Toxicology

Toxicology is the study of the adverse effects of chemicals or biological agents on living organisms. It is the study of symptoms, mechanisms, treatments and detection of poisoning.

History of Toxicology

Antiquity (3000 BCE–90 CE)

Middle Ages (476 CE – 1453)

   

Renaissance (1450–1600)

 

1700-1800

Origin of toxic agents

       Toxins

-      Released or produced by living organisms which will serve as toxic agents that provides them protection 
      as well as for capture and metabolism of food.

  Infectious agents

-Bacterial toxins: botulinum toxin, Staphylococcal toxin causing Toxic Shock Syndrome

-Fungal toxins/Mycotoxins: aflatoxin produced by Aspergillus flavus and Aspergillus parasiticus.

  Animal venoms

- Toxins produced in secretory glands and delivered during a biting or stinging act this targets acetylcholine receptors causing neuromuscular paralysis.

- Snake venom: contains crotalase enzyme that attacks fibrinogen causing internal bleeding as well as sarafotoxin which induces coronary vasoconstriction.

  Plant toxins

-      Toxins from plant have different active components. The most common effect to the body is gastrointestinal disturbances such as nausea, diarrhea and abdominal pain.

-      Others include allergies, local and systemic effects as well as neurologic disturbances.

  

  
        






     Toxicants

-      By products of anthropogenic activities.

 

                

          

Types of Toxic effects

• Mutagenicity: detection of possible ability to induce genetic alteration (mutation); UV light

• Carcinogenicity: detection of possible ability to induce abnormal clonal uncontrolled proliferation of genetically altered cells;  benzene, asbestos

• Teratogenicity: detection of possible deleterious effects on the developing fetus;  thalidomide

       

• Death: arsencic, cyanide
• Organ damage: ozone, lead

Forensic Toxicology& Drugs of Abuse

For our safety, let us familiarize ourselves with the different 
toxic and hazard symbols...

Photo credits:

• ADME properties
• Pathway of drug and its effects
• snake venom
• poisonous plants
• poison ivy, oak, sumac
• radiation 
• explosive

References:

• Historical Milestones and Discoveries Which Shaped the Toxicology Sciences by Steven G. Gilbert and Antoinette Hayes
• Toxicology introduction: Medical news
• A framework for describing diseases caused by toxic agents November, 2004 Boston Cure Project, Inc.
• General Principles of Pharmacology and Toxicology