Pollutants

Question 1

Define: Primary and secondary pollutants

Answer 1

Primiray: pollutants emmited directly into the air. (CO, NO/NOx, SOx, VOC, OM)

Secondary: are formed in the air when they react with other pollutants. (Sulfuric & Nitric Acid, NO2, Ozone, Secondary Particulates)

ie. Groundlevel ozone formed when NOx and VOC react in presence of light.

Question 2

Atmospheric layers:

Answer 2

Defined by temperature change

1: Troposphere (0-12km) (80% mass of atmosphere) (weather, N2 78%, O2 21%, water vap 3% 1.5: Tropopause (temp invert warmer than below)
2: Stratosphere (12-50km) 2.5. Stratopause
3: Mesosphere 3.5. Mesopause
4: Thermosphere 4.5. Thermopause
5: Exosphere 5.5. Exopause

Question 3

Pollutant types (classification)

Answer 3

Suspended particulate matter, gases, and vapors that are present in high concentration with net detrimental effects on environment and ecosystem as a whole

Question 4

CAC

Answer 4

Criteria Air Contaminants : SOx, NOx, CO, PM (PM10 and PM 2.5.

Also frequently set for Ozone, H2S, Lead, HF, Formaldehyde (HCHO).

Question 5

Greenhouse gases

Answer 5

CO2, Methane, N2O, CFC (chlorofluorocarbons), bromides/iodides, other gases (hydrocarbons, tropospheric ozone, water vapor), aerosols

Question 6

Ozone depleting substances

Answer 6

CFC, Halons, Carbon Tetrachloride, Methyl Chloroform

Question 7

Air pollution sources

Answer 7

Anthropogenic: Combustion (contaminants, incomplete combustion), transport, process emissions, consumer products and activities, personal

Natural: Biogenic (flaura, fauna), VOCs, pollen, geological, forest fires, weathering rock, ocean waves, wind (dust)

Question 8

Impacts of pollution

Answer 8

human/animal health, vegetation, property, visibility

Question 9

Airshed

Answer 9

Airmass that is geographically bound (valley, mtn… NOT country/municipal borders)

Question 10

Emissions vs immissions

Answer 10

emissions: emited
imissions: concentration ambient

Question 11

Particulate matter types

Answer 11

Coarse PM10 (typically natural sources), fine PM 2.5 (mostly human activities and reactions taking place in air; Finer particles are more damaging. 
Impact not only size but ALSO chemical composition
PM's most studied type of pollutant.
Larger fall out quicker due to gravity, finer float longer and can chemically react.

Question 12

Physical behaviour/movement of particles in atmosphere

Answer 12

• Diffusion (random Brownian molecular movement)
• Dispersion (external flow effect causing discrete movement)
• Rx with atmospheric gases for creation
• Coagulation (create bigger chunk)
• Condensation (vapour to liquid)
• Sedimentation (dry deposition removal)
• Precipitation (wet deposition removal)

Question 13

Particulate matter chem processes and composition

Answer 13

Org pollutants and NOx, Atmos gas to particle conversion, combustion process.

-Chem composition: inorg particles -toxic metals - org particles - radioactive particles

Human entry points: breathing, swallowing, dermal

Question 14

CO

Answer 14

• intermediate in oxidtion of methane by hydroxyl radical
• degradation chlorophyll in autum
• anthropogenic (more in less tech advance countries, inc. burning no scrubbing)
• Toxicity (prevents O2 in blood stream)

Question 15

NOx Nitrogen Oxides

Answer 15

NO - Colourless, odourless (competes with O2 in body)
NO2- pungent, red-brown
natural sources (lightning, biol process) combustion of fossil fuels (mostly NO)
NOX, NO less toxic NO2,
N2O, microbiol process, unreactive,

Question 16

Sulphur oxides

Answer 16

Human activities (S in coal, metallurgical processes)
Natural (Marine, volcanic, biol decay org matter)
Effects atmos SO2: inc breathing effort but not really toxic, harmful to plants, deterioration building materials, acid rain, NOX plus VOCs make ground level ozone

Question 17

Troposphere

Answer 17

oxidative medium (radicals: OH, NO3, O, HO2, H2O2) photochem rx, high conc water vapor.
-3 end removal processes: -chem conversion to h2o, o2 -dry deposition (gases absorbed by plants, water, soil)
-wet deposition
(goes elsewhere in system…)

CH4 dominant hydrocarb, gas phase chem involves oxidation of org molecules in presence of oxides of nitrogen with sunlight

Question 18

Air pollution and health

Answer 18

Mortality (death), Morbidity (disease) studies
Study controlled acute human exposure

AQHI: 1-10 scale takes into consideration: O3, OM2.5, NO2