- Published on 02 November 2013
- Written by Paul Armentano, NORML Deputy Director
Baltimore, MD: The psychoactive cannabinoid THC may be present in the breath of subjects who recently inhaled marijuana, according to clinical trial data published online in the journal Clinical Chemistry.
Investigators at the National Institutes of Health in Baltimore, Maryland and the Karolinska University Hospital in Stockholm, Sweden analyzed the exhaled breath of occasional and habitual marijuana consumers shortly after subjects inhaled a standardized cannabis cigarette of 6.8 percent THC. Researchers sought to identify whether THC, its primary metabolite THC-COOH, or cannabinol (CBN), a non-psychoactive cannabinoid, were present in breath at detectable levels following smoking.
Researchers reported identifying the presence of THC in both occasional and in regular consumers for limited periods of time following subjects' inhalation of marijuana. Authors concluded: "Among chronic smokers (n = 13), all breath samples were positive for THC at 0.89 hours, 76.9 percent at 1.38 hours, and 53.8 percent at 2.38 hours, and only one sample was positive at 4.2 hours after smoking. Among occasional smokers (n = 11), 90.9 percent of breath samples were THC-positive at 0.95 hours and 63.6 percent at 1.49 hours. One occasional smoker had no detectable THC."
No samples tested positive for the presence of the carboxy THC metabolite and only one subject tested positive for the presence of CBN.
Authors concluded that breath analysis potentially offers an alternative matrix for identifying subjects who had recently inhaled cannabis. The study did not attempt to correlate the detection of THC in breath with actual behavioral impairment of any kind.
Swedish researchers had previously reported in April that breath analysis is sensitive to the presence of THC in those who have recently consumed cannabis as well as other controlled substances. That study reported that 89 percent of subjects tested positive for THC in breath. Investigators reported that the results "confirmed the potential of exhaled breath as an alternative specimen for toxicological investigations."
- Published on 28 September 2013
- Written by Paul Armentano, deputy director of NORML
The internet is teeming with claims regarding the use of zinc supplements as a strategy for thwarting drug tests. But is there any hard science to support these anecdotes? The answer is "yes" -- and "no."
The most high-profile study substantiating these claims comes from the July/August 2011 edition of the Journal of Analytical Toxicology. The paper, entitled "Zinc Reduces the Detection of Cocaine, Methamphetamine, and THC By ELISA Urine Testing," assessed subjects’ use of zinc sulfate and zinc supplements as methods to trigger false-negative test results. During phase I of the study, participants adulterated positive urine samples with a zinc sulfate additive. During phase II, participants self-administered 200 mg doses of oral zinc supplements shortly after engaging in marijuana smoking. Investigators at the City University of New York concluded that zinc was effective as both an adulterant and as an oral supplement at masking the presence of carboxy THC on conventional urine tests.
“These results argue that the consumption of zinc supplements taken orally after light marijuana use can interfere with the detection of THC [metabolites] in urine samples for a 12- to 18-hour period,” authors determined. “We [also] conclude that zinc ion is a potential adulterant in urine samples tested for drugs. … Its effect in causing potential false-negative results in drug testing is robust and reproducible.” They concluded, “[W]e are aware of no suitable test to determine zinc adulteration in urine and conclude that zinc supplements are effective at subverting routine drug testing and undetectable by standards means.”
Sounds like a silver bullet, right? Not so fast says a newer paper published in the same journal this past July. In that study, researchers at the University of Utah School of Medicine reported that although zinc worked as an adulterant, it was only effective at doses “5,000 times higher” than what would be typically found in a non-adulterated sample. They reported: “We investigated the potential interference of zinc used as a direct adulterant. … Our data indicate that the total zinc concentrations required to directly interfere with EMIT-based testing are easily distinguishable from routine random urine total concentrations.”
The University of Utah study also cast doubt on the notion that the consumption of oral zinc supplements can successfully trigger false-negative results for the presence of THC metabolites, stating “[O]ral ingestion of zinc does not produce total zinc concentrations [in urine] capable of direct interference.” This latter conclusion, however, appears to be somewhat theoretical. Unlike in the 2011 study, no participants in this trial engaged in any actual marijuana smoking. Rather, researchers based this determination on the premise that zinc self-administration failed to produce the supplement’s presence in urine at the quantities they believed to be necessary to interfere with a positive drug test result.
