DOT Urine Drug Testing Not Working - New Government GAO Report

Now even the US Government knows the obvious ....

Drug testing without observed specimen collection, is a waste of time and money.





Private interest groups, consisting largely of urine drug testing laboratories, urine-centric TPA's, occupational health clinics, some unions, as well as a select group of archaic government bureaucracies (DOT, FAA, etc.) continue to exclusively support urine-based testing vs. superior, user-friendly technologies - most notably oral fluid / saliva and hair-based drug screening.

Oral fluid / saliva and hair-based drug screening technologies allow for observed specimen collection and are relatively non-invasive vs. traditional urine drug testing. Oral fluid delivers information on "current" / "on-the-job" drug and/or alcohol use, while hair detects "historical drug abuse".

• Oral fluid / saliva is suitable for random, post-accident, and reasonable suspicion testing, and also can be used for pre-employment testing.
• Hair is most appropriate for pre-employment testing, especially for employers that wish to track drug use history for a period of up to 90 days.

The DOT and other government agencies, including "regulatory agencies" such as SAMHSA are largely to blame for the continued emphasis upon traditional urine-based testing, and ultimately serving to help perpetuate America's problem with substance abuse.

Why? Government agencies resist moving to newer technologies either due to the fear of having to "do more work", and/or are impacted by private interest groups with heavy lobbying budgets and well established "old boy networks".
In their defense, the DOT claims "success" by noting a "2% positive rate". This is a blatant misuse of statistics. Of course the is only a 2% positive rate... as most drug abusers are cheating the test!
As noted below, if drug testing involved observed specimen collection, and/or more stringent techniques the positive rate soars to 10%.

Urine-based drug testing is simply:
1. too difficult, costly, and noxious to apply consistently and on a corporate-wide / industry-wide basis,
2. prone to drug abusers "beating the test".

Several documented cases support the above facts:
For example, a recent construction site that had a low "positive rate" using tradition urine drug testing, but had several site issues and eventually discovered hypodermic needles on-site.
When they implemented Avitar's oral fluid-based testing, conducing a full site-based random screen, the positive rate registered 20%!

Urine testing laboratories, in most cases, are not able to determine if urine samples are adulterated or substituted, other than in the most basic and severe cases.
Despite this fact, they continue to spread misinformation, claiming the opposite.
The Director of Workplace Drug Testing for SAMHSA is on record, testifying before Congress, that detect adulterants, that labs can only detect a very small fraction of the many products available on the Internet available to beat urine-based drug tests, and that substituted drug free urine and synthetic urine also are undetectable.

