28/08/2017
Is hair strand testing of children's hair scientifically reliable? Is there any accountability?
Whereas the detection of drugs in a child's hair unambiguously shows drug handling in the environment of the child, 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 in case of children for a realistic assessment of the toxic health risk and with the risk of making wrong decisions.
In seeking some redress for a parent, one might think that there would be, (as with any other expert field), a complaints body/ overarching expert institute to whom one could complain about evidence given by an expert and in particular their 'interpretation' of the hair strand test results. Suprisingly there isn't. So it is the case that any 'expert' giving evidence on hair strand testing interpretation is immune other than in the limited time Court setting with judges who are not trained in the forensics or sufficient level of Chemistry and Biology to make such rulings.
In Ontario Canada Motherirsk centre was subject to expert roports and a judgement on the validity of the system they used. The full report is worth reading to learn more but this section in particular is important
https://www.attorneygeneral.jus.gov.on.ca/english/about/pubs/lang/ -76
In the UK there has been limited debate on the subject with those with vested interests ruling the roost, however there was one company who were criticised and folded for erroneous testing, (see http://www.familylawweek.co.uk/site.aspx?i=ed101125). The Court accepted four general propositions:
a. The science is now well-established and not controversial.
b. A positive identification of a drug at a quantity above the cut-off level is reliable as evidence that the donor has been exposed to the drug in question.
c. Sequential testing of sections is a good guide to the pattern of use revealed.
d. The quantity of drug in any given section is not proof of the quantity actually used in that period but is a good guide to the relative level of use (low, medium, high) over time.
However Baker J added: "I conclude by emphasising again that in appropriate circumstances the family justice system requires, and will continue to require, expert evidence to ensure that it makes the right decisions about the future of children. I repeat what I said in Re JS [2012] EWHC 1370 (Fam) at para 47: 'Whilst the courts always have to be vigilant to guard against the proliferation of experts in family proceedings, the court must, in my judgment, always have available to it the necessary expertise to make the right findings in these important and difficult cases.' As Ryder J has recently observed in "Judicial Proposals for the Modernisation of Family Justice" (July 2012) (at para 41): 'In every case, the judge should be able to say: is your expert necessary i.e. to what issue does the evidence go, is it relevant to the ultimate decision, is it proportionate, is the expertise out with the skill and expertise of the court and those already involved as witnesses by reference to the published and accepted research upon which they can rely and of which the court has knowledge.' Plainly hair strand testing for drugs satisfies all of these criteria. But as this case illustrates, a high degree of responsibility is entrusted to expert witnesses in family cases. Erroneous expert evidence may lead to the gravest miscarriage of justice imaginable – the wrongful removal of children from their families."
The endorsements of the Court should have made it clear that this did not apply to hair strand testing of children's hair and this gets nowhere near the issue of interpretation of the results. How can the Court have good evidence from an expert when the issue of interpretation of the results from children's hair is so unknown. Further even now new research shows the presence of Cannaboids in adult hair does not prove cannabis consumption (see https://www.nature.com/articles/srep14906 ). To quote:- 'Hair analysis for cannabinoids is extensively applied in workplace drug testing and in child protection cases, although valid data on incorporation of the main analytical targets, ∆9-tetrahydrocannabinol (THC) and 11-nor-9-carboxy-THC (THC-COOH), into human hair is widely missing. Furthermore, ∆9-tetrahydrocannabinolic acid A (THCA-A), the biogenetic precursor of THC, is found in the hair of persons who solely handled cannabis material. In the light of the serious consequences of positive test results the mechanisms of drug incorporation into hair urgently need scientific evaluation. Here we show that neither THC nor THCA-A are incorporated into human hair in relevant amounts after systemic uptake. THC-COOH, which is considered an incontestable proof of THC uptake according to the current scientific doctrine, was found in hair, but was also present in older hair segments, which already grew before the oral THC intake and in sebum/sweat samples. Our studies show that all three cannabinoids can be present in hair of non-consuming individuals because of transfer through cannabis consumers, via their hands, their sebum/sweat, or cannabis smoke. This is of concern for e.g. child-custody cases as cannabinoid findings in a child’s hair may be caused by close contact to cannabis consumers rather than by inhalation of side-stream smoke.'
