AIR POLLUTION
OSH 320
AIR POLLUTION
CONCENTRATIONS:
FACTORS
THERMAL INVERSION
• Air temperature gradually increases with altitude
• Disperses pollutants by hot air rising from the ground
• Sometimes this is reverse
• Air decreases with altitude and then increases
• Air pollution is trapped
RADIATION INVERSION
• Heat radiates from the Earth’s surface at night
• Earth serves as a radiator
• The ground and air layer next to it cool off quicker than air
above
• Air above this layer creates a lid of warm air
• Air pollution is trapped at ground level
SUBSIDENCE INVERSION
• Warm, high pressure air mass stalls over an area & sinks
• Last longer than radiation inversions
• Can form over several states
• More of an issue in the summer along the coast
DUST DOME
• Larger cities
• Haze of smoke and dust (umbrella)
• Unique circulation of air patterns
• Air is warmer in the city compared to rural areas
• “Heat Island”
• “Dust plume”
CAUSES FOR HIGH TEMPERATURES
• People
• Industrial furnaces
• Utility Boilers
• Paved roads/parking lots
RURAL AREA TEMPERATURE REDUCTION
• Evaporative cooling due to vegetation
• Less people
PRECIPITATION
• Local climate is influenced primarily by particulates
• Condensation nuclei
• Small particles that absorb moisture
• Cause cloud formation
• Cities downwind experience precipitation
• More rain M-F
• Chicago---La Porte, IN
• Paris, France 31% higher rainfall on weekdays
DECREASED AVERAGE TEMPERATURE
• Increase particulates block out sunlight
• 1883 Volcano on the Dutch East Indies erupted
• Over a period of years the particles circled the globe several
times
• U.S. experience cooling
• Boston had snow in June
AIR POLLUTION DISASTERS
• They occur in densely populated areas
• They occur in heavily industrialized centers
• Accompanied by fog
• They are accompanied by thermal inversion
THE DONORA DISASTER
• Occurred in 1948 near Pittsburg, PA
• Home to factories that manufacture steel, wire, sulfuric acid &
zinc
• Thermal inversion occurred
• A fog closed in on the valley
THE DONORA DISASTER CONT.
• Blanket of sulfur dioxide, nitrogen dioxide and hydrocarbons
blanketed the air
• High School football game was cancelled due to several
players getting ill
• Motorist had to pull of the side of the road the haze
• 43% of the population became ill (5,910)
CHRONIC HEALTH EFFECTS
• Chronic Bronchitis
• Emphysema
• Lung Cancer
• Asbestosis
• CO poisoning
CHRONIC BRONCHITIS
• Persistent mucous build up
• Cough
• Exposure of sulfur and nitrogen dioxide
• Urban pollution & cigarette smoke contains the same
chemicals
EMPHYSEMA
• Breakdown of alveoli
• Air passes into the sacs to have access to the blood stream
• Pollutants that cause emphysema
• Sulfur dioxide
• Nitrogen dioxide
• Ozone
LUNG CANCER
• Carcinogens
• Air pollution in combination results in a synergistic effect
• Higher populated areas, increased risk
ABESTOSIS
• 1986 Congressed passed the Abestos Hazard Emergency
Response Act
• Inspection of schools required
• EPA regulations have helped control occupational exposures
• 1970’s many products eliminated from production
GLOBAL WARMING SPEECH
CONTROLLING PARTICULATES
• Bag house filters
• Asbestos
• Lead
• Dust
• Physically remove airborne particles form smoke stacks
• 99.99% of particulates can be removed
SMOG HOG
ELECTROSTATIC PRECIPITATOR
• Removes small diameter particles
• Commonly seen in coal-fired power plants
• Pollutants pass through positively and negatively charged
electrodes
• Will shut down periodically to allow dust particles to fall
• Can contain toxic heavy metals
CYCLONE FILTERS
• Heavy dust particles
• Gravity and a downward-spiraling air stream
• Air full of particulates strike against walls and fall to
the bottom of the cylinder
CONTROLLING SULFUR OXIDE
• Shift from high-to-low sulfur coal
• Pennsylvania, West Virginia, and Illinois
• Before 1970’s
• Some companies continued
• Early 1990’s many companies switched to low-sulfur coal to
avoid pollution control devices
LOW-SULFUR COAL
• Located in the western states
• Colorado, Montana, and Wyoming
• Strip mining was the only way to reach it
• Costly reclamation efforts must be taken to restore the land
back to it’s original state
• Costly transportation
COAL STRIPPING OPERATION
COAL CLEANING
• Mine high-sulfur coal and remove sulfur prior to burning
• Contains impurity called iron pyrite (Fool’s Gold)
• Tank mixes pulverized coal and water
• Iron pyrite is heavier than coal
SCRUBBING
• Removing sulfur from smoke stacks
• Power plants and factories
• A mist consisting of ground limestone and water is sprayed
into the smoke stacks
• Calcium in the limestone reacts with the sulfur
• Forms calcium sulfate
SCRUBBERS CONT.
