PPT 1 Flashcards
Toxicology, simply defined, is the
“study of poisons”
It is a field of science that helps us understand the harmful effects that chemicals, substances, or situations, can have on people, animals, and the environment.
Toxicology
It is a substance capable of producing adverse effects on an individual under appropriate conditions or appropriate amount.
Poison
It is almost always synonymous with “chemical” and includes drugs, vitamins, pesticides, pollutants, and proteins
Substance
Even radiation is a toxic substance. Though not usually considered to be a “chemical,” most radiations are generated from radioisotopes, which are chemicals.
It refers to the injury, such as structural damage to tissues.
Adverse Effects
It refers to the dosage of the substance that is sufficient to cause these adverse effects
Appropriate Conditions or Amount
This concept is important because according to it even a substance as innocuous [harmless]as water is poisonous if too much is ingested.
dose concept
He writes of the use of arrows poisoned with venom (ancient Greek – Toxicon) in the epic tales The Odyssey and The Iliad.
Homer (850 BCE)
This philosopher was charged with religious heresy and corrupting the morals of local youth, dies by hemlock poisoning (the active chemical is the alkaloid coniine).
Socrates (399 BCE)
This egyptian experiments with strychnine and other poisons on prisoners and the poor. She commits suicide by the bite of the Egyptian asp.
Cleopatra (69 BCE)
Jewish philosopher and physician who wrote Treatise on Poisons and Their Antidotes.
Moses Maimonides
What did Moses Maimonides write?
Treatise on Poisons and Their Antidotes.
This is the largest pandemic in recorded history. Worldwide, it kills about 75 million people.
The Black Death (1347)
How many people were killed from the Black Death between 1347-1351
About 25 million
A council of murderers
1419
A political body that carried out murders with poison for a fee
The Venetian Council of Ten (1419)
He identified the specific chemical components of plants and animals that are responsible for their toxic properties.
He also showed that varying the amount of the poison affects the severity of the effects.
Paracelsus (1493-1541)
“All substances are poisons; there is none that is not a poison. The right dose differentiates a poison from a remedy.”
Paracelsus
He experimented with bioaccumulation of poisons in animals and calls the procedure “passages”.
Leonardo da Vinci (1452–1519)
This pope died (possibly murdered) after eating Amanita phalloides, the death cap mushroom
Pope Clement VII (1478–1534)
It is New Zealand’s most poisonous toadstool – and one of the most poisonous fungi known.
Death cap (Amanita phalloides)
During the 1600, makes a reference to poisoning in his play Romeo and Juliet in Act 5: “Here’s to my love! O true apothecary! Thy drugs are quick. Thus, with a kiss I die.”
William Shakespeare (1564–1616)
A Roman woman and fortune-teller, forms a secret organization that sells an arsenic potion to women so they can murder their husbands.
Hieronyma Spara (1659)
He passed a royal decree forbidding apothecaries from selling arsenic or poisonous substances.
King Louis XIV (1682)
It is naturally present at high levels in the groundwater of a number of countries.
It is highly toxic in its inorganic form
Arsenic
Contaminated water used for drinking, food preparation and irrigation of food crops poses the greatest threat to public health from arsenic.
Long-term exposure to arsenic from drinking-water and food can cause cancer and skin lesions. It has also been associated with cardiovascular disease and diabetes. In utero and early childhood exposure has been linked to negative impacts on cognitive development and increased deaths in young adults.
The most important action in affected communities is the prevention of further exposure to arsenic by provision of a safe water supply.
He writes A Mechanical Account of Poisons, about poisonous animals and plants.
Richard Meade (1702)
Considered the father of modern toxicology, he established a systematic correlation between chemical properties and biological effects of poisons
Orfila (1787–1853)
He writes the first American book dedicated to poisons, Microchemistry of Poisons.
Theodore Wormley (1826–1897) (1869)
He writes Traite des Poisons, which describes the symptoms of poisons.
Mathieu Orfila (1813)
This act prevents the production or trafficking of mislabeled, adulterated, or poisonous foods, drugs and pharmaceuticals, medicines, and liquors.
The Pure Food and Drugs Act (1906)
This agency is established to regulate the content and safety of consumer drugs and food.
US Food and Drug Administration (FDA) - 1930
Minamata Bay in Japan is contaminated with mercury by a chemical plant. Thousands of adults and children are poisoned from eating fish contaminated with methyl mercury.
Minamata Disaster (1950s)
This occurred for 5 days, causing or progressing the death of about 12,000 people. It is a stimulus to the modern environmental movement.
The London Great Smog (also known as the Big Smoke)
He collaborates with scientists to produce the first large compilation of toxicology, Procedures for the Appraisal of the Toxicity of Chemicals in Foods.
