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AEROSOLS: types

• Dust• Smoke• Fly ash• pollen

• Cloud• Mist• Fog• smog

• SOLID • LIQUIID

Mount manitoba, June 1991

Asian brown cloud over China

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AEROSOLS: sources

• Dust• Smoke• Fly ash• pollen• plant fragments• cement• brake lining• tires• soil

chemical concentrationfactor (surface effects)

CCF = [aerosol]/[sea]

DUST SEA

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AEROSOLS: sizes

• > 400 nm scatter light• < 0.01 micron coagulate• > 10 micron settle out

• Typical size: 0.1-1 micron

AEROSOLS: how to measure them

Alphabet soup:

• COH• TSP• IP• TDF• PM10

• light scattering• collecting on filters

AEROSOLS: how to measure them

Alphabet soup:

• COH• TSP• IP• TDF• PM10

Coefficient of HazeDraw 300 meters through a filtermeasure absorbance x 100>6 bad for asthmatypical samples 5-10 micron

AEROSOLS: how to measure them

Alphabet soup:

• COH• TSP• IP• TDF• PM10

Total Suspended ParticulateWeighing after filteringUnits: μg/m3

“normal” ~ 10 μg/m3

sometimes 500 μg/m3 in cities

AEROSOLS: how to measure them

Alphabet soup:

• COH• TSP• IP• TDF• PM10

Inhalable ParticulatesGenerally IP ~ 0.45 TSP

AEROSOLS: how to measure them

Alphabet soup:

• COH• TSP• IP• TDF• PM10

Total Dust Fallunits: g m-2 month-1

should be < 7 g m-2 month-1

often exceeded in industrial areas

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AEROSOLS: how to measure them

Alphabet soup:

• COH• TSP• IP• TDF• PM10

Particulate matter < 10 micron

PM10 = TSP < 10 μ

50% (by mass) of a set of particles are less then 10 micron and 50% are between 10 and 20 micron.PM10 is what percentage of PM20?

[A] 0.1 %[B] 10 %[C] 16 %[D] 50 %[E] 95 %

50% (by mass) of a set of particles are 10 micron and 50% are 20 micron.All particles larger than 10 micron are filtered out. How much does the total number of particles go down?

[A] by 50%[B] by less than 50%[C] by more than 50%[D] It depends on the type of particle

10% (by mass) of a set of particles are 10 micron and 50% are 20 micron.All particles larger than 10 micron are filtered out. How much does the total surface area go down?

[A] by 50%[B] by less than 50%[C] by more than 50%[D] It depends on the type of particle

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coagulation

Wet deposition dry deposition

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150 PAHsWith 2 – 7 rings

CombustionProducts.Fly-ash vs. bottom-ash

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Particulate air quality in major world cities. Values are annual PM10 means. Horizontal line is WHO air quality guideline

NASA satelite image og Nox from ships