• 95% effective
• Calcium sulfate may be used in rock beds and dry wall
• Most goes to the landfill
• Can be added to existing plants
• Costly
• Produce toxic sludge
SCRUBBER
AUTOMOTIVE EMISSIONS
• Carbon monoxide, carbon dioxide, sulfur oxides, nitrogen
oxides, particulates, and VOCs
CATALYTIC CONVERTERS
• Muffler shaped device incorporated into the exhaust system
• Cells are honeycomb shape
• Honeycomb cells are coated with a catalyst (+chemical reactions)
• CO & VOCs react with catalyst & convert to carbon dioxide and
water
• Doesn’t remove nitrogen oxides
• Three way catalytic convertors (81’)
INSPECTION AND MAINTENANCE PROGRAM
• Automobile emissions are checked annually
• Minor adjustments made if needed to fuel injection system
(spark plugs, etc.)
• Portland, OR started the program and reduced emissions by
40% in one year
INCREASED FUEL EFFICIENCY
• 1975 Federal law placed to put a tax on all cars not meeting
specifications
• “Gas-guzzler” tax
• Lamborgini-6 miles/gallon
• Clinton repealed law in 1996
VOLKSWAGEN CRISIS
MANAGING OR REDUCING TRAFFIC
VOLUME
• Traffic lights on ramps in big cities help with traffic flow
• Termination of free parking in cities
• Placing an added tax on downtown parking fees
• Prohibiting commuters to driving to one day a week to
reduce commuter traffic
• Free bus passes issued by businesses or universities
NEW YORK CITY
• Bans all street parking in major business settings in
Manhattan
• Restricts cruising of taxis
• Has placed several bridges on a toll system
• Set aside one lane on busy roads for exclusive use of buses
REPLACING GASOLINE
• Replacing gasoline with ethanol
• Use of renewable resource
• Produces less air pollution
• It is still not a zero carbon fuel (farming)
• Can reduce global warming
• Contains 30% less fuel than gasoline
• Use of switch grass and plant materials-future
INTERNAL COMBUSTION ENGINES
• Since the Clean Air Act was introduced, hydrocarbon and
carbon monoxide emissions reduced by 90% & nitrogen
oxides were reduced by 70%
• We have an increase on amount of motor vehicles now
ELECTRIC CARS
• Pollutant free (100-150 mpg equivalent)
• They still require electricity
• Lead batteries which are bulky
• Can go 60-100 miles before recharging
• Newer lithium-ion batteries go 220 miles between charges
HYBRID CARS
• Electric engine and internal combustion
• Prius 40-50 mpg
• Some hybrids revert to gas on trips over 60 miles
• Amory Lovins
INDOOR AIR POLLUTION
• Gas ranges/furnaces
• Tobacco smoke
• New carpet
• Paint
• Hairspray/perfume
WHY WORRY ABOUT INDOOR AIR QUALITY
• Most our time is spent indoors
• Houses are more tightly insulated
• Paints, cabinets and carpet back release
VOC’s/formaldehyde
• Latex paint releases mercury
• “Out gassing”
FORMALDEHYDE
• Carpets
• Particle board
• Foam insulation
• Plywood
• Furniture
FORMALDEHYDE RISKS
• Eye Irritation
• Nausea
• Respiratory Issues
• Cancer
• OSHA PEL=3 ppm TLV=.3 ppm
CANCER RISK WITH MOBILE HOMES
• Relatively small air volume
• Poor air circulation
• Relatively large amounts of materials with formaldehyde
• Particle board
RADON
• Gas produced by uranium
• Natural decay release radon gas (radioactive)
• Found in rocks and soil
• Radon will quickly disperse in open air
RADON PROPERTIES
• Odorless
• Tasteless
• Colorless
INSIDE HOMES
• Radon gas decays to form lead and polonium
• Radon will decay in lungs and deposit lead
• Genetic mutation of surrounding cells can lead to cancer
• EPA estimates 20,000-30,000 lung cancer deaths each yr. due
to radon
• Accounts for 55% of all radioactive exposure
HIGH RISK AREAS
• Pennsylvania, New York and New Jersey
• One home in PA had a reading of 675 times acceptable
exposure to uranium
• Risk was compared to smoking 220 packs of cigarettes a day
LOWERING YOUR RISK
• Sealing cracks in the floor & walls
• Sub-slab depressurization
• Plastic layer over the ground beneath your house if on block
• Average cost to fix radon issue sis typically between $500$2,500
FACTS ON RADON
http://chfs.ky.gov/dph/info/phps/radongas.htm
• Radon detection kits
CONTROLLING INDOOR AIR POLLUTION
• Eliminate
• Tile instead of carpet
• Isolate
• Sealing subflooring before installing
• Ventilate
• Energy recovery ventilator