The history of aquatic toxicology began with early classifications of poisons by Dioscorides and theories of toxicologist Paracelsus that the dose determines whether a substance is toxic. Through the Middle Ages and later, understanding of bioavailability and effects of chemicals like metals, industrial byproducts like methanol and lead, and environmental issues like acid rain, eutrophication, and uncleaned industrial waste developed toxicology as a field. Major events included Minamata disease from mercury in industrial wastewater in Japan and destruction of fish stocks from acid rain in Europe and North America. Remedies involved reducing sulfur in fuels and removing it from emissions to curb acid rain.

1. THE HISTORY OF AQUATIC

2. INTRODUCTION
TOXICOLOGY :
SCOPE:
Mixture of science,art and creative thinking.
facts -predictions.
Father of toxicology-Paracelsus.
Modern father of toxicology-Mathieu Orfila

3. • Dioscorides : first classification of poisons, use of emetics in
treatment .
• Paracelsus : ”All substances are poisons; there is none which
is not a poison. The right dose differentiates a poison from a
remedy.”
• A physician – alchemist; set the basics of pharmacology,
toxicology and therapeutics; investigated the dose-response
relation.

4. • Toxicology dates to the earliest humans.
• Poisons played an important role in the history of mankind.
• They may either be lack of information or ignorance,
carelessness, untidiness, and, at worst, anger that may lead to
cases of deliberate poisoning.
Hemlock (Greek capital punishment)
Aconite (Chinese poison arrows)
HISTORY

5. • King Mithridates VI of Pontus
• Poisonings were so rampant in Rome, a law was enacted in
82BC. It made poisoning illegal, and later extended to careless
dispensers of drugs (an early regulatory effort!)

6. MIDDLE AGES
Concept of bioavailability:
• Based on the forms of toxicants, or what one eats/drinks
before ingestion, the chemical can be more or less readily
available in the body.
• Milk, butter and cream could delay intestinal absorption (due
to the fat content) Full stomach also delays absorption

7. 1890s-1900s
• Discovery of vital amines (vitamins) led to the wide-spread
usage of bioassays to determine whether these new chemicals
were beneficial.
• Development of neurotoxicity field due to the production of
bootleg liquor by-products (methanol & lead).
• Toxicology of metals due to the production of ‘The bomb’.
MODERN TOXICOLOGY

8. Minamata Disease ( 1950s – 1960s ,Japan)

9. Itai-Itai Disease ( ouch-ouch) 1950, Japan

10. • The first larger-scale aquatic environmental issue resulted
from lead water pipes that were used in large Roman scales.
• Sewage systems –Eutrophication.

11. • Upon industrialization acid rains become issue.
• Whole fish stocks especially salmonids were wiped out.
• European and North American countries.

12. Remedies:
• The use of fuels containing much sulphur be curbed.
• The use of coal in energy production be decreased.
• Smoke be cleaned.
• Removing sulphur from the gases.

13. • Untill the later part of the 20th centuary, waste water was
virtually always uncleaned.
• Uncleaned paper-and-pulp-mill effluents used to be the major
environmental question in western europe and North America
• At that time all the water areas close to the paper-and-pulp-
mill were dead.

14. THANK
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