Environmental exposure to illicit drugs is an indirect marker of harm. Exposure testing is different from random drug testing. Zero Metabolite ≠ Zero Exposure
• Child hair samples often do not contain drug metabolites, because the child has not ingested illicit substances.
• Standard drug tests use government workplace testing guidelines, which can report negative results even when a native drug is present.
• Hair testing is 3.5x more likely to detect methamphetamine exposure. Combined with the D/L methamphetamine isomer testing option, a hair test can give professionals the information they need to make an informed decision.
• The children in environments where they are exposed to illicit drugs are at higher risk for abuse and neglect. 4.2 times more likely to experience neglect, 2.7 times more likely to experience abuse, and 43% of child abuse cases involve substance abuse.
The Federal Interagency Task Force for Drug Endangered Children (2010)
Properly conducted forensic drug analysis of hair specimens is valuable for identifying exposure of children to environments where illicit substance abuse is a problem. Specialized drug testing for environmental exposure should take into account the differences between levels of native drug compounds and drug metabolites in the sample. Exposure testing should also recognize that workplace testing guidelines set forth by the Substance Abuse and Mental Health Services Administration (SAMHSA) are not the appropriate parameters for conducting this type of analysis. The health and well-being of a child are far too important to not take these factors into account.
Environmental exposure analysis can be carried out using several specimen types — oral fluid, urine, or hair for example — but is most effectively carried out using hair samples. For example, a recent study found that hair samples were 10 times and 3.5 times more likely than oral fluid and urine respectively to detect environmental methamphetamine exposure.
Many drug testing groups apply SAMHSA workplace drug testing guidelines to environmental exposure testing, but this is problematic for two reasons. First, responsibly done, exposure analysis should examine native drug compounds first and metabolites second. Under SAMHSA guidelines only drug metabolites are analysed for several drug classes. Marijuana exposure, for example, will result in detectable levels of native- THC in hair samples, but little or no carboxy-THC, the metabolite that results from marijuana ingestion, and which is mandated under SAMHSA as the analyte for cannabinoid testing. The same can be said for cocaine versus benzoylecgonine, the cocaine metabolite. When detected, drug metabolites in a child’s specimen may indicate very heavy drug use by adults and subsequent exposure to the child, heavy enough to cause incidental ingestion, or that the child has gained access to, and used, an adult’s illicit substance. But, testing solely for the drug metabolite, which can only occur from ingestion, may completely miss the signs of exposure evidenced by the presence of the native drug in the hair sample.