Descriptive Toxicology

1. Presentedby,
K. ABINAYA

2. • Toxicology is the science
of the adverse effects of
chemicals including drugs,
on living organisms.
• It involves observing and
reporting symptoms, mechanisms,
detection and treatments of toxic substances.

3. :
• Mechanistic toxicology (basic biology and chemistry)
• Regulatory toxicology ( rule making and compilance)
• Descriptive toxicology (testing)

4. • It is concerned directly with toxicity testing, which
provides information for safety evaluation and
regulatory requirements.
• Focuses on toxicity testing of chemicals, usually on
animals under wide range of exposure conditions and
then the results are correlated to human conditions.

5. • It provides dose-response information upon
exposure to harmful toxic agent.
• The results from the toxicity testing are typically
applied to approval of product use and regulating
allowable concentrations in the environment.

6. • Performs toxicity test to evaluate the risk that
exposure pose to humans.
• Develop safer drugs and medicines
• Develop treatments for
chemical exposures.
• Ensure safe food and
water supply.
• Forensics.

7. • Hazard identification
• Dose-response assessment
• Exposure assessment
• Risk characterization

8. • It determines the exposure to chemical can increase the
incidents of a particular adverse effect. It is done by,
1. Hazard identification data
2. Animal bioassay
3. Prediction of hazard-
structure activity relationship

9. • Relationship between the exposure, appearance and
duration of adverse effect.
• NOAEL
• LOAEL
• Acceptable Daily Intake

10. • Exposed population (General public or
selected groups)
• Duration of exposure
• Pathways and media

11. • Review toxicity and exposure assessment output
• Quantify risks
• Combine risk across all pathways
• Consider site specific human studies.

12. • In vitro (test tube) - useful in detecting potential
biochemical and genetic effects.
• In vivo (animal) - are essential for detecting health
effects.
• Experimental animals may be treated with high doses
over a lifetime to evaluate potential to cause cancer.

14.  Toxins may be evaluated qualitatively or quantitatively.
 Qualitative analysis provides information about the nature of toxins,
but quantitative analysis gives information about the chemistry of the
toxins and their concentration.
 Nonspecific instrumental analyses such as colorimetric and UV-visible
spectrophotometric analyses may be used for qualitative analysis of
toxins.
 Sophisticated techniques such as infrared spectroscopy, gas
chromatography, High Pressure Liquid Chromatography, and
immunoassay techniques may be employed to quantify the toxins.
LABORATORY ANALYSIS OF TOXINS

18. • To have an idea of toxic doses of xenobiotic for certain
organisms
• Evaluation of safe doses of those toxicants for certain organisms.
• The data on long term toxicity tests may be reliable for the
evaluation of safe level of toxicants.
• Evaluation and recommendation of maximum acceptable daily
intake.

19. • Chemical Manufacturers
• Pharmaceutical Industry
• US Federal Agencies and Programs
• National Toxicology Program (NTP)
• National Institute of Environmental Health Sciences ( NIEHS)
• Food and Drug Administration (FDA)
• State and Local Governmental Bodies