2. Lecture 1 History
What is Toxicology
Toxicology is a scientific discipline, overlapping with biology, chemistry, pharmacology, and medicine,
that involves the study of the adverse effects of chemical substances on living organisms and the
practice of diagnosing and treating exposures to toxins and toxicants.
History of Environmental Toxicology
3. Anitiquality of Toxicology
Knowledge of animal venoms and plant extracts for hunting, warfare, assassination is a recorded history.
The oldest known Writings, the Ebers Papyrus (circa 1500 B.C) tells about many recognized poisons like hemlock,
aconite, opium, and metals such as lead, copper and antimony.
Where as the book of Job (circa 1400 B.C) tells about poisoned arrows.
Theophrastus a student of Aristotle, included numerous references to poisonous plants.
Dioscorides, a Greek physician in the court of the Roman emperor Nero, made the first attempt at classifying poisons as
plant, animal, and mineral.
Middle age
The writings of Maimonides (Moses ben Maimon, A.D. 1135–1204) included a treatise on the treatment of poisonings
from insects, snakes, and mad dogs (Treatise on Poisons and Their Antidotes, 1198). Maimonides described the subject
of bioavailability, noting that milk, butter, and cream could delay intestinal absorption.
History of Environmental Toxicology
4. Redescription of Toxicology
“All substances are poisons; there is none that is not a poison.
The right dose differentiate a poison from a remedy.”
Paracelus between 17th and 18th century was a physician- alchemist focused on the primary toxic agents as a
chemical entity and Held that
• 1- Experimentation is essential in the examination of responses to chemicals
• 2-One should make a distinction between the therapeutic and toxic properties of chemicals
• 3-these properties sometimes but not always indistinguishly excepted by dose
• 4-one can be sure about the degree of specificity of chemicalsand their therapeutic toxic effects.
These principals became the foundation of dose-response relationship in the toxicology.
Age of enlightment of Toxicology
Orfila a Spanish physicist used autopsy material and chemical analysis systematically as a legal proof of
poisoning that became the foundation of forensic toxicology. His major work was in 1815 about the toxicity of
natural agents. Magendies’ research in 18th century lead the foundation of absorption and distribution of toxic
compounds.
German scientists Oswald Schmiedeberg and Louis Lewin trained 120 students who later populated the most
important laboratories of pharmacology and toxicology around the world.
History of Environmental Toxicology
5. Modern Toxicology
Since 1900 century toxicology has been coupled with health and occupational regulations with the
development of anesthetic and disinfectants.
In 1890-1900 the discovery of radioactivity, vitamins and vital amines led to use the first large scale
bioassay that was based on multiple animal studies to determine weather the new chemical is
beneficial or harmful to animals.
First publication was came in 1930 in the journal “Archive fur toxicology” in the same year NIH
National Institute of Health was established in USA.
In 1947 first major pesticide act was made and for that first time a chemical that not a drug nor a
food had to be shown to be safe and effective.
Scope of Environmental Toxicology
6. Food and Drug administration
The Food and Drug Administration (FDA or
USFDA) is a federal agency of the United States
Department of Health and Human Services, one of the
United States federal executive departments formed in 1906.
The FDA is responsible for
• protecting and promoting public health through the
control and supervision of food safety,
• tobacco products
• dietary supplements
• prescription and over-the-counter pharmaceutical drugs
(medications), vaccines, biopharmaceuticals, blood
transfusions, medical devices
• electromagnetic radiation emitting devices (ERED)
• cosmetics
• animal foods & feed and veterinary products.
Organizations and Symbols
7. THE Occupational Safety and Health
Administration (OSHA)
is an agency of the United States Department of Labor
formed in 1971.
OSHA's mission is to
• assure safe and healthy working conditions for
working men and women by setting and enforcing
standards and by providing training, outreach,
education and assistance.
• OSHA's workplace safety inspections have been
shown to reduce injury rates and injury costs without
adverse effects to employment, sales, credit ratings,
or firm survival
8. Beginning in the late 1950s and through the 1960s, Congress reacted to increasing public concern about the impact that
human activity could have on the environment. The 1962 publication of Silent Spring by Rachel Carson alerted the public
view about the detrimental effects on the environment of the indiscriminate use of pesticides.
President Richard Nixon proposed the establishment of EPA on July 9, 1970 and it began operation on December 2, 1970.
Conduct of EPA
Acceptable levels of chemicals in the environment
The agency conducts environmental assessment, research, and education. It has the responsibility of maintaining and
enforcing national standards under a variety of environmental laws, in consultation with state, tribal, and local governments.
It delegates some permitting, monitoring, and enforcement responsibility to U.S. states and the federally recognized tribes.
EPA enforcement powers include fines, sanctions, and other measures. The agency also works with industries and all levels of
government in a wide variety of voluntary pollution prevention programs and energy conservation efforts.
EPA works in
Asia/Pacific
Europe
Eurasia
Latin America and the Caribbean
Middle East
North America
Sub-Saharan Africa
Environmental Toxicology
9. Rachel Louise Carson (May 27,
1907 – April 14, 1964) American
marine biologist. In 1950s, Carson
turned her attention to some
problems that she believed were
caused by synthetic pesticides. The
result was the book Silent
Spring (1962), which brought
environmental concerns to an
unprecedented share of the
American people., it spurred a
reversal in national pesticide
policy, which led to a nationwide
ban on DDT 1972 and other
pesticides. It also inspired
a grassroots environmental
movement that led to the creation
of the U.S. Environmental
Protection Agency. US EPA
Environmental Toxicology
10. United Nations Environment Programme (UNEP) -
To protect the environment, The National Environmental Policy Act (NEPA) was written.
