The Science and Law of Air QualityThe Science and Law of Air Quality

Fundamental problem:• Science is inexact, with a continuum of limits,

errors and uncertainties– Environmental science is more uncertain than many

other disciplines because it addresses biological problems in both natural and human modified situations, including human health

• Law tends to require a “bright line” demarcation between good and bad, legal and illegal. – Environmental law is all the more demanding because

questions of risk and safety, cost and benefit, life and death are addressed

The Science and Law of Air QualityThe Science and Law of Air Quality• Air Quality

– Science of air quality• gasses • Particles

• Risk and Safety• Historical impacts of air pollution

• European and eastern US concerns• California problems - Example: Lead and CA freeways

• Clean Air Act – 6 (7) criteria pollutantCO (HC), SO2, NO2,,ozone, lead, and TSP mass

– Amendments and key modified regulations • 1977 (visibility in Class 1 areas), Example: Grand Canyon• 1987 TSP to PM10

• 1991 (regional haze and eastern sulfur reduction),• 1997 PM10 to PM2.5 (fine particles) Example: vf/uf, diesel, WTC

Global PerspectiveGlobal Perspective• Despite using 1/5 of the world’s energy and about 1/3 of

the worlds VMT, the US has much better air quality than most of the developed or developing countries• Air quality in major international cities outside of Western Europe

is usually appalling!

• California leads the nation in cleaning up smog• In 1965, Los Angeles was worse than Mexico City in 1995

• The Central Valley lags but still is not bad by global standards • There is no way that Fresno is really the 4th most polluted

urbanized area in the US (Sacramento is listed the 7th) since most forms of “pollution” are not considered in the ranking.

• Blue skies and good visibility in the Sacramento Valley each Fall (rice stubble burning suppressed); Bakersfield (oil improvement)

Health Impacts of Air PollutionHealth Impacts of Air Pollution

• 1890 – onward - Industrial Impacts – “black lung”, “brown lung”, silicosis, toxics, …..

• 1930s - Meuse Valley (FR) and Donamora, PA – 100s of excess deaths– Essentially ignored – The Great Depression

• London “killer” smog of 1952– First serious studies; doubled death rate

• Los Angeles becomes a national joke –

– stinging eyes, brown haze

Health Impacts of Air PollutionHealth Impacts of Air Pollution• 1970s – onward – Major work of health effects of ozone

in California– Health and welfare, including crops and forests

• 1980s – major EPA epidemiological studies – Harvard “6 cities study” over 10 years; Utah valley, others– Soon becomes the “Gold Standard”;– introduction of PM2.5 “fine particle” standard 1997

• 1990s – major international efforts at long term “epi” studies aided greatly by the decline in cigarette smoking

• 1990s - some gaseous pollutants de-emphasized• 2000 – better animal models, etc, isolate the heart as the

target of fine particles– Very fine/ultra fine particles arise as causal factors

0

0.5

1

1.5

2

2.5

Valu

es R

ela

tive t

o B

utt

e a

nd

Sh

asta

Ischemic Heart Mortality Annual PM10 Childhhod Asthma

Health and Aerosols in the Central Valley of CaliforniaData Relative to Shasta and Butte counties

70 80 90 100 110 120 130 140

Ischemic Heart Disease (% of state average)

0

50

100

150

200

Ann

ual V

alle

y P

M10

(ug

/m3)

PM10 mass and Ischemic Heart DiseaseCalifornia Central Valley

r2 = 0.56

70 80 90 100 110 120 130 140

Ischemic Heart Disease (% of state average)

0

0.05

0.1

0.15

Ozo

ne

Ave

rag

e To

p 3

0 h

rs (

pp

m)

Ozone and Ischemic Heart DiseaseCalifornia Central Valley

r2 = 0.18

Welfare Impacts of Air PollutionWelfare Impacts of Air Pollution• 1970s – onward – Major work in California

– Bimodal particle size distribution and visibility reduction– Effects of gaseous pollutants (ozone, PAN) on vegetation

• 1977 – National visibility studies (viz CAA 1977)– Airport visibility nationwide– First aerosol measurements Class 1 areas

• 1980s – start of national effort at aerosols and visibility (NPS, 1981; IMPROVE 1987)– First actions under CAA 1977 “plume blight” – control of haze at

Grand Canyon NP• 1991 Kuwaiti oil fires rekindle global climate /aerosol

connection– Major international studies ongoing– Aerosols now 80% of the uncertainty in global climate forcing

models

Calculation of Risk Calculation of Risk NRC Redbook 1983NRC Redbook 1983

1. Hazard identification a. Qualitative evaluation of adverse effects

2. Exposure assessmenta. “Maximally exposed individual” MEI versusb. Population at large

3. Dose responsea. Animal models, scaledb. Linear extrapolation to zero

4. Risk characterizationa. Reduction of lifespanb. Tumors, leukemia cases per 100,000 people in

specific regions

Problems with Risk AssessmentProblems with Risk Assessment

• Maximally exposed individual is not realistic for the person with maximum exposure

