This lecture includes Introduction to Toxicology and Related Terms are explained well in the easy language. Also, Concepts of Forensic Toxilogical Examination and it's significance is included in this lecture.

1. By: RAGHU KHIMANI
1 - INTRODUCTION
TO TOXICOLOGY

2. What is Toxicology?
Toxicum means poison
Logous means study
Fundamental science of
poison

3. Toxicology
o A discipline of science dealing with poisonous substances
which on entering the body of organisms cause
disturbances in their normal functioning leading to
harmful effects; the most severe of which may be death of
the organism.
Deals with the
o Properties, dose, action, symptoms, detection and estimation of
poison,
o Management and treatment of poisoning cases.

4. Toxicologist
o A scientist who is concerned with study of the
poisons.

5. What is Toxicity ?
o The term “Toxicity” is used to describe the nature of adverse effects
produced and the conditions necessary for their production.
o Before toxicity can develop, a substance must come into contact
with a body surface such as skin, eye, mucosa of the alimentary or
respiratory tract.

6. What is Toxic ?
o This term relates to poisonous or deadly effects on
the body.

7. What is a Toxic Effect ?
o Toxic effects refers to the health effects that occur
due to exposure to a toxic substance.

8. What is a Toxicant ?
o The term “toxicant” refers to toxic substances that
are produced by or are a by-product of human-
made activities.

9. What is a Toxin ?
o The term “toxin” refers to toxic substances that are
produced naturally.

10. What is a Toxic Symptom ?
o A toxic symptom is any feeling or sign indicating the
presence of a poison in the system.

11. What is Selective Toxicity ?
o This means that a chemical will produce injury to
one kind of living matter without harming another
form of life, even though the two may exist close
together.

12. What is a dose?
o The dose is the actual amount of a chemical that enters
the body.
o Dose-response suggests that a dose, or a time of
exposure (to a chemical, drug, or toxic substance), will
cause an effect (response) on the exposed organism.
What is dose-response?

13. What is the threshold dose?
o Threshold dose is a dose or exposure level below
which harmful or adverse effects are not seen in a
population.

14. The Median Lethal Dose (LD50)
o The amount (dose) of a chemical which produces death in
50% of a population of test animals to which it is
administered by any of a variety of methods.
Unit: mg/kg
o Normally expressed as milligrams of substance per
kilogram of animal body weight.

15. o However, this also means that LD50 is not the lethal dose for all
subjects; some may be killed by much less, while others survive doses
far higher than the LD50.
o Measures such as "LD1" and "LD99" (dosage required to kill 1% or 99%,
respectively, of the test population) are occasionally used for specific
purposes.
o Lethal dosage often varies depending on the method
of administration; for instance, many substances are less toxic when
administered orally than when intravenously administered. For this
reason, LD50 figures are often qualified with the mode of
administration, e.g., "LD50 i.v.“
o The related quantities LD50/30 or LD50/60 are used to refer to a dose
that without treatment will be lethal to 50% of the population within
(respectively) 30 or 60 days.
The Median Lethal Dose (LD50)

16. oExamples:
o Oral LD50 of grain alcohol: 10.6 g/kg in young rats, 7.06
g/kg in aged rats.
o Oral LD50 of nicotine: 50 mg/kg in rats.
o LD50 of Tetrahydrocannabinol (active ingredient found in
Cannabis): 3000 mg/kg in dogs and monkeys.
o LD50 of Batrachotoxin: estimated at 1 to 2 µg/kg in humans.

17. The Median Lethal Concentration (LC50)
o The concentration of a chemical in an environment
(generally air or water) which produces death in 50% of an
exposed population of test animals in a specified time
frame.
Unit: mg/L
o Normally expressed as milligrams of substance per liter of
air or water (or as ppm)

18.  Environmental Toxicology
 Occupational (Industrial)
Toxicology
 Regulatory Toxicology
 Food Toxicology
 Clinical Toxicology
 Descriptive Toxicology
 Forensic Toxicology
 Analytical Toxicology
 Mechanistic Toxicology
 Toxicogenomics
 Nano toxicology
Sub-disciplines of Toxicology

19. oStudies chemicals that are contaminants of food, water, soil, or the
air.
oDeals with toxic substances that enter the waterways, such as lakes,
streams, rivers and oceans.
Environmental Toxicology

20. oProtects workers from toxic substances and makes their work
environment safe.
Occupational (Industrial) Toxicology

21. oGathers and evaluates existing toxicological information to establish
concentration-based standards of “safe” exposure.
Regulatory Toxicology

22. oInvolves delivering a safe and edible supply of food to the
consumer.
Food Toxicology

23. oIs concerned with diseases and illnesses associated with
short term or long term exposure to toxic chemicals.
Clinical Toxicology