Finally, a to-be-published paper in the October 2013 issue of the American Journal of Clinical Pathology raises further questions regarding whether zinc additives are truly undetectable. Like the previous studies, it reaffirms that zinc adulterants can effectively invalidate a positive drug test result. But, unlike the studies before it, the trial’s authors acknowledge that two newly developed spot tests can rapidly identify the substance’s presence in urine.
Nonetheless, the internet rumors claiming that zinc may be an effective and clandestine tool for compromising drug detection ought not to be dismissed outright. First, most labs do not engage in spot testing for zinc, despite the development of newer technology allowing them to do so. Further, negative immunoassay samples are typically not analyzed further for the presence of less common adulterants or additives. In other words, even if zinc adulterated samples are “easily distinguishable” from non-adulterated samples, as claimed in the Utah study, lab testers would still have to engage in the time an effort to distinguish them -- something that most technicians are unlikely to do on specimens that initially test negative for the presence of illicit substances. Finally, there still remains little evidence disputing the notion that self-administration of zinc supplements interferes with carboxy-THC detection since, to date, no study seeking replicating the methods employed by SUNY research team has been conducted. That said, however, the only proven method for passing a drug test remains abstinence and, ultimately, the best strategy for thwarting drug testing is legalizing marijuana so that its off-the-job consumption is no longer of concern for authorities or employers.
- Published on 29 November 2012
- Written by Paul Armentano, NORML Deputy Director
Employees at US hospitals are testing more and more newborns for cannabis exposure. And, with alarming frequency, they are getting the wrong results. So say a pair of recent studies documenting the unreliability of infant drug testing.
In the most recent trial, published in the September edition of the journal Clinical Chemistry, investigators at the University of Utah School of Medicine evaluated the rate of unconfirmed 'positive' immunoassay test results in infant and non-infant urine samples over a 52-week period.
Shockingly, authors found  that positive tests for carboxy THC, a byproduct of THC screened for in immunoassay urine tests, were 59 times less likely to be confirmed in infant urine specimens as compared to non-infant urine samples. Overall, 47 percent of the infant 'positive' immunoassay urine samples evaluated did not test for the presence of carboxy THC when confirmatory assay measures were later performed.
Immunoassay testing the standard technology utilized in workplace drug testing relies on the use of antibodies (proteins that will react to a particular substance or a group of very similar substances) to document whether a specific reaction occurs. Therefore, a 'positive' result on an immunoassay test presumes that a certain quantity of a particular substance may be present in the sample, but it does not actually identify the presence of the substance itself. A more specific chemical test, known as chromatography, must be performed in order to confirm any preliminary analytical test results. Samples that test positive on the presumptive immunoassay test, but then later test negative on the confirmatory test are known as false positives.
False positive test results for cannabis¹ carboxy THC metabolite are relatively uncommon in adult specimens. Among newborns¹ specimens, however, false positive results for alleged cannabis exposure are disturbingly prevalent. 
For example, in April, researchers at the University of North Carolina reported in the journalClinical Biochemistry that various chemicals present in various baby wash products, such as Johnson's Head-to-Toe Baby Wash and CVS Baby Wash, frequently cross-react  with the immunoassay test to cause false positive results for carboxy THC. "[The] addition of Head-to-Toe Baby Wash to drug-free urine produced a dose dependent measureable response in the THC immunoassay," the investigators concluded . "Addition of other commercially available baby soaps gave similar results, and subsequent testing identified specific chemical surfactants that reacted with the THC immunoassay. Š Given these consequences, it is important for laboratories and providers to be aware of this potential source for false positive screening results and to consider confirmation before initiating interventions."
Following the publication of the UNC study, researchers at the University of Utah screened for the presence of baby soap contaminants in infant urine. Surprisingly, they didn¹t find any . Rather, they concluded that the disproportionately high rate of false positive test results discovered among their samples were the result of a cross-reaction with some other, yet to be determined constituent. They cautioned: "Until the compounds contributing to positive urine screen results in infants are identified, we encourage the use of alternative specimens for the detection and investigation of neonatal exposure to cannabinoids. Screen-positive cannabinoid results from infant samples should not be reported without confirmation or appropriate consultation, because they cannot currently be interpreted."
