Sorry for the title of the blog, but I wanted to get attention of potential readers. Almost as on queue with the prior post on “Pseudoscientists and snake oil salesmen in modern forensic science”, Minnesota launches itself into controversy. Please watch the below so we can discus.
Ok. Trying to use first void urine as a measure of ETOH is scientifically invalid for so many very basic reasons.
- It is at best a history of exposure to the analyte. It can NEVER EVER TELL IMPAIRMENT AT THE TIME OF DRIVING.
- It is non-specific and non-selective. As such, it is not a forensically acceptable method of analysis. It may be used as a screening test with limited value versus a full confirmation tests. it does not yield itself well any sort of confirmatory testing such as GC-FID or GC-MS. Many times enzymatic assaying is used to examine urine for ETOH or Drugs of Abuse.
- Epithetical cell slothing off during collection;
- At time of collection ph and temperature are not always recorded as they must be to determine whether or not it is a suitable sample;
- In the collection jars there is typically a lack of sodium fluoride or an insufficient amount in the specimen jar which can lead to exogenous ETOH production;
- Some methods and assays are indirect tests in that they only test for the detection of EtG as opposed to a direct test and measurement of ETOH. it is the difference between a metabolite versus the parent drug;
- Frequently the method of collection is not sound and subject to accumulation error. A first void tidal urine specimen will result in an artificial collection of waste products from perhaps many, many hours before versus a true midstream second void collection;
- There is a demonstrable universal lack of an acceptable conversion factor in the scientific community that can be applied from urine concentrations to BAC (i.e., 1.33 to 1, but it ranges from .021 to 2.66);
- Frequently there is a reporting of simply a presumptive positive result without quantification;
- Usually there is a lack of a sufficient and robust chain of custody, with insufficient proof of proper refrigeration, and lax transportation protocols
All of these deficiencies and more are with perfectly collected and analyzed urinalysis. And now we have what is shown in the video. Bad science. Lack of verification. People who are working in the lab who probably should not be.
You can go to Minnesota DWI Defense Blog to read the response of the government and to keep up-to-date with the developing boondoggle.
In another story that covered this event Prosecutors review DWI cases after lab results botched, the reporter states: “It wasn’t bad science, authorities say, just bad math.”
(Said oozing with sarcasm): Makes sense, doesn’t it because math isn’t science, right? It’s an art, isn’t it?
Math is the epitome of science and empiricism. Silly pseudoscientists.
The shame of it all is that they actually made a much larger error. When it was originally reported it was an error of 33%, but it seems as if it is an error of 50%. Now since it is DUI (or DWI as they call it Minnesota), people don’t seem to be too terribly alarmed.
Time to leave important decisions to real science. I think that all of the free world should condemn those few states who allow urinalysis to prove anything.