Lecture 6_Air Pollution and Community Health_Sept 14

Lecture 6_Air Pollution and Community Health_Sept 14 - Air...

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Unformatted text preview: Air Pollution and Community Health Health John R. Balmes, MD Clean Air Act Clean The U.S. EPA regulates six so-called “criteria” air The pollutants: pollutants: – Ozone – Nitrogen dioxide – Sulfur dioxide – Particulate matter (PM) – Carbon monoxide – Lead The EPA also regulates “hazardous” air The pollutants (HAPS) primarily because of adverse reproductive or cancer effects; the current list includes 188 chemicals. includes What is a “criteria” pollutant? What A pollutant for which the U.S. EPA has decided pollutant there is sufficient scientific evidence of health and/or welfare effects to provide a basis for regulating ambient levels. regulating The EPA then promulgates a National Ambient The Air Quality Standard (NAAQS) for that pollutant. pollutant. The law stipulates that there be an adequate The margin of safety to protect the most susceptible groups (e.g., children, the elderly, those with pre-existing disease) those What scientific evidence is used? used? Epidemiologic studies Controlled human exposure studies Animal toxicological studies Oxidative Stress Oxidative Ozone and particulate matter are capable Ozone of generating reactive oxygen species (ROS) when inhaled into the airways and alveoli of the lungs. alveoli Ozone Formation in the Atmosphere Ozone - Potential Public Health Impact Impact • Over 50% of U.S. population resides in Over areas that are not in attainment with the current EPA national ambient air quality standard (NAAQS) standard • Houston and Los Angeles are the cities Houston with the worst ozone problem in the U.S.; Mexico City has the highest ozone levels in North America. in Ozone Concentrations Across the U.S. Ozone – Acute Health Effects Ozone Sub-sternal chest discomfort Decreased lung function Airway inflammation Exacerbation of asthma Increased daily mortality Effects of Ambient Levels of Ozone on Lung Function Horstman et al. Am Rev Respir Dis 1990;142:1158-63. Ozone and Asthma Ozone EPIDEMIOLOGICAL STUDIES Multiple studies have shown increased ER Multiple visits for asthma in association with high ozone levels. ozone Panel studies of subjects with asthma have Panel shown increased symptoms and medication use and decreased lung function in association with ozone exposure. association Ozone Mortality Effect Ozone Several recent studies were published Several showing an effect of ambient ozone on daily mortality. daily – A US study involving 95 metropolitan areas US showed a 0.5% increase in mortality with a 10 ppb increase in ozone concentration. 10 – A European study of 23 cities showed a European 0.33% increase in mortality with a 10 µ g/m3 increase in ozone concentration. increase Dose–response of ozone 1 hour concentrations and daily deaths during the summer season Dose–response of ozone 1 hour concentrations and daily number of deaths during the summer season. Gryparis et al. AJRCCM 2004;170:1080-1087 Ozone Mortality (Jerrett at al. NEJM 2009) Ozone Mortality Ozone (Jerrett at al. NEJM 2009) Cause of Death Cardiopulmonary Ozone PM2.5 O3 adj for PM2.5 0.99 1.04 0.98 PM2.5 adj for O3 1.15 0.93 1.21 1.01 1.02 1.03 1.01 Respiratory 1.03 Cardiovascular 1.01 Ozone Mortality – Jerrett at al. NEJM 2009 2009 Chronic Exposure to Ozone Chronic Decreased flow rates at mid and low lung Decreased volumes (“small airways dysfunction”) have been found in college students in association with lifetime exposure to ozone (Kunzli et al.; Tager et al.). Tager Decreased flow rates have also been Decreased associated with >4 years of residence in a high ozone area (Galizia and Kinney). ozone Decreased growth of lung function associated Decreased with ozone exposure in Mexico City (Rojaswith Martinez et al.) Effects of Acute and Chronic Ozone Exposure on Lipid Peroxidation in Healthy Young Adults Young Chen et al. Environ Health Perspect 2007;115:1732-1737 Public Health Policy Implications: Ozone Implications: US EPA adopted a NAAQS for ozone of 0.08 US ppm over 8 hours in 1996. ppm EPA studies have shown decreased lung EPA function and airway inflammation in in healthy subjects exposed to 0.08 ppm over 6.5 hours with intermittent exercise. with Multiple epidemiological studies have shown Multiple associations with asthma health outcomes and 8-hour ozone levels below 0.08 ppm. 8-hour Should the EPA consider a stricter ozone Should standard? standard? Public Health Policy Implications: Ozone Ozone Based on a review of the scientific knowledge Based base, the U.S. EPA’s CASAC recommended a range for a new NAAQS for ozone of 60-70 ppb (0.06-0.07 ppm) in order to have an adequate “margin of safety” to protect the most susceptible groups. susceptible Bush EPA Administrator Johnson decided that Bush the NAAQS should be 75 ppb. the PARTICULATE MATTER (PM) PARTICULATE PM is a mixture, including particles of PM differing origin (combustion, crustal, biological) and varying size. biological) Particles of respirable size: PM10 includes so-called coarse fraction. PM2.5 is the fine fraction. PM <0.1 microns is the ultrafine fraction. PM <0.1 Particle Size Particle Hair cross section (60 µ m) Human Hair (60 µ m diameter) PM2.5 PM10 PM0.1 (10 µ m) (0.1 µ m) (2.5 µ m) PARTICULATE MATTER PARTICULATE Acute Health Effects increased