The Need for Change: Drug Testing in Construction
Lynn A. Corlett, C.S.P.
We all know that a drug free workplace is a safe workplace and the Michigan union skilled trades and contractors were ahead of their time when the MUST drug screening program was implemented 16 years ago in 1991.
However, times change, the drugs of choice change and the numbers of ways to “beat” the tests have changed.
It’s time again for the union skilled trades and contractors to leap ahead of the national status quo.
Recently the States of Hawaii and Georgia passed legislation to improve safety and reduce workers compensation costs through the implementation of on-site oral fluid / saliva drug screening.
The construction industry played a key role in driving these changes, especially in Hawaii. Organized labor in particular, as well as contractors, owners, and insurers recognized the following:
Drug abuse in the construction sector is as bad, if not worse than ever,
Effective drug testing, especially random drug testing is required to truly manage workplace substance abuse,
Observed specimen collection, convenience, and low cost are mandatory to ensure compliance.
This article attempts to address ... from the construction industry’s point of view:
Why should every construction site drug test?
Where do we go from here?
Why drug test? Simple.
10% of employees aged 18 – 49 years abuse drugs (not including alcohol), the construction industry runs 2x-3x this rate. Over 50% of reportable job-site accidents linked to substance abuse.
It’s clear that employee safety and the corporate bottom line are sufficient reasons to implement a drug free workplace program.
A need for change.
Pre-employment drug testing has become an intelligence test. Access to the internet has made defeating drug tests an easy task. Workers are able to get information on how to “flush” their system; adulterate samples; and there are even products like the Whizinator, which uses synthetic urine undetectable by current drug testing methods, designed to defeat observed urine collection.
Random drug testing, post-incident and reasonable suspicion modes are required components of any comprehensive, effective safety program.
The goal of any drug / alcohol policy is deterrence vs. “catching” employees. Random testing has consistently demonstrated to be singularly effective in reducing on-the-job substance abuse.Any effective testing mode must involve direct observation of specimen collection. But observed urine collection is embarrassing and degrading to both the observed and the observer.Arguably, there are more instances of drug abusers defeating unobserved techniques, such as traditional urine-based testing, than there are “positives”. Just look at nationwide statistics for validation. Seventy-seven percent (77%) of drug abusers are employed.
Furthermore most drug testing (approx. 90%) involves traditional urine laboratory-based pre-employment testing. Oral fluid worksOral fluid tests are cheaper, faster and easier to use than urinalysis… and unlike urine, can not be easily defeated.
Random testing via on-site oral fluid is fast, provides results within 5-15 minutes, and averages $20 per test. It has the additional advantage of detecting current, vs. historical drug use. Oral fluid tests typically detect from within minutes of consumption up to 2-3 days for most drugs (for THC, the psychoactive ingredient in marijuana, the maximum is 24 hours.). Urine testing can not detect drugs for up to the first several hours and is only an indicator of historical drug use. Furthermore, for THC, detection can go back as far as 30 days.
Do you as an employer really care what an otherwise dependable employee does at his/her home on the weekend?
Do you even have a right to know?
Also look at the true costs of urine-based random testing. In many cases our current program requires we send our employees off site for random testing. The cost involved includes not only the hourly labor rate, probably $50/hour with benefits, but the productivity loss also. The end result is that a typical off-site urine test is truly costing a job about $300 per test, and the effectiveness is questionable at best.
On-site oral fluid based testing works. Multiple case studies have documented significant improvements in accident reduction due to switching from urine-based to oral fluid-based drug screening.
Where do we go from here?
Occupational health, safety, and risk management professionals must lead the charge to effect change. We know what truly happens every day on our job sites. At the end of day, we “get it”. It’s time for us to update our current drug and alcohol free workplace program.
It’s time for the Michigan union skilled trades and contractors to again lead the charge in effecting change.
It’s time to implement oral fluid-based testing techniques at a few “pilot sites” and demonstrate the advantage of effective drug testing programs vs. the status quo.
References:
2006 United States Department of Health – Substance Abuse and Mental Health Agency (SAMSHA) National Survey on Drug Use & Health (NHSDA)- Office of Applied Studies. (2007) Results from the 2006 National Survey on Drug Use and Health: National findings (DHHS Publication No. SMA 07-4293, NSDUH Series H-32). Rockville, MD: Substance Abuse and Mental Health Services Administration.
Peter N. Cholakis and Roger Bruce (July 2007) Drug Testing in the Workplace – A look at oral fluid-based testing. Professional Safety Journal of the American Society of Safety Engineers, July 2007, 31-36.
Tuesday, September 25, 2007
Monday, September 24, 2007
Return on Investment - Drug Testing
Employee Theft and Fraud
- Average cost Per employee involved: $650
- U.S. Chamber of Commerce estimates 30% of all business failures are due to employee theft and fraud.
- 70% of these crimes are committed by repeat offenders.
