Presents the different toxic substances in the enviornment

1. Classification of Toxic Agents
Prepared by:
Catherine Cababa,RMT,M.Bio.Ed.,Ph.D.

2.  Heavy Metals
 Solvents and Vapors
 Radiation and
Radioactive Materials
 Dioxin/Furans
 Pesticides
 Plant Toxins
 Animal Toxins

3. Heavy Metals
 Arsenic
 Cadmium
 Lead
 Mercury

4. Arsenic
 Homicidal poison
 Used in ant poisons, rodenticides,
herbicides, weed killer, insecticides,
paints, wood preservatives, ceramics, etc.
 Potable water
 Wine
 Seafood

5. Major toxicologic forms
 Inorganic chemicals: sodium arsenate &
lead or copper arsenite
 Organic: carbasone & tryparsamide
 Arsine gas: in industries (most
dangerous form)

6. Primary Routes of Exposure
 ingestion
 inhalation
 tends to collect in skin, hair, & nails
 removed mainly through the urine, a few days after it is
ingested
 can result in some upset stomach
 Measuring arsenic in the urine is the main way to detect
arsenic exposure

7. Detection & Measurement
 Garlic odor of breath
 Metallic taste in patients’ mouth
Reinsch Test:
 Metallic copper in the presence of acid will
reduce as to elemental form
 Antimony, bismuth, mercury, & selenium can
also reduce copper

8. Reinsch Test
 a test for the presence especially of
arsenic, antimony, and mercury
 a strip of clean pure copper foil is heated
with the test material in acid solution and
then if a black or gray stain appears on
the foil, it is heated in a test tube to
produce a sublimate deposited in the
upper part of the tube in a form
characteristic of arsenic, antimony, or
mercury if any of these are present

9. Acute exposure :
 Death
 Fever
 Anorexia
 liver enlargement
Chronic exposure:
 poisoning of the nervous
system, liver damage, &
peripheral vascular
disease, which could
result in gangrene of the
lower limbs("black foot
disease“)
 Skin cancer
 Lung cancer
 Leukemia
 Kidney & bladder
cancers
 Dermatitis
 hyper pigmentation
 keratosis (or arsenical
keratosis

10. Cadmium
 byproduct of the mining and
smelting of lead and zinc
 primarily used for electroplating
activities

11. Distribution & Sources of Exposure
 can gather and concentrate in plants
 irrigation waters
 Fertilizers
 Shellfish
 Tobacco (each cigarette has approximately 1-2
µg of cadmium)
 Approximately 1 µg of cadmium may be found
in one liter of breast milk.
 Very little cadmium is absorbed through the
ingestion route, and it is not easily absorbed.

12. Side Effects
Acute toxicity through
ingestion of
contaminated
beverages or food
could result in:
 nausea
 Vomiting
 abdominal pain.
Acute toxicity through
inhalation may result
in:
 chemical pneumonia
and fluid in the lung.
Irritation of the nose
and throat, coughing,
dizziness, weakness,
chills, fever, chest
pains, and labored
breathing are also
symptoms.
 Acute cadmium
toxicity through
inhalation may result
in a condition known
as metal fume fever.

13. Side Effects
Chronic toxicity may result in:
 chronic obstructive pulmonary
disease
 emphysema
 kidney disease
 adverse affects to the
cardiovascular system and the
skeleton

14. Lead
 primarily used in the manufacture
of batteries, plastics, ceramic glass,
and paint products
 most widespread toxic metal on
earth and is the second most
hazardous substance found at sites
listed on the National Priorities List
(NPL)

15. Primary Route of Exposure
 Ingestion of lead-based paint flakes
and chips (e.g., pica-like behavior)
 breathing contaminated dust,
drinking contaminated water
 absorbing lead from lead-
contaminated glaze in pottery

16.  Cumulative poisoning dose:0.5 mg/day (0.5
g/day absorption is fatal)
 Half-life: 32 years
 Bone-largest body compartment/reservoir
 Typically results to: hypochromic normocytic
anemia
 Interferes with hemoglobin synthesis

17. Toxic effects of lead
 lead encephalopathy (brain disease) in children,
resulting in lethargy, vomiting, irritability, loss
of appetite, and dizziness
 In adults:high blood pressure, and adverse
reproductive effects (lowered sperm count and
sperm motility).
 Classic symptom of lead toxicity:Burton's lines,
purple-blue discolorations of the gums
 Primary measure for treating lead
toxicity:chelation therapy (binding of lead with
other metals to remove it from the body)

18. Measurements:
24-hour urine sample:
 Colorimetric using
diphenylthiocarbazone (dithizone) to
form a red complex
 Polarography
 AAS

