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A significant risk facility is a business operation that releases
toxic
substances into the air, when those substances have the potential to cause health
problems to people who live and work nearby. Health risks can be cancer or
non-cancer related, and non-cancer health risks are further divided into
acute (short-term) and chronic (long-term) risks.
Under the California Air Toxic Hot Spots and Information
Act, significant risk facilities are required to notify the public of the
risks they create and are required to reduce those risks to
less-than-significant levels.
Explanation of Risk
Definition of Significant Risk
Putting Risk into Perspective
Requirements of Significant Risk Facilities
Santa Barbara County's Significant Risk
Facilities
In this program, a health "risk" is the possibility that people
will experience health problems from breathing certain toxic substances in
the air. Everyone has the possibility of developing cancer or other
illnesses. Our exposure to some substances can increase our chance of
developing these illnesses — meaning we are more likely to develop them
than someone who has not been exposed. The increased risk is estimated using
computer models and performing what we call risk assessments, which
take into account a number of factors including: the amount and toxicity of
the substance; weather conditions; distance from the source of the substance
to people; the age, health and lifestyle of people living or working near
the source of the substance; and the amount of time people have been exposed
to the toxic substance.
"Increased cancer risk" describes the increased chance of getting
cancer from exposure to an air toxic. It's expressed as a probability: the
chance of so many additional people getting cancer in a group of one million
people.
Non-cancer health risks can include acute, or short- term health
problems such as eye irritation, respiratory irritation, and headaches, and chronic,
or long-term problems such as permanent damage to organs, the central
nervous system, or reproductive functions, and developmental problems in
children. Non-cancer health risk is defined by something called the
"Hazard Index" (HI). The HI is a ratio of the predicted exposure concentration of the facility’s reported emissions to a concentration considered acceptable to public health
professionals. For example, an HI of 2 means the concentration of toxics in the
air at the point of exposure is predicted to be twice as high as is
generally thought to be safe. The levels defined as "safe" are
designed to protect the most sensitive individuals in a population.
It's important to note that risk numbers do not refer to actual cases of
health problems that will occur from exposure to air toxics. The risk
assessments are computer calculations that are designed to provide a tool to
identify and reduce possible negative health effects. For more information,
see Putting Risk in Perspective.
The current thresholds that define a significant risk, set
and approved by APCD's Board of Directors, are:
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for cancer risk, 10 or more excess cancer cases
in a population of one million people (stated as "10 in a
million") and,
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for non-cancer acute and chronic risk, a
hazard index greater than 1. The HI is a ratio of the
exposure concentration of the facility’s reported emissions to a concentration considered acceptable to public health
professionals.
Every day, Santa Barbara County residents are exposed to toxic air
contaminants from automobiles, homes, businesses, and natural sources. Many of these
substances such as benzene, 1,3-butadiene, diesel soot, and perchloroethylene
can cause cancer. The risk posed by these sources is called the
"background" cancer risk. This is the chance that anyone living in
the area will develop cancer in their lifetime.
The risk from individual businesses' toxic air emissions is generally less than the background risk.
The health risk estimates for these facilities calculate only the additional
(above and beyond background) cancer risk caused by their emissions.
Among the largest contributors of air toxics are cars and trucks. A
recent study by the South Coast Air Quality Management District reported
that diesel particulate, or soot, accounted for 71% of the total cancer risk
from toxic air pollution in their region. The study is one of the most
comprehensive studies of urban toxic air pollution ever performed.
The
estimated background cancer risks due to air pollution for some selected areas of Santa
Barbara County are as follows:
| Downtown Santa Barbara: |
223 cancer cases per million |
| Santa Maria: |
98 cancer cases per million |
| Gaviota: |
47 cancer cases per million |
| Lompoc: |
40 cancer cases per million |
While this puts the risk from individual businesses in perspective, it does not imply that the risk from these individual businesses is acceptable or insignificant. Emissions from a particular business can create a "hot spot" where individuals can be exposed to
compound risks.
1. Preparation and Submittal of an Air Toxics Emission Inventory Plan and
Report document, updated every four years:
A company which emits toxics into the air must conduct a complete inventory
of all of the toxic air pollution it generates. For the smaller companies, which
make up the vast majority of the businesses subject to the law, the Air
Pollution Control District prepares the inventory for them as a group.
2. Risk Assessment, updated every four years:
A Hot Spots risk assessment is an estimate of the human health risk caused by
toxic air emissions from a business. It is a study that
quantifies the possible adverse health effects which may result from exposure to
routine emissions of toxic air contaminants. The health risk assessment cannot
predict health effects; it only describes the increased possibility of
adverse health effects. A risk assessment quantifies the probability of
developing cancer and/or other disease from exposure to toxic air contaminant
emissions. It is a key step in the Hot Spots program because it lays the
groundwork (if a facility is of significant risk) for the public notification
and risk reduction processes described below.
3. Public Notification
The primary goal of notification under the Air Toxics "Hot Spots"
Program is to inform potentially exposed individuals of significant health risks
associated with toxic air emissions routinely released from facilities in Santa
Barbara County. The significant risk facilities' first public notification
letters were sent to the affected public in the Spring of 1999.
4. Risk Reduction
If the results of a facility’s health risk assessment indicate a
significant health risk, the facility operator is required to conduct an
airborne toxic risk reduction audit and develop a plan to implement airborne
toxic risk reduction measures. Implementation of these measures must reduce the
risk from facility emissions below the significance risk level(s) within five
years of the date the plan is submitted to the APCD.
The following facilities are required to notify the public about
significant health risk associated with air toxic emissions, and to reduce the
health risk to below the significant level.
 Return to Air Toxics
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