In this case Cannabis was found in a 20 month old child. It was declared to be by contamination and not ingestion - During the course of the hearing – and very helpfully – Miss Little attempted to secure definitive advice from a Principal Forensic Toxicologist, Marcus Donahue. Miss Little's note of their telephone conversation includes this – "most likely Y has ingested cannabis – i.e. taken in to the body from either the passive inhalation of cannabis smoke or the unintentional / deliberate inhalation or by eating… Studies have shown that children of a similar age to Y can provide a positive result for both THC (tetrahydrocannabinol) and THC-COOH (carboxy-tetrahydrocannabinol) from the passive inhalation of cannabis smoke… THC concentrations in the hair of children (who are passive inhalers) can be in the same range in hair, or even higher, than adults who are using cannabis. This could be due to the children having a lower volume of distribution (from a lower body weight) compared to adults. THC-COOH concentrations in children's hair, however, would be expected to be lower than adult smokers (my emphasis)."
Full case at http://www.bailii.org/ew/cases/EWHC/Fam/2014/486.html
Essentially drugs can be found in hair through Passive inhalation of drug smoke, Contact with drug smoke, Contact with sweat or sebum (skin oil) of user of drugs, Physical contact of a drug substance accidental or meaningful ingestion of drugs. Where-as SOHT state that parent drug and metabolite must be found the Court recently accepted presence of the metabolite in this case can be indicative of consumption ie ingestion (see:-
http://www.pumpcourtchambers.com/blog/drugs-and-hair-strand-testing-after-r-2017-1-ewhc-364 however not presence of the parent drug alone!
In seeking answers to whom to complain about the interpretation and methodology used, after all to quoute Baker J 'Erroneous expert evidence may lead to the gravest miscarriage of justice imaginable – the wrongful removal of children from their families,"contact was made with various organisations. SOHT (the body of Hair strand test companies/ individuals involved in the industry) has a remit to attempt to set standards for the industry. When contacted they recommended 'You can complain to the Accreditation body, UKAS.' UKAS is not an appropriate body since their remit is 'UKAS is the UK’s National Accreditation Body, responsible for determining, in the public interest, the technical competence and integrity of organisations such as those offering testing, calibration and certification services.'
Fine if you are complaining about the hair strand test company and their equipment, but no good for the 'interpretation' of the results.
Another route given by SOHT was the forensic regulator. However they responded 'The role of the Forensic Science Regulator is limited to work done for the purposes of the Criminal Justice System (CJS). It follows that the Regulator is only able to deal with issues related to the CJS. Where hair analysis had been done as part of the CJS processes and similar work had been done as part of a separate, but related, family law proceeding the Regulator could only consider the work done on behalf of the CJS.' Which is no good when the work was done for the Police but the results then used in the Family law Court and interpreted by an 'expert.'
Dr Pascal Kintz when asked 'who is the independent complaints body and/ or regulator for hair strand testing/ experts when SOHT does not fulfill that role,' gave a short and simple reply – ''No-one.'' So there you have it.
Why is this such an issue? Let's take a scenario where a parent is under medication. The other parent accuses of the child being sedated in private law proceedings. System kicks off. Case becomes public law child protection issue. Parent has to have their child's hair tested and small amounts of their own medication are found in the child's hair.
For the layman, and those without having looked into these issues it would be simple, drug found so therefore must have been given them, yet this is not at all true. The hair strand test reveals the parent drug, ie minute traces of the drug the parent had been taking yet without testing for the metabolite, ie a related drug only formed by having been through the body systems, all it proves is the child had been exposed to that drug which could have been for a number of reasons:-
1.Contamination from surfaces, cutlery, plates, drinking vessels, hair brushes, daily contact etc etc.
2.Through contamination from sweat and/ or sebum whether via contact with skin, sweating, brushing your hand in the child's hair etc etc.
3.In the case of some drugs through exposure due to being in a place where powders or smoke are present.
