Slide 1Air Pollution BackgroundAir Pollution and HealthAir Pollution and its SourcesParticles Sizes and Airborne AgentsRespiratory System and Air PollutantsUS EPA Regulated ParticulatesUS EPA Regulated Particulates, ContinuedSlide 9Sources of all Air Pollutants Measured in California Hydrocarbons (HC), Carbon Monoxide (CO), Oxides of Nitrogen (NOx), Oxides of Sulfur (SOx) and Particulate Matter (PM)Health Conditions Associated with Air Pollution ExposureCommon Health Effects of Ambient Air PollutionAir Pollution and Cancer RisksWHO Air Quality GuidelinesWHO Guidelines - Air Quality and HealthPM Guideline ValuesPM and Health EffectsPM and WHO Health Effects GuidanceOzone WHO GuidanceOzone Health EffectsNO2NO2 Health EffectsSO2SO2 Health EffectsSlide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Air Pollution Background•A widely recognized problem in developed and developing nations•Definition: the presence of substances in air at concentrations, durations and frequencies that adversely affect human health, human welfare or the environment. •Humans suffered from blackening of lung tissue through long exposure to particulate air in smoky dwellings going back to ancient times.•Unhealthy air was the suspected cause of disease long before the relationship could be scientifically confirmed.Air Pollution and Health•A major environmental risk to health•Exposure: inhaled aerosols (particles) and gases•Estimated to cause ca. 2 million premature deaths worldwide/year•Exposure is largely beyond the control of individuals–But individuals can reduce household emissions and exposures•Requires action by public authorities at national, regional and international levels.Air Pollution and its Sources•Major pollutants:–Ozone–Sulfur dioxide–Oxides of nitrogen–Particles or particulates–Carbon monoxide–Volatile organic compounds–Trace metalsClean AirAir Pollution Sources & PollutantsMobile SourceStationary SourceParticles Sizes and Airborne AgentsRespiratory System and Air PollutantsParticles:>100 µM contact eyes, nose and throat; can be irritants>20 µM are inhaled but do not penetrate below the throat< 10 µM enter airways and may be deposited in respiratory system<2.5 µM deposit in alveoli with high efficiency (fine particles)< 0.1 µM remain suspended to be breathed out againUS EPA Regulated Particulates•Total Suspended Particulate Matter (TSP)–0.1 - 30 micrometer in diameter •PM10–aerodynamic diam. ≤10 micrometers–penetrate into lower respiratory tract; 0.1 and 10 micrometers size range is especially important•PM2.5–aerodynamic diam. of less ≤ 2.5 micrometers–airborne for several hours to days; long distance travel–Human respiratory system vulnerable from exposure to them–Composed of sulfates, nitrates, organic cds., ammonium cds., acidic materials, metals & other contaminants causing adverse health effects.–0.2 to 0.5 micrometer: common in combustion, waste incineration, and metallurgical sources–0.1 to 1.0 micrometers: significant emissions from industrial sourcesUS EPA Regulated Particulates, Continued•Particles less than 0.1 micrometer diam.–Combustion and metallurgical sources generate 0.01 to 0.1 micrometer particles. –Tend to agglomerate rapidly to yield particles in the greater than 0.1 micrometer range •Condensable Particulate Matter–Non-particulate matter that condenses and/or reacts upon cooling and dilution in ambient air to form particulate matter in the PM2.5 classification. within a few seconds after discharge from the stackSources of all Air Pollutants Measured in CaliforniaHydrocarbons (HC), Carbon Monoxide (CO), Oxides of Nitrogen (NOx), Oxides of Sulfur (SOx) and Particulate Matter (PM)** Residential fuel combustion, farming operations, construction, road dust, wind-blown dust, fires, waste burning, utility equipment and other miscellaneous sources.Health Conditions Associated with Air Pollution ExposureDisease/Condition Role of Air Pollution Associated FactorsAcute Bronchitis SO2, soot, petrochem. irritative effectsCigarette smoking may be synergisticAcute Respiratory Infections Increased risk in young children Poverty, malnutrition, pathogen exposureAsthma Aggravated by respiratory irritationPre-existing respiratory allergy; airway hyperactivityChronic bronchitis Cough/sputum aggravation Cigarette smoking; occup.Death Fine particulates incr. heart and lung diseasePre-existing heart and lung diseaseEye irritation Photochemical oxidants, aldehydes, peroxyacetyl nitrates and PM Differing susceptibilitiesHeadache Carbon monoxide incr. carboxyhemoglobinSmoking also increases carboxyhemoglobin; indirect effectLead toxicity Contributes to body burden Lead exposure sources at homeCommon Health Effects of Ambient Air Pollution•Respiratory symptoms most common•Cough, nose and throat irritation & mild shortness of breath.•Often associated with eye irritation and a sense of fatigue• Exacerbation of allergic symptoms is typical•Worsening of symptoms of asthmatics and those with chronic pulmonary disorder–Evidence of association between asthma attacks and atmospheric level of oxidants and sulfate•More frequent respiratory tract infections in areas with higher air pollution levels•Cardiovasculat effects from atmospheric CO–Reduces oxygen delivery to myocardium and may aggravate atherosclerosis•Air pollution respiratory effects increase strain on heart in people with chronic bronchitis•Mucosal irritation, nasal tickle, conjunctivitis•Eye irritation, esp. from particulates and photochemical oxidantsAir Pollution and Cancer Risks•Documented for community air pollution from point sources, such as smelters releasing arsenic (lung cancer)•Radon air pollution of indoor air (lung cancer)•Work place exposure to asbestos and mesothelioma of the lung•Central nervous system toxicity as learning disabilities in children from airborne leadWHO Air Quality Guidelines•WHO has air quality guidelines–Represent widely agreed, contemporary assessments of health effects of air pollution–Recommended targets for air quality at which the health risks are significantly reduced. •Recommend reducing particulate matter (PM10) pollution from 70 to 20 micrograms per cubic metre–Can reduce air quality related deaths by ca. 15%.•Will help countries reduce the global burden of disease from respiratory infections, heart disease, and lung cancer.WHO Guidelines - Air Quality and Health
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