Download Group 2 Food Toxicokinetics

Group Members
o Muhammad Shahid
o Ayesha Butt
o Laraib Shoaib
o Fatin Atique
o Fatima Sayed
Topic
• Margins of Safety
• Factors Affecting Toxicity
• Dose Response Relationship
• Manifestation of Organ Toxicity
Stay Attentive !
Activity is following this
presentation
“All substances are poisonous,
there is none which is not a poison;
the right dose differentiates a poison
from a remedy.”
Paracelsus Circa 1538
Chemical Poisons, Biological Toxins
Poison
–A chemical substance that can cause
illness or death when it enters our bodies.
Toxin
–A poison of biological origin, specifically a
protein molecule produced by a plant or animal.
The
terms are often used interchangeably.
Toxicity
Some
depends on dose.
substances are beneficial at low
concentration but are toxic at high conc.
Types of Foodborne Illness
Infection
– eating food contaminated with pathogens
Intoxication
– eating food contaminated with the toxins
(poisons) formed by bacteria
– eating food contaminated with other
biological or chemical toxins (poisons)
Toxin-mediated infection
– eating food contaminated with pathogens
that grow in the body and form toxins
(poisons)
Foodborne Diseases
Infections
Intoxications
Chemical
Poisoning
Poisonous
Plant
Tissues
Poisonous
Animal
Tissues
Toxicoinfection
Microbial
Intoxications
Other
Neurotoxins
Invasive Infection
Enterotoxins
Intestinal
Mucosa
Mycotoxins
(Fungal
Toxins)
Algal Toxins
Bacterial
Toxins
Diarrhogenic
Emetic
Enterotoxins
Neurotoxins
Other
Systemic
Other
Tissues or
Organs
(Muscle,
Liver, Joints,
Fetus, Other)
Controlling Bacteria
Good personal hygiene

Only allow healthy workers to handle food.
Have all workers wash their hands properly and
frequently.

Prevent cross-contamination
Store foods properly.
 Only use cleaned and sanitized utensils and surfaces for
food preparation.

Time-temperature control


Cook foods to proper temperatures.
Hold foods at proper temperatures.
Common Foodborne Bacteria

Bacillus cereus

Campylobacter

Clostridium botulinum

Clostridium perfringens

E. coli

Listeria monocytogenes

Salmonella

Shigella

Staphylococcus aureus

Vibrio

Yersinia
9
Food
Mixture of chemicals
Nutrients
(99,9%)
Toxin
Contaminants
Additives
Proper Food Handling
“Key recommendations”
for food safety
Recommendation 1: CLEAN
Clean hands,
food-contact
surfaces, fruits
and vegetables.
Do NOT wash or rinse meat and poultry as
this could spread bacteria to other12foods.
Wash your hands!
Handwashing is the most effective way
13
to stop the spread of illness.
How to wash hands
1. Wet hands with
WARM water.
2. Soap and scrub for
20 seconds.
3. Rinse under clean,
running water.
4. Dry completely
using a clean cloth
or paper towel.
14
Wash hands after …
Using bathroom or
changing diapers
Handling pets
Sneezing, blowing
nose & coughing
AND before ...
Touching a cut or
open sore
15
Handling food
Clean during food preparation
Wash cutting
boards, knives,
utensils and counter
tops in hot soapy
water after
preparing each food
and before going on
to the next.
16
Recommendation 2: SEPARATE
Separate raw,
cooked, and
ready-to-eat foods
while shopping,
preparing or
storing foods.
17
Use different cutting boards
Use one cutting board
for fresh produce and a
separate one for raw meat,
poultry and seafood.
18
When groovy isn’t a good thing
Replace cutting boards
if they become excessively
worn or develop
hard-to-clean grooves.
19
Use clean plates
NEVER serve foods on a
plate that previously held
raw meat, poultry or
seafood unless the plate
has first been washed in
hot, soapy water.
20
Recommendation 3: COOK
Cook foods to a safe
temperature to kill
microorganisms.
21
Which ground beef patty is cooked to
a safe internal temperature?
23
This IS a safely cooked
hamburger, cooked to
an internal temperature
of 160 degrees F, even
though it's pink inside.
This is NOT a safely cooked
hamburger. Though brown
inside, it’s undercooked.
Research shows some ground
beef patties look done at
internal temperatures
as low as 135 degrees F.
24
Recommendation 4: CHILL
Chill (refrigerate)
perishable foods
promptly and
defrost foods
properly.
25
DANGER
ZONE
Bacteria multiply
rapidly between
40 and 140 degrees F.
26
Recommended refrigerator
& freezer temperatures

Set refrigerator
at
40 degrees F or
below.

Set freezer at
0 degrees F.
27
The THAW LAW

Plan ahead to defrost
foods.

The best way to thaw
perishable foods is in the
refrigerator.
28
When to leave your leftovers

Refrigerated leftovers
may become unsafe
within 3 to 4 days.

If in doubt, toss it
out!
29
Recommendation 5: AVOID...

