Exam 3-Chapter 19 Flashcards
about smog/types
smoke + fog/industrial - irritating, grayish, soot and sulfur. can be from coal burning. photochemical - in morning traffic, brownish, irritating haze, warm and sunny areas
what is acid deposition
acid precipitation plus dry-particulate fallout
what is the ozone layer
stratospheric ozone layer protects Earth from harmful UV radiation
What are air pollutants
substances in the atmosphere that have harmful effects (gases/aerosols)
impacts of air pollution
plants stressed and vulnerable to drought and insects, acute exposure is life threatening, chronic exposure is gradual deterioration and premature mortality (air pollution is the greatest worldwide environmental health hazard).
CAIR
Clean Air Interstate rule - sets new lower caps on SO2 and NOx in 28 states/used cap-and-trade
how does acid deposition affect the environment
lakes become acidic, acid snow melt, dry fallout damages vegetation, acid leaching into the ground, acid snow and rain
general familiarity with the pH scale (and what acid and base is/difference between 5 and 6)
0-14. 0 is highly acidic like stomach acid, 7 is neutral like milk, 14 is highly basic like ammonia or lye (5 to 6=5 is ten times more acidic than 6)
why does tropospheric ozone only accumulate in the presence of VOCs and why
nitric oxide reacts with VOCs creating noxious compounds. ozone accumulates because nitric oxide is tied up
CSAPR
Cross-state air pollution rule (2011) - replaced CAIR/addressed same pollutants but adds several midwestern states/also required reduced NOx and SO2 from power plants/used cap-and-trade
effects of ozone on plants
ozone enters plants through stomata(pores). black flecks, yellow leaves, ambient levels damage soybeans, corn and wheat
secondary pollutants
formed by primary pollutants (ozone, sulfuric and nitric acid)
ABCs (atmospheric brown clouds)
from burning biomass and fossil fuels, blanket of pollution over central and south asia, south africa and amazon basin
How has clean air act affected emissions
have dropped significantly (lead and SO2 almost all removed). CO signifant drop by over half
how do CFC’s destroy the ozone layer
CFCs react with UV and release chlorine which can react with ozone to produce chlorine monoxide (COI). this results in mid-altitude ozone loss
how have we reduced air pollutants
Air pollution control act (1955) first federal regulations. Clean air act (1970) - EPA.
directly or inversely proportional to growth proxies
they have decreased despite increased GDP, miles traveled, population and energy use
what are the causes of acid deposition
burning fossil fuels releases sulfur dioxide and nitrogen oxides in troposphere. hydroxyl radicals oxidize tropospheric SO2 and NOx (sulfuric acid and nitric acid)
primary pollutants
direct product of combustion and evaporation (VOCs, CO, NOx, SO2, lead)
major products of hydroxyl radical neutralization of air pollutants
carbon dioxide, nitric acid, sulfuric acid and water
how are pollutants affected in the troposphere vs stratosphere
troposphere has air mixing and precipitation/site of weather so pollutants are usually removed within hours or days. the stratosphere resists cleansing because there is little or no vertical air mixing (pollutants stay much longer)
three major mechanisms to remove pollutants from the atmosphere
hydroxyl radicals (OH) - naturally occurring compound that oxidizes pollutants. Sea salts - picked by sea spray to help from raindrops that remove pollutants from the air. Sunlight - breaks down organic molecules.
what determines the level of air pollution
amount of pollutants entering the air and amount of space into which the pollution is added (dilution)
