Unit 7: Pollution

I lowkey think I'm gonna fail this test

Air Pollution is a global system:

Introduction of chemicals, particulate matter, or microorganisms into the atmosphere at concentrations high enough to harm plants, animals, and materials such as buildings or into other ecosystems.

Six outdoor criteria pollutants

-nitrogen oxides

-ozone (ground-level/tropospheric)

-sulfure dioxide

-carbon monoxide

-lead (other toxic metals)

-particulate matter

Clean air act (1970)

identified 6 pollutants that threaten humans and the environment.

Nitrogen Oxides

-motor vehicle and fossil fuel combustion

-natural: forest fires, lightning, soil microbes

-Respiratory irritant, acid rain, smog

Ground-Level Ozone

-Secondary pollutants formed by sunlight and water reacting with VOCs, NOx, and O2

-Respiratory irritant, damages plants

Sulfure Dioxide

-From combustion of coal and oil (naturally from volcanoes and forest fires)

-Respiratory irritant; affects plant issues

Carbon monoxide

-Formed during incomplete combustion of most matter

-Vehicle exhaust, other combustion

-Especially dangerous indoors with poor ventilation; manure, charcoal, kerosene

Lead

-From gasoline (phased out by 1996), paint in older buildings, pipes (flint)

-toxic to the CNS of living organisms

Particulate Matter

-combustion of fossil fuels and biomass

-diesel much worse than gasoline

-road dust, rock-crushing, volcanoes, fires, and dust storms

Other Major Pollutants

-hydrocarbons from building supplies and household products

-ex: benzene, toluene, formaldehyde

-coal and oil combustion, concentrations have increased in fish

-mercury

-carbon dioxide

Primary pollutant

Come directly from source like smokestack or exhaust pipe

Secondary pollutant

-have undergone transformation in the presence of sunlight, water, oxygen, or other compounds

-occurs more in daytime and in wet conditions

-Ozone, SO3, H2SO4, H2O2, HNO3, PANs

Noise pollution

Sound at levels high enough to cause physiological stress and hearing loss

Noise pollution sources

Domestic and industrial buildings, construction, teleportation

Harmful effects of noise pollution

cognitive, physical, and behavioral

Indoor Air pollution

Ex: natural; radon, mold, dust

Radon

naturally occurring radioactive gas, moves up through soil and enters homes via the basement or cracks.

Anthropogenic

-Insulation

-lead from paint

-VOCs from building materials, furniture, upholstry, and carpeting

Combustion

-Carbon monoxide

-NOx

-SO2

-Particulate Matter

-Tobacco Matter

Developing countries

-Indoor burning of wood, charcoal, dung, crop residues, coal

-Poor suffer the greatest risk

Developed Countries

-Indoor air pollution is a bigger problem than outdoor pollution

-11 of the common air pollutants are higher inside than outside

-Greater in vehicles than outside

-Health risks magnified people spend 90% of their time indoors or in cars

Main categories of photochemical smog

-Industrial smog

-Sulfurous smog

-London fog

-Winter smog

-Pea soup smog

-Caused by SO2 and particulates reacting with water vapor

-Biggest cause is coal

-Cool, humid conditions

Photochemical smog

-brown smog

-yellow smog

-Los Angeles smog

-Summer smog

-Caused by VOCs and NOx reacting with water vapor

-Biggest cause is cars (NOx) - Dry, warm conditions

VOCs

-Organic chemicals (contain the element of carbon) that have a high vapor pressure (evaporate quickly) at room temperature

-Very diverse group

-May be natural (plants) or anthropogenic (solvents, paint, dry cleaning, gasoline)

-Almost all scents you smell are some sort of VOC

-Range from harmless to toxic

Inversion

-Layer of warm air traps cool air beneath it

-Pollutants get trapped

-Especially in valleys

Catalytic converters (1975)

device for internal combustion engines that converts pollutants in exhaust into less harmful molecules

scrubbers

remove particulates and/or gases from industrial exhaust streams

Wet scrubbers

generally the most appropriate device for collecting both particulate and gas in a single system

Dry scrubbers

dry reagents are sprayed into an exhaust stream

Desulfurization

Reduce SO2 emissions