Why should hikers care about Ozone

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Why should hikers care about Ozone?
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Ozone The GOOD versus the BAD
GOOD OZONE
SMOG
Ozone (O3) is an odorless, colorless gas composed
of three oxygen atoms. Ozone in the stratosphere
is good because it blocks harmful UV radiation
from the sun. However tropospheric or
ground-level ozone, also known as SMOG, is
dangerous to our health and the environment.
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High Ground-Level Ozone Harms People and Plants
Photo from Clear the Air

• Ground-level ozone that is Unhealthy for
  Sensitive Groups or worse may cause
• Coughing or wheezing.
• Tightness in chest.
• Inflammation of lung tissue.
• Constriction of airways.
• Restriction of breathing.
• Asthma in children, and aggravation of
  asthma and allergies in others.

• High Ozone and Plants
• Ozone damage to plants was first recorded in
  the 1940s.
• High ground-level ozone is thought to be
  partially responsible for the decline of the
  Eastern White Pine and other sensitive species.

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What causes ground-level ozone to form?
Ground-level ozone (smog) forms when nitrogen
oxide pollutants from car and smokestack
emissions react with hydrocarbons like gasoline
vapor and natural organic gases in the presence
of sunlight.
Weather systems blow ozone-forming pollutants
from industrial and urban centers into rural
areas like the White Mountains of NH.
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What to know about ozone in the mountains
Daily Ground-Level Ozone Patterns - 2000
Low-elevation ozone concentrations usually rise
at midday when temperatures and solar radiation
are highest.
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At high elevation, ground-level ozone levels
remains relatively constant throughout the day
since air is less mixed above the planetary
boundary layer.
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Average O3 Concentration (ppb)
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Mt. Washington 6288 ft.
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Camp Dodge 1500 ft.
Conway 500 ft.
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0400
0800
1200
1600
2000
Hour
In a pollution event ozone can be unhealthy at
higher elevations but lower in the valleys due
to higher nighttime background, less mixing and
faster transport from a larger region.
Stratosphere
Troposphere (6-9 miles)
Stable Layer
Higher Levels of ozone occur at high elevations
Cloud Base
The planetary boundary layer is an invisible zone
above which air masses are more affected by
regional wind patterns than by local convection.
Mixing Layer
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AMC Research on Ground-Level Ozone
The Appalachian Mountain Club has been monitoring
ground-level ozone concentrations (reported in
parts per billion) on the summit of Mt.
Washington since 1986. The AMC also monitors
ground-level ozone at the base of Mt. Washington
in order to compare the differences between daily
ozone patterns at high and low elevation.
Mt. Washington Observatory at the Summit
During 1991-1992, the AMC, in conjunction with
the Harvard School of Public Health, researched
the effects of ozone on hikers. The study
concluded that exposure to higher ozone
concentrations during physical activity can
reduce lung function in healthy hikers. The
reductions occurred at levels below the current
health standard.
AMC ozone monitor in the summit building on Mt.
Washington. (AMC works in cooperation with the
Mount Washington Observatory, USFS, EPA and NH
Department of Environmental Services)
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How do I know when the Ozone levels are high?
An Example of Ground-Level Ozone Event Showing
the AQI Values

• Summertime
• The ozone season, when state agencies are
  required to monitor levels, is from April 1st to
  September 30th. That is because, in general, the
  sun and heat are needed for ozone to accumulate
  to levels that are unhealthy.

• The AIR QUALITY INDEX
• The EPA has developed an Air Quality Index (AQI)
  for six major pollutants ground-level ozone,
  particulate matter, carbon monoxide, sulfur
  dioxide, nitrogen dioxide and lead.
• The AQI relates daily average concentrations for
  each pollutant with the corresponding impacts on
  human health.
• The EPA web site shows the AQI regional values as
  seen in the picture to the right,
  www.epa.gov/airnow

• Ground-Level Ozone Forecasting
• State environmental agencies often forecast
  ground-level ozone AQI values daily by each
  county.
• The states of NH and NC have high-elevation
  ozone forecasts because mountain tops can have
  unhealthy levels compared to the valleys just
  below it.
• Have you checked the ozone forecast for today? Go
  to www.hikersforcleanair.org for state forecasts
  along the Appalachian Trail.

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Whats Being Done About Ground-Level Ozone
Pollution?

• Ground-Level Ozone Standards
• The Clean Air Act National ambient air quality
  standards stipulate that ozone should not exceed
  an hourly average of 125 ppb (Unhealthy). EPA
  will soon put into effect a more stringent
  standard which requires an eight hour average of
  85 ppb (Unhealthy for Sensitive Groups).
• If a county is considered in violation of the
  standard over an average three year period it is
  then considered non-attainment. The state
  must then plan how they will reduce emissions
  that are causing the violation in their State
  Implementation Plan (SIP) submitted to the
  Environmental Protection Agency. The graphic to
  the right shows non-attainment counties in red
  for 1997-1999.

• Emission Regulation of Ozone precursors
• Stationary Sources (e.g. power plants) tools
  include programs such as New Source Review, Acid
  Rain Provision, and the Regional Haze Rule.
• Mobile Sources (e.g. automobiles) tools include
  Tier II and California LEV.
• These programs act to control pollution
  emissions, including those that can lead to ozone
  formation.

• Interstate Transport Rule (Section 126)
• This section of the Clean Air Act protects
  states
• that are downwind of a pollution source.
• States that can not meet the national ozone
  standard by making reductions within their
  boarders can petition EPA to require the upwind
  states to clean up.

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What You Can Do To Protect Yourself and the
Environment
SMOG

• Use Less Electricity
• Use Clean Modes of Transportation
• Keep your vehicle well-maintained, keep tires
  properly inflated,
• and change oil regularly.
• Carpool and limit the amount you drive.
• Choose low-emission vehicles.
• Be Informed
• Listen to radio reports or check the web to find
  out the daily ozone forecast.
• Actively Participate in Regional Air Quality
  Policy
• Become a member of a conservation group. Keep up
  to date on pressing environmental issues and
  voice your opinion on proposed policy changes.
• Limit Exposure to High Ground-Level Ozone
• Limit strenuous outdoor activity or physical
  exercise when ozone levels are unhealthy.
• If ozone is forecasted to be high at low
  elevations, exercise during the early morning
  when temperatures are cooler.
• Reduce your exertion if you notice symptoms such
  as coughing, wheezing, tightness in the chest,
  and/or restricted breathing.