air pollution indoor
DESCRIPTION
ap env scienceTRANSCRIPT
Indoor Air Pollution
Indoor Air pollution
▪Indoor pollution 2-5 times greater than outdoor pollution
▪Well insulated buildings in warm climates allow buildup
▪People spend 70-98% time indoors…
▪Sick building syndrome▪dizziness, nausea, headaches, fatigue▪New buildings “sick” more often than older buildings▪“Offgassing”
Insert Fig 20-13
4 Most Dangerous Indoor Pollutants
▪Cigarette smoke
▪formaldehyde (from particle board, carpet, paneling, furniture)
▪radon-222 gas (natural decay of uranium releases gas in ground)
▪Very small fine and ultrafine particles
Formaldehyde
▪Colorless, extremely irritating gas used to manufacture common household materials
▪20-40 million Americans suffer from chronic breathing problems, dizziness, headaches, rashes, sinus & eye irritation and nausea from daily exposure to low levels
▪Sources: building materials, plastics, furniture, adhesives in carpeting and wallpaper, drapes, wrinkle free coating on clothing
Formaldehyde
▪1 ounce dose at 37% formaldehyde = lethal
▪allows no more than 16 ppb formaldehyde in the air in new buildings constructed for that agency.
▪Homes will often measure 0.076 ppm when brand new and 0.045 ppm after 30 days.
Radon-222
▪Colorless, odorless, tasteless, radioactive
▪Comes from the decay of uranium-238
▪common in granite, phosphate, uranium, shale soils & rocks
▪when rocks breakdown gas is released, normally filters through soil & diluted in atmosphere
▪problem if seeps into buildings; can potentially increase the risk cancer
▪Basements!
▪Radon is the 2nd leading cause of lung cancer after smoking!
Ultrafine Particles
▪Smaller than 100 nanometers, carbon based or metallic▪ Outdoor sources: volcanic lava, ocean spray, and smoke▪ Indoor sources: laser printers, fax machines, photocopiers, the peeling of
citrus fruits, cooking, tobacco smoke, penetration of contaminated outdoor air, chimney cracks and vacuum cleaners
▪Not effectively captured by most air pollution control equipment
▪Small enough to penetrate body defenses
▪Bring other cancer/toxic substances into body
▪Can cause chronic irritation that can trigger asthma attacks, aggravate lung disease and cause lung cancer▪ interfere with bloods uptake of oxygen and release of CO2, which strains the
heart and increases the risk of death from heart disease
Asbestos
▪Initially… next best thing…was used extensively due to extreme resistance to heat▪ firefighters uniforms, building walls, ceilings, SCHOOLS etc
▪Microscopic fibers decay-cannot be broken down by body when inhaled▪ lodges in lung and “saws” lung tissue over time → lung cancer▪172,000 Americans have died prematurely due to asbestos exposure▪Mesothelioma
Major health risk today concerning asbestos:
▪Among miners and workers in developing countries
▪Remodeling, Tear-out, Demolition workers
▪90% of these deaths can be prevented by:▪Wearing a mask▪Wetting asbestos▪Changing clothes before and after handling
Ways Body Protects Us From Air Pollution
▪Hairs in nose
▪Sticky mucus in lining of upper respiratory tract
▪Sneezing and coughing
▪Cilia in upper respiratory tract
▪BUT prolonged exposure can overload our defenses.
Air pollution health concerns…
▪ Air pollution can lead to:▪lung cancer▪asthma▪chronic bronchitis (often in children of smokers)▪Chronic obstructive pulmonary disorders▪emphysema- loss of lung elasticity can’t pull in air
▪Smoking makes all exposure worse-concentrated
radiation of lungs breaks down natural defenses
Air quality legislation
▪Clean Air Acts -1970 (1st major environmental law in US) 1977, 1990
▪EPA established NAAQS (national ambient air quality standards)
▪addresses acceptable levels of each pollutant
▪Focuses on pollution clean-up rather than prevention
▪Allows for SO2 emissions trading▪Enables the 110 most polluting power plants in 21 states to buy and sell
SO2 pollution rights
Cap and Trade Emissions trading
▪Each year a coal burning plant is given a certain number of emmission permits (called: “allowances”)
▪ Enacted as per the Acid Rain program of the Clean Air Act (1990)
▪ SO2 emissions were reduced by 50% from 1980 levels by 2007
▪ experts argue that the cap-and-trade system of SO2 emissions reduction has reduced the cost of controlling acid rain by as much as 80% versus source-by-source reduction
▪Coal plants that emit less than limit have a surplus of credits and can sell to other utilities, transfer to another plant, or “bank” for the future
▪Problem: “overallocation” setting the bar too low by setting the cap too high. Allows for banking of credits