CalEnviroscreen Version 1.1 - OEHHA - State of California

CalEnviroScreen 1.1
risk in vulnerable populations can often be described by
effect modifiers that amplify the risk. This research suggests
that the use of multiplication makes sense based on the
existing scientific literature.
2. Risk Assessment Principles: Some members of the general
population (such as children) may be 10 times more sensitive
to some chemical exposures than others. Risk assessments,
using principles first advanced by the National Academy of
Sciences, apply numerical factors or multipliers to account for
potential human sensitivity (as well as other factors such as
data gaps) in deriving acceptable exposure levels (US EPA,
2012).
3. Established Risk Scoring Systems: Priority-rankings done by
various emergency response organizations to score threats
have used scoring systems with the formula: Risk = Threat ×
Vulnerability (Brody et al., 2012). These formulas are widely
used and accepted.
Maximum Scores
for Combined
Components
Notes on Scoring
System
Component Group
Maximum Score*
Pollution Burden
Exposures and
Environmental Effects 10
Population Characteristics
Sensitive Populations and
Socioeconomic Factors 10
CalEnviroScreen Score Up to 100 (= 10 × 10)
* The scores for each group were rounded to one decimal place
before multiplying to calculate the CalEnviroScreen Score (for
example, 6.5 out of a possible 10)
In the CalEnviroScreen scoring model, the Population Characteristics
are considered to be a modifier of the Pollution Burden. In
mathematical terms, the Pollution Burden is the multiplicand and
Population Characteristics is the multiplier, with the CalEnviroScreen
Score as the product. Because the final CalEnviroScreen score
represents the product of two numbers, the final ordering of the
communities is independent of the magnitude of the scale chosen for
each (without rounding scores). That is, the communities would be
ordered the same in their final score if the Population Characteristics
were scaled to 3, 5, or 10, for example. Here, a scale up to 10 was
chosen for convenience.
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