• Repeated use of conservative assumptions (The EPA “Precautionary Principle”) propagates error

• No assessment of the fate of the pollutant under transport

• Failure to validate and test assumptions• Entire process often happens within the EPA –

science, evaluation, assessment, and standard setting, with major political conflicts of interest

Factors in Factors in SafetySafety Judgments Judgments• Risk assumed voluntarily Risk assumed x 1000!

involuntarily• Effect immediate Effect delayed• No alternatives available Many alternatives available• Risk known with certainty Risk not known• Exposure is essential Exposure is a luxury• Encountered occupationally Encountered non- occupationally• Common hazard Dread hazard• Affects average people Affects especially sensitive people• Will be used as intended Likely to be mis- used• Consequences reversible Consequences irreversible

Protection by Criteria and StandardsProtection by Criteria and Standards

Criteria and standards Example• Personal exposure standards radiation, (air?)• Ambient composition standards air, water• Product design standards seat belts, cars,

gasoline• Product performance standards car exhaust,

flammability of clothes

• Work practice standards air traffic controller hours

• Promotional claims standards truth in advertising?

• Packaging standards Childproof pill bottles

Clean Air Act 109 b.1Clean Air Act 109 b.1• National primary ambient air quality standards,

prescribed, under subsection (a) shall be ambient air quality standards the attainment and maintenance of which in the judgment of the Administrator, based on such criteria and allowing an adequate margin of safety, are requisite to protect the public health. Such primary standards may be revised in the same manner as promulgated.

– Question: Does “Requisite to protect public health” mean no harm to anyone? If not, which “anyones” don’t we protect?

– Question: How does “Adequate margin of safety” handle pollutants in which any amount produces some harm?

– Question: What should California's position be to this federal mandate?

TSPPM 10

PM 2.5

Particulate Matter in the Atmospheric – Particulate Matter in the Atmospheric – the Atmospheric Aerosolthe Atmospheric Aerosol

• Total Suspended Particulate mass TSP– < 35 μm

• Inhalable Aerosols PM10 – < 10 μm

• Fine Aerosols PM2.5 – < 2.5 μm

• Very fine aerosols, < 0.25 μm, ultra fine aerosols, < 0.10 μm

• 35 to 10 μm, mostly natural– Dust, sea salt, pollen, …

• 10 to 2.5 μm, largely natural– Dust, sea spray, some nitrates

• 2.5 to 0.25 μm, mostly man made– Fine dust, nitrates, sulfates,

organics, smoke• 0.25 to circa 0.01 μm, almost

entirely man made; – high temperature combustion,

heavy organics, soot, metalsJ ournal of Inhalation Research (1995).

Particle Size versus Persent Deposition

This figure shows the relationship between particle size and what percent is deposited in different parts of the respiratory

tract.

c

0.25 μm 2.5 μm

Particulate Matter in the Atmospheric – Particulate Matter in the Atmospheric – the Atmospheric Aerosolthe Atmospheric Aerosol

• Total Suspended Particulate mass TSP– < 35 μm

• Inhalable Aerosols PM10 – < 10 μm

• Fine Aerosols PM2.5 – < 2.5 μm

• Very fine aerosols, < 0.25 μm, ultra fine aerosols, < 0.10 μm

• 35 to 10 μm, mostly natural– Dust, sea salt, pollen, …

• 10 to 2.5 μm, largely natural– Dust, sea spray, some nitrates

• 2.5 to 0.25 μm, mostly man made– Fine dust, nitrates, sulfates,

organics, smoke• 0.25 to circa 0.01 μm, almost

entirely man made; – high temperature combustion,

heavy organics, soot, metals

Making of the EPA Fine Particle Making of the EPA Fine Particle StandardStandard

“Those who like law or sausage should never watch either one being made”

• CAASAC – 8 of the scientists said no new PM2.5 annual average standard was justified

• Of the 13 who wanted a standard, 6 said science could not support a numerical standard

• Of the 7 who supported a numerical standard, the choices ranged from 15 to 30 μg/m3 (average 22 μg/m3)

• The EPA staff recommended a standard in the range from 20 μg/m3 to 12.5 μg/m3

• The EPA Administrator (in a room with 11 others, none of whom were scientists) chose 15 μg/m3

Fine particles – age the lung and heart

Statistically, excellent connection between fine particles and health, including mortality