Some worthwhile papers looking at these issues are:-
Overview of hair analysis
http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-73562001000200015
http://mefanet.upol.cz/BP/2005/2/199.pdf
UN Guidelines
https://www.unodc.org/documents/scientific/ST_NAR_30_Rev.3_Hair_Sweat_and_Oral_Fluid.pdf
Phd thesis on the issues in-depth
https://clok.uclan.ac.uk/3031/1/Xiang_Ping_thesis_1-157.pdf
Research document for the Analysis of Drugs of Abuse in Human Hair:
Surface Contamination and Localization of Analysis
https://www.ncjrs.gov/pdffiles1/nij/grants/249856.pdf
No-one is safe with co***ne contamination from banknotes!
https://www.theguardian.com/society/2015/mar/19/contaminated-banknotes-caused-bus-driver-test-positive-co***ne
Pitfalls in hair analysis
https://gtfch.org/cms/images/stories/media/tk/tk71_2/Pragst1.pdf
Dr Pascal Kintz came up with a novel analysis of the same drug in similar circumstances to a similar case, comparing the analysis in this case it appears that the article Interpretation of hair findings in children: about a case involving carbamazepine is summarised as 'This office has been recently involved in a case dealing with child custody, where the final outcome was difficult to establish. The following concentrations were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the hair of a 21-month-old girl: 154 (0-1 cm), 198 (1-2 cm), 247 (2-3 cm), and 368 pg/mg (3-4 cm) after decontamination. Obviously, the concentrations measured in the hair were much lower than those observed in patients under daily treatment. In this sense, the frequency of exposures appears as infrequent (low level of exposure), with marked decrease in the more recent period. However, the girl was never prescribed carbamazepine and the mother, who was under carbamazepine therapy, denied any administration. The Judge asked if this could result from a single exposure and at which period. At least, three possible interpretations of the measured carbamazepine concentrations were addressed: (1) decrease in administration in the more recent period; (2) increase of body weight due to growing, so the same dosage will result in lower concentrations in hair; and (3) sweat contamination from the mother at the time the girl is with her in bed, the older hair being in contact longer with the bedding. In this case, it was impossible to conclude that the child was deliberately administered carbamazepine. The results of the analysis of hair could indicate that she was in an environment where carbamazepine was being used and where the drug was not being handled and stored with appropriate care. There are many differences between the hair from children and those from adults: hair from children is thinner and more porous, the ratio anagen and catagen phases are not maintained, and the growth rate can be different, at some periods, from the usual 1 cm/month. These differences, together with the influence of PK-PD parameters are reviewed in this paper, as a basis for suitable interpretation. In view of these results it is proposed that a single hair analysis should not be used firmly to discriminate long-term exposure to a drug when dealing with children.' The full article is at http://onlinelibrary.wiley.com/doi/10.1002/dta.1596/full
So from this accepted article, on those levels of Carbamazepine it is impossible to say that the child ingested the drug, but that contamination could explain the levels of parent drug found. Almost all data on children has been extrapolated from adults, with no way that the new and novel forensic science can be sure that their guesswork is right. Cut off levels for children are being used as the same ones for adults with no taking into account the major differences between children and adults. Children's different metabolism and body mass isnt being taken into account, and neither are cut off levels varied from those of adults!
The amounts being measured are usually reported in Nanograms for adults, but in order to impress the court experts appear to often use picograms as it appears more. To put this is context:-
1kg = 1000gm = 1 000 000 000 000 000 pg
1gm = 1000mg = 1 000 000 000 Ng = 1 000 000 000 000 pg
1mg = 1 000 000 ng = 1 000 000 000 pg
1 Ng = 1000pg
For someone on a dosage of 400mg twice per day on Carbamazepine translated into Ng equivalent this is 800, 000, 000 Ng and 800, 000, 000, 000 Pg on a daily basis or 24 000 000 000 000 pg in a month.
In researching the issues, as having some higher level experience of Chemistry there are a number of issues not being addressed by the experts in their reporting:-
1.Child are not little adults. Their metabolism and body mass is completely different, the lower the body mass the higher the level of drug will register givin a false level reading. Metabolism is completely different and cannot be compared to adults.
