| Ozone
Awareness
Q. What is
ground-level ozone, and where does it come from?
A.
Ozone is a colorless gas that can be found in the air we breathe. An
ozone
molecule is composed of three atoms of oxygen - one more than the
oxygen
molecule we need to sustain life. The extra oxygen atom makes ozone
extremely
reactive. While it occurs naturally in the Earth's upper atmosphere,
where
it shields the Earth from the sun's ultraviolet rays, it is also found
close to the surface. This ground level ozone is a harmful air
pollutant.
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Ozone
is the primary ingredient in urban smog. It is formed by a chemical
reaction
between volatile organic compounds (VOCs) and oxides of nitrogen (NOx)
in the presence of sunlight. Sources of VOCs and NOx include:
• on-road vehicles
such as autos, trucks and buses
• off-road engines
such as lawn and garden equipment, all-terrain vehicles, aircraft,
motor
boats, locomotives, and construction and farm equipment
• large industry
and stationary combustion sources such as chemical plants, petroleum
refineries,
and coal-fired and natural gas power plants
• storage and
transport of petroleum and related products
• small industry
and area-wide sources such as gas stations, printers, auto body shops,
dry cleaners, bakeries, paper mills, pesticides and other chemicals
• consumer products
such as oil-based paints and solvents
Click
here for: Ground-level Ozone Basic Information
Q.
Is ozone
considered "good" or "bad"?
A.
Both, actually. Ozone concentrations can reach unhealthful levels when
the weather is hot and sunny with relatively light winds. Although it
acts
as a protective layer when high above the earth, ozone near the ground
can cause or contribute to serious health problems. Remember this
rhyme:
"Ozone: good up high, bad nearby."
Click
here for: Ozone: Good Up High, Bad Nearby
Click here for: Achievements
in Stratospheric Ozone Protection
Q.
Why is ozone
hazardous to our health?
A.
High concentrations of ozone near ground level can be harmful to
people,
animals and crops. As it builds up, it becomes toxic, causing shortness
of breath, coughing, wheezing, headaches, nausea, and eye and throat
irritation.
People who suffer from asthma, bronchitis, emphysema or other
respiratory
disease have even more trouble breathing when the air is polluted. It
can
be worse in children, the elderly, and those who work or exercise
outdoors.
Click
here for: Ozone and Your Health
Q.
How does
ground-level ozone harm the environment?
A.
Ground-level ozone interferes with the ability of plants to produce and
store food so that growth, reproduction, and overall plant health are
compromised.
By weakening sensitive vegetation, ozone makes plants more susceptible
to disease, pests, and environmental stresses.
Click
here for: Health & Environment Impacts
Q.
What are
the EPA's standards for ozone?
A.
The Environmental Protection Agency (EPA) has established an ozone
health
standard to limit human exposure to harmful concentrations of
ground-level
ozone. The ozone standard is .075 parts per million over an eight-hour
period.
The EPA looks at the annual fourth-highest day, which is averaged over
a three-year period to determine whether an area exceeds the National
Ambient
Air Quality Standards.
Click
here for: 8-Hour
Ground-level Ozone Designations
Click here for: March 12,
2008 - EPA strengthened National Standards for Ground-Level Ozone
Q.
When is an
Ozone Action Day declared?
A.
An Ozone Action Day will be declared in central Arkansas when the ozone
levels for the metropolitan area are forecast to exceed the National
Ambient
Air Quality Standards. The forecasted air quality on these days will be
in the unhealthy range.
Q.
What area
is effected by Ozone Action Days?
A.
The Central Arkansas Ozone Action Days program applies to the central
Arkansas
area, which includes the counties of Pulaski, Faulkner, Lonoke and
Saline.
However, persons living outside this area may also be effected by high
ozone concentrations on Ozone Action Days and should take appropriate
actions.
Click
here to find out about Central Arkansas.
Q. How do people
find out when an Ozone Action Day is declared?
A. You can subscribe
to EnviroFlash from the U.S. EPA.
This is a free service that provides you with information about the air
quality at the location of your choice via a daily email.
Click
here to access the EnviroFlash page.
A.
Fax and/or e-mail notifications of Ozone Action Days are provided to
local
news media, participating employers, and other organizations (usually
by
3 p.m. in advance of an Ozone Action Day). Television and radio
stations
and newspapers are provided with information and encouraged to inform
the
public. The NOAA Weather Radio is also notified and provides broadcast
reports of Ozone Action Days. Other participating organizations are
notified
and encouraged to notify their employees and others to take appropriate
actions on Ozone Action Days. Most local governments and some other
organizations
display a yellow Ozone Alert flag on Ozone Action Days and the day
before
an Ozone Action Day. Organizations located in central Arkansas wishing
to participate in the Ozone Action Days program may request to be
notified
by fax when Ozone Action Days are declared.
Click
here to download an OAD Notification Request Form.
Q. What
is the Air Quality Index (AQI)?
A.
The EPA and others are working to make local air quality information as
available to the public as weather information. The AQI format focuses
on the health effects of breathing polluted air. The AQI is like a
yardstick
that runs from 0 to 500. The higher the AQI value, the greater the
level
of air pollution and health risk. A specific color has been assigned to
each AQI category to make it easier to quickly understand the
significance
of air pollution levels. The AQI can help you determine what actions to
take to protect your family's health as ambient air quality levels
reach
the unhealthy range. The Arkansas Department of Environmental Quality
forecasts
the AQI for the worst air pollutant on the current day (i.e., ozone,
particulates,
etc.). The daily AQI is posted on ADEQ's website (usually by 9:00 a.m.)
and reported in some daily newspapers (usually on the following day).
Click
here for the Daily AQI
Q.
What are
the two basic types of Ozone Action Days?
A.
There are two basic types of Ozone Action Days.
An
OZONE ADVISORY will be declared when the AQI is code orange,
indicating
that prolonged outdoor exertion is unhealthy for sensitive groups
(i.e.,
children and people with asthma or other breathing problems). Actions
to
reduce the formation of high ozone concentrations should be taken the
day
before a code orange day, as well as on code orange days.
An OZONE
ALERT will be declared when the AQI is code red, indicating that
prolonged
outdoor exertion is unhealthy for everyone. Actions to reduce the
formation
of high ozone concentrations should be taken the day before a code red
day, as well as on code red days.
Q.
How are Ozone
Action Days declared?
A.
During the ozone season (May through September), Ozone Action Days are
declared based on daily ozone forecasts prepared by the Arkansas
Department
of Environmental Quality. When ground level ozone is forecast to reach
unhealthy levels, the Arkansas Department of Environmental Quality and
the Arkansas Department of Health declare an Ozone Action Day. The ADEQ
posts the daily ozone forecast on their website (usually by 2:00 p.m.)
during the ozone season. The ozone forecasts use the AQI format.
Click
here for the Daily Ozone Forecast
| Q.
What should be done when the Ozone Forecast is code
yellow? |
A. Unusually sensitive people should consider
limiting
prolonged
outdoor exertion even when the ozone forecast is code yellow.
Click
here to learn who is at risk from exposure to ground-level ozone.
In
order to
help protect public health and to keep from having code orange days,
actions
to reduce the formation of high ozone concentrations should be taken on
code yellow days.
Click
here to help Reduce Ozone Formation.
What
should be done if the Ozone Forecast is code purple?
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