Drug testing is conducted in a number of situations from job applications to sporting events. Interested parties get samples from the subject and examine these in the lab to see if there are any traces of banned substances. The test can be performed in many different ways. The sample choice will depend on the type of drug being checked, the resources of the facility, the time constraints, and so on. Bodily fluids are often used such as the saliva, the urine, or the blood. In some cases, however, strands of hair are taken as a sample for examination. The follicles can hold plenty of clues about the substances consumed by the subject.
Hair Drug Screening
This is a type of testing in which hair samples are the primary means of identifying the kinds of drugs taken by the person in question. Only a small amount is necessary to reach a conclusion. The traces can be found in the hair follicles, including their metabolites or the chemicals produced by the body after their consumption. These chemicals eventually make their way into the blood stream until they reach the scalp and the follicles. It can take a while before they complete the journey but they typically stay for quite a while before they are expelled from the body.
Relevant Time Period
Hair grows at a different rate for different people. Some take a long while before they see their strands getting longer. Others seem to need a haircut every month or even every week. The reliability of the hair screening will depend on this rate for each individual. On the average, the test can cover up to 90 days. This means that traces can still be seen on the follicles 90 days after the consumption of a drug. This is the longest coverage offered by a sample — quite a massive step up from any of the fluid-based alternatives. It is actually possible to test for a period that is greater than this by cutting longer strands.
About Hair Growth
In a typical test, the sample will be obtained by cutting the more recent growth measuring 1.5 inches from the scalp. These strands will be subjected to scrutiny inside the lab. This makes sense this the average growth on the head is about half an inch per month. Getting 1.5″ means that the testing period covers 3 months or 90 days. Of course, these are all approximations given the variance for each case. For those with a faster rate, this length may only be able to cover the past two months. For those with a slower rate, this length may be enough to cover the past four months. About 50-70 stands are taken weighing over 40 mg.
Substances That Can Be Detected
The testing methodology will be chosen depending on the kinds of drugs that need to be checked. Some will appear better with one sample and not another. When it comes to hair, the laboratory technicians should be able to detect things like marijuana, cocaine, methamphetamine, opiates, and phencyclidine. These are some of the most commonly abused types of drugs right now with all of them being included in the Federal Government’s mandatory list. In short, those who have been taking these drugs will generally be caught even if they stop doing so about 90 days from the testing date. They must stop much earlier to be sure of passing a hair follicle drug test. Better yet, they shouldn’t take these banned substances at all.
About Body Hair
We all know that the head is not the only place where hair can grow. There is hair all over our bodies from our face down to our legs. In fact, the hair on our arms stand up when we feel overwhelmed as in goose bumps. Some of these hairs grow in places where we don’t really want them so we shave them off on a regular basis. Do drug testers get hair samples in other areas of the body? The answer is yes, they could. However, it isn’t usually done this way. This is because the rate of growth is much slower so it’s hard to place the time period in which the substances were taken.
Dealing with Extreme Cases
We have established that hair strands on the head are the preferred source of samples. They grow at a fairly predictable rate at a good length so it is easy to obtain samples and examine the traces within the covered period. This method should work in the majority of the cases but there are instances when it may fail. For example, there are people who suffer from baldness so they cannot be expected to produce the amount of hair necessary for the test. The lab technicians may still try to get whatever samples they can from the head and augment these with hair from other parts of the body. Pubic hair is generally excluded. If this proves inadequate, then urine testing may be recommended.
The Effectiveness of Hair Testing
Body fluid testing has its own strengths but hair tests have proven to be invaluable when trying to determine usage over a long time period. The problem with blood is that the traces are quickly flushed out of the bloodstream within a few days. It would be easy for users to skip for while just to get good results before going back to the habit. The same is true for urine though the metabolites tend to linger a bit longer. With hair follicles, the 3-month coverage makes it much harder to mask usage.