278 airpollutants

Air Pollution: 

Air Pollution Smog: PAHs, PM, Ozone, SOx, NOx

Air: 

Air

Disturbance of Nutrient Cycles: 

Disturbance of Nutrient Cycles

Slide4: 

Table 20-1 Page 436 KNOW Table 17-1 Major Classes of Air Pollutants and Table 17-2 Class Carbon oxides Sulfur oxides Nitrogen oxides Volatile organic compounds (VOCs) Suspended particulate matter (SPM) Photochemical oxidants Radioactive substances Hazardous air pollutants (HAPs), which cause health effects such as cancer, birth defects, and nervous system problems Examples Carbon monoxide (CO) and carbon dioxide (CO2) Sulfur dioxide (SO2) and sulfur trioxide (SO3) Nitric oxide (NO), nitrogen dioxide (NO2), nitrous oxide (N2O) (NO and NO2 often are lumped together and labeled NOx) Methane (CH4), propane (C3H8), chlorofluorocarbons (CFCs) Solid particles (dust, soot, asbestos, lead, nitrate, and sulfate salts), liquid droplets (sulfuric acid, PCBs, dioxins, and pesticides) Ozone (O3), peroxyacyl nitrates (PANs), hydrogen peroxide (H2O2), aldehydes Radon-222, iodine-131, strontium-90, plutonium-239 (Table 3-1, p. 49) Carbon tetrachloride (CCl4), methyl chloride (CH3Cl), chloroform (CHCl3), benzene (C6H6), ethylene dibromide (C2H2Br2), formaldehyde (CH2O2)

Photochemical Brown Smog: 

Photochemical Brown Smog

Slide6: 

Photochemical smog

Thermal Inversions: 

Thermal Inversions Cities near mountain ranges When a warm front follows a cold front Result: intense local smog

Gray Smog Chemistry: 

Gray Smog Chemistry Coal combustion: C (in coal) + O2 ----- CO2 (and 2CO) + soot S (in coal) + O2 ----- SO2 (sulfur dioxide) Metal smelters: PbS + O2 ----- SO2 Then: 2 SO2 + O2 ----- 2SO3 (sulfur trioxide) SO3 + H2O ----- H2SO4 (sulfuric acid) H2SO4 + 2NH3 ----- (NH4)2SO4 (ammonium sulfate) Ammonium sulfate and soot give gray color to smog What factors affect smog formation?

Slide9: 

BBC: London Smog 1952

Particle Size: 

Particle Size >5 microns- filtered out 1-5 microns- trapped in lungs <1 micron-aveolar region

Respiratory Physiology: 

Respiratory Physiology Regions of deposition

Occupational Exposures: 

Occupational Exposures

What are PAHs?: 

What are PAHs? naturally occurring formed via incomplete combustion more than 100 different PAHs Soot: complex PAH mixtures (& other stuff) colorless, white, or pale yellow-green solids in pure form faint pleasant odor Anthracences, fluoranthese, pyrenes, perylenes All info from CDC, ATSDR

PAHs: Sources of Exposure: 

PAHs: Sources of Exposure Burning of coal, oil, gas, wood, garbage, tobacco and charbroiled meat Asphalt and roofing tar Used in medicines and to make dyes, plastics, and pesticides Superfund Sites (nearly 50% of sites)

Environmental fate of PAHs: 

Environmental fate of PAHs Released as smoke, in surface waters via industrial/sewage plants and from leaking hazardous waste containers Not very water soluble, but can sink to sediment or contaminate groundwater Exist as vapors or attached to airborne particles (transported great distances) Degrade in sunlight, but bioaccumulate too

Routes of Exposure: 

Routes of Exposure Occupational Inhalation Indoor/Outdoor air pollution Hazardous waste sites Food consumption Drinking contaminated water or cow's milk. Nursing infants of mothers living near hazardous waste sites

Disposition: 

Disposition Lipophilic stored mostly in your kidneys, liver, and fat less in spleen, adrenal glands, and ovaries Some detoxified/others activated via P450 metabolism Residence time of only a few days, excreted in the feces and urine

PAH metabolism: 

PAH metabolism Epoxides Quinones

PAHS and Cancer: 

PAHS and Cancer English Chimney Sweeps Initiators via adduct formation epoxides and quinones Activate other carcinogens via P450-induction Can also act as promotors

Comparative PAH Toxicity: 

Comparative PAH Toxicity How are these determined? How are they used?

Toxicity: 

Toxicity Reproductive effects Reproductive impairment (mice) Low birth weight, birth defects (mice) Immune suppression (animals) Vascular toxicity initiation (mutation) Promotion (protein kinase C)

Detection: 

Detection Urinary metabolites 1-hydroxypyrene Adducts (in blood, urine, feces) DNA Hemoglobin Serum proteins Autopsy: concentrations in fat

Particulate Matter: 

Particulate Matter Definition: particles found in the air, including dust, dirt, soot, smoke, and liquid droplets Sources cars, trucks, buses, factories, construction sites, tilled fields, unpaved roads, stone crushing, and burning of wood.

PM characteristics: 

PM characteristics Size matters PM2.5 pose the greatest risk Mixture matters Metals, allergens, etc.

Health Effects of PM: 

Health Effects of PM aggravated asthma coughing difficult or painful breathing chronic bronchitis decreased lung function Cardiac function impairment premature death

Respiratory Physiology: 

Respiratory Physiology

Common Respiratory Ailments: 

Common Respiratory Ailments Asthma

Common Respiratory Ailments: 

Common Respiratory Ailments Edema Bronchitis

Common Respiratory Ailments: 

Common Respiratory Ailments Emphysema Fibrosis

Clean Air Act: 

Clean Air Act EPA to develop NAAQS for 7 major outdoor pollutants Non-attainment areas EPA set emission standards for 300 compounds Congress to set timetable for achieving them

PM Nonattainment areas: 

PM Nonattainment areas