the following are examples of primary air pollutants except
Tropospheric ozone- Ozone is a secondary pollutant (photochemical smog)
The type(s) of ultraviolet radiation most strongly absorbed by ozone in the stratosphere is/are
UV-B and UV-C
Will the cure mentioned in the article be effective against indoor pollution in developing countries? Discuss why or why not.
Ultraviolet light would NOT be effective in developing countries. The major source of indoor pollution in developing countries is the burning of biomass and coal for heating and cooking. These fuels are usually burned in open-pit fires that are inefficient and lack the proper mixture of fuel and air for complete combustion. This results in the production of carbon monoxide and particulates, which would not be controlled or cured by ultraviolet light.
The accumulation of tropospheric ozone at night depends mainly upon the atmospheric concentration of
Voliate organics (VOCs or hydrocarbons)
Natural Sources of air pollution include all of the following except
Waterfalls