- Up to 70% of employee theft is drug related
Cost of Negligent Hiring
- Average cost per incident: $150,000
- Courts are holding companies liable in negligent hiring cases not only for what they knew about a new employee, but also what they should have known.
Employee Turnover]
- Average cost per incident: $32,000
- Turnover costs average 1.5 times a person’s yearly salary
Workplace Violence Estimated
- Average cost per incident: $1,000,000
- Violence at work is a serious problem, with homicide now the #2 cause of death in the workplace.
- Up to 70% of criminal arrests are drug related
Accidents / Worker's Comp.
- Average cost $10,000 + per incident
- 50%+ related to substance abuse
- Average cost Per employee involved: $650
- U.S. Chamber of Commerce estimates 30% of all business failures are due to employee theft and fraud.
- 70% of these crimes are committed by repeat offenders.
- Up to 70% of employee theft is drug related
Cost of Negligent Hiring
- Average cost per incident: $150,000
- Courts are holding companies liable in negligent hiring cases not only for what they knew about a new employee, but also what they should have known.
Employee Turnover]
- Average cost per incident: $32,000
- Turnover costs average 1.5 times a person’s yearly salary
Workplace Violence Estimated
- Average cost per incident: $1,000,000
- Violence at work is a serious problem, with homicide now the #2 cause of death in the workplace.
- Up to 70% of criminal arrests are drug related
Accidents / Worker's Comp.
- Average cost $10,000 + per incident
- 50%+ related to substance abuse
Wednesday, September 19, 2007
Significant Changes to Employee Drug Testing Laws
Significant Changes to Substance Abuse Testing Laws
Recently the States of Hawaii and Georgia passed legislation in support of workplace drug testing, specifically relative to oral fluid-based/saliva drug on-site screening, and workers compensation premium credits. These actions highlight the need for effective drug-free workplace programs as well convenient drug screening technologies that can be applied consistently, across all modes of testing, especially, however, for random, post-incident, and reasonable suspicion.
It is critical that drug-free workplace safety initiatives are enhanced for the betterment of the American workplace as a whole: employers, employees and families, insurors, etc.
Drug abuse is as bad as it has ever been in our places of employment as well as school systems, and hopefully, these new statutes are a sign of a commitment to change.
Our society cannot continue to sweep America's drug abuse problem under the rug. Abuse of prescription drugs, especially pain-relievers, has superseded marijuana and is is a dangerous trend world-wide.
Arguably, “recreational” marijuana use outside of the workplace may have little, if any, impact to employers or employees, excluding the obvious legal issues. The non-medical use of prescription pain relievers, however, in addition to being potentially lethal, commonly leads to addiction and even escalates to heroin use. The safety and wellness aspect of prescription drug abuse is a very serious issue that must be addressed.
Hawaii
A law that became effective on July 1, 2007, now allows employers to perform on-the-job drug testing using instant, on-site oral fluid/saliva drug screening devices. Oral fluid tests are cheaper, faster and easier to use than urinalysis, hopefully leading to more widespread and consistent drug testing programs.
While it may surprise many, the construction industry and locals unions in particular strongly advocate the new legislation as a means to replace the typical, more expensive laboratory-based urine drug testing. With oral fluid, initial results are available in minutes, and observing the sample collection mitigates the prevalent practice of drug abusers “beating the test” via sample adulteration or substitution. Urine laboratory testing typically required the expensive practice of sending employees off-site to a clinic or laboratory, a process that takes at least 3-4 hours with results available for 24-48 hours. As noted by Lt. Governor Aiona of Hawaii, "Drug and alcohol abuse remain a problem in Hawaii's workforce. The law will go a long way towards helping to promote a drug-free workplace. This measure provides a cost effective on-the-job alternative to laboratory tests that can be costly and difficult to schedule."According to the U.S. Department of Labor, drug or alcohol abuse is involved in the majority of fatal accidents in the workplace. These laws represent an effort by the State Government to make the workplace safer for everyone.Although the new law permitting oral drug testing was effective on July 1, 2007, in many cases collective bargaining agreements will have to be updated before companies can start using the non-FDA approved tests. This procedure isn't expected to take long, however, since the unions - as well as management and the State Government - are in favor of the new law. According to union sources, they welcome the improved safety and working conditions that the tests will introduce.
One representative of the Pacific Resource Partnership, an alliance between contractors and the Carpenters Union Local 745, said construction workers and the industry pushed for the new tests as a way to decrease costs and save time while keeping job sites safe."This is something that I think is going to be a great asset for employers, especially in the construction industry where public safety is a huge factor," said Lt. Governor Aiona.
Georgia
In a similar bill, Governor Perdue of Georgia recently signed Senate Bill 96 into law which provides the option for companies throughout Georgia to drug test employees using an on-site rapid result oral fluid/saliva devices.
