During new hair formation, drugs, chemicals and medications can be incorporated into the hair. There the substances end up being stored and they grow fixed into the hair matrix externally. In a trip meter-like manner, information is later able to be delivered about exposure at a particular time point – or at least that has been our reasoning until now.
Fire alarm due to antimony
Just how false analysis can be is something that many cases have shown: eight years ago a chief firefighter in Florida sounded the alarm, believing many of his co-workers to be poisoned. In his worried state he engaged the American health department CDC (Centers for Disease Control and Prevention) after antimony levels were detected in the hair of 30 firefighters. More than a million firefighters carry uniforms in which antimony monoxide is utilised as a fire retardant. The CDC confirmed the strongly elevated levels in the hair analysis but still gave the all-clear.
Blood and urine probes had no such elevated levels – which is evidence supporting the idea that the misinterpretation of hair analyses can lead to erroneous assessments. The CDC also gave the all-clear in other cases involving elevated mercury levels.
Drug analytics and failure potential
Hair analysis plays an extremely important role in forensic drug analytics. The consumption of illegal substances is able to be detected after months or even after years. The need for such testing is substantial. On the internet one can now apparently solve the problem with little money. Zydot® is supposed to draw all contaminants and illegal substances out of urine. Zydot ultra clean is said to even wash drugs and medications out of the inner parts of the hair.
Drug findings in hair demonstrate pitfalls
Until now it had been believed that drug analytics in hair deliver watertight evidence. In order to disprove this, toxicologist Prof. Volker Auwärter and his team at the University of Freiburg (Germany) swallowed capsules with the synthetic cannabis active substance dronabinol.
Over a period of a month they took 2.5mg of it daily. Oral intake is supposed to ensure that the hair is prevented from getting contaminated. THC was detectable in the blood of subjects, but did not turn up in head and beard hair or in body hair. The breakdown product THC-COOH, which is created exclusively in the body, was indeed found in the hair.
Until now it has been assumed that the substance manages to find its way through the bloodstream to the hair root, thereby demonstrating that the consumer has consumed cannabis actively and not taken it up passively. The test disproves this already legally utilisable false assumption. The metabolite managed to get onto the surface of the hair via sweat and sebum. Conversely this also means that a negative hair probe finding does not tell us anything about cannabis consumption.
“The new findings in particular with respect to analyses of children’s hair are of significance in the context of custody rights”, says Auwärter, “since cannabinoid-transfer is highly probable with close body contact and can lead to the fully wrong conclusion”. In several court proceedings parents had their custody rights removed on account of hair probes from children being able to demonstrate the presence of drug metabolites, although the parents had insisted that they had not given any drugs.
Cutting instead of blowing?
For some ten years now information on alcohol drinking behaviour has been able to be recorded via retrospective hair analytics. For this purpose the alcohol markers ethyl glucuronide (EtG) and fatty acid ethyl ester (FAEE) are ascertained quantitatively.
Ethyl glucuronide is created in the liver even with only minor alcohol consumption. Hair analysis is well suited to “medical-psychological examination” employed as an abstinence control. The cut-off level used here is 7 pg/mg. Alcohol abuse and abstinence behaviour is able to be shown over a long time period when looking at hair. In driving aptitude diagnoses three centimetres of a head-proximal section of hair is normally examined and if the measured level falls below the cut-off level abstinence of three months can be justifiably asserted.
A supplementary examination of fatty acid ethyl ester (FAEE) can act as a sensible addition to some questionnaires. Fatty acids released from fat via metabolic processes react with ethanol to form fatty acid ethyl esters. This occurs in the sebum glands in the hair, where this product is stored and is progressively spread into the hair during hair growth.
Ethanol metabolites are detectable in serum for hours, in urine for seven days, in full blood for over two weeks and in the hair over months. In a consensus of the Society of Hair Testing a FAEE concentration of over 0.5 ng/mg hair and/or EtG concentration of over 30 pg/mg hair in scalp proximal 0–6 cm is interpreted as distinct evidence of excessive and regular alcohol consumption.
Blond or brunette – this is decisive
Use of hair analysis for the purpose of acquiring evidence of doping is permitted in France. It is nonetheless not approved by the World Anti-Doping Agency (WADA). A positive finding alone is not sufficient grounds for a ban.
Colourings and pigments such as melanin in hair concentrate certain substances at elevated levels. Those with dark hair can end up with more drugs or other substances incorporated in their hair. In contrast these substances are stored in blonde hair in more minor amounts, says a study by Skopp et al.
Hair biomonitoring is controversial
Patients who suspect environmental contamination, pollution in the workplace or the undersupply of trace elements to lie at the origin of an ailment hope to obtain help through hair analyses.
Hair analyses for quantifying environmental stresses have been increasingly offered in the last years in diverse places.
No recognised norms, reference or environmental medicine-based thresholds have been ascertained for environmental medicine-based results analysis. Information on normal range is characterised in general by considerable variations from element to element and from laboratory to laboratory.
With respect to screening procedures which can be used for larger populations, the human-biomonitoring commission of the Austrian Federal Environment Office assessed hair analysis to only be able to be employed in examining contamination from nicotine, inorganic arsenic compounds and lead.
The US-American Agency for Toxic Substances and Disease Registry (ATSDR) views hair analysis as only being suitable in establishing methyl mercury contamination in individual cases.