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Externality on Theory

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AACIMP 2009 Summer School lecture by Yoshio Matsuki. "Environmental Externalities of Energy Options - Basics and Applications" course. 3rd hour.

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Externality on Theory

  1. 1. Air Pollution and Health Impact Y. Matsuki August 8, 2009 Presented at NTUU “KPI”
  2. 2. What’s new on the public health issue? Loss of life expectancy for chronic mortality from air pollution [Dockery et al 1993, Pope et al 1995] have found positive correlations between exposure to particles and total mortality
  3. 3. Epidemiology of Acute Health Effects Table of contents - Introduction - Studies of air pollution episodes - Health effects at low levels of air pollution - Acute Morbidity - Daily time-series mortality studies - Slope of the mortality exposure-response relationship and lead-lag relationships - Acute Morbidity - Hospital usage - Exacerbation of asthma - Respiratory symptoms - Lung function - Restricted activity
  4. 4. Introduction It’s about human health and pollution. Where in the world is this story about? When did this story start? What changed for the last 10-15 years?
  5. 5. Air pollution episodes Where the most dramatic episode occurred and when? What happened? Mortality and morbidity How? Respiratory and cardiovascular Cardiopulmonary disease What was the level of particle and SO2? 500 g/m3 – 2 mg/m3 If not old days, where do these levels exist?
  6. 6. Health effects at low level of air pollution What was the primary interest to air pollution policy among the most developed nations for the last 20 years? To determine the lowest level The length of exposure to cause health impacts Threshold was often assumed.
  7. 7. Health effects at low level of air pollution With improved air monitoring, is threshold proven? No threshold, or bellow ambient level in the US in 1996. Many of the studies suggest linear model. What is necessary to prove it? Number of time-series studies
  8. 8. What are the health effects? Mortality Hospitalization for respiratory and heart disease Aggravation of asthma Incidence and duration of respiratory symptoms Lung function Restricted activity
  9. 9. Acute Mortality Daily time-series mortality studies US EPA reviewed Ostro 1993, Schwartz 1994c, Dockery & Pope 1994, Pope et al. 1995b. What these studies observed? Changes in daily death counts associated with short-term changes in particulate air pollution. a near linear function.
  10. 10. What do you see from those table and figures? Consistency in estimated effects Statistically significant effect Estimated Range? 0.5 percent – 1.6 percent in daily mortality for each 10 g/m3 increase in PM10 concentration. Weighted mean? About 0.8 percent
  11. 11. Percent increase in Mortality per 10 g/m3 increase in PM10 Mortality Cases/ g/m3 ? 0.5 percent – 1.6 percent in daily mortality for each 10 g/m3 increase in PM10 concentration. 5 x 10-4 – 1.5 x 10-3 Cases/ g/m3 Weighted mean about 0.8 percent 8 x 10-4
  12. 12. Mortality by respiratory disease and cardiovascular disease Large effect on respiratory disease mortality Also cardiovascular disease causing death
  13. 13. Shape of the mortality exposure-response relationship and lead-lag relationships PM10 concentration in typical US cities 10 to 120 g/m3 Max 365 g/m3 in the Utah Valley How is in Ukraine?
  14. 14. Shape of the mortality exposure-response relationship and lead-lag relationships What does it say? Typically near linear or log-linear Three possibilities: (1) no threshold (2) threshold is bellow existing pollution levels (3) looking more linear than it really is.
  15. 15. Shape of the mortality exposure-response relationship and lead-lag relationships Increased mortality occurred concurrently or within 1-5 days following an increase in air pollution.
  16. 16. Acute Morbidity Hospital usage What happened in the Utah Valley during the winter of 1986-1987? A labor dispute resulted in the closure of the local steel mill, the largest single source of particulate emission. This winter PM10 ave. 51 g/m3 , max. 113 g/m3 Previous year ave. 90 g/m3 , max 365 g/m3 Children hospital admission for respiratory disease dropped 50 percent.
  17. 17. Acute Morbidity Hospital usage What was the argument by Lamm et al. (1994)? Not closure of the steel mill, but Respiratory Syncytial Virus (RSV) What was the argument by Pope (1991)? Not by the virus.
  18. 18. Acute Morbidity Hospital usage What is the exposure-response of the hospital admission of all respiratory diseases? 0.8 – 3.4 % increase per 10 g/m3 by PM10 8 x 10-4 – 3.4 x 10-3 Cases/ g/m3 by PM10
  19. 19. Acute Morbidity Hospital usage Emergency department visit % increase by 10 g/m3 increase of PM10 0.5 – 3.4 (ave. 1.0) % increase/ 10 g/m3
  20. 20. Exacerbation of asthma Respiratory symptoms Asthma, Bronchodilator Cough
  21. 21. Exacerbation of asthma What is the exposure-response relation of asthmatic attack? 3 % increase in asthmatic attacks with 10 g/m3 increase of PM10 3 x 10-3 cases/ g/m3 What is the exposure-response relation of bronchodilator use? 1.1 – 12 % (ave. 3.0) increase with 10 g/m3 increase of PM10 3.0 x 10-3 cases/ g/m3