He is co- founder of the Society of Toxicology and its journal Toxicology and Applied Pharmacology.
Arnold J Lehman (1961)
During 1980, this was founded in Brussels, Belgium.
The International Union of Toxicology
Many are reported in New Zealand along with the discovery that these are toxic.
1994 – harmful algal blooms (HABs) in NZ
Shellfish banning begins due to appearance of poisonous shellfish.
1995
The death of dogs on Auckland beaches leads to the discovery of deadly tetrodotoxin in grey side-gilled sea slugs (eaten or mouthed by the dogs).
2009
Legislation is passed that all countries in the European Union use liquid chromatography-mass spectrometry methods (rather than mouse bioassays) to detect known toxins and measure toxicity levels in shellfish.
The Cawthron Institute in Nelson developed these methods.
2012
Toxicology is also used in laboratory experiments on animals to establish dose- response relationships.
Toxicology also deals with the way chemicals and waste products affect the health of an individual.
It is concerned with the study of chemicals that contaminate food, water, soil, or the atmosphere.
It also deals with toxic substances that enter bodies of waters such as lakes, streams, rivers, and oceans.
This sub-discipline addresses the question of how various plants, animals, and humans are affected by exposure to toxic substances.
Environmental Toxicology
It is concerned with health effects from exposure to chemicals in the workplace. This field grew out of a need to protect workers from toxic substances and to make their work environment safe.
Occupational (Industrial) Toxicology
Occupational diseases caused by industrial chemicals account for an estimated 50,000 to 70,000 deaths, and 350,000 new cases of illness each year in the United States (1).
It gathers and evaluates existing toxicological information to establish concentration-based standards of “safe” exposure. The standard is the level of a chemical that a person can be exposed to without any harmful health effects.
Regulatory Toxicology
It is involved in delivering a safe and edible supply of food to the consumer. During processing, a number of substances may be added to food make it look, taste, or smell better.
Fats, oils, sugars, starches and other substances may be added to change the texture and taste of food. All of these additives are studied to determine if and at what amount, they may produce adverse effects.
Food Toxicology
A second area of interest includes food allergies. Almost 30% of the American people have some food allergy. For example, many people have trouble digesting milk, and are lactose intolerant. In addition, toxic substances such as pesticides may be applied to a food crop in the field, while lead, arsenic, and cadmium are naturally present in soil and water, and may be absorbed by plants.
Toxicologists must determine the acceptable daily intake level for those substances.
It is concerned with diseases and illnesses associated with short term or long-term exposure to toxic chemicals.
Clinical toxicologists include emergency room physicians who must be familiar with the symptoms associated with exposure to a wide variety of toxic substances in order to administer the appropriate treatment.
Clinical Toxicology
It is N. The United States Environmental Protection Agency (EPA), the Occupational Safety and Health Administration (OSHA), and the Food and Drug Administration (FDA), use information from these studies to set regulatory exposure limits.
Descriptive Toxicology
It is used to help establish cause and effect relationships between exposure to a drug or chemical and the toxic or lethal effects that result from that exposure.
Forensic Toxicology
It identifies the toxicant through analysis of body fluids, stomach content, excrement, or skin.
Analytical toxicology
It makes observations on how toxic substances cause their effects. The effects of exposure can depend on a number of factors, including the size of the molecule, the specific tissue type or cellular components affected, whether the substance is easily dissolved in water or fatty tissues, all of which are important when trying to determine the way a toxic substance causes harm, and whether effects seen in animals can be expected in humans.
Mechanistic Toxicology
Metals differ from other toxic substances in that they are neither created nor destroyed by humans. Their use by humans plays an important role in determining their potential for health effects.
Their effect on health could occur through at least two mechanisms: first, by increasing the presence of heavy metals in air, water, soil, and food, and second, by changing the structure of the chemical.
For example, chromium III can be converted to or from chromium VI, the more toxic form of the metal.
Nearly everyone is exposed to solvents. Occupational exposures can range from the use of “white-out” by administrative personnel, to the use of chemicals by technicians in a nail salon.
When a solvent evaporates, the vapors may also pose a threat to the exposed population.
It is the release and propagation of energy in space or through a material medium in the form of waves, the transfer of heat or light by waves of energy, or the stream of particles from a nuclear reactor
Radiation
The Chernobyl accident in 1986 was the result of a flawed reactor design that was operated with inadequately trained personnel. The resulting steam explosion and fires released at least 5% of the radioactive reactor core into the environment, with the deposition of radioactive materials in many parts of Europe.
He writes Traite des Poisons, which describes the symptoms of poisons.
Mathieu Orfila (1787-1853)
He writes the first American book dedicated to poisons, Microchemistry of Poisons.
Theodore Wormley (1869)
