How does toxicology work

Impaired driving investigations aim to determine the level of alcohol or drug s in the body. These levels are compared to legislated levels to determine if an offence has been committed or to scientific literature to predict human performance, specifically driving ability under the effects of drugs.

Drug levels can also be used to determine if an individual died from a drug overdose. A forensic toxicologist may work in a laboratory which focuses primarily on cases proceeding within the criminal system e. Laboratories may also provide both services e. The Centre of Forensic Sciences. Forensic toxicology labs use state of the art chemical and biomedical instrumentation capable of detecting small amounts of toxic materials.

Currently, there is not one analytical technique that will detect, identify and determine the level of all toxins within the body and therefore the toxicologist must make informed decisions on what analyses to proceed with, based on the amount of sample submitted for analysis and the suspected drugs within the body.

Forensic toxicologists may also provide support to law enforcement in maintaining their impaired driving programs for both drugs and alcohol, and will provide specialized support for the operation of alcohol breath testing instrumentation. For cases of poisoning where gaseous or volatile substances are involved, samples of brain, lungs and blood must be collected immediately using gas-tight containers, and if possible, tarred, cooled glass containers.

Hair has been used in variety of toxicology settings to provide a history of drug exposure and has therefore found applications in workplace drug testing, in monitoring of persons on probation or on parole for drug use, in insurance testing to verify the truthfulness of statements made by applicants relating to whether they use drugs or are smokers, in drug-facilitated sexual assault and in other types of criminal case- work.

Chemicals in the bloodstream may be transferred to the growing hair and stored in the follicle, providing a rough timeline of drug intake events. However, testing for drugs in hair is not standard throughout the population.

For eg- If two people consumed the same amount of drugs, the person with the darker and coarser hair will have more drug in their hair than the lighter haired person when tested.

This raises issues of possible racial bias in substance tests with hair samples. The hair sample may then be placed into aluminum foil, an envelope, or plastic collection tube and stored at room temperature until analysis. The use of oral fluid is gaining importance in forensic toxicology for showing recent drug use, e. It can be collected non-invasively, conveniently and without invasion of privacy and is most commonly collected fluid from the oral cavity for the determination of drugs.

It is composed of many things and concentrations of drugs typically parallel to those found in blood. Sometimes referred to as ultra filtrate of blood, it is thought that drugs pass into oral fluid predominantly through a process known as passive diffusion. Drugs and pharmaceuticals that are highly protein bound in blood will have a lower concentration in oral fluid.

It is one of the post-mortem specimens. The availability of autopsy specimens in postmortem toxicology allow for a more flexible analytical approach to the analysis, although some specimens have more value than others when specific drugs or poisons are involved in the death.

The fact that vitreous humor resides in an anatomically isolated and protected area of the body behind the lens of the eye , coupled with its good stability as a biological fluid, makes this specimen more resistant to putrefactive changes than other postmortem specimens. All available vitreous fluid from each eye should be collected separately.

These are important analyses for the evaluation of diabetes, degree of hydration, electrolyte imbalance, postmortem interval and the state of renal function prior to death. Gastric content is a potentially valuable specimen for analysis in postmortem and clinical cases. Oral ingestion remains the most popular means of exposure to drugs and poisons.

Therefore, gastric contents are essential for screening tests. All of the available sample should be collected without the addition of a preservative. Undigested pills and tablets should be separated and placed into plastic pillboxes for analysis.

After opening the abdominal cavity, the stomach should be tied off and then removed, subsequently emptying the contents into a container and documenting the total amount. Suspicious items such as tablet remnants and herbal matter etc. Tissue samples collected in postmortem investigations generally provide supplemental information to the toxicologist to assist in interpretation of their results.

In STA, analysis of the correct tissue specimen may be vital to the identification or confirmation of an unknown causative agent.

When tissues are sampled they should be collected quickly and placed immediately into airtight containers. Liver, kidney, brain, lung and spleen are the most frequently collected postmortem tissues. This area of forensics has evolved to mean the study of illegal drugs and legal ones such as alcohol. It has been already discussed above that forensic toxicology can identify poisons and hazardous chemicals which can be used in interpreting the outcome or the real situation.

The chemical makeup of each substance is studied and they are also identified from different sources such as urine or hair. Forensic toxicology deals with the way that substances are absorbed, distributed or eliminated in the body the metabolism of substances. When learning about drugs and how they act in the body, forensic toxicology will study where the drug affects the body and how this occurs. While there are many uses for forensic toxicology testing, the most familiar one to most people is likely to be drug and alcohol testing.

