The Health Effects of Air Pollution

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The Health Effects of Air Pollution

• Robert M. OKeefe, Vice President
• Health Effects Institute
• National Workshop on Improvement of Urban Air
  Quality of Pakistan
• Lahore
• December 2004

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Assessing the Health Effects of Air Pollution

• Health Effects Institute
• Air Pollution and Health Effects
• Public Health And Air Pollution in Asia Program
  PAPA
• The existing Asia science literature
• New Asian studies
• Conclusions

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The Health Effects Institute

• Founded in 1980 to provide impartial,
  high-quality science on health effects of vehicle
  and other emissions
• Joint and Equal Core Funding from
• Government (U.S. EPA)
• Industry (28 Worldwide Vehicle Manufacturers)
• Today many partners worldwide ADB, WHO, EU
  California ARB (CARB), Oil, other Industries
• Independent Expert Science Committees oversee and
  peer review all research
• Over 225 studies - Americas, Asia, Europe -
  ozone, carbon monoxide, particulate matter,
  diesel exhaust, benzene, butadiene, methanol,
  others

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Air Pollution and HealthWhat we know about the
effects
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Air Pollution has Many Effects

• Health
• Respiratory, cardiovascular morbidity
• Mortality
• Heritage
• Nitric Sulfuric Acid erosion
• Natural Resources
• Acidification (lake and stream biology)
• Mercury deposition (fish tissue)
• Visibility
• Agriculture
• Ozone crop effects (40 reduction in rice, soy
  yield in Pakistan city)
  
• (Wahid 2003 Veranasi)

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Many Sources of Air Pollution in Asia

• Non-Combustion
• Agricultural cultivation
• Street sweeping
• Windblown sand
• Unpaved roads
• Paved roads (asbestos, rubber etc)
• Construction

• Combustion
• Open burning
• Brick Kilns
• Vehicles
• Trash burning
• Factories
• Power generation
• Cooking in slums

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Vehicle Emissions and Exposure

• Must consider all effects of the system
• different vehicle types -
• 2 and 3 wheelers
• cars
• trucks and buses
• vehicle plus fuels (and fuel components)
• tailpipe emissions plus evaporative emissions
• maintenance of system

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Major Vehicle/Fuel Emissions

• Air Toxics
• Aldehydes
• formaldehyde
• acetaldehyde
• others
• Benzene
• 1,3-butadiene
• Methanol
• Polycyclic organic matter (e.g. PAHs)

• Carbon Monoxide
• Diesel Exhaust
• Particulate Matter (PM)
• Lead
• Nitrogen Oxides (NOx) and Hydrocarbons (HC)
• Precursors to Ozone and PM
• Nitrogen Dioxide

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Health Effects

• Different Pollutants have Different Effects
• Carbon Monoxide - circulatory system, heart
• Ozone - respiratory system, lung
• Lead - nervous system, brain
• PM - lung, potential effects on heart
• Diesel, Air Toxics - cancer, respiratory effects
• There are potential effects of the Mixture

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Health Effects

• Some populations more sensitive than others
• Children
• Elderly
• people with heart and lung disease
• Asthma is growing
• 150 million asthmatics worldwide
• Increasing in most countries (2 to 5 per year)
• Asthmatics much more sensitive to air pollution

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Particulate Matter (PM) Health Effects

• High levels of PM (e.g. 500 ?/m3) known to cause
  premature death
• e.g. London 1952
• Recent studies in US, Europe, Asia, South America
  have found association of PM with death at much
  lower levels (lt 50ugm3)
• no evidence of a threshold (safe level)
• Progress made to identify a plausible biological
  mechanism for these effects results not yet
  definitive

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PM - The Epidemiology Studies

• A Number of Epidemiology Studies
• Europe Studies Harvard 6 Cities Study

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PM Health Effects - India, ThailandSource
Chhabra 2001, Pande 2001, Vichit-Vadakan, 2001
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Ozone Health Effects

• Known to cause inflammation in respiratory tract
• Effects have been demonstrated for short term,
  long term effects are less certain
• some people appear to develop tolerance
• Reduces ability to breathe (lung function) for
  some people
• Increases hospitalization for asthma, other lung
  diseases
• New US study finds Ozone mortality effects
  (Domenchi et. al 2004)

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Ozone Health Effects

• Some humans have been shown to have reduced lung
  function (measured as FEV1) after exposure to
  ozone

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Diesel Health Effects

• Diesel Engines have substantial advantages
• higher fuel efficiency
• lower CO and CO2 emissions
• However, they also emit high levels of
• particulate matter, NOx, and chemicals attached
  to the particles (e.g. PAHs)
• Two major types of health effects
• acute effects (e.g. exacerbating asthma)
• cancer effects

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Diesel Effects on Childhood Illness (Brunekreef,
et al Study in 24 Dutch schools)
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Assessing Diesel Cancer Risk

• In general, some 30 studies of effects on workers
  have provided best data
• Consistent small (20-40) increase in lung
  cancer associated with exposure
• Some questions about each study
• Leading International Agencies (WHO, IARC, US
  NIEHS, US EPA) have concluded diesel is a
  probable human carcinogen

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Sulfur Dioxide

• Emitted from fossil fuel combustion
• especially from coal burning facilities, high
  sulfur fuels
• Can impair breathing in asthmatic children and
  adults
• Has been associated, along with PM, with
• increased aggravation of heart and lung disease
• premature mortality
• Recent study in Hong Kong (Lancet 2002) has
  found
• substantial reductions in SO2 emissions can
  result in measurable improvements in mortality
  and illness

