O4: Cases of chronic systemic cannabis exposure in young children determined by hair analysis

Abstract

Introduction The detection of passive exposure to drugs present in the environment is often considered a critical pitfall in the use of hair analysis. This capability, however, of hair analysis to detect environmental exposures is of substantial benefit in identifying children passively exposed to drugs in their environment through direct exposure to drug smoke or ubiquitous presence of drug residues on surfaces in the home. In these two cases, children under the age of two years presented to hospital with clinical signs of possible drug intoxication. Child #1 has been removed from his biological home due to concerns about neglect and presented as excessively somnolent. Child #2 presented to hospital with signs of acute intoxication including emesis, sedation, impaired motor coordination, and produced a positive urine analysis for THC. Investigation for chronic environmental drug exposure was undertaken for both of these children and additional family members by collection of hair samples. Methods Hair samples were segmented to reflect the relevant time period of analysis applying a growth rate of one centimetre of hair per month. A minimum of 80 milligrams of hair was decontaminated with methlylene chloride, pulverized, extracted, and analyzed by liquid-chromatography tandem-mass spectrometry for the presence of THC-carboxylic acid. Additional analysis for exposure to cocaine and cocaine metabolites (benzoylecgonine, norcocaine, cocaethylene) was conducted by GC-MS analysis following segmentation of 10 milligrams of hair, overnight incubation in methanol, and derivatization by BSTFA. Results Child #1 tested positive for THC-carboxylic acid in a fivemonth section of hair at a concentration of 0.43 picograms per milligram, cocaine at a concentration above 16.00 ng/mg, benzoylecgonine at a concentration of 2.36 ng/mg, and trace amounts of norcocaine. An older sibling also tested positive for cocaine, benzoylecgonine, and THC-carboxylic acid. Sibling (n = 3) hair drug concentrations in this family were inversely proportional to age. Child #2 tested positive for THC-carboxylic acid in a six-month section of hair at a concentration of 0.22 picograms per milligram. Both parents tested negative for cannabinoids in hair, which was consistent will clinical suspicion that the exposure occurred outside of the family home. Conclusion Due to an absence of evidence that THC-carboxylic acid can be found in environmental cannabis smoke or in sweat analysis of cannabis users, coupled with the decontamination of these hair samples; the findings suggest that both children and one sibling have experienced chronic systemic cannabis exposure due to the presence of THC-carboxylic acid in their hair samples. Child #1 also presents with a high risk of systemic cocaine exposure due to the presence of norcocaine in their sample. These cases highlight the clinical value of hair analysis in determining chronic exposures in pre-verbal children, incapable to self-reporting their experiences to health-care providers.