The best answer here would be 4. First, a 50% drop in
ACE must be put into context with what test was used, and the history of exposure. As it
turns out, the clinic only did the serum or pseudo ACE test. The serum ACE test may have a
lot of variance due to factors other than insecticide exposure. As serum ACE is produced
by the liver, any illness causing liver compromise may interfere with the test (poor liver
function, less serum ACE produced, creating a false positive test). Furthermore, a more
detailed occupational history of the work exposure indicated that he only applied
herbicides, which would not cause depression of the ACE. In fact, most of the chemicals
applied to corn after it has emerged from the ground, are herbicides. The greatest amount
of insecticides used on corn is applied with the seed through the corn planter.
The fact that the employee was sick from an undetermined
source warranted that a competent physician see him. As it turned out, the employee had
hepatitis A, and that was the cause of the depressed ACE.
When screening workers for insecticide exposure, it is
ideal to conduct baseline tests and followup if necessary with both the serum and red
blood cell tests. The RBC test will be depressed much longer than the serum test, but it
is not as subject to other variables. In the instance of this case, if the worker had both
tests done, the RBC ACE would not have been depressed, helping to provide correct medical
advice in a more timely manner, and possibly avoiding a wrong diagnosis.
Our I-CASH protocol to the AgriSafe clinics is to do
both serum and RBC ACE tests. However, when both are not possible for cost or other
reasons, then conduct the serum ACE test. If there is a depression in the serum ACE, then
evaluate the case as above using the exposure history, and perhaps repeating with the RBC
and serum ACE tests.