GAO: Easy to cheat on trucker drug tests
Three-quarters of testing sites don’t provide secure conditions, report finds
The Transportation Department estimates that fewer than 2 percent of truck drivers test positive each year for controlled substances.
But when Oregon conducted its own tests, 9 percent of truck drivers tested positive.
Dozens of products on the Web are marketed to truckers as fail-safe ways to defeat the mandatory drug tests.
WASHINGTON - Undercover federal investigators discovered that it was surprisingly easy to cheat on random drug tests designed to catch truck drivers who use drugs, NBC News has learned.
Undercover investigators with the Government Accountability Office (GAO), the investigative arm of Congress, used bogus truck driver’s licenses to gain access to 24 drug-testing sites.
They found that 75 percent “failed to restrict access to items that could be used to adulterate or dilute the [urine] specimen, meaning that running water, soap, or air freshener was available in the bathroom during the test.”
The GAO team also bought drug-masking products over the Web and was able to mix them with real specimens at the drug-testing sites “without being caught by site collectors,” the agency said in a report scheduled to be made public ThursdayDrug - screening labs never realized that there was a problem.
“Every drug masking product went undetected by the drug screening labs,” said the report, a copy of which was obtained by NBC News.Rep.
Jim Oberstar, D-Minn., chairman of the House Transportation and Infrastructure Committee, said the report was “frankly astonishing and shocking and dismaying.
You can manipulate the tests, you can mask substance abuse and go undetected on the roadways.”Oberstar, who planned to hold a hearing Thursday, said the drug-testing system was broken and was placing other drivers in danger.“It fails, it is not sufficient, it is not protecting the public interest,” he said.
How many are cheating?
The Transportation Department estimates that fewer than 2 percent of truck drivers test positive each year for controlled substances in random federal tests.
But when Oregon law enforcement officials conducted their own random tests this year, 9 percent of truck drivers tested positive.
Dozens of products widely available on the Web are marketed to truckers as fail-safe ways to defeat the mandatory drug tests.
“My first reaction was total disbelief. I just felt sick,” said Kathleen Ellsbury, whose husband, Tony Qamar, was killed two years ago when a truck driver in Washington state lost his load of logs on a curve, crushing Qamar’s car.
Also killed was Daniel Johnson, a fellow seismologist at the University of Washington.Ellsbury learned later that the truck driver, who was sentenced to 4½ years in prison for vehicular homicide, had previously been convicted of possessing methamphetamines and that he had meth in his blood at the time of the crash.
“The system has big holes, let’s say that,” said Ellsbury, who said she had a message for truck drivers who might be tempted to cheat:
“I’d like to be standing right outside the bathroom and hold up a picture of my husband — remind them there's consequences.”
Truckers promise to do betterSpokesmen for the trucking industry said truck drivers were among the safest drivers on the road, with much lower rates of drug use than the general population. Still, they said, having roughly 30,000 drivers test positive each year was unacceptable.
Lisa Myers is chief investigative correspondent and Richard Gardella is an investigative producer for NBC.

BCTD Building Construction Trades Department " New " Drug Testing Program - A Costly Mistake

For Safety Professionals attempting to innovate and improve efforts can be frustrating, largel due to the fact that politics can easily supersede logic.



That said, while potentially well-intentioned, the "new" Building and Construction Trades Department - BCTD drug testing program ( which oddly requires outdated and relatively ineffective urine-based testing as well as the use of a specific laboratory, third party administrator, and their specific product and services ) represents a step backwards...not forward ,



more importantly, however, this archaic structure does NOT serve the best interests of unions, union members, contractors, insurers, or owners.



The Need for Change:

Abuse in the Construction SectorWe all know that a drug free workplace is a safe workplace and the union skilled trades and contractors were ahead of their time years 16 years ago, when urine-based drug testing was introduce by innovators as evidence by the MUST program, LEAD, and others.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.



It's time again for union's to put politics aside and address the issue from from a safety point of view:



Why should every construction site drug test?

Simple. While 10% of employees aged 18 – 49 years abuse drugs (not including alcohol), the construction industry runs 2x-3x this rate.With 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 works

Oral 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?“This measure (on-site oral fluid drug testing) provides a cost effective on-the-job alternative to laboratory tests that can be costly and difficult to schedule."- Aiona, Lt. Governor, HawaiiAlso 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.



Here are actual results from a contractor who switched from urine-based to oral fluid-based drug screening:













Where do we go from here?
Occupational health, safety, and risk management professionals must assist in driving change. This groups and only this group knows what truly happens every day on our job sites. At the end of day, they “get it”.It’s time for safety professionals to join with all constituencies to update current drug and alcohol free workplace programs to assure compliance and effectiveness.

It’s also time for the 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

Schools Infested with Drugs

New Study: Schools Infested with Drugs - August 17, 2007
A New Study from the National Center on Addiction & Substance Abuse (CASA) suggests that US Schools are infested with drugs. The survey revealed that at least once a week on their school grounds, 31 percent of high school students (more than four million) and nine percent of middle school students (more than one million) see illegal drugs used, sold, students high and/or drunk. At least weekly, 17 percent of all high and middle school students (4.4 million) personally see classmates high on drugs at school.

Construction Safety / Drug Testing: Michigan AGC / MUST Drug Testing

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.

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

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.

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.