In 1967, the International Olympic Committee (IOC) and the International Cycling Union became the first sporting organizations in the world to ban the use of performance-enhancing drugs, sometimes also known as doping, in an effort to stop drug misuse during the 1968 Olympics. To be effective, the new measures had to be underpinned by a system of testing athletes and others closely involved in sports for banned substances. Forensic toxicologists carry out sports testing for a range of drugs, from steroids and beta-blockers, to growth hormones and diuretics. It is not clear how widespread the use of drugs in sports really is, but those who do cheat, including trainers, frequently use new substances in an attempt to evade the testers. It is up to the forensic toxicologist to keep a step ahead by developing new, sensitive, and, above all, reliable methods for sports testing.
The technology for sports testing was somewhat primitive prior to the early 1980s. Stimulants, like amphetamines , could be detected through reliable tests, but other substances in common use, like anabolic steroids, could not. However, this changed with the introduction of gas chromatography/mass spectrometry (GC/MS) systems, which can accurately analyze most organic compounds of the type used in sports doping. Unfortunately, some athletes bent on cheating used GC/MS to their own ends, testing their urine to see how long it took the drugs to leave their system. This enabled athletes to know when to stop taking the drugs before a game or competition where they were likely to be tested. This led to sporting organizations extending testing into the training period, so an athlete could be tested, without warning, at any time. Unfortunately, this too created problems, as some athletes trained in distant locations and could not always be contacted easily to have a test performed.
In the early days of sports testing, organizations did not always appreciate the importance of the chain of custody of a sample. Security from tampering and contamination could not necessarily be guaranteed. This led to several successful appeals against "false positives" where an athlete had tested positive for a drug he or she had not in fact taken. Today, many of these logistic problems have been reduced or even eliminated. Athletes competing at high levels are aware of the necessity of testing and are prepared for it, even if they do not all accept it. The toxicology laboratories operate more professionally and with a higher degree of scientific accuracy and reliability.
Anabolic steroids are one of the most well known drugs used in sports, both at elite and recreational levels. Related to the male hormone testosterone, anabolic steroids cause muscle growth, increased strength, and sharper reflexes, which is why such drugs have been abused in the context of most Olympic sports as well as team sports. Steroids allow the user to train more often at higher intensity without the risk of injury. However, steroids can damage the user, causing hair loss, impotence, acne, liver damage, heart muscle damage, and aggressive behavior (sometimes known as "steroid rage"). Steroids can readily be detected by GC/MS.
In 2005 the United States Congress tackled the issue of anabolic steroid use in professional baseball when it subpoenaed a panel of former and current allstars, including former St. Louis Cardinal Mark McGwire—who once held the record for the most home runs hit during a single season—to provide testimony about the frequency of steroid use in the game. The House Committee concluded that officials in charge of baseball have not adequately policed the issue, which resulted in enhanced testing policies, along with increased suspensions and penalties for players who test positive for performance-enhancing drugs. As of April 2005, additional hearings were pending regarding use in other sports, including the National Football League (NFL).
One controversial anabolic steroid is nandralone, which several athletes across the globe have been accused of using. However, some debate exists over testing for the steroid nandrolone. In the body, it is broken down into a substance called 19-norandrosterone (NA) and measurement of levels of this in urine samples is the basis of drug tests. The IOC considers levels of above 2 nanograms/milliliter for men and 5 nanograms/milliliter for women as evidence of nandrolone misuse. The number of individuals testing positive for nandrolone appears to have increased in recent years, as the sensitivity of the detection technology has increased. Some athletes claimed false positive results with the new technology. A review found no problem with the testing procedure, but also found a number of reasons why it is at least theoretically possible to test positive for nandrolone without actually taking the banned substance.
The nandrolone test cannot determine the actual source of NA in the urine. Besides coming from knowingly ingested or injected nandrolone, NA can also be produced by the body itself. Self-produced NA levels are not usually above the IOC's limits. There is also some limited evidence that physiological factors, such as vigorous exercise and the stress of injury, might push NA levels into the positive range. Findings against this include a study of 370 male competitors at the 1996 Winter Olympics in Nagano, Japan, which found that none had a concentration of NA above 0.4 nanograms per milliliter.
