Outline Recognition Historical Perspective Deadly episodes U.S. - - PDF document

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Ambient Air Pollution and Health: Epidemiologic Bench to Bedside

John R. Balmes, MD University of California, San Francisco and Berkeley

Disclosure

• I am the Physician Member of the California

Air Resources Board

Outline

• Historical Perspective
• U.S. Air Quality Regulation

– “Criteria” Pollutants

• Outdoor Air Pollution

– What Do We Know – New Evidence

• Household Air pollution

– What Do We Know – New Evidence

Recognition

• Deadly episodes

(Donora, Meuse Valley, London)

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Air Quality Regulation in the U.S.

• Clean Air Act (1963)
• U.S. EPA (1970)
• National Ambient Air Quality Standards

EPA Criteria Pollutants

• Ozone
• Nitrogen Dioxide
• Particulate Matter
• Sulfur Dioxide
• Carbon Monoxide
• Lead
• The EPA also regulates “hazardous” air pollutants

(HAPS) primarily because of adverse reproductive

• r cancer effects; the current list includes 188

chemicals.

Outdoor Air Pollution

• Multiple sources
• Mixture of gases and

particulate matter

• Traffic‐related air

pollution

2/27/2017 3 Outdoor Air Pollution

• Increased contribution to the Global Burden
• f Disease (2013 Comparative Risk

Assessment, Lancet, 2015)

• 14% of new cases and 15% of exacerbations of

childhood asthma attributed to TRAP in a study of 10 European cities (Eur Respir J, 2013)

• Rapidly increasing pollution in mega‐cities of

the developing world

Outdoor Air Pollution

• Increased contribution

to the Global Burden of Disease (2010 Comparative Risk Assessment, Lancet, 2012)

• Rapidly increasing

pollution in mega‐cities

• f the developing

world

Household Air Pollution

• 40% of the world’s

population cooks with solid fuels

• Increased risk of low birth

weight and pneumonia in children

• Increased risk of chronic
• bstructive pulmonary

disease (COPD), lung cancer, cataracts, cardiovascular disease in adults

• Major contributor to

ambient air pollution in developing countries

Global Burden of Disease and Comparative Risk Assessment 2013

GBD 2013 Risk Factors Collaborators. Lancet 2015 Dec 5;380(10010):2287-323 ALRI COPD

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Outdoor Air Pollution Known Health Effects ‐‐ Respiratory

• Asthma and Chronic Obstructive Pulmonary

Disease (COPD)

– Exacerbations – New‐onset

• Respiratory infections (pneumonia)
• Increased pulmonary mortality
• Lung cancer

Ozone

• Prototypic
• xidant

pollutant

• Major source:

motor vehicle emissions

• Photochemistry

during sunny afternoons

Ozone: Health Effects

• Respiratory symptoms,

lower lung function, airway inflammation in healthy individuals

• Asthma

– Exacerbations – New onset

• Mortality

Am J Respir Crit Care Med 2010;182:307‐16.

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Chronic Exposure to Ozone and Mortality

(Jerrett at al. NEJM 2009)

Nitrogen Dioxide (NO2)

• Oxidant gas
• Sources:

combustion of fossil fuels

– Motor vehicle emissions – Power plants

• Marker of traffic

emissions

Nitrogen Dioxide: Health Effects

• Decreased lung

function growth

• Asthma

– Exacerbation – New‐onset

Gauderman et al. NEJM 2004;351:1057‐1067 N Engl J Med 201;372:905

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N Engl J Med 201;372:905 Am J Respir Crit Care Med 2013;188:309‐318 Early‐life Exposure to Nitrogen dioxide (NO2)

Particulate Matter (PM)

• PM is a mixture, including particles of differing
• rigin (combustion, crustal, biological) and

varying size.

• Multiple sources

– Ultrafines (PM<0.1): Fossil fuel combustion – PM2.5: Fossil fuel combustion – PM10‐2.5: Road dust and crustal material

Particle Size

Human Hair (60 m diameter) PM10 (10 m) PM2.5 (2.5 m) Hair cross section (60 m) PM0.1 (0.1 m)

2/27/2017 7 Particle deposition

Particulate Matter: Health Effects

• Asthma

– Exacerbation – New‐onset

• Decreased lung function growth
• Mortality

– Ischemic heart disease

• Lung cancer

An Association between Air Pollution and Mortality in Six U.S. Cities

Dockery et al. N Engl J Med 1993;329:1753‐1759 Thorax 2014;69(7):660‐5.