Causally, most of fine particle mass is totally harmless even in massive

doses….• EPA’s current thinking: health effects caused by

1. Biological agents (fungi, bacteria, viruses, spores..)

2. Acidic aerosols

3. Fine metals such as iron in the lung

4. Insoluble very fine and ultra fine particles

5. High temperature organic matter

Visibility reduction is mostly caused by fine Visibility reduction is mostly caused by fine particles, < 1 particles, < 1 m; sulfates, organics m; sulfates, organics

(smoke), soil, nitrates, soot, and sea salt (smoke), soil, nitrates, soot, and sea salt

12 to 55 to 2.5

2.5 to 1.151.15 to 0.75

0.75 to 0.560.56 to 0.34

0.34 to 0.240.24 to 0.09

< 0.09

Coarse Fine Particle Diameter (microns) Very fine Ultra-fine

0

5

10

15

20

25

Re

lati

ve

Co

nc

en

tra

tio

n

Soils Sulfates

Typical Sacramento/San Joaquin Valley Particle Sizes

Soils

Sulfates

Typical Haze Particles

Deep lung deposition

PM 2.5

PM 10

Example #1: Lead and the Example #1: Lead and the California freewaysCalifornia freeways

• Data on human health effects of lead cause the California ARB to pass a standard - < 2.5 μg/m3

– These levels were thought to be violated near freeways in LA, many in low income areas

• Research on ozone shows ARB that radical technology was needed to correct LA’s problem – the catalytic converter – on all new cars– But the catalytic converter, which makes CO into CO2

and HC into H2O and CO2, needs lead free gasoline– However, the catalytic converter also changes SO2

from the sulfur in gasoline into sulfuric acid

0 150 300 450 550

Distance (feet) from upwind site

0

1

2

3

4

5

Mic

rog

ram

s/m

3 p

er

10,0

00 v

/hr

Lead Bromine Br/Pb ratio x 5000 Sulfur

Fine Particulate Profiles from Los Angeles FreewaysSan Diego at Harbor, August, 1972

Freeway

Wind

Effect of roadway distance and configuration on downwind concentrations of lead 1.

Roadway Distance 27 m 40 m 100 m 160 m

At grade Calculated 4.0* 3.4 1.4 0.41* not scaled!

At grade Measured 4.0 3.1 1.4 0.35

Depressed Measured 4.5 1.7 0.26

Elevated Measured (2 sites)

4.8 2.3 3.1 (3.5)(one site)

1 - per 10,000 v/hr

Reduction in ozone precursors in LA roughly Reduction in ozone precursors in LA roughly tracks ozone declinetracks ozone decline

1980 1985 1990 1995 2000 2005

Year

0

500

1000

1500

2000

2500

Tons

/day

NOx ROG (reactive organoc gasses)

Trends of ozone Precursors in Los Angeles

Los Angeles 1 hr Ozone MaximumLos Angeles 1 hr Ozone Maximum

Global background

Los Angeles Ozone 8 hr 4Los Angeles Ozone 8 hr 4thth Highest 3 yr Highest 3 yr AverageAverage

Global background

Alameda County Ozone 8 hr 4Alameda County Ozone 8 hr 4thth Highest 3 Highest 3 yr Averageyr Average

Global background

Fresno Ozone 8 hr 4Fresno Ozone 8 hr 4thth Highest 3 yr Highest 3 yr AverageAverage

Global background

0

0.5

1

1.5

2

2.5

Valu

es R

ela

tive t

o B

utt

e a

nd

Sh

asta

Ischemic Heart Mortality Annual PM10 Childhhod Asthma

Health and Aerosols in the Central Valley of CaliforniaData Relative to Shasta and Butte counties

Particulate Matter in the Atmospheric – Particulate Matter in the Atmospheric – the Atmospheric Aerosolthe Atmospheric Aerosol

• Total Suspended Particulate mass TSP– < 35 μm

• Inhalable Aerosols PM10 – < 10 μm

• Fine Aerosols PM2.5 – < 2.5 μm

• Very fine aerosols, < 0.25 μm, ultra fine aerosols, < 0.10 μm

• 35 to 10 μm, mostly natural– Dust, sea salt, pollen, …

• 10 to 2.5 μm, largely natural– Dust, sea spray, some nitrates

• 2.5 to 0.25 μm, mostly man made– Fine dust, nitrates, sulfates,

organics, smoke• 0.25 to circa 0.01 μm, almost

entirely man made; – high temperature combustion,

heavy organics, soot, metals

1810

5.623.2

1.81

0.560.32

0.180.1

0.0560.032

0.0180.01

Coarse MOUDI Stage Diameter (micrometers) Ultra- Fine

-0.02

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

Mic

rog

ram

s/cm

2

Mass/200Sulfur

LeadZinc x 10

Calcium Phosphorus

For micrograms/m3, times 8.7DELTA Group, S-XRF, UC Davis

Diesel Particles by MOUDI Impactor and S-XRFSample Run # 4, CA Fuel; no grease

PM 2.5

PM 0.25 ?

