Chapter 6 Notes Part 1 Forensic toxicology

Dr. Death In 1998, 81 year old Kathleen Grundy was found dead, lying on her sofa fully dressed. Her physician, Dr. Harold Shipman,visited her just hours before her death. Dr. Shipman informed Mrs. Grundy’s daughter that an autopsy would not be necessary.

Dr. Death A few days later, a will surfaced leaving all of Mrs. Grundy’s money to Dr. Harold Shipman. The will was immediately recognized as a forgery and Mrs. Grundy’s body was exhumed. The toxicology report revealed a lethal dose of morphine.

Dr. Death This resulted in a closer look at Dr. Shipman. Local undertakers were already suspicious at the number of his patients who were dying. All of these patients were elderly women, found fully dressed and lying on a bed or sofa.

Dr. death As the investigation continued, the extent of his crimes became clear. One clinical audit estimated that he killed 236 of his patients over a 24 year period. Most of these deaths were caused by a lethal dose of heroin or morphine.

Dr. death Officially convicted of 15 murders, Harold Shipman hanged himself in his jail cell in 2004.

The role of forensic toxicology With the uncontrolled use of drugs becoming more and more of a worldwide problem, the role of toxicology has gained new significance.

The role of Forensic Toxicology Toxicologists detect and identify drugs and poisons in body fluids, tissues, and organs. Toxicologists can work in forensic science but also in the general medical field.

The role of forensic toxicology Forensic toxicologists deal with matters that pertain to the violation of criminal law only. Many forensic toxicology systems work with or are a part of the medical examiner’s office.

The role of forensic toxicology Forensic toxicologists handle frequent and numerous cases dealing with the presence of alcohol in the body.

The Role of Forensic Toxicology Beyond alcohol, the job of the forensic toxicologist is an extremely complicated web of poisons and drugs.

The role of forensic toxicology The toxicologist is presented with body fluids and organs and must determine what drugs and poisons are present. There are thousands upon thousands of possibilities. The substances will be present in extremely tiny concentrations.

The Role of Forensic Toxicology Many drugs immediately change form chemically upon entering the body. For example, heroin is immediately converted to morphine in the human body.

The Role of Forensic Toxicology From living persons, blood and urine are collected for toxicological testing.

The role of forensic toxicology From deceased persons, the medical examiner will decide what biological specimens will be sent for toxicology testing.

Toxicology of alcohol Testing for alcohol is one of the most common responsibilities of the forensic toxicologist. To understand the toxicology of alcohol, you must understand how alcohol is processed by the body.

Metabolism of alcohol Metabolism is how the body breaks down and transforms chemicals into other chemicals that are easier to eliminate. There are 3 steps to metabolism: absorption, distribution, and elimination.

Metabolism of alcohol Alcohol (ethyl alcohol) is a colorless liquid usually diluted with water and consumed as a beverage.

Metabolism of alcohol Alcohol appears in the blood within minutes of being consumed and continues to increase in concentration as it is absorbed from the stomach and small intestine.

Metabolism of alcohol During absorption and distribution, alcohol enters the bloodstream and is carried to all parts of the body.

Metabolism of alcohol Many factors determine the rate at which alcohol is absorbed, including: Alcohol content of beverage Amount consumed How much food is in the stomach What type of food is in the stomach

Metabolism of alcohol As the alcohol is circulated by the bloodstream, the body begins to eliminate it. Alcohol is eliminated by oxidation and excretion.

Metabolism of alcohol 95-98% of the alcohol consumed is eventually oxidized by the liver to carbon dioxide and water.

Metabolism of alcohol The remaining 3-5% of the alcohol consumed is excreted unchanged through the breath, urine, and perspiration.

Metabolism of alcohol The alcohol exhaled in the breath is in direct proportion to the blood alcohol concentration.

Alcohol in the circulatory system Blood-alcohol levels have become the accepted standard for relating alcohol intake to its effect on the body.

Alcohol in the circulatory system To understand the meaning and results of blood alcohol levels, the movement of alcohol through the circulatory system must be understood.

Alcohol in the circulatory system 20% of alcohol consumed is absorbed through the walls of the stomach. The other 80% is absorbed through the small intestine.

Alcohol in the circulatory system After being absorbed, the alcohol is pumped through the liver, to the heart, the lungs, back to the heart, and out to all the tissues of the body.

Analysis of blood for alcohol Gas chromatography is the most widely used approach for determining alcohol levels in blood samples.

Analysis of blood for alcohol Using this technique, the alcohol can be separated from the rest of the blood sample and measured.

Alcohol and the law Every state in the U.S. must establish and enforce laws regulating the operation of motor vehicles. The blood alcohol standards are relatively uniform across all 50 states.

Alcohol and the law The initial recommendation for legal blood-alcohol concentration for operating a vehicle was 0.15%. This was eventually lowered due to further testing to 0.08% In 1992, 0.08 was recommended as the legal measure of drunk driving, and was officially enacted in 2000.

Alcohol and the law Currently, a person is considered legally intoxicated with a BAC level of 0.08. No other qualifications are necessary.

Alcohol and the law Other countries, such as Ireland, Japan, the Netherlands, and Norway, have stricter legal limits, at 0.05% BAC.

Alcohol and the law At the 0.08 level, you are 4 x more likely to be in an accident compared to a sober person. As 0.15, you are 25 x more likely to be in an accident compared to a sober person.

95-98% of alcohol in the body is oxidized to what two substances? REVIEW 95-98% of alcohol in the body is oxidized to what two substances? Carbon dioxide and dehydrogenase Water and acetic acid Acetaldehyde and acetic acid Water and carbon dioxide

REVIEW 2. Which of the following individuals would have the lowest Blood Alcohol Concentration? John, 200 lbs, has had 8 drinks on a full stomach. Frank, 170 lbs, has had 4 drinks on an empty stomach. Gary, 240 lbs, has had 6 drinks on an empty stomach. Stephen, 180 pounds, has had 6 drinks on a full stomach.

REVIEW 3. With a blood alcohol level of 0.15, the chances for involvement in an accident are 50 times greater 25 times greater 10 times greater 75 times greater