As in Hawaii, initial qualitative results are available in minutes, and if “negative” an employee goes back to work. Any “non-negative” (preliminary positive) results are sent to a lab for a GC/MS or LC/MS/MS quantitative analytical testing prior to substantive employers’ actions such as mandatory enrollment in employee assistance programs/counseling, removal from safety-sensitive duties, and/or suspension.
Per Governor Perdue, the bill which overwhelmingly passed the State Senate and House of Representatives, "had the strong support of the Georgia Chamber of Commerce and many other advocates of safe and drug-free workplaces that protect not only business owners, but employees and consumers as well.Companies using on-site oral fluid/saliva screens will now receive a 7.5 percent reduction in their worker's compensation insurance premiums. Summary
Drug testing in the workplace is not only legal, it may very well be part of an employer’s responsibility to provide a safe workplace for employees. The United Supreme Court has ruled that drug testing, including random drug testing, is legal. Furthermore, per the Department of Labor, OSHA, it is an employer’s responsibility to provide a safe workplace for all employees.
Assuming a comprehensive safety program is in place, a safe workplace is simply not possible without also maintaining a comprehensive drug-free workplace program inclusive of employee education, drug testing, and employee assistance/counseling.
Regardless of the specimen type used such as oral fluid/saliva, urine, or hair, it is critical that specimen collection be directly observed, and that drug testing is done on a regular basis. This includes; random, post-incident, reasonable suspicion, and return-to-duty mode. Pre-employment testing, while currently the most widely practiced of modes, is referred to by many experts as an “intelligence test”, and should not be relied upon exclusively.
When combined with education, and employee assistance programs, comprehensive drug-free workplace programs consistently result in a reduction in reportable site accidents of up to 50% or more, as well as multiple other safety and “bottom-line” benefits.
Recently the States of Hawaii and Georgia passed legislation in support of workplace drug testing, specifically relative to oral fluid-based/saliva drug on-site screening, and workers compensation premium credits. These actions highlight the need for effective drug-free workplace programs as well convenient drug screening technologies that can be applied consistently, across all modes of testing, especially, however, for random, post-incident, and reasonable suspicion.
It is critical that drug-free workplace safety initiatives are enhanced for the betterment of the American workplace as a whole: employers, employees and families, insurors, etc.
Drug abuse is as bad as it has ever been in our places of employment as well as school systems, and hopefully, these new statutes are a sign of a commitment to change.
Our society cannot continue to sweep America's drug abuse problem under the rug. Abuse of prescription drugs, especially pain-relievers, has superseded marijuana and is is a dangerous trend world-wide.
Arguably, “recreational” marijuana use outside of the workplace may have little, if any, impact to employers or employees, excluding the obvious legal issues. The non-medical use of prescription pain relievers, however, in addition to being potentially lethal, commonly leads to addiction and even escalates to heroin use. The safety and wellness aspect of prescription drug abuse is a very serious issue that must be addressed.
Hawaii
A law that became effective on July 1, 2007, now allows employers to perform on-the-job drug testing using instant, on-site oral fluid/saliva drug screening devices. Oral fluid tests are cheaper, faster and easier to use than urinalysis, hopefully leading to more widespread and consistent drug testing programs.
While it may surprise many, the construction industry and locals unions in particular strongly advocate the new legislation as a means to replace the typical, more expensive laboratory-based urine drug testing. With oral fluid, initial results are available in minutes, and observing the sample collection mitigates the prevalent practice of drug abusers “beating the test” via sample adulteration or substitution. Urine laboratory testing typically required the expensive practice of sending employees off-site to a clinic or laboratory, a process that takes at least 3-4 hours with results available for 24-48 hours. As noted by Lt. Governor Aiona of Hawaii, "Drug and alcohol abuse remain a problem in Hawaii's workforce. The law will go a long way towards helping to promote a drug-free workplace. This measure provides a cost effective on-the-job alternative to laboratory tests that can be costly and difficult to schedule."According to the U.S. Department of Labor, drug or alcohol abuse is involved in the majority of fatal accidents in the workplace. These laws represent an effort by the State Government to make the workplace safer for everyone.Although the new law permitting oral drug testing was effective on July 1, 2007, in many cases collective bargaining agreements will have to be updated before companies can start using the non-FDA approved tests. This procedure isn't expected to take long, however, since the unions - as well as management and the State Government - are in favor of the new law. According to union sources, they welcome the improved safety and working conditions that the tests will introduce.
One representative of the Pacific Resource Partnership, an alliance between contractors and the Carpenters Union Local 745, said construction workers and the industry pushed for the new tests as a way to decrease costs and save time while keeping job sites safe."This is something that I think is going to be a great asset for employers, especially in the construction industry where public safety is a huge factor," said Lt. Governor Aiona.
Georgia
In a similar bill, Governor Perdue of Georgia recently signed Senate Bill 96 into law which provides the option for companies throughout Georgia to drug test employees using an on-site rapid result oral fluid/saliva devices.