2.No Judge should make a determination based on the results of the hair strand tests alone and certainly not on the presence of the parent drug alone.
3.The Court needs to be made fully aware that you cannot compare assumptions from adults to children and that the science is not fully developed and unsafe given the unknown factors.
4.Average growth of hair is highly different between adults and children and even between children.
5.It does not need homogenous concentrations in the hair for it to be contamination. There are many factors that can lead to the amounts in hair becoming less in the newer hair such as residual run out, and increasing body mass of the child. Similar decreasing amounts are found in many studies of adults and are indicative of nothing.
6.No judge should make a decision based on children's hair strand testing without testing for the metabolite.
7.There must be consideration of other sources of contamination such as from sweat/ sebum, skin to skin contact, exhalation, sneeze, saliva, traces of a kiss, or the sharing of possessions such as hairbrushes/ flannels/ surfaces, sharing flannels/ toothbrushes/ drinking from same glass, physical contact, etc etc the younger child neded more personal care and attention from parent/caregiver thus exposure would be higher.
8.There has been no research to show the extent to which sweating affects exposure of any chemicals from adult sweat/ hair to children's hair but it is a well-known possibility. Carbamazepine was studied in Carbamazepine levels in head hair of patients under long-term treatment: a method to evaluate the history of drug use. T Psillakis, AM Tsatsakis, P Christodoulou, M Michalodimitrakis, N Paritsis and E Helidonis J Clin Pharmacol 1999 39: 55. The experi ments showed a reduc tion on drug concentra tions from the 1st to the other seg ments: this is due to drug degradation over time or to drug extraction from the hair by washing with hair cosmetics. The demonstration of the wash out of CBZ is not a newly established phenomenon. 40 patients were involved from the age of 5 upwards. The dura tion of CBZ treatment affects the CBZ hair levels only slightly. On the other hand, hair CBZ levels were found to be dependent on the dosage of CBZ. Higher val ues of CBZ levels were monitored when increased doses of CBZ were administered to the patients.There was no correlation between serum and 1st hair sec tion CBZ concentration because the serum drug level was dependent not only on dosage but also on other parameters, such as albumin levels or the patient’s weight! The possibility that drugs can be transferred into the hair during its growth from other physiologic pools, such as sweat or sebum, cannot be discounted, because drugs such as amphetamine, co***ne, methadone, and certain antiepileptic drugs have been detected in these matrices and incorporation has been demonstrated. In a study entitled Relation Between Dosage of Carbamazepine and Concentration in Hair and Plasma Samples From a Compliant Inpatient Epileptic Population, Therapeutic Drug Monitoring, they found a consistent incorporation of carbamazepine over time in such a population. The linear relation between daily dosage and hair concentration also shows that even up to a daily dosage of 2400 mg, the incorporation process does not appear to become saturated. The significant variation in carbamazepine concentration between patients receiving the same daily dosage was not unexpected, given the established variability in absorption and metabolism of the drug.
9.The limit of detection (LOD) is the lowest level at which the presence of a substance can properly be said to be detected. The limit of quantification (LOQ) is the lowest level at which the amount of a substance is sufficient for it to be quantified. If results are below the LOD or even below the LOQ they are at the limits of the test's capabilities and, as a result, there can be significant analytical errors within this range. In addition, the LOQ can vary depending on the "noise" produced by the instruments being used. Further levels maybe below LD but in any event LOQ is so low in perspective it is very very difficult to make assumptions in the case with parent on long-term prescribed drugs.
10.Some experts say that detection of no parent drug in the wash means that contamination can be ruled out. It cannot as the level of free surface contamination in the hair maybe below LD, the history of storage of the hair needs to be taken into account as well as frequent washing of children's hair never mind that some drugs are volatile and\ or lipophilic and readily absorbed into the hair.
Absorption into hair
Some drugs are highly volatile and lipophilic, which means that they bind easily and pe*****te easily, hair is mainly made up of protein, between 65 and 95 % and between 1 and 9 % lipids. These cells change to a shingle-like structure and contain amorphous proteins. The cell membrane complex consists of proteins and a protein–lipid complex originating from previous cell membranes. This part of hair is most vulnerable to chemical and mechanical attack and is the primary diffusion point for incorporation and elimination of drugs.