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AIR POLLUTANT CONCENTRATIONS 1988 - 95 IN HONG
KONG
HALF YEARLY MEAN LEVELS
80
Fuel restriction on sulphur
PM10
60
NO2
50 reduction in SO2 after the intervention
SO2
Micrograms per cubic metre
40
O3
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No change in other pollutants
0
1992
1993
1994
1995
Year
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REDUCTIONS IN DEATHS AFTER SULPHUR RESTRICTION
0
-1
-1.6
-2
-1.8
-2.4
Reduction in annual trend
-3
-2.8
-4
-4.2
-5
-4.8
-6
15-64
65
15-64
65
15-64
65
All causes
Cardiovascular
Respiratory
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Air Toxics Health Effects

• Benzene
• a known human carcinogen
• studies in U.S. and Chinese workers have shown
  link between exposure and increased leukemia
• Metals
• Range of effects, heart, reproductive,
• cancers

• 1,3 Butadiene
• a probable or known human carcinogen
• studies in laboratory animals and US and Czech
  workers have shown effects
• Aldehydes, PAHs
• Cancers, Irritants

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Air Pollution and Health in AsiaThe Public
health and Air Pollution Program (PAPA)
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The Problem Air Pollution in Asia High Levels
in Many Cities (2000-2001)
400
SPM Limit 90 µg/m3 (WHO, 1979)
350
PM10 Limit 50 µg/m3 (USEPA, 1997)
SO2 Limit 50 µg/m3 (WHO, 1999)
300
3
NO2 Limit 40 µg/m3 (WHO, 1999)
250
200
concentration in µg/m
150
100
50
0
Pune
Seoul
Busan
Manila
Tokyo
Osaka
Jakarta
Kolkata
Bangkok
Mumbai
Colombo
Shanghai
New Delhi
Singapore
Chongqing
Hong Kong
Source Benchmarking Report on Air Quality in
Asian cities Stage 2, 2004 (forthcoming)
SO2
NO2
SPM
PM10
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Lancet October, 2002
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Environmental Burdens Premature Deathssource
WHO Global Burdon of Disease
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The Challenge Expanding current science base to
inform Asian air regulatory decisions

• Air pollution poses clear health effects
• Western research is relevant to Asian
  populations, however extrapolation poses
  challenges
• Population characteristics
• Pollution sources and mixes
• Are observed risks similar?, greater?, smaller?
• A clear need for representative air pollution
  health studies of local Asian populations

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PAPA Program

• Partnership with CAI-ASIA to understand the
  health effects of air pollution in Asia, now and
  in the future
• Active effort underway
• Published Scientific Review and Meta Analysis of
  what is known today about health effects in Asian
  cities
• Conducting series of epidemiological studies in
  representative Asian cities
• Understand local impact
• Combine to provide Asia-wide understanding
• Publish a Comprehensive Assessment of the state
  of air pollution and health across Asian cities
• Build capacity of local scientists
• Overall Goal
• Quality science to inform key Asian regulatory
  policy decisions

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Health Effects of Outdoor Air Pollution in
Developing Countries of Asia A Literature Review

• Systematic identification of 140 peer-reviewed
  Asian studies 1980-2003
• Special focus on studies of daily changes in air
  pollution and health
• Conduct first ever Asian meta analysis
  quantifying risks, finding initial similarities
  with West
• Identify knowledge gaps to guide future research
• Active communication to policy makers

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Studies of Air Pollution and Health in Asia
19802003
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Many Health Effects Studied
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Daily Mortality Initial ResultsAsian Risk
Estimates Similar to West
Estimates Using Pre-GAM Results (without
revision)
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New Research in Asian Cities

• To strengthen base of Asian Health Science
• Eight new studies of air pollution and health now
  underway in Asian cities
• Acute (short term) effects studies in
• Bangkok, Hong Kong, Shanghai, Wuhan
• Strong teams, quality data
• Long Term (chronic) effects
• Guangzhou, China pilot study in elderly cohort
• New!
• Study teams now identified in India Chennai
  Delhi Ludhiana

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PAPA Looking Ahead

• A Special Challenge Understanding the
  interaction among air pollution, poverty, and
  health
• In Asia high levels of air pollution, dense
  population, extensive poverty are prevalent
• Some initial evidence (mostly from West) that the
  poor face worse effects from air pollution
• Could be due to
• Different exposures (roadside, indoor,
  occupational)
• Poorer SES\health status (nutrition, medical
  care) leading to higher susceptibility
• Other factors
• Potential Public health implications could be
  significant
• New study under design in Ho Chi Minh City to
  understand poverty effects

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Conclusions

• Air Pollution from many sources, including
  vehicles, fuels have been shown to have effects
  on mortality, morbidity
• Problem will grow with economic expansion
• WHO estimates place air pollution mortality in
  hundreds of thousands across South Asia, Eastern
  Mediterranean region (including Pakistan)
• While studies are extrapolated from developed
  world, initial PAPA Review and analysis tend to
  confirm results in Asian populations, though many
  limitations exist
• The PAPA program is building a better base of
  Asian health and air pollution science
• New studies across Asia, with capacity building
  as a priority
• Role of poverty in air pollution to be assessed

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Conclusions

• Better air monitoring needed over long term
• To determine current status, monitor ongoing
  progress and assess health, communicate to public
• However, Pakistan urban conditions also warrant
  near term action
• Visible emissions wide-spread
• Dense population level, clear exposure
• Acute effects commonplace
• Provided basis of action in many countries (UK,
  HK, others) before comprehensive monitoring

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Thank You!

• Bob OKeefe
• rokeefe _at_healtheffects.org
• www.healtheffects.org