Yet despite these warnings, in many instances, hospitals fail to confirm the results of presumptive drug tests prior to reporting them to state authorities. (Because confirmatory testing is more expensive the immunoassay testing, many hospitals neglect to send such presumptive positive urine samples to outside labs for follow up analysis.) Ironically, such confirmatory tests are required for all hospital employees who test positive for illicit substances. But presently, no such guidelines stipulate that similar precautions be taken for newborns or pregnant mothers. Explains Lynn Paltrow, Executive Director of the organization National Advocates for Pregnant Women : "NAPW has had calls from numerous parents who were subjected to intrusive, threatening, and counterproductive child welfare interventions based on false or innocent positive test results for marijuana. We have learned that pregnant patients receive fewer guarantees of accuracy than do job applicants at that same hospital."
Regardless of whether or not the drug screen results are confirmed, the sanctions for those subjects who test positive are often swift and severe. Typically, any report of alleged infant exposure to cannabis will trigger a host of serious consequences ranging from the involvement of social services to accusations of child endangerment or neglect. In some instances, mothers whose infants test positive for carboxy THC will lose temporary child custody rights and be mandated to attend a drug treatment program. In other instances they may be civilly prosecuted. At least eighteen states  address the issue of pregnant women¹s drug use in their civil child neglect laws; in twelve states  prenatal exposure to any illegal drug is defined by statute as civil child abuse. (One state, South Carolina, authorizes the criminal prosecution of mothers who are alleged to have consumed cannabis, or any other illicit substance, during pregnancy and carry their baby to
Of further concern is the reality that the hospital staff¹s decision to drug test infants or pregnant mothers appears to be largely a subjective one. There are no national standards delineating specific criteria for the drug testing of pregnant women, new mothers, or their infants. In fact, the only federal government panel ever convened to advise on the practice urged against its adoption. As a result, race and class largely influence who is tested and who isn¹t. For example, a study  published in the Journal of Women's Health reported that "black women and their newborns were 1.5 times more likely to be tested for illicit drugs as non-black women," after controlling for obstetrical conditions and socio-demographic factors, such as single marital status or a lack of health insurance. A separate study  published in The New England Journal of Medicine reported similar rates of illicit drug consumption during pregnancy among both black and white women, but found that "black women were reported [to health authorities] at approximately 10 times the rate for white women."
How many mothers have been accused of child neglect or abuse because of false positive drug test results? Nobody knows for sure. But no doubt some mothers have been penalized solely as a result of the test¹s inherent fallibility and many more are likely to face similar sanctions in the future. That¹s because the practice of drug testing infants for cannabis exposure remains a relatively popular even though there exists limited, if any, evidence to justify it.
"No child-health expert would characterize recreational drug use during pregnancy as a good idea," writes  Time.com columnist Maia Szalavitz. "But it¹s not at all clear that the benefits, if any, of newborn marijuana screening particularly given how selectively the tests are administered justify the potential harm it can cause to families."
Richard Wexler, executive director of the National Coalition for Child Protection Reform agrees , telling Time.com that the emotional damage caused by removing an infant child from their mothers, as well as the risk of abuse inherent to foster care, far outweigh any risks to the child that may be caused by maternal marijuana use during pregnancy.
In fact, the potential health effects of maternal marijuana use on infant birth weight and early development have been subject to scientific scrutiny for several decades. One of the earliest and most often cited studies on the topic comes from Dr. Melanie Dreher and colleagues, who assessed neonatal outcomes in Jamaica, where it is customary for many women to ingest cannabis, often in tea, during pregnancy to combat symptoms of morning sickness. Writing in the journal Pediatricsin 1994, Dreher and colleagues reported  no significant physical or psychological differences in newborns of heavy marijuana-using mothers at three days old, and found that exposed children performed better on a variety of physiological and autonomic tests than non-exposed children at 30 days. (This latter trend was suggested to have been a result of the socio-economic status of the mothers rather than a result of pre-natal pot exposure.)