Main point of NEPA was to brings to light is that
• it "assures that all branches of government give proper consideration to the
environment prior to undertaking any major federal actions that significantly affect
the environment." This law was enacted on January 1, 1970 and to date, more than
100 nations around the world have enacted national environmental policies modeled
after NEPA.
This law also founded the Council on Environmental Quality (CEQ). The importance of
CEQ was that it helped further push policy areas.
CEQ created helpful environmental programs that were very beneficial.
Some include
• The Federal Water Pollution Control Act (RCRA)
• Toxic Substance Control Act, Resources Conservation and Recovery Act (RCRA and the
Safe).
CEQ was essential in creating the foundation for most of the "current environmental
legislation except for Superfund and asbestos control legislation."
Environmental Toxicology
11. The Toxic Substances Control Act (TSCA) is a United States law, passed
by the United States Congress in 1976 and administered by the United
States Environmental Protection Agency (EPA). TSCA regulates the introduction
of new or already existing chemicals. When the TSCA was put into place, all
existing chemicals were considered to be safe for use
Main objectives
• to assess and regulate new commercial chemicals before they enter the
market
• to regulate chemicals already existing in 1976 that posed an "unreasonable
risk to health or to the environment", as for example PCBs, lead, mercury
and radon
• to regulate these chemicals' distribution and use.
• TSCA does not separate chemicals into categories of toxic and non-toxic
Environmental chemistry
12. The Clean Air Act of 1963.
To control air pollution in 1963. It is one of the most comprehensive air quality laws in the
world administered by (EPA)
• Authorizing research into techniques for monitoring and controlling air pollution.
• It was first amended in 1965, by the Motor Vehicle Air Pollution Control Act, which set
required standards for controlling the emission of pollutants from certain automobiles,
beginning with the 1968 models.
• A second amendment, enabled the government to increase its activities to investigate
enforcing interstate air pollution transport and for the first time to perform far-reaching
ambient monitoring studies and stationary source inspections.
• The 1967 act also authorized expanded studies of air pollutant emission inventories,
ambient monitoring techniques, and control techniques.
• In 1970 comprehensive federal and state regulations for both stationary (industrial)
pollution sources and mobile sources.
Further amendments were made in 1990 to address the problems of acid rain, ozone
depletion, and toxic air pollution, The amendments also established new auto gasoline
reformulation requirements, set Reid vapor pressure (RVP) standards to control Evaporative
emissions from gasoline, and mandated new gasoline formulations.
Environmental Toxicology
13. DOT Packaging and
shipping of hazardeous
materials.
Shipping of hazardous materials is
regulated by the U.S. Department
of Transportation (DOT) and the
International
Air Transport Association
(IATA). Shipping hazardous materi
als can pose danger to anyone
who may come into contact with
the shipment.
18. Strategic Approach to International Chemicals Management (SAICM)
This initiative was adopted at the International Conference on Chemicals Management (ICCM), which took place
from 4–6 February 2006 in Dubai gathering Governments and intergovernmental and non-governmental
organizations. It defines a policy framework to foster the sound worldwide management of chemicals.
• This initiative covers risk assessments of chemicals and harmonized labeling up to tackling obsolete and
stockpiled products.
• Are included provisions for national centers aimed at helping in the developing world, train staff in chemical
safety as well as dealing with spills and accidents. SAICM is a voluntary agreement.
Globally Harmonized System of Classification and Labelling of Chemicals (GHS) proposes harmonised hazard communication
elements, including labels and safety data sheets. It was adopted by the United Nations Economic Commission for Europe
(UNECE) in 2002.
• This system aims to ensure a better protection of human health and the environment during the handling of chemicals,
including their transport and use.
• The classification of chemicals is done based on their hazard. This harmonisation will facilitate trade when implemented
entirely.
Lecture 3 Strategies and conventions
19. Stockholm Convention
The Stockholm Convention is a global treaty to protect human health and the environment from persistent organic
pollutants(POPs). It entered into force, on 17 May 2004, and over 152 countries signed the Convention. In May 2009, nine new
chemicals are proposed for listing which then contained 12 substances.
Rotterdam Convention
The objectives of the Rotterdam Convention are: • to promote shared responsibility and cooperative efforts among Parties in the
international trade of certain hazardous chemicals in order to protect human health and the environment from potential harm; •
to contribute to the environmentally sound use of those hazardous chemicals, by facilitating information exchange about their
characteristics, by providing for a national decision-making process on their import and export and by disseminating these
decisions to Parties. Thos convention has 72 signatory countries. The text of the Convention was adopted on 10 September 1998
by a Conference in Rotterdam, the Netherlands. The Convention entered into force on 24 February 2004. The Convention creates
legally binding obligations for the implementation of the Prior Informed Consent (PIC) procedure.
Basel ConventionThe Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and their Disposal is a
global environmental agreement on hazardous and other wastes. It came into force in 1992. The Convention has 172 Parties and
aims to protect human health and the environment against the adverse effects resulting from the generation, management,
transboundary movements and disposal of hazardous and other wastes.
Minamata Convention on Mercury is an international treaty designed to protect human health and the environment from
anthropogenic emissions and releases of mercury and mercury compounds signes in 10 October 2013 by 128 countries. The
objective of the Minamata Convention is to protect the human health and the environment from anthropogenic emissions and
releases of mercury and mercury compounds.