As in Hawaii, initial qualitative results are available in minutes, and if “negative” an employee goes back to work. Any “non-negative” (preliminary positive) results are sent to a lab for a GC/MS or LC/MS/MS quantitative analytical testing prior to substantive employers’ actions such as mandatory enrollment in employee assistance programs/counseling, removal from safety-sensitive duties, and/or suspension.
Per Governor Perdue, the bill which overwhelmingly passed the State Senate and House of Representatives, "had the strong support of the Georgia Chamber of Commerce and many other advocates of safe and drug-free workplaces that protect not only business owners, but employees and consumers as well.Companies using on-site oral fluid/saliva screens will now receive a 7.5 percent reduction in their worker's compensation insurance premiums. Summary
Drug testing in the workplace is not only legal, it may very well be part of an employer’s responsibility to provide a safe workplace for employees. The United Supreme Court has ruled that drug testing, including random drug testing, is legal. Furthermore, per the Department of Labor, OSHA, it is an employer’s responsibility to provide a safe workplace for all employees.
Assuming a comprehensive safety program is in place, a safe workplace is simply not possible without also maintaining a comprehensive drug-free workplace program inclusive of employee education, drug testing, and employee assistance/counseling.
Regardless of the specimen type used such as oral fluid/saliva, urine, or hair, it is critical that specimen collection be directly observed, and that drug testing is done on a regular basis. This includes; random, post-incident, reasonable suspicion, and return-to-duty mode. Pre-employment testing, while currently the most widely practiced of modes, is referred to by many experts as an “intelligence test”, and should not be relied upon exclusively.
When combined with education, and employee assistance programs, comprehensive drug-free workplace programs consistently result in a reduction in reportable site accidents of up to 50% or more, as well as multiple other safety and “bottom-line” benefits.
Thursday, September 13, 2007
False Negatives & False Positives
Qualitative Results
A qualitative drug test is one that provides a dichotomous result, that is, it indicates whether a sample is positive or negative for a specified drug. However, there are four possible results of a qualitative drug test.
A true-positive result occurs when the test correctly identifies the presence of a drug in the sample taken.
A false-positive result is one where the test incorrectly detects the presence of a drug where in fact no drug is present.
A true-negative result occurs when the test correctly confirms the absence of a drug.
A false-negative result is one where the test fails to detect the presence of a drug when it is in fact present.
Interpreting a Positive Test Result
A positive result indicates that the specific drug (or class of drug) is present at or above the designated cut-off level. Typically, the cut-off concentration is set to the lowest concentration the drug can be reliably detected following consumption. It considers environmental and analytical variability caused by such factors as passive contamination/ingestion, technological limits, etc.
False-positives resulting from qualitative screening
A false-positive result can occur when a benign substance in the biological sample mimics the chemical effect of the targeted substance on the test. The test indicates a positive result even though the targeted drug was absent. Such results have reportedly occurred after ingestion of antihistamines, certain anti- inflammatory drugs, cold and flu medications, and poppy seeds (Selavka, 1991). The false-positive rate for particular testing methods is discussed in the relevant chapters below. Although levels are generally low, it does highlight the necessity of appropriate confirmatory testing with parent / metabolite quantification to identify and safeguard against this.
Interpreting a Negative Test Result
In the majority of cases a negative result indicates that the parent drug (typcially the active ingredient) and / or its metabolites are absent in the biological sample. It does not mean that the person has not used the substance in the days or weeks prior to testing. The amount of drug present in the sample at the time of sample collection, and thus whether a positive result is obtained, is determined by a number of factors which include: the cut-off level used; the testing schedule employed; the biological sample analyzed; when the drug was ingested; the amount of drug ingested; the form in which it was ingested; and physical and pharmacological characteristics of the user.
False-negatives
When an initial screen result in negative and (1.) the individual ingests a drug and the concentration of the drug in the sample is at our above the cut-off, or (2.) the individual ingests a drug and the concentration of of the sample is below the the cut-off due to sample adulteration or substitution, the result referred to as a “false-negative”.
Relative to urinalysis, there are a number of actions an individual can take, to increase the likelihood of a false-negative result. An individual can adulterate the specimen via dilution by drinking excessive amounts of water (in vivo adulteration), or by adding water or chemicals that will affect the test (in vitro adulteration) (Coleman & Baselt, 1997). Hair testing may be susceptible to excessive washing (Rohrich, Zorntlein, Potsch, et al., 2000), bleaching (Yegles, Marson & Wennig, 2000) and other cosmetic hair treatment (Skopp, Potsch & Moeller, 1997). There are no currently proven methods to adulterate or substitute oral fluid.
