Air Quality 10-1 : Air Pollutants Flashcards
Natural sources of air pollution are;
-Windstorms that spread dust clouds
-Salt evaporation along the earth’s coasts
-Production of materials that have biological origin (e.g., mold spores, pollen, & organic material from plants & animals).
-Forest fires
-Methane gas originated from the digestion of food by an animal
-Radom gas
-Volcanic eruptions
Anthropogenic Sources of Air Pollution:
Stationary Sources
-Electric generating plants
-factories & manufacturing complexes
-oil refineries
-chemical plants
-incinerators
-landfills
Anthropogenic Sources of Air Pollution:
Mobile Sources
1) On-road vehicles [cars, trucks, buses]
2) Off-road vehicles [dune buggies, snowmobiles]
3) Nonroad vehicles [airplanes, ships, and trains]
Mobile Sources & Air Pollution
According to the EPA, motor vehicles produce nearly half of two major causes of smog
According to the EPA, motor vehicles produce nearly half of two major causes of smog;
1) Volatile Organic Compounds (VOCs)
2) Nitrogen Oxides (NOx)
~Almost 75% of carbon monoxide, & more than half of emissions of toxic air pollutants.
Types of Air Pollutants
{Two Types}
1 of 2
1) Primary Pollutants,
Released from a
process directly in the atmosphere:
sulfur oxide (SO), Nitrogen oxide (NO),
carbon monoxide(CO), lead, volatiles
organic compounds (VOCs), & other
metals & minerals
Types of Air Pollutants
{Two Types}
2 of 2
2) Secondary Pollutants,
formed from the
reaction or interaction of primary
pollutants in the atmosphere (PM2.5,
PM10, ozone)
Name environmental impacts that air pollution has:
- Morbidity & death
- Property damage
- Reduces visibility
- Harms forests
- Harms lakes & other bodies of water
- Injures wildlife
Criteria Pollutants
Group of very common air pollutants regulated by the EPA on the basis of health & environmental impact criteria.
-Nitrogen oxides (NO, NO2) -Carbon monoxide
-Ozone
-Lead
-Sulfur dioxide (SO, SO2)
-Particulate matter (PM10, UFP, PM2.5)
- Hazardous Air pollutants
- Haze & Reduced Visibility
Criteria Pollutants : Ozone (O3)
Ozone (O3), is three oxygen atoms bonded together into a molecule.
~ Has a harp smell that stems from a series of chemical reactions among products of combusting fossil fuels.
~Up in the atmosphere, O3 protects the earth from UV light.
Health effects of round-level ozone:
-Inflammation & irritation of the respiratory tract
-Affects lung function
-Exasperation of allergies
-Irritation of eyes
Criteria Pollutants : Carbon Monoxide (CO)
Carbon Monoxide (CO), a colorless, odorless, poisonous gas product of incomplete combustion of carbon-based fuels (methane, gasoline, oil, wood)
Exposure to high Carbon Monoxide (CO) level;
Exposure to high CO levels
can result in death or negative
health outcomes:
- Aggravates coronary heart
disease - Negative impact on
vasculature, lung, airways.
CO has 210 higher affinity for binding with hemoglobin than O2.
Criteria Pollutants : Nitrogen Oxides (NOx)
Nitrogen Oxide (NOx), result from combustion of gasoline & coal.
~Gases made up of a single molecule of nitrogen combined with one or two molecules of oxygen.
*Affects the lungs & respiratory system
*Main component of acid rain
Particulate Matter (PM)
[Coarse particles]
PM10 , or coarse particles (10 µm-2.5 µm)
–Because their size, usually reach the upper respiratory tract causing irritation & inflammation
Particulate Matter
[Fine particles]
PM2.5 (<2.5 µm->0.1 µm), or fine particles
–Capable of being inhaled deeply into the lungs translocating into the blood
–Are not cleared readily from the body
–Associated with 60,000 deaths annually in the US.
Particulate Matter (PM)
[Ultra fine or nano size particles]
Ultra fine particles (UFP) or nano size particles <0.1µm.
After reaching the alveoli, they translocate into the blood causing systemic
effects:
–Inflammation
–Oxygen radical species (ORS)
–Arterial stiffness & remodeling
Particulate Matter: Size
SLIDE 17
Particulate Matter : Composition
~Metal particles re-entrain from the soil to the air.
Their characterization is important for understanding the association between metal pollutants & disease.
(Traces of metals are also present in fossil fuels, coal, gasoline, and diesel).
Particulate Matter : Composition (continued information)
Metal & metal salts including platinum chloride,
tungsten carbide, beryllium, nickel, chromium, cobalt,
iron, & aluminum in PM have been reported as
possible cause of asthma
Fenton’s reaction: Fe2 + H2O2
= Fe3 + OH. (hydroxide anion) + H+; Fe3+H2O2=Fe2 + OOH.(hydroperoxideanion) + H+
Temperature Inversion
~An atmospheric condition during which a warm layer of air stalls above a layer of cool air that is closer to the surface of the earth.
Temperature Inversion & Pollutants:
~During a temperature inversion, pollutants can build up when they are trapped close to the earth’s surface.
Air Quality Standards
The Air Quality Index is used in order to provide the public with an indication of air quality in a local area on a daily basis.
-It focuses on health effects you may experience within a few hours or days after breathing polluted air.
NAAQS
National Ambient Air Quality Standards (NAAQS)
These are federal standards set for air pollutants.
Air Quality Standards:
Primary Standards
Primary Standards set limits to protect public health, including the health of ‘sensitive’ & ‘vulnerable’ populations such as asthmatics, children, & the elderly.
Air Quality Standards:
Secondary Standards
Secondary Standards set limits to protect public welfare, including protection against decreased visibility, damage to animals, crops, vegetation, & buildings.
The EPA reviews the scientific literature for the National Air Quality Standards every ______ years and decides if there is need to revise.
5 years