As can be expected,lipophilic drugs are preferentially deposited in the cell membrane complex. Three additional key chemical and physical factors, namely the melanin content of hair and the lipophilicity and the basicity of the drug itself, also influence drug incorporation (Pragst, 2006). The degree of disposition of a drug in hair closely relates to these three key factors, and Nakahara et al. (1995) have reported that a number of drugs have an affinity for melanin in vitro. Nakahara concluded that numerous factors, including pH, the presence or absence of various functional groups within the specific molecular configuration of the scrutinized drugs, and the presence of eumelanin (as opposed to pheomelanin) are important in this respect Pragst (2006).
Pascal Kintz notes in his book that lipophilic (referred to as lipid loving drugs in P Kintz’s book) drugs pass easily through the cell membrane of the hair shaft in vitro and in vivo. Stout and Ruth in Pascal Kintz’s book concluded the more lipophilic the substance, the higher is it’s accumulation in hair, owing to it’s greater ability to pass through cell membranes.
Both in vivo and in vitro experiments have taken place in the lab with many drugs to simulate binding and uptake in hair. Another thing to mention about these particular drugs is that they come from a group called prodrugs, which means that the drugs produce their own active metabolite, it becomes active when the bodies enzymes activate it (p450) so now we know that with other drugs when metabolite is weaker than the parent drug after ingestion but with a prodrug the metabolite is active so can be stronger than the parent compound in some cases.
Framework for the incorporation and removal of drugs into and out of hair. The passage of time and hygiene are important components for contamination. Freshly contaminated hair is more readily detected as contaminated than is hair that has been rinsed because of the high concentration of drugs on the outside. Over time, the loosely bound drugs on the surface can migrate into the interior and become more tightly bound. Additionally, hygiene removes the surface-bound drugs. (Blank, D.L. and Kidwell, D.A., in DrugTesting in Hair, Kintz, P., Ed., CRC Press, Boca Raton, FL, 1996, p. 17.)
In summary, there is little support for inaccessible regions in hair. The data that are the basis for this model can readily be explained by diffusion through a chemical barrier. Because of the porous nature of hair, which varies due to cosmetic treatments and genetics, hair can entrap drugs quickly from the environment, and the drugs will not readily be removed. After normal hygiene, these entrapped drugs will look like those from a drug user to any wash kinetic procedure. Interpretation of a positive result must be made with caution to account for drugs that may be present in the environment of a nondrug user.
Fresh contamination is more representative of a consistent drug user, where time has not elapsed for personal hygiene to remove the loosely bound surface contamination.
Early work was criticized for not following the exact procedures specified, with the implication being that if only the procedures had been followed exactly, these contaminated hair samples would have been determined as contaminated. To more fully evaluate wash kinetics and remove any doubt that proper procedures were being followed, we sent (in a blind fashion) negative hair samples, hair from known drug users, hair from the children of drug users, and negative hair exposed to drugs in our laboratory to a commercial laboratory for analysis. Many of the hair samples from the users came back as contaminated (which was surprising) or as “use cannot be determined.” However, one of the four negative hair samples, exposed in the laboratory, was reported as positive.
Drugs that are placed on hair when it is dry or in organic solvents are readily removed. This early work may have provided a false sense of security that hair could be effectively decontaminated. In contrast to dry or organic solvents, when hair is exposed to aqueous solutions of drugs, the hair readily incorporates the drugs, and the hair is difficult to decontaminate. Water is an important part of this process because it provides a medium for diffusion of the drugs into the hair, and it expands the cuticle and the proteins in the hair, facilitating hair permeability.
For furthe information, similar concerns or media interest please email [email protected]
88. Studies have suggested that, following chronic or heavy use of a drug, certain drugs such as co***ne may persist in tissues for at least a few months after the last use. As a result, it cannot be discounted that, following chronic or heavy use of a drug, tissue depots may result in low positive…