Separate population studies have reported similar results. A 2002 survey  of 12,060 British women reported, "[C]annabis use during pregnancy was unrelated to risk of perinatal death or need for special care." Researchers added that "frequent or regular use" of cannabis throughout pregnancy may be associated with "small but statistically detectable decrements in birthweight." However, the association between cannabis use and birthweight failed to be statistically significant after investigators adjusted for confounding factors such as the mothers' age, pre-pregnancy weight, and the self-reported use of tobacco, alcohol, caffeine, and other illicit drugs." A 1999 survey  of 12,885 Dutch mothers reported similar findings after controlling for maternal tobacco use. "The use of cannabis is not a major prognostic factor regarding the outcome of pregnancy," the authors concluded. A 1997 meta-analysis  of 32,483 mothers published in the journal Addiction also reported, "There is inadequate evidence that cannabis, at the amount typically consumed by pregnant women, causes low birth weight." Most recently, a 2010 population-based study  by the Centers for Disease Control and Prevention reported similar outcomes.
Investigators with the National Center on Birth Defects and Developmental Disabilities surveyed mothers who delivered live-born infants without birth defects between 1997 and 2004. After adjustment for potential confounding factors, researchers concluded that "cannabis use was not associated with mean birth weight or gestational age or with low birth weight or preterm delivery."
Longitudinal data assessing the potential impact of pre-natal cannabis exposure on a child¹s neurobehavioral and cognitive functioning is less definitive. While some studies have reported  an adverse association between frequent prenatal marijuana exposure and childhood intellectual development, particularly in the realm of Œexecutive functioning ', other studies evaluating less frequent maternal marijuana use have reported  no such deficits in infant development or increased risk  of psychiatric disorders. Further complicating interpretation of this data is that researchers are typically unable to determine whether these outcomes are the result of cannabis exposure or other pre-natal or post-natal environmental factors. However, among the studies reporting a potential adverse association, authors often affirm these effects tend to be subtle and that they are far less significant than those outcomes associated with the maternal use of alcohol or tobacco.
"Based on my 30 plus years of experience examining the newborn, infants, toddlers, children, adolescents and young adults born to women who used marijuana during pregnancy it is important to emphasize that to characterize an infant born to a woman who used marihuana during pregnancy as being Œphysically abused¹ and/or Œneglected¹ is contrary to all scientific evidence," wrote Canadian researcher Peter Fried one of the world¹s foremost experts on the effects of social use of alcohol, nicotine, and marijuana during pregnancy in a 2009 affidavit, excerpted on the NAPW website. "The use of marijuana during pregnancy (in the absence of other factors that may put a child at risk for physical abuse and/or neglect) has not been shown by any objective research to result in abuse or neglect."
Nonetheless, this lack of hard data demonstrating definitive dangers associated with the intermittent maternal use of cannabis has not stopped others in the field from proclaiming  that any infant exposure to cannabinoids may lead to a variety of unproven detrimental outcomes including childhood hyperactivity and sudden infant death syndrome. (In reality, preclinical studies have documented that the activation of cannabis receptors as well as the production of the endogenous cannabinoids are essential for proper prenatal and post-natal development, in particular the stimulation of appetite  and proper digestion.) Such claims have no doubt fostered the present environment whereby stiff legal penalties and/or the loss of parental rights exist for mothers who are alleged to have consumed cannabis during pregnancy. Moreover, child protective services are also now proactively removing children from the homes of families who use cannabis even in cases where the parent¹s use is in compliance  with state law. And in at least one state, Arizona, pediatric groups are seeking  additional legislation to "prevent pregnant women from receiving recommendations for marijuana; require physicians who recommend marijuana to ask patients if they are pregnant; and require women to submit to pregnancy tests when seeking [medicinal cannabis] recommendations."
Overkill? Absolutely, warns  Wexler. "[T]here is no evidence that smoking pot endangers children [and] there is overwhelming evidence that needless foster care endangers children." Nonetheless, as long as most states, and the federal government in particular, continue to define cannabis as a Schedule I prohibited substance, one can expect that state regulators, prosecutors, and hospital staff will continue to overzealously and selectively target suspected marijuana consuming mothers and their children regardless of whether such interventions are scientifically warranted or in the best interest of the child.