24. oIs concerned with gathering toxicological information from animal
experimentation.
oThese type of experiments are used to establish the chemical
dosage that would cause illness and death.
Descriptive Toxicology

25. oHelps to establish cause and effect relationships between
exposure to a drug or chemical and the toxic or lethal
effects that result.
Forensic Toxicology

26. oIdentifies the toxicant through analysis of body fluids,
stomach content, excrement, skin, or suspected containers.
Analytical Toxicology

27. oMakes observations on how toxic substances cause their
effects.
Mechanistic Toxicology

28. oUnderstanding the genetic basis of responses to chemical and
physical exposures can help to predict which individuals will respond
best, and with the least side effects, to particular pharmaceutical
agents and also to predict which individuals will be most at risk from
specific occupational and environmental exposures.
Toxicogenomics

29. oThe prefix, “nano,” implying a billionth of an amount, has been
appropriated for “nanotechnology,” the science of extremely small
materials.
oAn increasing number of consumer and other products are now
made of nanoscale substances.
oThe corresponding study of the safety and potential hazards of
nanoparticles and nanotubules is known as Nano Toxicology.
Nano Toxicology

30. o The Drug and Cosmetics Act – 1940
o Amendment of the Drug and Cosmetics Act - 1945
o The Drugs Control Act – 1950
o The Drugs and Magic Remedies Act – 1954
o NDPS Act – 1985
Various Acts

31. o Heavy Metals
o Solvents and Vapors
o Radiation and Radioactive Materials
o Dioxin/Furans
o Pesticides
o Plant Toxins
o Animal Toxins
Classification of Toxic Agents

32. o Their effect on target organs (liver, kidney, hematopoietic system,
etc.)
o Their use (pesticide, solvent, food additive, etc.)
o The source of the agent (animal and plant toxins)
o Their effects (cancer mutation, liver injury, etc.)
o Physical state (gas, dust, liquid)
o Labeling requirements (explosive, flammable, oxidizer)
o Chemistry
Subcategories for Classifications

33. o The Agency for Toxic Substances and Disease Registry (ATSDR)
o The United States Environmental Protection Agency (EPA)
o The Centers for Disease Control and Prevention (CDC)
o The National Center for Environmental Health (NCEH)
o The National Institute for Safety and Health (NIOSH)
o The Nuclear Regulatory Commission (NRC)
o The Food and Drug Administration (FDA)
o The American Conference of Governmental Industrial Hygienists (ACGIH)
Toxicological Information Sources

34. Places where you can get information include:
o Toxicology Data Network (TOXNET)
o CHEMTREC (Chemical Transportation Emergency Center)
o MEDTEC (Medical Transportation Emergency Center)
o Material Safety Data Sheets (MSDS)
o ATSDR (Agency for Toxic Substances and Disease Registry)
Electronic Databases

35. Concepts of Forensic
Toxicological Examination
& it’s Significance

36. Specimen (Physical Evidence)
o Fluids: Blood, Urine, Vitreous Humour, Oral Fluid, Semen,
Stomach Contents, Bile.
o Organs: Skin, Lungs, Hair and Fingernails, Liver, Kidney,
Bone, Other (heart, brain, etc.)

37. Guidelines for the collection of
Physical Evidence
Specimen Evidence Identification Wrapping and
packing
Remarks
Blood : Liquid for
toxicological use
2-5 ml of blood and
preservative mixture
Label ,stopper and
seal.
Investigator initials
Use universal sterile
bottle
Preservative
desired.
Refrigerate. Can
freeze.
Drugs
1. Liquids
All Label and seal.
Investigator initials
Make sure container
does not leak. Seal.
2. Powders, pills
and solids (found
in paper bags)
All to 30 gm Label and seal.
Investigator initials
Seal with tape to
prevent any loss
Place them in
plastic bags to
prevent any loss.

38. Specimen Evidence
(Amount)
Identification Wrapping and
packing
Remarks
Urine 20-50 ml of urine Label , stopper and seal.
Investigator initials
Use sterile bottle.
Seal tight with lid.
Preservative not
desired. Refrigerate.
Liver Half the liver,
800 gm
Label , stopper and seal.
Investigator initials
Use wide mouthed
sterile glass bottle.
Seal tight with lid
Preservative desired.
Refrigerate.
Kidney One kidney or
half portion of
both the kidneys.
Label , stopper and seal.
Investigator initials
Use wide mouthed
sterile glass bottle.
Seal tight with lid
Preservative desired.
Refrigerate.
Guidelines for the collection of
Physical Evidence

39. Specimen Evidence
(Amount)
Identification Wrapping and
packing
Remarks
Entire stomach
and its contents
Entire stomach
and its contents
lingered at both
ends.
Label , stopper
and seal.
Investigator
initials
Use wide mouthed
sterile glass
bottle. Seal tight
with lid
Preservative
desired.
Refrigerate.
Portion of small
intestine
Portion of small
intestine lingered
at both ends.
Label , stopper
and seal.
Investigator
initials
Use wide mouthed
sterile glass
bottle. Seal tight
with lid.
Preservative
desired.
Refrigerate.
Guidelines for the collection of
Physical Evidence

