apes air pollution

troposphere

• where we live

• air is most dense

• where weather happens + where all pollution is

• gets cooler as elevation rises b/c Earth’s surface is the heat source

stratosphere

• 2nd layer

• where the ozone layer is

• temp. rises w/ altitude

• gases released from volcanic eruptions stay here

outdoor air pollution is considered pollution if…?

it is concentrated enough to cause harm to people and ecosystems

primary pollutants

emitted directly into the air

• eg. CO

secondary pollutants

products of chemical reactions in the air

• eg. NO_x → photochemical smog

carbon monoxide (CO)

source:

• incomplete/inefficient combustion

• vehicles, furnaces, generators

HH impact:

• MAINLY A HH CONCERN

• binds to hemoglobin and prevents oxygen transfer → leads to headaches, nausea, dizziness, and eventually death

• chronic exposure: heart attacks, lung disease

• acute exposure: headache, nausea, drowsiness, death

carbon dioxide (CO₂)

source:

• burning fossil fuels

• deforestation

HH impact:

• none

environmental impact:

• climate change

• ocean acidification

nitrogen oxides (NO_x)

source:

• high-temp engines

• coal plants

• lightning/high intensity forest fires

• vehicles

HH impact:

• respiratory irritant → heart and lung disease

environmental impact:

• precursor to acid deposition + smog

sulfur dioxide (SO₂)

source:

• volcanoes (natural)

• burning coal

HH impact:

• respiratory irritant

environmental impact:
- precursor to acid deposition

particulate matter (PM)

solid particles + liquid droplets small enough to remain suspended in air → fine + ultrafine particles most damaging

source:

• dust storms

• construction

• volcanoes

• forest fires

• burning fossil fuels

HH impact:

• respiratory irritant

environmental impact:

• blocks light for photosynthesis

heavy metals (Pb, Cd, Hg, etc.)

source:

• burning coal and industry

HH impact:

• cancer

• learning disabilities

• mutations

environmental impact:

• bioaccumulate + biomagnify

volatile organic compounds (VOCs)

gaseous + made up of hydrocarbons

source:

• industrial solvents

• car exhaust

• pine trees

HH impact:

• respiratory irritant

environmental impact:

• precursor to smog

acid deposition

precipitation below a pH of 5.6 → falls as precipitation/dry deposition (crystals))

• SOx + NOx precursors → mix w/ water vapor in air

• remains in atmosphere for 2-14 days

consequences of acid deposition

• kills plants → displaces aluminum from rock into soil

• impacts ability to hold onto nutrients

• pH can change aquatic life → bigger problem for smaller bodies of water

• resp. disease from dry deposition — HH

• damages human-made structures — economic

natural reduction of acid deposition

• settling

• precipitation

• ocean spray wash-out

• winds

• chemical reactions (neutralization)

factors that increase acid deposition

• urban buildings slow winds

• hills/mountains

• high temperatures inc. reaction rates

• VOCs

• volcanoes

• grasshopper effect → transport by global winds from another city to a new place

• thermal inversion layer

thermal inversion layer

• caused by warm fronts especially from ocean systems

• causes a buildup of pollution

• ozone and smog particularly bad

Clean Air Acts

1970:

• set standards for air quality and fines on emissions

• funds for pollution control research

• allows citizens to sue parties for violating

1990:

• strengthens standards for auto emissions, toxic air pollutants, etc.

ambient air quality standards

standards for 6 criteria pollutants: CO, NOx, SO2, O3, Pb, and PM

• no legislature around CO2

• standards for 188 hazardous chemicals

baghouse filter

fabric filter → removes PM

scrubbers

send exhaust in → spray mist → toxins dissolve in water

• removes PM, SO2, + NOx

• causes water pollution

electrostatic precipitator

removes ALL PM (incl. ultrafine particles)

vapor recovery nozzle

VOCs pumped out of gas tank → recover gasoline

catalytic convertor

reduces amt of NOx, CO, and gas fumes (VOCs) emitted from cars

ozone

• stratospheric = good

• tropospheric = bad

• formed by oxygen and high energy light → UV light breaks apart O2 and stray O molecule joins O2 → O3

• not a stable molecule → O3 naturally decays into O2 and O

stratospheric ozone

• good

• absorbs harmful UV radiation — UV-B+C

• hole in the ozone layer

chlorofluorocarbons (CFCs)

• major cause of the hole in the ozone layer

• primarily used as a refrigerant

• very persistent molecule → one molecule has a BIG impact

• strong greenhouse gas

• prevent formation of new ozone and facilitate breakdown

Montreal Protocol

agreement between 24 countries to phase out the use of CFCs → huge success

• passed in 1987

• will take a long time for the environment to recover from CFCs b/c they remain in the atmosphere for a very long time

tropospheric ozone

• very bad

• secondary pollutant → formed from NOx, VOCs, and UV light

• concentration varies w/ season + time of day due to UV concentration and temperature

• consequences: formation of smog, resp. irritant, damage to plant leaves

• monitored by CAA

photochemical smog

• secondary pollutant

• mix of pollutants: O3, NOx, PM, & VOCs

• O3 = major component

indoor air pollution

• different sources in developing/developed countries

• more harmful than outside → level s generally higher in homes (5x) and cars (18x)

common indoor pollutants

• pesticides + lead → common in old paint

• dust mites + droppings

• molds + mildews

• formaldehyde + other VOCs

• asbestos

• radon

asbestos

from insulation/other building materials

• very strong carcinogen

• no longer used but still present in old buildings

radon

comes from radioactive decay that seeps + settles into basements

• strong carcinogen

• natural pollutant

sick building syndrome

when there is a build up of indoor VOCs, chemical contamination, biological contamination, + other materials that cause residents/those inside to feel sick

• symptoms: headache, nausea

• solution: air out building

• common in new office buildings

main source of indoor pollution in developing countries

burning biomass/coal in an open fire indoors

• PM, CO, NOx

health effects of indoor pollution

• asthma aggravation

• emphysema

• lung cancer

• heart disease

dose-response studies

different experimental groups with different doeses

• usually animal studies

• goal: to find LD-50 + ED-50

• acute + chronic studies

LD/ED-50

• LD-50: lethal dose that kills 50% of individuals

• ED-50: effective dose that causes 50% of individuals to display harmful but nonlethal effects

threshold

dose where any impact was had

safe dose

• animals: LD-50/10

• humans: LD-50/1,000 (super cautious for people)

acute study

lasts 1-4 days; studies short-term effects

chronic study

long-term; often from young age to reproductive age

retrospective studies

looks at human/animal populations over time (exposed/non-exposed)

• looks at past events

• est. exposure to a chemical in environment + evaluates health problems

• eg. Bhopal, India → maj. pesticide leak

prospective studies

monitors people going forward if they are already exposed/might be in the future

• used for tobacco/alcohol studies, vapes, lead exposure on IQ

bioaccumulation

process of a toxin being absorbed + accumulating in an individual/s body

• typically fat-soluble

biomagnification

• producer gets