- Published on 02 June 2013
- Written by Allen St. Pierre, NORML Executive Director
Ann Arbor, MI: Schools that institute student drug testing programs are likely to experience a rise in students' consumption of so-called 'hard' drugs, according to observational trial data published this month in the Journal of Adolescent Health.
Researchers at the University of Michigan, Institute for Social Research analyzed the impact of student drug testing programs in some 250,000 high school and middle-school students over a 14-year period. Investigators reported that random drug testing programs of the student body, as well as programs specifically targeting student athletes, were associated with "moderately lower marijuana use," but cautioned that drug testing programs overall were "associated with increased use of illicit drugs other than marijuana."
An estimated 14 percent of middle school students and 28 percent of US high school students are now subject to some form of drug testing.
Urinalysis, the most common form of student drug testing, screens for the presence of inert drug metabolites (breakdown products), not the actual parent drug. Because marijuana's primary metabolite, carboxy-THC, is fat soluble, it may be present in urine for days, weeks, or in some cases even months after past use. By contrast, most other illicit drug metabolites are water-soluble and will exit the body within a matter of hours. Authors of the study speculated that students subjected to drug screens were switching from cannabis to other illicit drugs that possessed shorter detection times.
"Random SDT (student drug testing) among the general high school student population, as well as middle and high school subgroups targeted for testing, was associated with moderately lower marijuana use; however, most forms of testing were associated with moderately higher use of other illicit drugs, particularly in high school," authors concluded. "These findings raise the question of whether SDT is worth this apparent tradeoff."
Commenting on the findings, the study's lead author affirmed, "It is clear that drug testing is not providing the solution for substance-use prevention that its advocates claim."
Previous assessments of student drug testing programs have reported that those subjected to such programs are no less likely to report consuming illicit drugs, tobacco, or alcohol than their peers.
- Published on 25 August 2012
- Written by Allen St. Pierre, NORML Executive Director
Salt Lake City, UT: False positive drug test results for cannabis are far more common to occur in infant urine samples than in those provided by non-infants, according to a study published online in the journal Clinical Chemistry.
Researchers at the University of Utah School of Medicine and ARUP drug testing laboratories in Salt Lake City investigated the rate of unconfirmed 'positive' immunoassay test results in infant and non-infant urine samples over a 52-week period.
Authors reported that positive tests for carboxy THC, a byproduct of THC screened for in immunoassay urine tests, were 59 times less likely to be confirmed in infant urine compared to non-infant urine samples. Overall, 47 percent of the infant 'positive' immunoassay urine samples evaluated did not test for the presence of carboxy THC when confirmatory assay measures were later performed.
Immunoassay tests rely on the use of antibodies (proteins that will react to a particular substance or a group of very similar substances) and document whether a specific reaction occurs. Therefore, a 'positive' result on an immunoassay test presumes that a certain quantity of a particular substance may be present in the sample, but it does not actually identify the presence of the substance itself. A more specific chemical test, known as chromatography, must be performed in order to confirm any preliminary analytical test results. Samples that test positive on the presumptive immunoassay test, but then later test negative on the confirmatory test are know as false positives.
In April, researchers at the University of North Carolina reported that chemicals present in various baby wash products, including Johnson's Head-to-Toe Baby Wash and CVS Baby Wash, frequently cross-react with the immunoassay test to cause 'false positive' results for carboxy THC. However, in this latest study, none of the unconfirmed immunoassay test results were due to contaminants from baby wash soaps.
Researchers concluded: "Until the compounds contributing to positive urine screen results in infants are identified, we encourage the use of alternative specimens for the detection and investigation of neonatal exposure to cannabinoids. Screen-positive cannabinoid results from infant samples should not be reported without confirmation or appropriate consultation, because they cannot currently be interpreted."
Infants may be drug tested in situations where their mothers are suspected of consuming illicit substances during pregnancy or have tested positive for illicit substances themselves. However, critics of infant drug testing argue that the hospital staff's decision regarding whether to conduct such tests is often subjective and potentially discriminatory. For example, a 2007 study published in the Journal of Women's Health reported that "black women and their newborns were 1.5 times more likely to be tested for illicit drugs as non-black women," after controlling for obstetrical conditions and socio-demographic factors, such as single marital status or a lack of health insurance.
Twelve states legally define prenatal exposure to any illegal drug as child abuse.