respiratory symptoms decrements in lung function increased bronchodilator use increased hospitalizations for respiratory increased disease (pneumonia, asthma, bronchitis) disease increased cardiopulmonary mortality Diesel Exhaust Diesel Mixture of oxidant Mixture gases and particulate matter (PM) matter PM has a carbon core PM with surfaces characterized by complex chemistry and physical structure and Diesel exhaust Diesel contains oxidizing agents that can injure cells and lead to inflammation. inflammation. Diesel Exhaust: Acute Health Effects Acute Diesel exhaust can induce airway Diesel inflammation Diesel exhaust particles enhance nasal Diesel allergic responses in humans. allergic Occupational exposures are associated Occupational with acute decrements in lung function. with Respiratory Effects of Exposure to Diesel Traffic in Persons with Asthma McCreanor et al. N Engl J Med 2007;357:2348-2358 Pathways of PM-induced Acute Cardiovascular Events (Mills) Myocardial Ischemia during 15-min of Exercise-Induced Stress and Exposure to 300 μg/m3 Diesel Exhaust or Filtered Air in 20 Subjects Mills et al. N Engl J Med 2007;357:1075-1082. PM-associated Mortality PM-associated Epidemiological Data Multiple time-series studies have shown Multiple cardiopulmonary mortality to be associated with levels of PM. associated Several longitudinal studies have also Several linked chronic PM exposure and mortality. mortality. An Association between Air Pollution and Mortality in Six U.S. Cities Mortality Dockery et al. N Engl J Med 1993;329:1753-1759 Fine-Particulate Air Pollution and Life Expectancy in the United States Expectancy Pope et al. N Engl J Med 2009;360:376-386. Fine-Particulate Air Pollution and Life Expectancy in the United States Expectancy Pope et al. N Engl J Med 2009;360:376-386. PM: Chronic Respiratory Effects Effects Decreased rate of growth in lung Decreased function in association with PM2.5 function exposure observed longitudinally in So. CA Children’s Health Study. CA Increased risk of lung cancer associated Increased with PM2.5 in U.S. cities (Pope et al.) with Children’s Health Study Effect of Air Pollution on Lung Development from 10 to 18 Years of Age Gauderman et al. N Engl J Med 2004; 351:1057-1067. Current PM NAAQS Current Particulate Matter (PM10) – 150 µg/m3 24-hour (not be exceeded more than once per year on average over 3 years) Particulate Matter (PM2.5) – 15 µg/m3 Annual (3-yr average of the mean concentration at single or multiple communityconcentration oriented monitors) oriented – 35 µg/m3 24-hour (3-year average of the 98th percentile of 24-hour concentrations at each population-oriented monitor within an area) Public Health Policy Implications: PM Implications: On the basis of the epidemiologic data On re: cardiopulmonary mortality risk, should the EPA promulgate a stricter PM standard? standard? Should the current annual standard be Should lower to protect children from the effects of chronic exposure on growth of lung function? lung Measuring the gains from improved air quality in the San Joaquin Valley quality Hall et al. J Environ Manage 2008;88:1003-15. Measuring the gains from improved air quality in the San Joaquin Valley quality Hall et al. J Environ Manage 2008;88:1003-15. Surface Goods Movement Surface Exposures to oxidant gas and particle Exposures pollution from surface goods movement (primarily powered by diesel engines) can be high for people who live near ports, railroads, highways and distribution centers. distribution People of color and low SES are the People most likely to be exposed. most Container Ships Container Inter-modal Shipping Facilities Inter-modal Container Trucks and Trains Container Distribution Centers Distribution Distribution Trucking Distribution Demographics of Children Living Near Freeways Near – Children of color 3x more likely to Children live near high traffic density in California Gunier et al., California Dept of Health Services, 2003 Gunier School ↓ – Schools near busy roads Schools have a disproportionate number have of children who are economically of disadvantaged and non-white disadvantaged RS Green et al, Environ Health Perspect 2004;112:61. RS Particle Exposures Near Freeways Particle Zhu et al, 2002 …more more black carbon (diesel marker) near 710 freeway… freeway… Zhu et al 2002 Real People Live Near Freeways Real Truck on 710 Freeway ↓ Real People Live Near Train Yards Real Real People Live Near Distribution Centers Centers Distribution Center ↓ Effect of Exposure to Traffic on Lung Development from 10 to 18 years of Age Development (Gauderman et al. Lancet 2007) Burden of Disease in California due to Air Pollution due The current annual health impacts of exceeding state The health-based standards for O3 and particulate matter: health-based – 6,500 premature deaths 6,500 – 4,000 hospital admissions for respiratory disease – 3,000 hospital admissions for cardiovascular 3,000 disease – 350,000 asthma attacks 350,000 – 2,000 asthma related emergency room visits – elevated school absences due to respiratory elevated conditions conditions – reduced lung function growth rate reduced (CARB) ...
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This note was uploaded on 09/29/2009 for the course NUTRI SCI 10 taught by Professor Amy during the Spring '08 term at University of California, Berkeley.

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