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et al. European Heart Journal 2015;36:83‐93 Newby DE, et al. European Heart Journal 2015;36:83‐93

Fine‐Particulate Air Pollution and Life Expectancy in the United States

Pope et al. N Engl J Med 2009;360:376‐386.

Traffic

• Mixed emissions

– Gases (CO, SO2, NO2) – VOCs – PM – Road dust

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Traffic: Health Effects

• Asthma
• Decreased lung

function growth

Environ Health Perspect 2010;118:1021–1026

New Health Effects

• Adverse birth outcomes

– Low birth weight – Preterm birth – Birth defects

• Cognitive development and decline
• Obesity and Diabetes

– Oxidative stress – Systemic inflammation

Environ Health Toxicol 2015;30:e2015011. Birth Weight

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Preterm Birth Jerrett et al., Prev Med 2010 Jerrett et al., Environ Health 2014

Polycyclic Aromatic Hydrocarbons (PAHs)

• PAHs are formed by incomplete combustion of

carbon‐containing materials (wood, coal, diesel, gas; also cooked food and tobacco smoke)

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Rundle et al., Am J Epidemiol 2012

Air Pollution and Diabetes

• Several studies have shown associations

between diabetes in adults and exposure to traffic‐related air pollution (TRAP)

• Evidence also building for children

– Two studies have shown associations between ozone and type 1 diabetes (Hathout et al., Pediatr Diabetes 2006; Malmquist et al., Environ Res 2015*) *also NO2 – Three recent studies of minority children in Los Angeles have shown associations with glucose dysregulation and TRAP (Gilliland and colleagues, Diabetes Care 2016; Pediatr Obes 2016; Diabetes 2017)

Environ Int 2017 Jan 30

Potential Mechanism

• Air pollution can induce oxidative stress

and systemic inflammation

• PM2.5 induced adipose tissue

inflammation and insulin resistance in a mouse model of diet‐induced obesity (Sun

et al. Circulation 2009)

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Suspected Effects ‐‐ Neurological

• Cognitive development in children
• Accelerated cognitive decline in adults
• Neurodegenerative disease (e.g., Parkinson’s

Disease and Alzheimer’s Disease)

Risk Modifiers

• Age
• Sex
• Race/ethnicity
• Socioeconomic status
• Neighborhood
• Stress
• Diet
• Obesity
• Diabetes
• Other exposures (e.g., tobacco smoke,

biomass smoke, occupational vapors, dusts, fumes)

PNAS 2009;106:12406‐11. Environ Health Perspect 2007;115:1140‐6

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Air Pollution Exposure Inequality

• People of color and low SES have

– Greater exposures to outdoor air pollution – Disproportionate proximity to polluting land uses and toxic emissions

• Poor communities have more health‐

damaging factors and less health‐promoting amenities

– More fast food and liquor stores – Less green space and recreational programs

Inequality Curve

Environ Sci Technol 2009;43:7626–34. Environ Sci Technol 2009;43:7626–34.

Research Needs

• Better understanding of impacts of extrinsic

neighborhood factors on observed air pollution‐ health effects associations

– poverty, unemployment, segregation, crime, foodscape, built environment

• Better understanding of air pollution‐stress

interactions

– biological mechanisms – biomarkers

• Methods to characterize and model cumulative

impacts

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Source: American Lung Association in California Land Use, Climate Change and Public Health Issue Brief, 2009 53

Health Effects of Climate Change

Ozone Increases with Higher Temperatures

Capitman and Tyner, 2011

Heat Waves and Ozone

• During the heat waves in Europe in summer

2003 there were thousands of excess deaths above the seasonal average.

• Epidemiological studies suggest that 20‐50%
• f the total excess deaths could be attributed

to elevated O3 and particle levels that

• ccurred during the heat waves.

(Filleul et al.;Johnson et al.)

55

The Major Sources of Smog and Soot also Contribute to Greenhouse Gases and Aerosols

56

2/27/2017 15 Conclusions

• Improved air quality will

have a major impact on public health

– Strong governmental policies required – Transportation and energy production should move away from combustion of fossil fuel – Such an approach is needed to mitigate climate change

Thank you Question 1

• Which of the following have been associated

with exposure to air pollution?

a) Diabetes b) Asthma c) Stroke d) Low birth weight e) All of the above

Question 2

• Which of the following is not considered a

component of traffic‐related air pollution?

a) Nitrogen oxides b) PM2.5 c) Ozone d) Carbon monoxide

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Question 3

• Which of the following is not true?

a) Ozone is a secondary pollutant for which exposure is regional b) Nitrogen oxides are primary pollutants that are precursors for the generation of ozone c) Climate change will lead to increased ambient

• zone

d) Ozone exposure has been associated with low birth weight