What COVID-19 deniers can teach us about impaired driving science | Kyla Lee
Tuesday, September 15, 2020 @ 2:10 PM | By Kyla Lee
This has been on my mind lately, because it tells us a lot about science and how we are willing to accept it as proof of facts.
Science frequently, much like our courts, relies on evidence of the existence of something to support that it was there. In the same way that archaeologists look for clues about ancient civilizations, scientists often look for clues about the presence of certain substances or viruses to determine that they were there. Not being able to isolate a particular particle or molecule has not necessarily been a problem in science, because proof can be established based on — you guessed it — circumstantial evidence.
In our court system, we often rely on circumstantial evidence to prove or disprove facts at trial. Science does the same. So, the complaint that scientists cannot isolate the virus (which, in fact, they can and have) does not really hold water.
A good example of this comes from impaired driving science.
In impaired driving cases, evidence of the offence is usually obtained through various types of tests. These include physical co-ordination tests, breath tests, urine tests and blood tests. Each of these is accepted and, in some instances, codified in the Criminal Code, as reliable for this purpose.
The public outcry against COVID-19 testing far exceeds that against impaired driving testing.
And, curiously, impaired driving is less deadly than COVID-19 ...
So, let’s break down each type of test.
Breath tests themselves use two types of analytical method: infrared chamber and fuel cell. In an infrared chamber, light passes through the particles in the breath sample, to reach a receptor. The amount of light that passes through the chamber tells the receptor how much of the substance is found in the breath.
But, of course, other substances allow the same or similar amounts of light to pass through. These are called interfering substances. The breath test instrument is not looking for ethanol. It is not isolating the ethanol molecules. Rather, it is looking for circumstantial evidence that ethanol, or something that closely resembles it, may be present.
Fuel cells operate in a similar fashion. They are similar to a battery, coated in black platinum and acid. The breath sample is drawn onto the fuel cell, where it oxidizes on the coated surface. This generates an electrochemical current. The strength of the current is determined by the oxidation process. This then tells the device whether it is detecting ethanol or something else. But again, the device is not looking for ethanol molecules. It is not isolating the alcohol. Rather, it is looking for evidence of the existence of alcohol because it behaves in a certain way when introduced to the surface of a fuel cell. There are, however, interfering substances that can act like alcohol and produce the same result.
Blood testing may be the closest approximation to isolating ethanol molecules. Blood tests are run through a gas chromatography instrument. But the blood itself is not tested. Rather, the blood is turned into a gas, and then run through a column where it interacts with the walls of the column. The various particles in the gas then leave the column at different times, known as elusion times.
Ethanol is detected based on the amount of time it takes the particles to leave the column. The instrument then identifies it as alcohol based on the elusion time. The instrument is not measuring ethanol, but rather the amount of time for a particle to show up. Other than a calculation of time, the instrument has no ability to say that something is ethanol or not.
And then we have urine, the body’s dumpster. In urine testing, scientists do not look for actual substances but their metabolites. These are like leftover pieces of crust and crumbs and a smear of peanut butter. If you see that, you could conclude there was a peanut butter sandwich. But you cannot be certain when someone ate it, or how much they ate, and there is a high probability you could be wrong.
Finally, there is physical co-ordination testing. I think it does not require much explanation why this does not isolate ethanol molecules.
Despite the various methods used to test for impaired driving in Canada, we do not see street-wide protests decrying our impaired driving laws and demanding better testing. We do not see concerned citizens getting behind the wheel after drinking and demanding that it is their right to do so, the same way they demand the ability to enter public and private spaces unmasked.
The absurdity of the scientific claims about COVID-19 and the need to isolate the virus in rapid screening testing is about as absurd as saying that since there are interfering substances in fuel cell, infrared, blood and urine testing and because the ethanol molecule itself is not being isolated, we should scrap the impaired driving laws.
Public safety legislation does not always have to be based on the best possible aspirational science. Rather, it should be based on the best science we have at the time, with the understanding that we are constantly striving to learn more and do better.
Strangely, when it comes to impaired driving, science no longer strives to learn more and do better with breath, blood or urine testing. But when it comes to COVID-19, the scientific community has been and continues to be working around the clock to learn as much as they can, as fast as they can.
Kyla Lee is a criminal lawyer and partner at Acumen Law Corporation in Vancouver. Her practice focuses on impaired driving. She is the host of a podcast, Driving Law, and a weekly video series Cases That Should Have Gone to the Supreme Court of Canada, But Didn’t! She is called to the bar in Yukon and British Columbia. Follow her at @IRPLawyer.
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