Quantitative Results
Quantitative drug testing involves the determination of the specific concentrations of a parent drug and/or its metabolite(s) in a sample, typically via GC/MS and LC/MS/MS. In addition to confirmatory testing of qualitative screening results, quantitative results quantitative results using blood or oral fluid / saliva specimens can provide additional information regarding the quantity and frequency of drug use (Cone, 1997). Blood and/or oral fluid / saliva may also be useful when establishing impairment levels for certain drug classes. Urine and hair specimens are generally considered effective for historical use only. With knowledge of the drug’s pharmacokinetic parameters, including its half-life, an estimate of the frequency of new drug use can be obtained using quantitative analysis (Cone, 1997, Huestis and Cone 1998).
The Physiology of Urine Production
Urine is produced continuously by the kidneys and may be considered an ultrafiltrate of blood. During urine production the kidneys reabsorb essential substances. Excess water and waste products, such as urea, organic substances and inorganic substances, are eliminated from the body. Parent drugs (typically the active ingredient) are often present in urine in very low concentrations or not detected at all. Therefore distinguishing between codeine, heroin and morphine use, for example, can be difficult. Furthermore, inter-subject variations in urine drug concentrations, even after similar dosing, is high.
Absorption into urine is usually slow when a drug is orally administered and excretion may be delayed for several hours (approximately 6-9 hours) .Generally, a urine specimen will contain the highest concentration of parent drug and metabolite at this time period. As drug elimination usually occurs at an exponential rate, for most illicit drugs a dose will be eliminated almost completely within 48 hours. A number of factors influence detection times including the quantity of drug administered, parent drug and metabolite half- life, cut-off level used, and a number of physiological factors. It is also noted that for many of drugs, frequent, multiple dosing over extended periods of time can cause the drug to accumulate in the body resulting in significantly extended detection times.
The Physiology of Oral Fluid
Salivary gland is a term used to include any tissue that normally discharges a secretary product into the oral cavity. Thus, oral fluid refers to the mixture of fluid in the oral cavity. Saliva is a complex aqueous fluid (99% water) containing electrolytes (principally sodium,potassium, chloride and bicarbonate), proteins (mostly enzymes, including amylase) and muncin (Kidwell, Holland & Athanaselis, 1998). The mucin gives oral fluid its sticky character. Saliva also contains cell and food debris and oral microorganisms. The composition and production of oral fluid is determined by the relative contribution of the different glands, which in turn is dependant on a variety of factors including nutritional and emotional state, sex, age, season of the year, time of day, and a variety of diseases and pharmacological agents (Höld, 1996; United Nations, 1998)
The three major salivary glands are: (1) the parotid, at the top of the mouth, (2) the submandibular, at the base of the tongue, and (3) the sublingual, at the sides of the oral cavity. The parotid gland, responsible for about 25% of the saliva produced, excretes saliva derived primarily from blood plasma (serous fluid); the submandibular and sublingual glands excrete both serous fluid and mucin and contribute approximately 71% and 4% respectively (Kidwell, Holland & Athanaselis, 1998). The volume of saliva produced by an adult ranges from 500 to 1500 ml per day. Unstimulated saliva has a pH range between 5.6 and 7. Stimulation increases the pH to a maximum of 8 (Kidwell, Holland & Athanaselis, 1998).
A thin layer of epithelial cells separates the salivary ducts from the systemic blood circulation (capillaries). The lipid membrane of these cells determines which molecules may be transferred from blood plasma into oral fluid. Three routes have been identified that may transport a drug across the lipid membrane; these include active transport (secretion), passive diffusion through the membrane across a concentration gradient, and diffusion through pores in the membrane (ultrafiltration) (Höld, de Boer, Zuidema & Maes, 1996,United Nations, 1998). Some molecules with a low molecular mass (i.e. ethanol) may diffuse through the water-filled pores in the membrane. Other small molecules are primarily transported through secretion. For larger molecules (most drugs of abuse), passive diffusion across a concentration gradient is thought to be the major factor in transport (Höld, de Boer, Zuidema & Maes, 1996; Huestis & Cone, 1998). Equilibrium occurs between plasma and saliva. In plasma a large proportion of a drug is bound to proteins. Drug concentrations in oral vary with the free fraction of drug in plasma, and therefore mimic concentrations found in blood (Cone, 1993).
Interpretation of Drug Concentrations in Saliva
Saliva has been shown to be a suitable matrix for the detection of drugs of abuse, specifically cocaine and benzoylecgonine (e.g. Cone, 1993; Schramm, Craig, Smith, et al., 1993), heroin, 6-MAM and morphine (e.g. Goldberger, Darwin, Grant, et al., 1993), codeine (in Huestis & Cone, 1998b), methadone (e.g. Wolff, 1991) and amphetamines (Cone, 1993). Cannabis use is somewhat more difficult to detect in saliva though it has been shown to be possible (e.g. Menkes, Howard, Spears, et al., 1991). Saliva drug concentrations generally correlate well with the free fraction of drug in blood (Cone, 1993; Kidwell, Holland & Athanaselis, 1998).
