Carbon Oxides ______- colorless, odorless gas; highly ______- colorless, odorless gas CO- car exhaust, burning forests or grasslands, tobacco smoke, open fires, inefficient stoves CO2- most is from the result of the natural carbon cycle; the rest is from burning fossil fuels, clearing CO2 absorbing forests CO- reacts with hemoglobin in red blood cells and reduces blood’s ability to transport O2. Chronic exposure leads to asthma, emphysema, mental impairment, coma, death CO2- global warming and climate change Catalytic Converters- converts dangerous CO emissions from cars to CO2 Nitrogen Oxides and Nitric Acid NOx refers to NO and NO2 ____- colorless gas that forms when nitrogen and oxygen gas react In the air, NO reacts with O2 to form NO2 (a reddish brown gas) ___________- NO2 reacts with water vapor to form nitric acid (component of acid rain) greenhouse gas NO- combustion engines and coal burning power plants (Lightening and bacteria can also produce NO as part of the nitrogen cycle.) N2O- emitted from fertilizers, animal waste, and from the burning of fossil fuels NO- photochemical smog, can irritate eyes, nose, and throat and aggravate asthma , suppress plant growth Nitric Acid- photochemical smog, acid deposition N2O- leads to an increase in global warming Sulfur Dioxides and Sulfuric Acid ____- colorless gas with irritating odor ________ acid- SO2 in the air is converted to sulfuric acid (H2SO4) and sulfate salts SO2- combustion of coal, oil refining, and smelting of sulfur oxides Both SO2 and Sulfuric Acid- acid deposition, reduce visibility, aggravate breathing problems, damage trees, soil and aquatic life, corrode metals, and damage paint and stone on buildings and statues. Name Characteristics Sources Effects Particulates Suspended ________________ Matter (SPM) Most comes from natural sources like SPM is linked to adverse respiratory effects, reduce visibility, corrode metals
Variety of solid particles and liquid droplets that remain suspended dust, wildfires, and sea salt Human sources- coal burning plants, industrial plants, cars, unpaved roads Fine Particles- <10micrometers in size Ultrafine- <2.5micrometers in size These are the most dangerous particulates: irritates nose and throat, damages lungs, asthma, Toxic Particulates- lead, cadmium, and PCBs can cause mutations, reproductive problems, etc Ozone _____- Colorless, highly reactive gas- major component of photochemical smog Secondary pollutant Humans are INCREASING ozone in the troposphere and DECREASING ozone in the stratosphere Ozone in the TROPOSPHERE= BAD ozone -breathing problems, aggravate lung and heart disease, irritate eyes, damages plants in the STATOSPHERE= GOOD ozone -protects us from harmful UV rays Volatile Organic Compounds (VOCs) -Exist as gases in the air -Most are hydrocarbons -Benzene Plants, wetlands, termites, rice paddies, landfills, oil wells, cows belching Industrial solvents, dry cleaning fluids, gasoline, plastics, paints Can cause leukemia (from benzene exposure), blood disorders, dizziness, death Case Study: Lead is a Highly Toxic Pollutant- Lead (Pb) is a potent neurotoxin that does not break down in the environment. Exposure causes nervous system impairment, lowered IQ, shortened attention span, etc. Between 1976 and 2000, there has been a huge drop in lead poisoning cases because the government banned leaded gasoline and leaded paint. Some children are still being exposed because of: leaded paint found in homes built before 1960 and illegal use that continued through 1978 as well as toys that are made overseas in countries that have not banned lead paint. Science Focus: Detecting Air Pollutants One way to detect air pollutants is through a biological indicator- Lichen Lichen forms from a mutualistic relationship between fungi and algae. They are good indicators because they continually absorb air. Highly Polluted Area= grey-green crusty lichen or none at all Moderate Air Pollution= orange crusty lichen
effects of air pollution. - 2.2 million of those deaths are due to indoor air pollution. 18-6: How Should We Deal with Air Pollution? EPA has established *The 6 outdoor criteria air pollutants: Carbon Moxide 4. Nitrogen Dioxides Particulates 5. Ozone Sulfur Dioxide 6. Lead *Hazardous Air Pollutants (HAPS)- emissions standards *Toxic Release Inventory (TRI)- factories, mines, refineries must report their release of toxic chemicals Congress has passed air pollution laws, but is room for improvement: US relies mostly on pollution clean up, rather than prevention We have failed to increase fuel efficiency in cars Little regulation of oceangoing ships Airports are exempt from regulations Laws don’t regulate emissions of CO2 Ultrafine particles are not regulated Does not deal with indoor air pollution Outdoor Air Pollution Solutions Indoor Emissions Trading (aka: Cap and Trade) allows major “polluters” to buy and sell emissions allotments to help reduce SO2 emissions Burn low sulfur coal Disperse emissions above thermal inversion layer with tall smokestacks. Use mass transit Give large tax breaks for those who buy low polluting vehicles Inspect car emissions throughout the year Rely more on renewable energy sources Improve energy efficiency Carbon Capture and Storage (aka Carbon Sequestration)- Ban smoking Stricter formaldehyde emissions from carpet and furniture companies Use office machines in well ventilated areas Less polluting cleaning supplies Circulate buildings air through rooftop greenhouses Use exhaust hoods for stoves Prevent radon infiltration Distribute cheap, efficient stoves or solar cooker to developing countries Develop cheap tests for indoor air pollutants Radon detectors
-reduce unnecessary use of antibiotics -reduce antibiotic use in livestock 17-3: What types of Chemical Hazards Do We Face? List the 5 most substances to human health: arsenic 2. lead 3. mercury 4. chloride 5. PCBs Describe the 3 major types of toxic agents: Carcinogens Mutagens Teratogens -causes cancer EX: arsenic, benzene, chloroform, formaldehyde, PCBs, UV light -causes mutations in DNA EX: some preservatives in food causes harm or birth defects to a fetus or embryo EX: ethyl alcohol, lead, formaldehyde, mercury, PCBs PCBs: What was it used for? A class of 200 chlorine containing compounds that were widely used as lubricants, hydraulic fluids, electrical insulators, ingredient in paints, fire extinquishers, fire retardants in fabrics, and pesticides. Why was it banned? Banned in 1977 by the US Congress because it has been linked to liver cancer and learning disabilities in children Why are PCBs still causing issues even after it has been banned? PCBs are persistent chemicals that breakdown very slowly and are fat soluble and can be biomagnified. Therefore, it can still be found in our soil, air, and water. Briefly describe how chemicals affect each of the body systems: Immune System Nervous System Endocrine System -some chemicals like arsenic, methylmercury, and dioxins weaken the immune system to the point where it can’t fight off diseases -chemicals that are neurotoxins can cause behavioral changes, learning disabilities, retardation, ADD, and paralysis -Endocrine disruptors -some chemicals are HAA (hormonally active agents) that hormones that impair reproductive development as well as physical disorders EX: atrazine, DDT, PCBs, BPA -some chemicals are hormone blockers Mercury: Where does it come from? Natural Sources- released from rocks, soil, volcanos Human Sources- coal burning power plants, waste incinerators, metal ore