Some herbal and nutritional supplements also contain anabolic steroids, including nandrolone. The labels on such products may be incomplete or incorrect, or the products themselves might be contaminated. It's possible that some athletes are ingesting nandrolone unknowingly with sports supplements (especially if they take more than one supplement at a time). Current rules state that such ignorance is no defense against a drug charge. Testing methods need to be developed so they can properly distinguish the source of NA in urine, another challenge for the forensic toxicologist.
Most of the other drugs in common use are detected by GC/MS. Stimulants like amphetamines increase reaction time and decrease fatigue. They have been used in American football and cycling, but are perhaps less popular than in previous years because they are so readily detected by GC/MS. Betablockers are used to reduce trembling and anxiety in sports such as snooker and archery; however, they also have medical uses such as blood pressure control. Diuretics increase the flow of urine and may be abused in sports where weight control is an issue. They have also been used illicitly to help flush other drugs out of the system.
Human growth hormone seems to be increasing in popularity and has similar effects to anabolic steroids. It increases muscle strength and is thought not to have the same side effects as steroids. Growth hormone was historically in short supply, as it had to be extracted from human pituitary glands. It can now be made in a purer form by genetic engineering and it is this recombinant form that many athletes use, despite its expense. A related substance is insulin-like growth factor (IGF-1). Interest in this substance is sure to increase in the wake of gene therapy experiments that show how mice injected with the gene for IGF-1 have up to 30% greater muscle strength and muscle mass than ordinary mice. The animals also have better performance in resistance training.
Genetic engineering has also produced a hormone called recombinant erthyropoietin (EPO), which helps the body to produce more red blood cells and increases endurance in sports like running and cycling. The problem with testing for substances like growth hormone, IGF-1, and EPO is that they so closely resemble the natural versions of these molecules produced by the human body, and the need exists for more sophisticated tests. For instance, a separation technique called isoelectric focusing has shown the differences between natural and recombinant EPO, but more research is needed before it can be generally accepted. Such tests are also quite expensive.
Before the recombinant version became available, it was not unknown for athletes to utilize "blood doping," a process in which the athlete would transfuse himself with his own blood (drawn earlier and then stored for later use) or blood donated by another individual. This process increases the number of red blood cells, allowing the athlete's blood to carry more oxygen to the muscles and theoretically increasing performance levels on the day of the competition. This practice (particularly when the athlete's own blood is used) is difficult to detect in the laboratory. Yet recently forensic tests have been used to expose athletes when the blood is donated from someone else. In April 2005 professional cyclist and Olympic gold medal winner Tyler Hamilton was suspended from racing for two years after blood tests indicated the presence of blood doping via transfusion with donated blood. As of May 2005, Hamilton maintained his innocence and asserted his intent to appeal his suspension.
Currently, most sports testing is done on urine rather than blood samples. It is easy to perform a random test on a urine sample and such samples are simple to store and process. The way in which drugs are excreted into urine is also well understood, so results from the test can be related to the athlete's drug-taking behavior. More accurate results, however, could perhaps be obtained from taking blood tests. A urine test gives a quick and easy screen, which can indicate the presence of a drug. The urine test, if necessary, can be followed up by confirmatory blood tests. Replacing urine tests with finger-prick blood tests may give more accurate results, especially for newer substances such as EPO, but athletes may see it as unnecessarily invasive. There is also the risk of exposing laboratory staff to infection from blood-borne disease, albeit this risk may be small. More expertise is also needed for the storage and handling of blood samples.
Many of these same issues arise in another emerging field of forensic toxicology—workplace testing. Increasingly, employers will not tolerate their workforce being under the influence of alcohol or drugs and want to carry out random screening to ensure their requirements are being met. Blood testing could be interpreted as an infringement on the employee's liberty as the purpose is non-medical—as it is in sports testing.
A challenge for forensic toxicology is the use of body fluids as a medium for accurate drug testing without being unnecessarily invasive. When it comes to sports testing, there may be even bigger questions to address in the future. For example, what if athletes undergo gene therapy to increase their dose of IGF-1 and so increase their strength and endurance? How will it be possible to determine the presence of new genetic material in the genome? The new ethical questions posed by the issue of fairness in sport can only lead to the development of forensic toxicology as a science.
see also Gas chromatograph-mass spectrometer; Toxicology.