Little Scioto River, OH, USA Worksheet Example Evidence of Exposure or Mechanism

Example Worksheet : Evidence of Exposure or Mechanism	Little Scioto River, OH, USA
Step 3: Evaluate Data from the Case
Candidate causes considered on this worksheet:	PAHs

Data:

Bile Metabolites measured in white suckers from the Little Scioto River.

Figure W1-7. Bile metabolites (ug/mg protein) measured in white suckers from the Little Scioto River.

Analysis/Discussion:
Bile metabolites show evidence of exposure to PAHs at the site. Concentrations are low but no measurements at upstream site are available for comparison.

Evidence Scoring Table:
Finding	Interpretation	Score
Data show that exposure or the biological mechanism is clear and consistently present.	This finding strongly supports the case for the candidate cause, but is not convincing because it does not establish that the level of exposure or mechanistic action was sufficient to cause the effect.	+ +
Data show that exposure or the biological mechanism is weak or inconsistently present.	This finding somewhat supports the case for the candidate cause.	+
Data show that exposure or the biological mechanism is uncertain.	This finding neither supports nor weakens the case for the candidate cause.	0
Data show that exposure or the biological mechanism is absent.	This finding strongly weakens the case for the candidate cause, but is not convincing because the exposure or the mechanism may have been missed.	- -
Data show that exposure or the biological mechanism is absent, and the evidence is indisputable.	This finding refutes the case for the candidate cause.	R

**Table W1-9.** Evidence of exposure scores for candidate causes.
Candidate Cause	Result	Score
PAHs	Evidence of PAH exposure observed	+