Principles of Toxicology

Principles of Toxicology (overview)

  • An Introduction to A Small Dose of Toxicology
  • Basic Principles of Toxicology
    • Dose-Response
    • Risk = Hazard X Exposure
    • Individual Sensitivity

Everyday Examples of Toxicology

What Aspect of Toxicology?



Developed as a sedative in the early 60s but found to cause a rare birth defect, phocomelia. In 1962 legislation was passed that new drugs must undergo sufficient animal and human testing prior to approval for use by the FDA.

Hong Kong

a) Many chickens and birds in Hong Kong were killed to stop the spread of a potentially deadly avian virus that could move to humans
b) Why was Hong Kong a British colony? This was in part due to the opium wars, when England and other countries wanted to promote the use of opium to the Chinese population. Consider our own current “war on drugs.”

Princess Diana

At the time of death her driver may have had too much alcohol to drink.
Ambassador to Mexico A number of years ago a former governor of Massachusetts (Weild) was denied the opportunity to become the ambassador to Mexico because US Senator Jesse Helm thought he was “soft on drugs”. Yet this senator was from a key tobacco-growing state and a major supporter of the tobacco industry (and hence nicotine). Who is soft on drugs?

$276 Billion

Money lost or spent due to the consumption of alcohol or drug abuse, car accidents, lost work, etc.

$65 Billion

Money lost or spent due to tobacco-related illnesses or disease.


Our food supply is depends on and is contaminated with pesticides. Artificial sweeteners, flavors, and colors are used. Mercury contaminates some fish.


Loud noise can damage hearing and can cause an even greater effect in combination with certain drugs


The dust in your home may contain many hazardous contaminants. e.g. lead or pesticides. Many of these can be tracked in the home on shoes or by pets. Removing shoes can reduce contamination in the home.

12,000 Children

Estimated number of children with Fetal Alcohol Syndrome

Coeur d’Alene, Silver Valley, ID

Town contaminated by lead

Solar Radiation (ultraviolet light)

Sunburn, cancer


Found in drinking water, and old smelter and mining sites; causes skin disease and cancer

The Effect of Dose and Body Size on Response

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For a given body size, the larger dose produces a greater effect (left), and for a given exposure, the smaller body size receives a greater effect and larger dose (right).

The Effect of Dose and Body Size on Response: an Idealized Dose-Response Graph

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The horizontal axis indicates the dose in mg/kg of body weight, while the vertical axis is the percent of maximum response. For very low dose there is no or little response. The response increases with the dose until the maximum response is reached and increasing the dose has no additional effect.


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Principles of Toxicology Chapter

PowerPoint Presentation


More Information and References

Teaching Resources

  • US National Library of Medicine. Toxicology Tutorials. Site offers three tutorial lessons on toxicology.
  • Society of Toxicology (SOT). K-12 Resources. US toxicology organization site has a variety of useful information and links to educational resources on toxicology and related biological sciences.

European, Asian, and International Agencies

  • Organization For Economic Co-Operation And Development (OECD). Chemical Safety and Biosafety. OECD Site contains general information on environmental and chemical health and safety.
  • European Commission. Public Health. European Commission has extensive health-related information in many languages. European Environment Agency. European Environment Agency has extensive environmental health-related information in many languages.
  • National Institute for Clinical Excellence (NICE). NICE was set up as a Special Health Authority for England and Wales and its role is to provide patients, health professionals, and the public with authoritative, robust, and reliable guidance on current "best practice."
  • Chemical Safety Information from Intergovernmental Organizations. INCHEM is a means of rapid access to internationally peer-reviewed information on chemicals commonly used throughout the world, which may also occur as contaminants in the environment and food. It consolidates information from a number of intergovernmental organizations whose goal it is to assist in the sound management of chemicals.
  • International Programme on Chemical Safety (IPCS). Pesticide Data Sheets. Site has large list of pesticide data sheets.
  • World Health Organization (WHO). The World Health Organization, the United Nations' specialized agency for health, was established on April 7, 1948. WHO's objective, as set out in its constitution, is the attainment by all peoples of the highest possible level of health. Information is in English, Spanish, and French.

