Air Pollution: What are the health risks

at current levels in the U.S?

Junfeng (Jim) Zhang

Professor of Global and Environmental Health

NOx SIP call

RVP phased in

The NAAQS - getting better all the time

Bachmann 2007;57:652-97

Fine-Particulate Air Pollution and Life Expectancy in the United States. Arden Pope, III, Ph.D., Majid Ezzati, Ph.D., and Douglas W. Dockery, Sc.D N Engl J Med 2009;360:376-86

Reductions in air pollution accounted for up to 5 months or 15% of total increased life expectancy (2.7 years) since 1970 Clean Air Act.

4

What are risks at current levels?

• For mortality:

– Short-term increases in mortality

– Longer-term increases in mortality

• For morbidity:

– Diverse adverse respiratory effects

– Adverse cardiovascular effects

– Other effects: reproductive, etc

-2.00 -1.00 0.00 1.00 2.00 3.00 4.00

% change

Chicago

Minneapolis

Colorado Springs

New Haven

St. Paul

Overall

Tacoma

Spokane

Seattle

Tucson

p < 0.05

Schwartz

1999

Schwartz

1997

% Change in daily emergency admissions for

cardiovascular disease associated with a 10

µg/m3 increase in daily PM10 concentration

Air Pollution and Reproductive Effects

0

20

40

60

80

100

120

140

160

180

Re

cord

Co

un

t

Publication Year *partial year data

PubMed search string: ("air pollution"[MeSH Terms] OR ("air"[All Fields] AND "pollution"[All Fields]) OR "air pollution"[All Fields]) AND ("reproduction"[MeSH Terms] OR "reproduction"[All Fields] OR "reproductive"[All Fields])

*

SCIENTIFIC AND POLICY CHALLENGES

The Narrowing Range of Exposure

PM level

NAAQS 1971

Risk

NAAQS 1987

NAAQS 1997

NAAQS 2006

Policy-Related Background

National Ambient Air Quality Standardshttp://www.epa.gov/ttn/naaqs/standards/pm/s_pm_index.html

What is the Form of the Concentration-Response Relationship?

Concentration

RiskSublinear

Supra-linear

Linear, Threshold

Linear, No-threshold

Policy Implication: For the same amount of risk reduction, different amount of concentration reduction is needed under different shapes of concentration-response curves.

Air Pollution & HealthJ. Jason West

Dept. of Environmental Sciences & EngineeringUniv. of North Carolina, Chapel Hill

How do we understand air pollution?

WRF Met model

SMOKE Emissionprocessor

CMAQAir quality

model

Burden of disease model

Recommendations for future measurements

Emissionsinventories

Met measurements

AQ, satellitemeasurements

Emissions Concentrations Health Effects

Exposure

17

Global mortality burden – ACCMIP

ensembleOzone-related mortality PM2.5-related mortality(*)

470,000 (95% CI: 140,000 - 900,000) 2.1 million (95% CI: 1.3 - 3.0 million)

(*) PM2.5 calculated as a sum of species (dark blue)

PM2.5 as reported by 4 models (dark green)

Light-colored bars - low-concentration threshold (5.8 µg m-3)

Silva et al. ERL 2013

18

Global Burden: PM2.5-related mortality

CPD+LC mortality , deaths yr-1 (1000

km2)-1, multi-model mean in each grid cell , 6 models

Global and regional mortality per year

RegionsTotal

deaths

Deaths

per

million

people

(*)

North America 43,000 152

Europe 154,000 448

Former Soviet

Union128,000 793

Middle East 88,700 371

India 397,000 715

East Asia 1,049,000 1,191

Southeast Asia 158,000 564

South America 16,800 92

Africa 77,500 327

Australia 1,250 78

Global 2,110,000 665

1

(*) Exposed population (age 30 and

older)Silva et al. (2013)

Brauer et al., 2012

Combining multiple data streams: measurements, model, satellite

Global burden of disease of outdoor air pollution

Lim et al., 2012

3.2 million deaths per year(95% CI:2.8 – 3.6 million)

WHO GBD 2010

Some uncertainties

• Sources – understanding difficult sources like fires, windblown dust, residential sources.

• Chemical mechanisms – improve complex processes like SOA formation, PM size-composition.

• Observations – lack of observations in rural regions, new opportunities with satellites.

US Policy-relevant analyses

Analysis of individual sector contributions to US air pollution mortality.

Fann et al., EST, 2013

Co-benefits of global GHG mitigation for air quality and health

Avoided air pollution-related deaths

from global GHG reductions:

2030: 0.5 ± 0.2 million yr-1

2050: 1.3 ± 0.5

2100: 2.2 ± 0.8

2030

Monetized health co-benefits

(blue & red) vs. cost of GHG

reduction (green):

West et al., NCC, 2013

Better relating atmospheric science and health impacts

• Communities need to work together more!

– Use models and satellites to estimate exposure for epidemiologic studies.

– Better measure key pollutants of interest (ultrafine PM, chemical components of PM, metals).

– Estimate air pollution by source for epidemiologic studies.

– Better relate “ambient concentration” with personal exposure to drive health studies.

Goal for Today’s Discussion

Identify 3-5 recommendations and opportunities to improve scientific understanding of air pollution and its healtheffects.

• Foci – a city, NC, USA, global• Aspects of science – understanding sources,

atmospheric processes, mechanisms of health impacts, epidemiology.

• Links with other problems – climate change, mobility, energy, economics, related health effects.

Science & Health Recommendations

• Communication of science to public & policy – what is the nugget?– Make it personal– Citizen science, ozone gardens, daily air pollution communication– Overcoming scientific demoralism– How to visualize air quality & health effects?– Training scientists to communicate. Use communication professionals.

• Analysis inspired by policy – Importance of different sectors, sources – Agriculture is underappreciated & undercontrolled in NC

• Improving health effects studies– Take advantage of key health data (NC DETECT)– Relation of air pollution with precursors of disease (anxiety, pain, mood, obesity)– Susceptible populations– Analysis of Mixtures, pollutant properties– Citizen science– Effects of bioaccumulation, understand toxicity.

• Atmospheric scientists and health scientists working together better– Better methods to work across scales.– Provide info on sources.

• Plan for interventions to prevent health effects– Diet & exercise as mitigating factor.– Working with susceptible populations