Midterm 2020

Question 1

What is air quality

Answer 1

Air quality is the measurement/indication of relative safety of the air we breath. It can be indoor (residential/work) or outdoor (ambient or ground level)

Question 2

Most significant pollutant

Answer 2

Electricity and transportation are the most significant air pollutant - coal, incomplete combustion –CO2

Question 3

Primary vs secondary contaminents

Answer 3

Primary: direct emission from a source such as fuel combustion in a car
Secondary: formed within the atmosphere from reactions of primary contaminent sna d precurzor components such as ozone

Question 4

Importance of air quality

Answer 4

To protect the environment and human health, diseases from air pollution and the global warming crisis

Question 5

Greenhouse gases

Answer 5

Can be both biogenic or anthropogenic or both:
Bio: OM breaking down, volcanoes, radon gas, forest fries
Anthro: industry, factories, heating, cars
Both: water vapour, CO2, Methane
Anthro can increase risk of Bio (forest fires, farming, …)

Question 6

Air Quality and engineering

Answer 6

Desinging/managing indoor air quality (HVAC),
Monitoring and modelling indoor & ambient air quality such as their sources, impacts
Reluatory compliance reporting

Question 7

How to monitor air quality

Answer 7

Indoor: CO and smoke detectors, DuskTrak
Outdoor: national/international regulatory targets, ambient/ ground level reporting

Question 8

Air Pollution

Answer 8

Closely linked w the start of the industrial revolution,
condition of the air from the presence of any substance that directly or indirectly endagers the health, safety or welfare of humans or the environment

Question 9

Structure of the Atmosphere

Answer 9

Pressure: 101.325kPa
Density: mass of air/unit volume
Temperature: controlled by gases that absorve UV/infrared radiation
All decrease typically with distance from the earth

Question 10

Convection and air quality

Answer 10

Transfer of energy between objects and environment due to fluid motion, can be forced (air movement), free by mecahnical means or buyancy as sun heats, advective (horizonal movement by wind), radiation (electromagnetic waves)

Question 11

Atmosphere Components

Answer 11

Troposphere: lower 10km, temp decreases with altitue
Stratosphere: 10-50km, temp inversion due to ozone absorbing UV
Mesosphere: 50-90km: temp decreases with altitude
Thermosphere: 90-100km, temp increase as O2 and N2 absorb UV

Question 12

Airshed vs watershed

Answer 12

Airshed: agreed upon boundaries that impact air quality in a defined region, not finite as it changes depending on the pollutant as each travels differently within the atmosphere
Watershed: finite area that water is bound by topography, not agreed upon, just naturally is

Question 13

Components of trophosphere

Answer 13

Planetary Boundary Layer: extends from earths surcace to 0.5-3km, pullutants emitted cumulate here making it an ever changing layer
Free trophosphere: above PBL extends 3-10km and temps decreases quickly with increasing latitude

Question 14

Fixed vs Variable Gases

Answer 14

Fixed: well-mixed gases that make up more than 99% of all gases in atmosphere, concentrations do not change easily
Variable: abundance varies in space and time and are what make up pollutants (CO2, N2O, CH4, water vap)

Question 15

Mixing Ratio

Answer 15

Number of moles per mole of air as it measures the atmosphere composition

Question 16

Volumetric/gravimetric unit conversion

Answer 16

Get MM of 1 mol of comound in kg, divide by volume in m3 from PV=nRT, at 0

Question 17

4 categories of air pollution

Answer 17

1. Criteria AIr Pollutant (most regulated, NOx, SOx, O3)
2. Persistent Organic pollutants (POPs) (resistant to env degradation, ex. DDT, pesticides)
3. Heavy metals (lead, mercury)
4. Air Toxics (cancer causing, birth defects, ex. benzene)

Question 18

Sinks: Removal Process

Answer 18

Bulk: scavenging through precipitation/aerols; atmospheric reactions
Interfacial: facilitated by MO processes wehere atmosphere meets a surface such as vegetation, soil, and water

Question 19

Organic Aerosols

Answer 19

Primary: organic particulate matter/vapour emitted directly into atmosphere
Seondary: When POA’s undergo photochemical oxidation reactions and or condense

Question 20

Creterion Gaseous Pollutatns

Answer 20

SOx (sulfur oxides) SO2, combustion from sulphurous coal, PM, on the decline with improvement of fuel refinery
NOx (Nitrogen oxides), NO2, vehicles, combustion, creates O3
Ground level ozone, O3, sunlight + NO2+volatile hydrocarbons, can travel long dictances and deposit in rural areas due to NO scavenging from cities

Question 21

Indoor air quality

Answer 21

VOCs, NO2 (cooking/smoking), PM2.5, radon, asbestos

Question 22

Ship Emissions

Answer 22

Cause line or point source pollution due to poor quality diesel type fuels. Causes air quality to decrease in port cities, increases PM2.5, NOx, SO2, CO2. Not much regulation

Question 23

Common Air Pollution Disasters

Answer 23

London Smog in 1952: cheap coal and temp inversion
Chernobyl episode: the one where the nuclear reactor explosed and radioactive material was released
Fukushima nuclear disaster: nuclear reactor failure, radiation released

Question 24

Further describe London Smog Episode

Answer 24

Cold front came causing a temperature inversion therefore trapping the sulfurous coal emissions of three huge factories. Caused SO2 levels to be 80x their normal amount and black smoke to be 1000x. Caused the eaths of 4000-12000 people both during the week and in proceeding weeks
London is in a valley

Question 25

Acidic smog

Answer 25

SO2 smoke + fog, water vapour and SO2 aborb onto PM

Question 26

Factors in early air pollution

Answer 26

1. Early industrial revolution therefore no regulations for air quality and unknown effects of sulfurous coal
2. Unique topography and climate conditions (valley, temp inversion)
3. Winter months
4. Dense population with heavy industrialization

Question 27

Temperature Inversion

Answer 27

WHen air high up is warmer than the ground level air
the sun heats the earth with shortwave radiation and earth emits longwave radiation back to generate heat. Heath rises and earths surface cools quickly. OR warm ir in the atmosphere sinks as it decreases in elevation and increases its compression forces therefore trapping pollutants

Question 28

Acute and long term health effects from exposure to NOx, SOx, O3

Answer 28

Acute: reduced lung function, inflammation of eyes/nose/mouth/respiratory tract,
Chronic: cancer, asthma, cancer
Both: heart/circulatory system, macrophages

Question 29

Macrophages

Answer 29

Defence against PM/microbes through absorbing particles and bacteria in aveoli through phagocytosis to enter lung

Question 30

Improvements in air qulaity since 1970s

Answer 30

Less coal, air emission regulations, scrubbers to remove PM, SO2, NOx

Question 31

Bioaerosols

Answer 31

Mould, dust mites, fungi…

um scale can cause infection or allergies. Bioaerosols form when these things are disrupted and spores are relaseased

Question 32

Air pollution and ecosystems

Answer 32

O3 impacts vegetation performance, reduces biomass production and decreases biodiversity
Acidic rain and soil can form
Global warming will cause 1/5th of land surfaces to undergo moderate ecosystem changes
Cabon cycle and biogeochemical cycles will be impacted