The methyl parathion tests were run in a similar manner
except that the benzene samples were analyzed by a gas
chromatograph and the fact that the number of samples was
limited by the need for other workers to use the GC system.
With the system off the methyl parathion level was 0.8 /ig/L;
with the corona on it was less than 0.006 Mg/L (the detection
limit of the chromatograph) suggesting an effective decrease
of 99.3% or more