This type of testing is commonly performed in the transportation industry and in workplaces. Another use is for drug overdoses, whether these are intended or accidental. People who drive with a blood alcohol concentration over the accepted legal limit can also be accessed through toxicology testing.

Another application of forensic toxicology relates to sexual assault that involves the use of drugs. Various drugs are used today for the purposes of rendering the victim unable to fight the attacker, who then proceeds to sexually assault the victim.

Through toxicology testing, a victim can find out what drug was given and can then be treated accordingly. There are a lot of substances and poisons in our world many of which impact how we function in work and society. Forensic toxicology is also applied in cases of post-mortem investigations where toxicology is required to establish if an excessive intake of the drug occurred and, if so, whether this contributed to death. Forensic toxicology testing allows forensic scientists to identify substances and determine a pattern of use.

Suicidal, homicidal and accidental cases of poisoning are common in India and in other countries. With the availability of various agents like pesticides, insecticides, drugs, chemicals the probability of the misuse of the same is happening. The substances of preference for poisoning are aconite, strychnine, calotropis, oleander, copper, mercury, arsenic etc. The forensic toxicology laboratory, thus, analyzes body fluids and tissues to determine the presence of these substances.

Toxicologists conduct the analysis, issue reports on their findings, and provide court testimony to interpret the test results. Arising out of a growing concern over the burgeoning incidence of poisoning worldwide, coupled with a lack of public awareness about its seriousness, the government has incorporated provisions regarding the abuse of poison and admissibility of the reports of medical examinations into the Indian legislation.

It is dealt below in following parts:. In India mostly poisons are used for robbery and suicidal purposes. For eg- Datura is used by that sect of the thugs who poisoned wayfarers. Even today the poisoning and robbing of travelers was of frequent occurrence in India. Therefore, the administration of a poison is a criminal offence whenever-.

In so far as the Indian legal system and its position is concerned, when Indian Evidence Act or the Code of Criminal Procedure, were enacted, legislature could not anticipate the tremendous development of modern science and technology and its deep impact on the forensic science as well as well as administration of justice. However, the Supreme Court has opined, in a case concerning specifically with the medical examination of a victim of rape, that medical jurisprudence is not an exact science.

Therefore such evidences have to be seen along with the physical and circumstantial evidence in every case. For collection of blood samples, S. So it shall be lawful for a registered medical practitioner at the request of the police officer not below the rank of sub-inspector and for any person acting in good faith in his aid and under his direction, to make such an examination of the person arrested as is reasonably necessary in order to ascertain the facts which may afford such evidence and to use such force as is reasonably necessary.

This section does not specifically say whether it would be applicable for DNA tests also. This section does not state that the police officer shall be entitled to personally collect semen, blood, hair root, urine, vaginal swab, etc for the purpose of investigation himself. The new Explanation now stands which include within its ambit examination of blood, blood stains, semen, sputum, swabs, sweat, hair samples and finger nails by the use of modern techniques in the case of sexual offences including DNA profiling and such other tests which is necessary in a particular case.

Though, S. By issuing direction to the police officer to collect blood samples from the accused and conduct DNA test for the purpose of further investigation under S. The incidence of poisoning in India is among the highest in the world, and it is estimated that more than 50, people die every year from toxic exposure. The commonest agents in India appear to be pesticides organophosphates, carbamates, chlorinated hydrocarbons, and pyrethroids , sedative drugs, chemicals corrosive acids and copper sulfate , alcohols, plant toxins datura, oleander, strychnos, and gastro-intestinal irritants such as castor, croton, calotropis, etc.

This was the first criminal case in India solved by the help of forensics and an attempt was made by the criminals to conceal a homicide by firearm by putting the dead body on fire. However a clever and systematic forensic investigation revealed the true cause of death. In general, however, individuals are best served by pursuing their undergraduate education in forensic toxicology through an institution that is accredited by the Forensic Science Education Programs Accrediting Commission FEPAC.

Many individuals seeking additional training and recognition in forensic toxicology often pursue professional certification through one or more of the following:.

To become certified through the American Board of Toxicology, candidates must possess one of the following:. Candidates must take a certification examination, which includes assessment in three, major areas:. The American Board of Forensic Toxicology offers certification as a forensic toxicology specialist. Study must include an adequate education in biology and chemistry, which may include pharmacology or toxicology.

Candidates must also have at least 3 years of full-time experience in forensic toxicology. Certification is dependent upon passing a comprehensive written examination on the principles and practice of analytical toxicology.