Saturday, February 23, 2013

there have been errors

i never mind admitting making mistakes,
that is why we scientist review things.
The errors were with metals results that had been reported to me and then i tried to correlate them.
The errors were two-fold:
In the database numbers were divided into a base number and before the number, an "operator".  The operator could be the less than sign or a not detected symbol, in a query I wrote, used the base number of the result instead of the combination of using a less than operator and the not detected operator as 0.
They are not actually zero, but they are less than whatever detection limit was achieved in analysis.
This made a big difference in the Arsenic report, which previously had shown 3 tests results at the action level.  Each of those results were a less than 10, meaning that arsenic has not been found elevated in any of the 227 tests that i had on record.
Cadmium results were correct:  there was one test above the MCL of 64 tests, however the level was recorded as 40 mg/L (i used mg/L as the base measurement) and it was really 40 ug/L, a huge difference.
Chromium was correct, 1 test was above the MCL of 36 tests.  The only thing i can say is that it was performed in 1989 and we never saw another elevated Chromium level.
Apparently all the other test result did not have this error.
The errors occurred during the years after my operation and i knew i was not doing that well and would be prone to errors and is one of the reasons i retired.

1 comment:

Unknown said...

Just so every one knows - i still support metals testing -very little has been done except for the basics: lead, copper, iron and manganese.
Arsenic, and uranium are very important and even though lead and copper have been done evidence suggests that they should be continued even more so.\