40. Guides to the collection of Physical
Evidence, cont.
Specimen Evidence
(Amount)
Identification Wrapping
and packing
Remarks
Stomach
aspirates
All Stomach
aspirates
Label , stopper
and seal.
Investigator
initials
Use wide
mouthed
sterile glass
bottle. Seal
tight with lid.
Preservative
desired.
Refrigerate.
Food
remains and
poisoned
food
Send adequate
Food remains
and poisoned
food
Label and seal.
Investigator
initials
Pack in clean
strong brown
papers.
Preservative
not desired.
Refrigerate.

41. Specimen Evidence
(Amount)
Identification Wrapping and
packing
Remarks
Poisons Send adequate
amount of poison
Label and seal.
Investigator initials
Pack in clean strong
brown papers.
Contaminated
utensils
All Label and seal.
Investigator initials
Pack in clean strong
brown papers.
Traditional/
native
medicine
Send adequate
plant parts i.e.
root, leaves,
flowers, etc.
Label and seal.
Investigator initials
Pack in clean strong
brown papers.
Use air drying
for
preservation.
Guidelines for the collection of
Physical Evidence

42. Sample Collection &
Preservation Technique
o When blood comes for blood alcohol analysis, KF and KCl
are added to it as preservatives. The bottle having 5 ml of
blood is coated by POP-plasticine to avoid the evaporation.
o Any biological evidence is preserved in glass bottles with
formalin to avoid the fungal growth that may happen in
plastic bottles.
o Whenever any death is occurred due to poisonous
injection or syringe, the part of the skin is cut of specified
length and send to the FSL.

43. o In case of Kidneys, either one kidney or half portion of both the
kidneys are preserved and sent to the FSL.
o In case of Liver, in adult, half of the liver and in child, full liver is sent
to the FSL.
o In dead body, blood is collected from the heart and pulmonary artery
& peripheral vein.
o In case of Urine, 20-50 ml of urine is collected and preserved using
KF crystals and send to the FSL.
o In any case of fluid like urine, we can detect the metabolites of acidic,
basic drugs and pesticides.
Sample Collection &
Preservation Technique

44. Care taken during Chemical Analysis
o During Autopsy, if any organ is removed from the body, it
should never be placed on any surface or in any container,
which is not clean.
o If a refrigerator is available, all organic substances should be
kept in it as soon as possible after removal from the body.
o The specimen from the blood, urine, bile, pancreas and
vitreous should be placed in the glass containers as this fluids
can leach out plastic polymers from the wall of container,
which may mark some compounds & interfere with analysis.

45. o Blood is a specimen of choice for detection of poison, as it
gives the best indications of the quantity of drug exerting
an effect on the person at the time of death.
o In living person, the concentration of poison is lower in
venous blood as compared to arterial blood because tissue
may take up the compound from arterial supply.
o In case of Urine, it is suitable to do single direct spot test,
because there is no protein binding to prevent extraction.
Care taken during Chemical Analysis

46. Information to be supplied to the FSL
The pathologist should provide all available information to the
toxicologist.
◦ Brief details of the symptoms if any & length of the illness.
◦ If poison taken is not known, drugs or poisons to which the disease was known
to have excess including medication being taken.
◦ History obtained from family members & friends.
◦ Empty container, if found at the scene.
◦ Autopsy findings.

47. Documents needed to be submitted
to FSL along with the sample
o A copy of FIR if available, brief facts of the case
submitted by police, after that case name, age, sex.
o Copy of autopsy report with detailed observation &
findings. It should also clearly mention the specific
name of the poison for the detection estimation for
which the viscera is send, if there is any previous
analysis done, reference should be also mentioned.

48. o The forwarding letter by the I.O. requesting to examine
the submitted samples and informing the findings to the
medical officer.
o An authority letter from a magistrate or relevant officer
for chemical examiner to examine the viscera.
Documents needed to be submitted
to FSL along with the sample

49. Significance

50. Significance
o Blood samples taken from the deceased or a victim can be
analyzed to determine if there are toxic substances
present in the blood stream. Blood samples are often
analyzed to determine the level of intoxication in drink
driving cases.
o Urine samples taken from a living person can be analyzed
to health problems such as kidney disease and diabetes.
Samples can be tested to identify drug use and is more
commonly known for its role in pregnancy testing.

51. o Hair samples can be tested to provide a rough
estimate of timescales in substance abuse.
o Saliva is increasingly being used to provide evidence
of drug abuse and in drink driving cases.
o Samples of tissues and cells taken during surgery
determine the type and spread of a disease such as
cancers and gangrene.
Significance