Saliva can be used to provide both qualitative and quantitative information on the drug status of an individual undergoing testing for all drugs of abuse reviewed (Cone, 1993).
Much research into saliva testing has examined its utility as an alternative test matrix to blood and urine.
A qualitative drug test is one that provides a dichotomous result, that is, it indicates whether a sample is positive or negative for a specified drug. However, there are four possible results of a qualitative drug test.
A true-positive result occurs when the test correctly identifies the presence of a drug in the sample taken.
A false-positive result is one where the test incorrectly detects the presence of a drug where in fact no drug is present.
A true-negative result occurs when the test correctly confirms the absence of a drug.
A false-negative result is one where the test fails to detect the presence of a drug when it is in fact present.
Interpreting a Positive Test Result
A positive result indicates that the specific drug (or class of drug) is present at or above the designated cut-off level. Typically, the cut-off concentration is set to the lowest concentration the drug can be reliably detected following consumption. It considers environmental and analytical variability caused by such factors as passive contamination/ingestion, technological limits, etc.
False-positives resulting from qualitative screening
A false-positive result can occur when a benign substance in the biological sample mimics the chemical effect of the targeted substance on the test. The test indicates a positive result even though the targeted drug was absent. Such results have reportedly occurred after ingestion of antihistamines, certain anti- inflammatory drugs, cold and flu medications, and poppy seeds (Selavka, 1991). The false-positive rate for particular testing methods is discussed in the relevant chapters below. Although levels are generally low, it does highlight the necessity of appropriate confirmatory testing with parent / metabolite quantification to identify and safeguard against this.
Interpreting a Negative Test Result
In the majority of cases a negative result indicates that the parent drug (typcially the active ingredient) and / or its metabolites are absent in the biological sample. It does not mean that the person has not used the substance in the days or weeks prior to testing. The amount of drug present in the sample at the time of sample collection, and thus whether a positive result is obtained, is determined by a number of factors which include: the cut-off level used; the testing schedule employed; the biological sample analyzed; when the drug was ingested; the amount of drug ingested; the form in which it was ingested; and physical and pharmacological characteristics of the user.
False-negatives
When an initial screen result in negative and (1.) the individual ingests a drug and the concentration of the drug in the sample is at our above the cut-off, or (2.) the individual ingests a drug and the concentration of of the sample is below the the cut-off due to sample adulteration or substitution, the result referred to as a “false-negative”.
Relative to urinalysis, there are a number of actions an individual can take, to increase the likelihood of a false-negative result. An individual can adulterate the specimen via dilution by drinking excessive amounts of water (in vivo adulteration), or by adding water or chemicals that will affect the test (in vitro adulteration) (Coleman & Baselt, 1997). Hair testing may be susceptible to excessive washing (Rohrich, Zorntlein, Potsch, et al., 2000), bleaching (Yegles, Marson & Wennig, 2000) and other cosmetic hair treatment (Skopp, Potsch & Moeller, 1997). There are no currently proven methods to adulterate or substitute oral fluid.
Quantitative Results
Quantitative drug testing involves the determination of the specific concentrations of a parent drug and/or its metabolite(s) in a sample, typically via GC/MS and LC/MS/MS. In addition to confirmatory testing of qualitative screening results, quantitative results quantitative results using blood or oral fluid / saliva specimens can provide additional information regarding the quantity and frequency of drug use (Cone, 1997). Blood and/or oral fluid / saliva may also be useful when establishing impairment levels for certain drug classes. Urine and hair specimens are generally considered effective for historical use only. With knowledge of the drug’s pharmacokinetic parameters, including its half-life, an estimate of the frequency of new drug use can be obtained using quantitative analysis (Cone, 1997, Huestis and Cone 1998).
The Physiology of Urine Production
Urine is produced continuously by the kidneys and may be considered an ultrafiltrate of blood. During urine production the kidneys reabsorb essential substances. Excess water and waste products, such as urea, organic substances and inorganic substances, are eliminated from the body. Parent drugs (typically the active ingredient) are often present in urine in very low concentrations or not detected at all. Therefore distinguishing between codeine, heroin and morphine use, for example, can be difficult. Furthermore, inter-subject variations in urine drug concentrations, even after similar dosing, is high.
Absorption into urine is usually slow when a drug is orally administered and excretion may be delayed for several hours (approximately 6-9 hours) .Generally, a urine specimen will contain the highest concentration of parent drug and metabolite at this time period. As drug elimination usually occurs at an exponential rate, for most illicit drugs a dose will be eliminated almost completely within 48 hours. A number of factors influence detection times including the quantity of drug administered, parent drug and metabolite half- life, cut-off level used, and a number of physiological factors. It is also noted that for many of drugs, frequent, multiple dosing over extended periods of time can cause the drug to accumulate in the body resulting in significantly extended detection times.
