What is
Particulate Matter ??
Particulate matter (PM) is:
• A mixture of particles found in the air,
including dust, dirt, soot, smoke, and liquid
droplets.
• Some particles are large or dark enough to
be seen as soot or smoke.
• Others are so small that individually they
can only be detected with an electron
microscope.
Particles with diameter 2.5 micrometers and
smaller are referred to as “Fine”
Particles with diameters between 2.5 and 10
micrometers are referred to as “Coarse”
Sources of fine particles
•All types of combustion
-Motor vehicle
-Power plants
-Wood burning, etc.
-Some industrial
processes
Sources of coarse particles include
crushing or grinding operations and
dust from paved or unpaved roads
Ambient Fine
Particles
• Can stay in the atmosphere from days to weeks,
and travel hundreds of miles.
• Particles can be transported long distances and
impact large of numbers of people
Health effects of fine particulates
Why are they bad?
- Too small to be filtered by the nose/mouth
- Can be inhaled deeply into the lungs where they
can cross directly into blood stream like oxygen
- Asthma attacks (possible asthma onset)
- Heart attacks
- Strokes
- Premature death (crib death in children)
- Cancer
The average American breathes 3,400 gallons of
air each day, making ambient air pollution a major
environmental problem.
Chemical Composition of PM2.5
•
•
•
•
•
•
Sulfates
Nitrates
Elemental carbon
Organic carbon
Trace elements such as metals
Varying amounts of water.
Sulfates
Sulfur dioxide (SO2), mainly from combustion of fossil
fuel, is oxidized in the atmosphere to form sulfuric acid
(H2SO4) particles. Ammonium sulfate (NH4)2SO4 is the most
common sulfate species in ambient aerosol samples
.
•Nitrogen oxides (NOx= NO + NO2) are formed during
combustion or any high temperature process involving air
•Eventually can be converted in the atmosphere into
both nitric acid (HNO3) particles and the particulate
ammonium nitrate (NH4NO3).
Elemental Carbon.
Chain agglomerates of very small elemental carbon
(EC) particles are formed during combustion, such as
in open hearth fireplaces, wood stoves and diesel
engines.
Organic Carbon.
Several categories of organic carbon (OC) compounds
are also often found in ambient air, as follows:
– Primary-anthropogenic (man-made).
Incomplete combustion also leads to
hundreds of organic compounds being
present in the atmosphere as particles,
including polycyclic (Polynuclear) aromatic
hydrocarbons (PAHs).
– Secondary-anthropogenic. Some complex
organic compounds react with ozone or other
atmospheric constituents to form particles.
– Primary biogenic. Viruses, some bacteria,
and plant and/or animal cell fragments may
compose a portion of the fine particulates in
the atmosphere.
– Secondary biogenic. Terpenes, which are
cyclic olefins released by plants, also react in
the atmosphere to yield organic particulate
matter.
Trace Elements
A variety of metals and nonmetals are volatilized during the
combustion of fossil fuels,
smelting of ores, and incineration
of wastes and are emitted as fine
particles (or vapors which rapidly
form fine particles).
PM2.5 Monitoring in Southwestern PA
The Air Quality Index (AQI)
• A method of grading the health risks that
air quality poses on specific days
• Days are ranked as good, moderate,
unhealthy for sensitive groups, unhealthy,
and very unhealthy
• Based on the forecasted level of PM2.5.
Monitoring the Air Quality
Index, which forecasts the
air quality for the day, is
important if you belong to
a particularly at-risk group
such as:
• The elderly
• Children
• People with pre-existing
respiratory or
cardiovascular conditions
Clear Day in Pittsburgh
Air Quality Action Day
DID YOU KNOW?
• The Pittsburgh area was recently ranked
the 3rd worst air quality in the County, for
fine particulates – American Lung
Association, 2010 State of the Air Report
Can I reduce my exposure to
particulate matter?
• Avoid exposure where possible to sources of airborne particles such
as tobacco smoke, wood smoke and vehicle exhaust.
• Avoid prolonged outdoor exertion near high-traffic areas especially if
it is a higher pollution day.
• Stay informed about the daily air pollution levels and the associated
health implications. You can sign up to receive an AQI forecast by
email each day here.
http://www.dep.state.pa.us/aq_apps/aqpartners/default.asp
• Use high quality filters for heating and air conditioners. Change
filters frequently. Consider using a room, car and/or house air
cleaner. There are a variety of types so research your needs and
follow proper maintenance recommendations. High-Efficiency
Particulate Air (HEPA) filters are better for smaller particles.