Martes, Hulyo 10, 2012

Toxicology: A Danger Zone

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Fig 1: Toxic Hazard Symbol


What comes in to your mind when you see this sign?? For me, I think of danger, with the skull and bones crossed it really seem that there is a danger. During my childhood days, I thought that when I touch a chemical or substance with a sign like that attached to it my hands would be molten. I was really afraid that time.




 DEFINITION
Toxicology is the study of the adverse effect of chemicals in organisms especially on humans, its symptoms, route of exposure, detection of toxicity, mechanisms, and treatment.In layman's term, toxicology is the study of poisons.

Just a brief history, during early times cave dwellers discovered the poisonous plants and animals, and they used their extracts for  hunting and as weapons. There was also a written evidence that opium, hemlock, arrow poisons and some metals were used to against their enemies and for execution.  

DIVISION OF TOXICOLOGY
  1. Analytical Toxicology - is the study of determining  the toxicant through analysis of body fluids, stomach content, excrement or skin. 
  2. Clinical Toxicology - is the study of interrelationships between exposure and disease state.  
  3. Descriptive Toxicology - it uses the results from animal experiments to predict what  level of exposure will cause injury or harm in humans.
  4. Environmental Toxicology -  is the concerned with the study on chemicals that can contaminate food, water, soil or the atmosphere.
  5. Forensic Toxicology - it is concerned with the medicolegal cases of toxin exposure.
  6. Food Toxicology - is  involved in delivering a safe and edible supply of to the consumer.
  7. Mechanistic Toxicology - is a study in it elucidates the cellular and biochemical effects of toxins. ti provides a basis on rational therapy designs and development of tests to assess the toxicity of individual to certain chemicals.
  8. Occupational (Industrial) Toxicology - it is a study which is concerned with the effects on health from exposure to chemicals in the working area. This is to protect workers from toxic substances and to make their working environment safe. 
  9. Regulatory Toxicology - it gathers and evaluates existing toxicological information to establish concentration-based standards of safe exposure.
TERMINOLOGY
Toxicity - refers to the degree in which a substance is poisonous or can cause injury. It is dependent on the following factors: duration and route of exposure, structure of the chemical, dose and human factors.

Toxic - refers to the poisonous or deadly effect  of chemical in the body.

Toxicant - is any chemical than can injure or kill living organisms. The term is used when referring to human-made products.  

Toxin - refers to toxic substance that is naturally produced. it is any poisonous substance of microbial, vegetable or synthetic chemical that reacts with certain cellular components to alter growth or development, or kill cells or the organism itself. 


EXPOSURE TO TOXINS
Exposure to toxic agents can occur in various reasons. it can be an intentional suicide attempt, wherein person uses a toxic chemicals or overdose of drug to kill himself. It may be only caused by accidental exposure which frequently occurs in children and accidental drug overdose of either therapeutic or illicit drugs which is frequently occurs in adults. Occupational exposure occurs in agricultural and industrial settings.

ROUTE OF EXPOSURE:
  • Ingestion
  • Inhalation
  • Transdermal absorption









 Reference:
Bishop et al, Clinical Chemistry: Techniques, Principles, Correlations. 6th Edition. Lippincott Williams & Wilkins. 2005. Chapter 30. pg. 622

 




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