The Physiology of Oral Fluid
Salivary gland is a term used to include any tissue that normally discharges a secretary product into the oral cavity. Thus, oral fluid refers to the mixture of fluid in the oral cavity. Saliva is a complex aqueous fluid (99% water) containing electrolytes (principally sodium,potassium, chloride and bicarbonate), proteins (mostly enzymes, including amylase) and muncin (Kidwell, Holland & Athanaselis, 1998). The mucin gives oral fluid its sticky character. Saliva also contains cell and food debris and oral microorganisms. The composition and production of oral fluid is determined by the relative contribution of the different glands, which in turn is dependant on a variety of factors including nutritional and emotional state, sex, age, season of the year, time of day, and a variety of diseases and pharmacological agents (Höld, 1996; United Nations, 1998)
The three major salivary glands are: (1) the parotid, at the top of the mouth, (2) the submandibular, at the base of the tongue, and (3) the sublingual, at the sides of the oral cavity. The parotid gland, responsible for about 25% of the saliva produced, excretes saliva derived primarily from blood plasma (serous fluid); the submandibular and sublingual glands excrete both serous fluid and mucin and contribute approximately 71% and 4% respectively (Kidwell, Holland & Athanaselis, 1998). The volume of saliva produced by an adult ranges from 500 to 1500 ml per day. Unstimulated saliva has a pH range between 5.6 and 7. Stimulation increases the pH to a maximum of 8 (Kidwell, Holland & Athanaselis, 1998).
A thin layer of epithelial cells separates the salivary ducts from the systemic blood circulation (capillaries). The lipid membrane of these cells determines which molecules may be transferred from blood plasma into oral fluid. Three routes have been identified that may transport a drug across the lipid membrane; these include active transport (secretion), passive diffusion through the membrane across a concentration gradient, and diffusion through pores in the membrane (ultrafiltration) (Höld, de Boer, Zuidema & Maes, 1996,United Nations, 1998). Some molecules with a low molecular mass (i.e. ethanol) may diffuse through the water-filled pores in the membrane. Other small molecules are primarily transported through secretion. For larger molecules (most drugs of abuse), passive diffusion across a concentration gradient is thought to be the major factor in transport (Höld, de Boer, Zuidema & Maes, 1996; Huestis & Cone, 1998). Equilibrium occurs between plasma and saliva. In plasma a large proportion of a drug is bound to proteins. Drug concentrations in oral vary with the free fraction of drug in plasma, and therefore mimic concentrations found in blood (Cone, 1993).
Interpretation of Drug Concentrations in Saliva
Saliva has been shown to be a suitable matrix for the detection of drugs of abuse, specifically cocaine and benzoylecgonine (e.g. Cone, 1993; Schramm, Craig, Smith, et al., 1993), heroin, 6-MAM and morphine (e.g. Goldberger, Darwin, Grant, et al., 1993), codeine (in Huestis & Cone, 1998b), methadone (e.g. Wolff, 1991) and amphetamines (Cone, 1993). Cannabis use is somewhat more difficult to detect in saliva though it has been shown to be possible (e.g. Menkes, Howard, Spears, et al., 1991). Saliva drug concentrations generally correlate well with the free fraction of drug in blood (Cone, 1993; Kidwell, Holland & Athanaselis, 1998).
Saliva can be used to provide both qualitative and quantitative information on the drug status of an individual undergoing testing for all drugs of abuse reviewed (Cone, 1993).
Much research into saliva testing has examined its utility as an alternative test matrix to blood and urine.
Friday, September 7, 2007
THC Detection in Oral Fluid / Saliva
THC Detection
First and forement, devices / techniques must screen for THC-delta-9 in oral fluid NOT THC-COOH and/or delta-11, etc. The latter is a metabolite found only in urine at any level that can be commonly detected, the former is the active ingreadient of marijuna and found in oral fluid.Detection of THC-delta-9 in oral fluid has repeatedly been demonstrated to be possible from connsumption... up to 24 hours post consumption.The following is one of several references available on this topic:Relationship of (9)-tetrahydrocannabinol concentrations in oral fluid and plasma after controlled administration of smoked cannabis byHuestis MA, Cone EJ.Intramural Research Program,National Institute on Drug Abuse, National Institutes of Health,Baltimore, Maryland 21224. J Anal Toxicol. 2004 Sep;28(6):394-9ABSTRACTUnderstanding the relationship of (9)-tetrahydrocannabinol (THC) concentrations in oral fluid and plasma is important in interpretation of oral fluid test results. Current evidence suggests that THC is deposited in the oral cavity during cannabis smoking. This "depot" represents the primary or sole source of THC found when oral fluid is collected and analyzed. In this research, oral fluid and plasma specimens were collected from six subjects following smoking of cannabis cigarettes containing 1.75% and 3.55% THC. There was at least one week between each cannabis administration. Plasma specimens were analyzed by gas chromatography-mass spectrometry (GC-MS) and paired oral fluid specimens were analyzed by radioimmunoassay (RIA). In addition, one individual's oral fluid specimens were also analyzed by GC-MS. These data are unique in that they represent simultaneous or near simultaneous collection of oral fluid and plasma specimens in subjects following controlled cannabis dosing. The first oral fluid specimen, collected from one subject at 0.2 h following initiation of smoking, contained a THC concentration of 5800 ng/mL (GC-MS). The similarity in oral fluid and plasma THC concentrations following the dissipation of the initial "contamination" indicates the likelihood of a physiological link between these specimens. Recent studies have shown that sublingual or transmucosal administration of pure THC results in direct absorption of intact THC into the bloodstream, thereby bypassing the gastrointestinal tract. The current study demonstrates that THC is deposited in the oral cavity and remains for up to 24 h following cannabis smoking. The decline in THC oral fluid concentration over this time suggests that there may be absorption of THC into blood as previously shown with pure THC. Passive cannabis exposure studies appear to indicate that positive oral fluid tests for THC can occur shortly after cannabis smoke exposure, but results were negative within 1 h. Consequently, when very recent passive exposure to cannabis smoke can be ruled out, it is concluded that a positive oral fluid test provides credible evidence of active cannabis use.
