Society of Hair Testing Interview: Dr Pascal Kintz

You don’t get the name 'The Father of Hair Testing' without good reason, and Dr Pascal Kintz has certainly earned the title. Over three decades, he has helped advance the science to the extent that hair testing is now routine. As well as being a founding member - and later president - of the Society of Hair Testing, Dr Kintz has also provided analysis on a number of high profile cases, including determining the then-Ukrainian presidential candidate Viktor Yushchenko had been poisoned with dioxin in 2004.

We caught up with Dr Kintz to discuss the past and future of hair testing ahead of the 22nd Scientific Meeting of the SoHT, where he will be one of the keynote speakers.

Cansford Labs: What is it about the world of hair testing that fascinates you? What first sparked your passion and what drives you?

Dr Pascal Kintz: In the late 1980s, it was difficult to test for drugs at the nanogram to milligram level – a real challenge. Today, even if the analytical aspects are more or less solved, there is still a great debate on how to interpret the findings. To be an active participant in this field, shaping how results will be interpreted, is not only very challenging, but also very exciting.

CL: What are the biggest changes and advancements in the sector that you've seen since the late 80s?

PK: It seems strange to think that now, at a time when our analysis is so accurate, that we once couldn't even detect certain substances, but it's true. So, the biggest changes have really been in analysis and discovery. Progress in the testing of hair for drugs has really been linked to advances in analytical science. In 1979, only radiolabelled immunoassays (RIA) were sensitive enough to detect the presence of a drug in a hair sample. However, scientists were only able to detect a group of substances, due to cross reactivity in the immunoassay.

For example, in the group of opiates, it was not possible to distinguish an over-the-counter drug - such as codeine or ethylmorphine - from a prescribed drug like morphine, or a drug of abuse, like heroin. The result was just a simple “yes” or “no” for the presence of opiates. Later, the use of GC/MS allowed scientists to specifically identify the analytes and to document the possible abuse of drugs, such as heroin.

As I said, the analytical aspects of hair testing have now more or less been solved, but the interpretation of those results is still hotly debated.

CL: Are there other substances that we can test for now that we couldn’t before?

PK: Because of low concentrations in hair, cannabis identification has only been performed relatively recently in comparison to heroin, amphetamines or cocaine. The development of bench-top LC/MS/MS testing has also allowed the identification of a single dose of pharmaceuticals, in the picogram range, which is 1,000 times less concentrated than cocaine or opiates. The same technology was also useful to test for alcohol markers, with cut-offs at 7 or 30 pg/mg for ethyl glucuronide.

CL: The 22nd Scientific Meeting of the SoHT is coming up in June. What can attendees expect?

PK: Attendees will be presented with new data, new interpretations and new perspectives. And, of course, the meeting will bring together all the active scientists involved in hair testing to meet and discuss their findings. This conference will be a place to acquire new scientific knowledge – but it will also be a place to discuss business.

CL: Can you tell us a little about your keynote? For example, what are the difficulties in interpreting hair test results from children?

PK: Whereas the detection of drugs in a child’s hair unambiguously shows drug handling in the child’s environment, it is difficult to distinguish between systemic incorporation into hair after ingestion or inhalation and external deposition into hair from smoke, dust or contaminated surfaces. However, the interpretation of hair results with respect to systemic or only external exposure is particularly important for a realistic assessment of the toxic health risk to the child.

CL: Is it harder to run tests on samples taken from children?

PK: Excepting the lower amount of biological material in children versus adults, there is no specific analytical problem when processing samples from children. The issue is the interpretation of the findings, with respect to the different pharmacological parameters.

Children are not "little adults" but rather immature individuals whose bodies and organ functions are in a continuing state of development. It is not surprising, therefore, that the pharmacokinetics and toxicity of most drugs vary considerably throughout the paediatric age range and they may differ profoundly from findings in adults. It must be considered that the amount of hair from children available for analysis can be low, particularly when several drugs have to be tested.

It must also be noted that hair from children is finer, more porous, and has a higher risk contamination from sweat than adults. Also, because of the changing speed at which hair grows, it is very difficult to state any window of detection when testing for drugs in young children.

CL: Are you able to hair test newborn babies?

PK: That’s even more complicated as it has been demonstrated that drugs can be incorporated during pregnancy into the hair of the foetus, which will contribute to positive findings after delivery. Trans-placental transfer of drugs, with accumulation in fetal hair, has been documented. Hair measurement for drugs of abuse or pharmaceuticals in neonates is a useful screening method to detect intrauterine exposure to the drug.

Also, it seems that there is a good correlation between the amount of the drug that was consumed by the mother during pregnancy and the hair findings of the newborn at the time of delivery.

However, several weeks or months after delivery, identification of a drug in the hair can indicate in-utero exposure, exposure after delivery or a mix of both situations. No paper has been published about the disappearance of drugs from hair after discontinuation of use or exposure in the case of in-utero exposure.

CL: You're known as the 'Father of Hair Testing'. How do you feel about the name?

I’m more than happy. But I am not alone. Manfred Moeller, from Germany, opened the doors of this new science for me. Later, discussions with him and with Ed Cone, Naresh Jain and Hans Sachs allowed this field of forensic science to truly take shape.

CL: What is next in your studies?

PK: To have hair used in doping control. I have been working on this topic since 1997 – but it’s very political!

In June this year, Cansford Laboratories will be hosting the 22nd Scientific Meeting of the Society of Hair Testing, a two-day conference exploring the latest discoveries, studies and findings in the world of hair testing. Dr Kintz will be presenting a keynote session, titled, “Difficulties when interpreting hair analysis results for children. Special focus on
methadone”.