Alex Cuclis Houston Advanced Research Center HARC

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Alex CuclisHouston Advanced Research Center
(HARC)
Particulate Matter What Floats in the Air?
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What Floats in the Air?

• Particulate Matter
• Total Suspended Particulates
• Aerosols
• Haze

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What Floats in the Air?

• Particulate matter consists of tiny particles
  in the atmosphere that can be solid or liquid
  (except for water or ice) and is produced by a
  wide variety of natural and manmade sources.

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Size Matters

• Total Suspended Particulates (TSP) range from 0
  50 microns
• Human hair is about 70 microns in diameter.
• gt 50 micron particulates tend to settle out of
  the air.

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Size Matters

• PM10 PM50 too large for respiratory system
• PM2.5 PM10 - can enter lungs through mouth.
• PM2.5 and less can enter lungs through nose.

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Primary and Secondary PM

• Primary particles, such as dust from roads or
  elemental carbon (soot) from wood combustion, are
  emitted directly into the atmosphere.
• Secondary particles are formed in the
  atmosphere from primary gaseous emissions.
  Examples include sulfates, formed from SO2
  emissions from power plants and industrial
  facilities, and nitrates, formed from NOx
  emissions from power plants, automobiles, and
  other types of combustion sources.

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Sources of PM2.5

• Primary mobile source emissions account for
  approximately 25-33 of fine PM mass.
• Primary emissions from cooking account for
  approximately 10-15 of fine PM mass.
• Primary point source emissions of fine
  particulate matter have not yet been estimated.
• Secondary emissions of organic carbon and
  elemental carbon make up approximately 25-30 of
  fine PM mass. - Dave Allen

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Sources of PM10

• Fly ash from power plants,
• Carbon black from automotive industries
• Various manufacturing processes,
• Ash from wood stoves and fireplaces
• Agriculture and forestry practices
• Fugitive dust sources (paved and unpaved roads)
• - Dave Allen

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Sources of PM10

• In the U.S., PM10 emissions from fuel combustion,
  industrial processes, and transportation each
  contribute about one-third of the traditionally
  inventoried particulate source categories. These
  source categories, however, only account for 6
  of total PM10 emissions nationwide. The vast
  majority of PM10 emissions are from natural
  sources, agriculture, forestry, wildfires,
  managed burning, and fugitive dust.

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Chemistry Matters

• The chemical composition of particles depends on
  location, time of year, and weather.
• The different constituents of PM are the result
  of very different types of emissions, and
  therefore, as emission reduction plans are
  developed to reduce health impacts of fine
  particulate matter, it will be important to
  understand whether particular chemical or
  physical properties of the PM are causing health
  impacts.

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Travel Time Matters

• How long?
• PM10 particles can stay in the air for minutes
  or hours, while PM2.5 particles can stay in the
  air for days or weeks.
• What distance?
• PM10 particles can travel as little as a hundred
  yards or as much as 30 miles. PM2.5 particles can
  go many hundreds of miles.

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Travel Time Matters

• Examples
• The fires of Mexico
• The Dust of Africa at times makes up 50 of the
  breathable particles in Miami

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Travel Time Matters

• Gravity is the driving force for settling, but
  does not control the rate of settling.
• Many individual particles cannot be seen by the
  naked eye, but as a group they can be seen by
  satellites.

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Deposition Matters

• When it rains
• Humidity
• Wind Speed
• Size
• Composition/Chemistry

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Smoke from Mexico
April 16, 2003
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Dust from Saharan Africa
July 16, 2003