North American Agencies

  • Health Canada. Health Canada provides extensive health-related information in English and French.
  • Canadian CHEMINDEX database. The CHEMINDEX database contains information on over 200,000 chemicals; record contains identification information on a unique chemical substance, including chemical names and synonyms, the CAS registry number, and a list of the CCINFO databases containing information on that substance.
  • Canadian MSDS Database. Material Safety Data Sheets on over 120,000 compounds from 600 North American manufacturers and suppliers.
  • US National Library of Medicine. This site provides access to probably the greatest sources of reference material in the world. The Health Information section has specific areas related to toxicology as well as many searchable databases.
  • US Environmental Protection Agency (EPA). Contains a wealth of information on many common environmental pollutants such as lead, mercury, and pesticides, including regulatory information. The site also has a great kids section.
  • US Environmental Protection Agency (EPA). Integrated Risk Information System (IRIS). "IRIS is a database of human health effects that may result from exposure to various substances found in the environment." An excellent source of information about many compounds and a great starting place.
  • US Environmental Protection Agency (EPA). Toxics Release Inventory (TRI) Program. "The Toxics Release Inventory (TRI) is a publicly available EPA database that contains information on toxic chemical releases and other waste management activities reported annually by certain covered industry groups as well as federal facilities."
  • US National Toxicology Program (NTP). In 1978 the Department of Health and Human Services (DHHS) established the NTP to coordinate toxicological testing programs, strengthen the science base in toxicology, develop and validate improved testing methods, and provide information about potentially toxic chemicals to health regulatory and research agencies, the scientific and medical communities, and the public.

Non-government Organizations

  • Environmental Defense Fund. The Environmental Defense Fund is dedicated to protecting the environmental rights of all people, including future generations. Among these rights are clean air and water, healthy and nourishing food, and a flourishing ecosystem.
  • North American Association for Environmental Education (NAAEE). NAAEE is a network of professionals, students, and volunteers working in the field of environmental education throughout North America and in over 55 countries around the world. Since 1971, the association has promoted environmental education and supported the work of environmental educators.

Library References

  • National Library of Medicine. US TOXNET. TOXNET is a cluster of databases on toxicology, hazardous chemicals, and related areas.

Introductions to Toxicology and Risk

  • Ottoboni, Alice. The Dose Makes the Poison: A Plain Language Guide to Toxicology, 2nd Edition. New York: Van Nostrand Reinhold, 1991. A very good introduction to toxicology.
  • Berger, Bob. Beating Murphy's Law: The Amazing Science of Risk. New York: Delta, 1994. A fun look at risk in everyday life.
  • Morgan, M. Granger. "Risk Analysis and Management". Scientific American 269, (1993): 32-41. This is a good short overview of many of the issues in risk analysis.
  • Kent, Chris. Basics of Toxicology. New York: Wiley, 1998. More detailed overview but still accessible.

Reference Books (lots of good information, but costly)

  • Hayes, A. Wallace (ed). Principles and Methods of Toxicology, 5th Edition. London: Taylor & Francis, 2007.
  • Klaassen, Curtis D. (ed). Casarett & Doull's Toxicology: The Basic Science of Poisons, 7th Edition. New York: McGraw-Hill, 2007. One of the classic toxicology textbooks that contains more than anyone wants to know about toxicology.
  • Hardman, Joel G. et al. (eds). Goodman and Gilman's The Pharmacological Basis of Therapeutics, 12th Edition. New York: McGraw-Hill, 2010. A detailed book on the pharmacological (i.e. beneficial) and toxicological (i.e. adverse) effects of drugs. Also considerable basic physiological information.
  • US Congress, Office of Technology Assessment. Neurotoxicity: Identifying and Controlling Poisons of the Nervous System. Washington, D.C.: US Government Printing Office, 1990. An excellent overview of toxicology with an obvious emphasis on chemical agents that affect the nervous system.
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