19. Mercury
 third most toxic substance in the
environment
 used to produce vapor lamps,
fluorescent tubes, thermometers, &
electrical products

20. Side Effects:
 Organic mercury primarily affects the brain
 Methyl mercury is the most toxicological form of the
element and, by its accumulation in the central
nervous system (CNS), may result in neurotoxic effects
in adults and toxicity in the fetuses of mothers
exposed to methyl mercury during pregnancy
 Metallic mercury is slowly absorbed by the
gastrointestinal system and is not as toxic as methyl
mercury
 Inorganic mercury (mercury salts) primarily affects the
kidneys. Exposure to mercuric salts may lead to
abdominal cramps and bloody diarrhea

21. Side Effects
 Chronic mercury exposure may lead to tremor
and personality disturbances and permanent
CNS damage
 Acute mercury exposure can be assessed by
measuring the level of mercury in blood
 Chronic exposure is best assessed by
measuring the amount of mercury in urine
 Chelation therapy is typically used in acute
mercury poisoning

22. Solvents and Vapors
 Occupational exposures can range
from the use of "white-out" by
administrative personnel, to the use
of chemicals by technicians in a nail
salon
 When a solvent evaporates, the
vapors may also pose a threat to
the exposed population

23. Radiation and Radioactive Materials
 the release and propagation of
energy in space or through a
material medium in the form of
waves, the transfer of heat or light
by waves of energy, or the stream
of particles from a nuclear reactor

24. Radiation and Radioactive Materials
Ionizing radiation:
 affects the bone
marrow, resulting
in a decrease in red
blood cell
production,
reddening of the
skin,
gastrointestinal and
reproductive
effects, cataracts,
birth defects, and
respiratory illness
Non-ionizing
radiation
 mutagenic and
carcinogenic
effects, primarily
by UV radiation,
which can alter the
repair mechanisms
for DNA and
potentially lead to
skin cancer.

25. Other Side Effects
 Ingestion of radium may result in
bone cancer
 radiation is associated with skin,
thyroid, and lung cancers,
particularly among uranium mine
workers

26. Dioxin/Furans
 Dioxin, (or TCDD) was originally
discovered as a contaminant in the
herbicide Agent Orange
 Dioxin is also a by-product of
chlorine processing in paper
producing industries

27. Pesticides
 Insecticides
 Herbicides
 Fungicides
 Fumigants
 rodenticides

28. Insecticides
 Organochlorides
 Organophosphates
 carbamates

29. Organochloride insecticides
 peripheral nervous system (PNS) through
dermal absorption, inhalation, and ingestion
 also decrease antibody production, placing
a person at risk for infection
 E.g.DDT persists and bioaccumulates in the
environment, which is why it is no longer
manufactured as a pesticide

30. Organophosphorous
 headache
 anxiety
 chest tightness
 Seizures
 loss of consciousness
 abnormal heart beat
 liver dysfunction
 E.g. Malathion, seem to enhance the immune
response in some circumstances.
Parathion has been known to decrease
antibody production.

31. Herbicides
 E.g. 2,4,5-T, 2,4,-D & 2,3,7,8 - TCDD
(dioxin) are toxic to both animals and
humans
 Liver problems and nerve damage
may result from chronic herbicide
exposure, while chloracne is a classic
symptom of herbicide dermal
exposure.

32. Fungicides
 used in the treatment of fruit trees
and vegetables and have a
relatively low toxicity
 Skin irritation, headache, nausea,
vomiting, lethargy, and dermatitis
are classic symptoms of some
fungicides, such as creosote and
hexachlorobenzene

33. Fumigants
 used to eradicate insects, bacteria, and
rodents
 typically used on fruits, vegetables, ships,
and buildings
 E.g. Methyl bromide is a classic fumigant
that may result in dermatitis, pulmonary
irritation, headache, nausea, vomiting,
dizziness, and dementia from exposure
via inhalation and dermal exposure

34. Rodenticides
 used primarily to eradicate rats,
mice, rabbits, and gophers
 E.g. Warfarin is a rodenticide that
causes severe adverse health
effects

35. Plant Toxins
 Different portions of a plant may contain
different concentrations of chemicals
 Some chemicals made by plants can be
lethal
 E.g. taxon, used in chemotherapy to kill
cancer cells, is produced by a species of
the yew plant.

36. Animal Toxins
 can result from venomous or poisonous
animal releases
 Venomous animals are usually defined as
those that are capable of producing a
poison in a highly developed gland or
group of cells, and can deliver that toxin
through biting or stinging
 Poisonous animals are generally regarded
as those whose tissues, either in part or
in their whole, are toxic

37. That’s All!
Thank you!