Pollution Flashcards
point source
from a specific location such as a pipe
nonpoint source
from over an area such as runoff
BOD
biological oxygen demand; amount of dissolved oxygen needed by aerobic decomposers to break down organic materials
eutrophication
rapid algal growth caused by an excess of nitrates (NO3-) and phosphates [PO4(3-)] in water
hypoxia
when aquatic plants die, the BOD rises as aerobic decomposers break down the plants, the DO drops and the water cannot support life
minamata disease
(1932-1968, Japan) mental impairments caused by methylmercury (CH3Hg+) poisoning
primary air pollutants
produced by humans and nature (CO, CO2, SOx, NOx, particulates)
particulate matter
source: burning fossil fuels and diesel exhaust
effect: reduces visibility and respiratory irritation
reduction: filtering, electrostatic precipitators, alt. energy)
nitrogen oxides (NO3)
source: auto exhaust
effects: acidification of lakes, respiratory irritation, leads to smog and ozone
equation for acid formation: NO + O2 = NO2 + H2O = HNO3
reduction: catalytic converter
sulfur oxides (SO3)
source: coal burning
effects: acid deposition, respiratory irritation, damages plants
equation for acid formation: SO2 + O2 = SO3 + H2O = H2SO4
reduction: scrubbers, burn low sulfur fuel)
carbon oxides (CO and CO2)
source: auto exhaust, incomplete combustion
effects: CO binds to hemoglobin, reducing blood’s ability to carry O2; CO2 contributes to
global warming
reduction: catalytic converter, emission testing, oxygenated fuel, mass transit
ozone (O3)
formation: secondary pollutant,
NO2 + uv = NO + O* O* + O2 = O3, with VOCs (volatile organic compounds)
effects: respiratory irritant, plant damage
reduction: reduce NO and VOC emissions
radon (Rn)
naturally occurring colorless, odorless, radioactive gas, found in some types of soil and rock, can seep into homes and buildings, formed from the decay of uranium (U), causes lung cancer
photochemical smog
formed by chemical reactions involving sunlight (NO, VOC, O*)
acid deposition
caused by sulfuric and nitric acids (H2SO4, HNO3), resulting in lowered pH of surface waters
greenhouse gases
ex: H2P, CO2, O3, CFCs, methane (CH4)
effect: they trap outgoing infrared (heat) energy, causing earth to warm
greenhouse gases
ex: H2P, CO2, O3, CFCs, methane (CH4)
effect: they trap outgoing infrared (heat) energy, causing earth to warm
effects of global warming
rising sea level (thermal expansion), extreme weather, drought, famine, extinctions
causes of ozone depletion
CFCs, methyl chloroform or trichloromethane (CHCl3), carbon tetrachloride (CCl4), halon (haloalkanes), methyl bromide (CH3Br) - all of which attack stratospheric ozone
effects of ozone depletion
increased UV, skin cancer, cataracts, decreased plant growth
LD50
the amount of a chemical that kills 50% of the animals in a test population
mutagen
causes hereditary changes through mutations
teratogen
causes fetus deformities
carcinogen
causes cancer
threshold dose
the maximum dose that has no mesureable effect
temperature inversion
layer of dense cool air trapped under a layer of warm dense air, pollution trapped in layer may build to harmful levels (common in LA and Mexico City)
sources of mercury
burning coal, compact flourescent bulbs
major source of sulfur
burning coal