PM 10

11

11

22

22

33

33

44

44

45

55

56

66

67

77

77

88

88

99

99

910

1010

1011

1111

1112

1212

1212

Month of the year, 2002

0

20

40

60

80

100

120

Mic

rorg

ams/

m3

PM2.5 Mass, 2001

Aerosols at the Fresno 1st Street Supersite

EPA 24 hr standard

EPA annual standard

1014

1923

2731

48

1216

2024

293

711

1519

2327

15

913

1721

2529

37

11

March April May June July, 2001

0

10

20

30

Na

no

gra

m/m

3

PM10 PM2.5

Strontium Aerosols at Fresno during the FACES StudyDRUM Impactor, S-XRF Analysis Data, 6 hr resolution

1216

2024

281

59

1317

2125

292

610

1418

2226

304

812

1620

2428

15

913

1721

2428

26

1014

18

July August September October November December, 2001

0

5

10

15

20

25

30

35

Na

no

gra

m/m

3

PM10 PM2.5

DRUM Impactor, S-XRF Analysis Data, 3 hr resolution

1516

1718

1920

2122

2324

2526

2728

2930

12

34

56

78

910

1112

1314

1516

1718

1920

21

November December

0

50

100

150

200

250

300

Nan

ogra

ms/

m3

Phosphorus x 10 Sulfur Potassium Zinc x 10

Aerosols at the Fresno First Street Super-siteVery fine (0.26 > Dp > 0.09 micron) elemental concentrations for FACES, CARB

S-XRF analyses via DELTA Group, UC Davis

Very fine aerosols characteristic of Very fine aerosols characteristic of diesels/smoking carsdiesels/smoking cars

So what if Fresno in winter is Impacted So what if Fresno in winter is Impacted by diesels and smoking cars ?by diesels and smoking cars ?

“It is important to note that the estimated health risk from diesel particulate matter is higher than the risk from all other toxic air contaminants combined….

“In fact, the ARB estimates that 70 percent of the known statewide cancer risk from outdoor air toxics is attributable to diesel particulate matter”.

“The ARB does not routinely monitor diesel particulate matter concentrations”.

ARB Almanac 2001, pg. 346

Example #2: Yosemite NP, Navajo Example #2: Yosemite NP, Navajo Power Station and Grand Canyon NPPower Station and Grand Canyon NP

• CAA amendments of 1977 identified Grand Canyon NP as a “Class 1” area in which visibility had to be protected (to “close” to natural background) from human impact

• If an anthropogenic plume were identified as impacting the park, NPS could request EPA for hearings on mandated mitigation

• Navajo Power station in Page, AZ, was a large coal fired power plant with no SO2 controls located 18 miles from the east end of the park.

• The NPS wanted this cleaned up! I was in charge of the aerosol science

Visibility reduction is mostly caused by fine Visibility reduction is mostly caused by fine particles, < 1 particles, < 1 m; sulfates, organics m; sulfates, organics

(smoke), soil, nitrates, soot, and sea salt (smoke), soil, nitrates, soot, and sea salt

12 to 55 to 2.5

2.5 to 1.151.15 to 0.75

0.75 to 0.560.56 to 0.34

0.34 to 0.240.24 to 0.09

< 0.09

Coarse Fine Particle Diameter (microns) Very fine Ultra-fine

0

5

10

15

20

25

Re

lati

ve

Co

nc

en

tra

tio

n

Soils Sulfates

Typical Sacramento/San Joaquin Valley Particle Sizes

Soils

Sulfates

Typical Haze Particles

Deep lung deposition

Informational Resources for this TalkInformational Resources for this Talk

• San Joaquin Valley Unified Air Quality Management District– http://www.valleyair.org

• California Air Resources Board - Almanac of Emissions and Air Quality and http://www.arb.ca.gov/html/aqe&m.htm

– Routine monitoring – ADAM http://www.arb.ca.gov/adam– Special Studies - CRAPAQS, FACES, ….

• US Environmental Protection Agency– Routine monitoring – AIRS data base – Special studies – Fresno Super-site,

• US Interagency Monitoring for Protected Visual Environments (IMPROVE) – Yosemite and Sequoia NP

– Routine monitoring – http://vista.cira.colostate.edu/improve/– Special studies – Yosemite Study, summer, 2002

• Research Projects – – Universities – UC Davis http://delta.ucdavis.edu (I’ll post this talk) FACES, UN

Reno Desert Research Inst., CORE http://nurseweb.ucsf.edu/iha/core.htm– Non Governmental Organizations – ALASET HETF, Valley Health Study and

Sacramento/I-5 Transect Study; HEI www.healtheffects.org• Federal resources NOAA HYSPLIT http://www.arl.noaa.gov/ready/hysplit4.html