AMATS
Air Quality Update
April 2012
Municipality of Anchorage
Department of Health and Human Services
Status Report
 Carbon
monoxide (CO)
 Particulate matter (PM10 & PM2.5)
 Ozone
 Airborne lead
 Air toxics (benzene)

Sulfur dioxide, nitrogen dioxide
CO




Colorless odorless gas
produced by incomplete
combustion
79% of emissions from
motor vehicles
Highest concentrations
occur on cold mid-winter
days with strong
temperature inversions
Residential areas tend to
have highest concentrations
Anchorage CO Trend
30.0
2nd max 8-hr average (ppm)
25.0
20.0
15.0
CO NAAQS = 9 ppm
10.0
5.0
0.0
1980
1996
1985
1990
1995
2000
2005
2010
Comparison with CO Concentrations in Selected
Western Cities in U.S. (2010)
Highest 8-hour
Concentration
(ppm)
2nd Highest 8hour
Concentration
(ppm)
Number of
Exceedances of the
NAAQS
Anchorage, AK
6.9
6.1
0
Fairbanks, AK
5.0
4.1
0
Las Vegas, NV
3.4
3.0
0
Phoenix, AZ
3.3
3.2
0
El Paso, TX
3.3
2.8
0
Denver, CO
3.1
2.4
0
Ogden, UT
2.4
1.9
0
Reno, NV
2.4
2.1
0
Portland, OR
2.4
2.4
0
Spokane, WA
2.3
1.9
0
Salt Lake City, UT
2.2
1.9
0
Albuquerque, NM
2.0
2.0
0
Sacramento, CA
1.9
1.9
0
Seattle, WA
0.8
0.7
0
Metropolitan Area
PM10 and PM2.5
Width of human hair
PM10
(10µm)
PM2.5
(2.5 µm)

Linked with asthma and other
respiratory health problems

Death rates in hospitals
increase when PM2.5
concentrations are high

Anchorage studies show that
there are more doctor visits for
asthma when PM10 levels
increase
PM10

Occasional violations of the
NAAQS in spring at Tudor Road
site due to road dust.

Magnesium chloride is being used
to suppress dust along 40 miles of
high volume roadways in
Anchorage and Eagle River.

Eagle River regularly violated
NAAQS in late-1980’s before
roads were paved

Strong winds transported dust
from glacial river valleys in Mat Su
causing exceedances of NAAQS
in 2003, 2007, 2009, and 2010.
September 24, 2010
MODIS satellite image
PM2.5

Generally low concentrations in
Anchorage (ranked 6th cleanest city
for year-round PM2.5 pollution by ALA)

C14 analysis of Anchorage samples
suggests that most PM2.5 is from
wood smoke

Assembly passed outdoor wood boiler
ordinance restricting installations to
those meeting EPA-certified Phase 2
standards.
NESCAUM
2006
No obvious upward or downward trend
in PM10 or PM2.5 during past 10 years
PM10
PM10 NAAQS = 150 ug/m3
150
100
PM2.5
50
0
2001
2003
2005
2007
2009
2011
98th percentile (ug/m3)
2nd max (ug/m3)
200
40
PM2.5 NAAQS = 35 ug/m3
30
20
10
0
2001
2003
2005
2007
2009
2011
Ozone (O3)

Secondary pollutant produced by a
chemical reaction between oxides of
nitrogen and volatile organic
compounds in the presence of
sunlight.

Ozone in stratosphere protects us
from UV

Causes respiratory irritation,
coughing, pain

Highest concentrations seen
downwind of major urban centers in
summer

O3 levels in Anchorage and Eagle
River were among the lowest 1% of
sites in U.S.
Ozone is the main
ingredient in “smog.”
Airborne Lead





EPA study of 15 mid-sized
airports serving piston
aircraft
Unlike gasoline, aviation fuel
still contains lead additive
One-year study at Merrill
Field will conclude Oct 2012
Will not be used to assess
attainment with the new
ambient lead standard
Preliminary data suggest
that concentrations at Merrill
Field are below standard
Air toxics (benzene)
DHHS is monitoring ambient benzene to assess impact of
new EPA limits on the amount of benzene in gasoline
Phase 1 (completed)
Phase 2 (planned)

Oct 2008 – Oct 2009

Aug 2012 – Aug 2013

Gasoline benzene ≈ 5%

Gasoline benzene <1.3%

Found average ambient benzene
levels at Garden site in Airport
Heights to be in 98th percentile of
U.S. sites

How much will ambient benzene
concentrations be reduced?
Garden site
(Anchorage)
Annual Average [benzene] = 1.1 ppb
Galena Park, TX
(near Houston)
Annual Average [benzene] = 1.1 ppb
Summary

CO has fallen dramatically and is expected to continue to decline,
but more slowly than the past.

PM10 is a problem during spring break up. Magnesium chloride is
used to control dust on major roads. Unpaved road problem in
Eagle River has been resolved.

PM2.5 is fairly low but could pose a problem if wood burning
increases.

Ozone levels are among lowest in the U.S.

Benzene concentrations were among highest in U.S. in 2008-09.
The impact of lowering the gasoline benzene content from 5% to
1.3% or lower will be evaluated this coming year.