  22. 22. Respiratory symptoms Lower Respiratory symptoms Wheezing, dry cough, phlegm, shortness of breath, chest discomfort/pain What is the exposure-response relation of lower respiratory symptoms? Ave. 3.0 % increase in lower respiratory symptoms with 10 g/m3 increase of PM10 3.0 x 10-3 cases/ g/m3 Upper Respiratory symptoms Runny nose, stuffy nose, sinusitis, sore throat, wet cough, head cold, hay fever, red eyes Statistically insignificant association observed.
  23. 23. Key words Pneumonia COPD: chronic obstructive pulmonary (lung) disease Coronary Artery Disease Disrythmias (such as slow heart rate) Congestive Heart Failure
  24. 24. Lung function FEV: forced expiratory volume (a measure of lung function) FVC: forced vital capacity PEF: Peak expiratory flow
  25. 25. Epidemiology of Chronic Health Effects Table of contents - Introduction - Mortality Studies - Population-based (ecologic) mortality studies - Research needs for improved study designs - Prospective Cohort Mortality Studies - Harvard six-cities study - Implication of prospective cohort mortality results - Chronic Health Effects; Morbidity - Chronic differences in lung function - Chronic respiratory symptoms and disease
  26. 26. Introduction What is the difference between the acute effects and the chronic effects? Acute: associated with short term (day to day change) Chronic = long-term: a long time + cumulative effects of repeated exposure If acute effect exists, is there also chronic effect by the same pollutant? Not automatically
  27. 27. Mortality Studies Population-based mortality studies What is the summary of the population-based cross- sectional study? Average mortality is higher in cities with higher fine particulate and sulfate particulates. How the other risks were controlled? Smoking rate, education levels, income levels, poverty rates, housing density, etc were included in the regression models. What is the coefficients of air pollution related mortality? About 3 % per 10 g/m3 4 x 10-3 per g/m3
  28. 28. What are limitations of Population- based Studies? Systematic and/or analytical bias Study designs Data sets Analytic techniques Regression analysis Hypothesis testing Controlling some other factors Size of the estimated association Comparison with the current pollution level to the chronic mortality is not appropriate, Because now the pollution level is lower than years ago. Cannot control for individual differences in cigarette smoking, and other risk factors.
  29. 29. What are limitations of Population- based Studies? Age, poverty, health care, occupations, cigarette smoking, housing quality, cooking fuels vary among cities and potentially could be confounding the apparent air pollution associations.
  30. 30. Improved study designs What are 2 important issues 1970s – 1980s Threshold Study design – what evidence needed? If threshold, what will become easier? To establish the acceptable goal for pollution control
  31. 31. Prospective Cohort Mortality Studies 3 cohort mortality studies With improved study design
  32. 32. Prospective Cohort Mortality Studies Not on the data available for the population as a whole, But, it analyzes the incidence of health effects in a sample of individuals. Negative aspect: It relies on community-based air pollution monitoring. Costly and time-consuming
  33. 33. Harvard six-cities study 14-16 follow up of 8,111 adults living in 6 cities of the US TSP, PM10, PM2.5, SO4, H+, SO2, NO2 and O3 levels were monitored. What is most strongly associated with mortality risk? Smoking But, after controlling for individual differences (age, sex, smoking, body mass, education, occupational exposure), Differences in relative mortality risks across 6 cities were strongly associated with difference in pollution levels in those cities. PM10, PM2.5, SO4 than TSP and SO2, H+, or ozone.
  34. 34. Shape of the figure Mortality risk and fine particulate Nearly linear No threshold
  35. 35. Implications of prospective cohort mortality results The increased risk from air pollution bigger or smaller than cigarette smoking? Small But, there is a correlation.
  36. 36. Summary Mortality Acute exposure Total 0.5-1.5 %/10 g/m3 5 x 10-4 – 1.5 x 10-3 (cases/ g/m3) Chronic exposure 3 – 9 %/10 g/m3 3 x 10-3 – 9 x 10-3 (cases/ g/m3)
  37. 37. Exposure-Response Function f(r,C(r,Q)) PM10 and Nitrates Health impact cases/(year.person. g/m3) Long-term Mortality 2.60E-4 Chronic Bronchitis 7.65E-5 Restricted Activity Days 5.0E-2 Work Days Lost 1.0E-2 Hospital Admissions Cardiovascular, Respiratory 6.00E-5, 2.56E-6 Asthmatic adults Bronchodilator 6.00E-2 Lower respiratory symptoms 1.63E-1 Infant Mortality 2.78E-5 Asthmatic children Cardiovascular, Respiratory 7.8E-2, 1.0E-1
  38. 38. f(r,C(r,Q)) SO2 Health impact cases/(year.person. g/m3) Short-term Mortality 2.30E-6 Hospital Admissions Admissions 2.84E-6 Source: Rabl 2001
  39. 39. Concentration of the pollution( g/m3) C(x,Q) Gaussian Plume Model Q - h2 C = ---------------- exp [--------] 21/2 3/2 ux z z 2
  40. 40. z
  41. 41. z
  42. 42. Atmospheric Stability Day Night Surface Wind Incoming Solar Radiation Thinly Heavy Speed Overcast Cloud (meter/second) Strong Moderate Slight or clear sky <2 A A-B B 2-3 A-B B C E F 3-5 B B-C C D E 5-6 C C-D D D D >6 C D D D D
  43. 43. Weather observation Day Wind Speed Wind Direction Atmospheric Stability(A, (meter/second) E, ESE, SSE, S….. B… .F) Aug 7 1800 1900 2000 2100 2200 2300 2400 Aug 8 0600 0700 0800 0900 2100 0900

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