First and forement, devices / techniques must screen for THC-delta-9 in oral fluid NOT THC-COOH and/or delta-11, etc. The latter is a metabolite found only in urine at any level that can be commonly detected, the former is the active ingreadient of marijuna and found in oral fluid.Detection of THC-delta-9 in oral fluid has repeatedly been demonstrated to be possible from connsumption... up to 24 hours post consumption.The following is one of several references available on this topic:Relationship of (9)-tetrahydrocannabinol concentrations in oral fluid and plasma after controlled administration of smoked cannabis byHuestis MA, Cone EJ.Intramural Research Program,National Institute on Drug Abuse, National Institutes of Health,Baltimore, Maryland 21224. J Anal Toxicol. 2004 Sep;28(6):394-9ABSTRACTUnderstanding the relationship of (9)-tetrahydrocannabinol (THC) concentrations in oral fluid and plasma is important in interpretation of oral fluid test results. Current evidence suggests that THC is deposited in the oral cavity during cannabis smoking. This "depot" represents the primary or sole source of THC found when oral fluid is collected and analyzed. In this research, oral fluid and plasma specimens were collected from six subjects following smoking of cannabis cigarettes containing 1.75% and 3.55% THC. There was at least one week between each cannabis administration. Plasma specimens were analyzed by gas chromatography-mass spectrometry (GC-MS) and paired oral fluid specimens were analyzed by radioimmunoassay (RIA). In addition, one individual's oral fluid specimens were also analyzed by GC-MS. These data are unique in that they represent simultaneous or near simultaneous collection of oral fluid and plasma specimens in subjects following controlled cannabis dosing. The first oral fluid specimen, collected from one subject at 0.2 h following initiation of smoking, contained a THC concentration of 5800 ng/mL (GC-MS). The similarity in oral fluid and plasma THC concentrations following the dissipation of the initial "contamination" indicates the likelihood of a physiological link between these specimens. Recent studies have shown that sublingual or transmucosal administration of pure THC results in direct absorption of intact THC into the bloodstream, thereby bypassing the gastrointestinal tract. The current study demonstrates that THC is deposited in the oral cavity and remains for up to 24 h following cannabis smoking. The decline in THC oral fluid concentration over this time suggests that there may be absorption of THC into blood as previously shown with pure THC. Passive cannabis exposure studies appear to indicate that positive oral fluid tests for THC can occur shortly after cannabis smoke exposure, but results were negative within 1 h. Consequently, when very recent passive exposure to cannabis smoke can be ruled out, it is concluded that a positive oral fluid test provides credible evidence of active cannabis use.
Detection Windows vs. Specimen Type
The primary goal of any drug-free workplace policy is to deter substance abuse.
In order to accomplish this end, a combination of education, drug testing, and employee assistance / counseling is required.
Relative to the drug test the following elements must be present:
1. Ability to detect current / on-the-job drug abuse.
2. Convenience for both donor and test administrator.
3. Observed specimen collection.
Only oral fluid / saliva meets all three objectives.
Urine can only detect historical drug abuse and there is no relationship between drug metabolite concentration and impairment and/or time drug was ingested. Observed collection is not possible in most workplace settings.
Hair is the best method for detecting historical drug abuse, and allows for observed collection. However, is only suitable for pre-employment testing as it can not detect drug consumption within the past seven days.
Oral fluid can detect drug consumption within minutes of consumption, up to 2-3 days for many drugs. THC detection is limited to approximately 24 hours, however, the impairment period for marijuana is generally reported to be one hour (two hour maximum).
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