Raw (unpasteurized)
milk or milk products

Raw or partially cooked
eggs and foods
containing raw eggs

Raw and undercooked
meat and poultry

Unpasteurized juices

Raw sprouts
Most at risk are infants, young children,
pregnant women, older adults and the
immunocompromised.
30
31
Should you keep or toss …
Pizza left on the counter overnight?
32
Toss it out!
Even if you reheat pizza
left on the counter
overnight, some bacteria can
form a heat resistant toxin
that cooking won’t destroy.
33
Should you keep or toss …
Perishable food left out from the noon
meal until the evening meal?
34
Toss it out!
Perishable foods – such as
meats, gravy and cooked
vegetables – should be
refrigerated within TWO
hours.
35
Should you keep or toss …
Cut/peeled fruits and vegetables at
room temperature for over TWO
hours?
36
Toss it out!

Once you have cut
through the protective
skin of fruits and
vegetables,
bacteria can enter.

Refrigerate cut or peeled
fruits and vegetables
within TWO hours.
37
Should you keep or toss …
Leftovers in the refrigerator
for
over a week?
38
Toss it out!

Refrigerated leftovers
may become unsafe
within 3 to 4 days.

You can’t always see
or smell if a food is
unsafe. It may be
unsafe to taste a food.
39
Remember:
40
41

The dose–response relationship, describes the change in effect
on an organism caused by differing levels of exposure or doses
to a stressor usually a chemical after a certain exposure time.
This may apply to individuals or populations.
 The science of toxicology is based on the principle that there is
a relationship between a toxic reaction (the response) and the
amount of poison received (the dose). An important
assumption in this relationship is that there is almost always a
dose below which no response occurs or can be measured. A
second assumption is that once a maximum response is
reached any further increases in the dose will not result in any
increased effect.

The dose response relationship does not hold true, in regards to a true allergic
reactions. Allergic reactions are special kinds of changes in the immune system;
they are not really toxic responses.

The difference between allergies and toxic reactions is that a toxic effect is directly
the result of the toxic chemical acting on cells.

Allergic responses are the result of a chemical stimulating the body to release
natural chemicals which are in turn directly responsible for the effects seen.
Measures of exposure

Exposure to poisons can be intentional or unintentional. The effects of exposure to
poisons vary with the amount of exposure.

Usually when we think of dose, we think in terms of taking one vitamin capsule a
day or two aspirin every four hours.

Contamination of food or water with chemicals can also provide doses of chemicals
each time we eat or drink.

These measures tell us how much of the chemical is in food, water or air. The
amount we eat, drink, or breathe determines the actual dose we receive.

Concentrations of chemicals in the environment are most commonly expressed as
ppm and ppb.
Dose effect parameters

Potency: The sensitivity of an organ or tissue to the drug. A
highly potent drug evokes a larger response at low
concentrations, while a drug of lower potency evokes a small
response at low concentrations. It is proportional to affinity and
efficacy.

Efficacy: The maximum effect that a drug can produce,
regardless of dose. Efficacy is the relationship between
receptor occupancy and the ability to initiate a response at the
molecular, cellular, tissue or system level. The response is
equal to the effect.

A true assessment of chemical toxicity involves comparisons of numerous doseresponse curves covering many different types of toxic effects

The knowledge gained from dose-response studies in animals is used to set
standards for human exposure and the amount of chemical residue that is allowed
in the environment. Numerous dose-response relationships must be determined, in
many different species. Without this information, it is impossible to accurately
predict the health risks associated with chemical exposure. With adequate
information, we can make informed decisions about chemical exposure and work
to minimize the risk to human health and the environment.
Manifestation of
organ toxicity
All organ systems can be targets of toxic
exposures.
•The accumulation of anti-microbrial drugs and their metabolic
byproducts in organs or the exposure of organs to the toxicants can be
toxic, leading to organ damage.
Target organ toxicity
Types of organ specific toxic effects are:
•Blood/vascular toxicity
•Dermal or occular toxicity
•Genetic toxicity
•Hepato toxicity
•Immuno toxicity
•Nephrotoxicity
•Neurotoxicity
•Reproductive toxicity
Blood or cardiovascular toxicity
Blood and cardiovascular toxicity results from
xenobiotics acting directly
On cells circulating blood, bone marrow and
heart.
Examples of blood and cardiovascular toxicities
are:
•can result from exposure to noise and to
chemicals such as carbon monoxide and tobacco
smoke
•Hypoxia due to carbon monoxide binding of
Dermal toxicity
Dermal toxicity may result from direct contact or internal d
the skin. Effects range from mild irritation to severe chang
Corrosivity, hypersensitivity, and skin cancer.
Tetracycline (antimicrobial drug)can cause phototoxicity,
Examples of dermal toxicity are:
•Dermal irritation due to skin exposure to gasoline
•Dermal corrosion due to skin exposure to sodium
•Dermal hypersensitivity due to skin exposure to poison iv
•Skin cancer due to ingestion of arsenic or skin exposure
Eye Toxicity
Eye toxicity results from direct contact or internal distribut
The cornea and conjunctiva are directly exposed to toxica
This rash seen
on a forearm is
a typical
reaction
observed when
an antibiotic
causes
phototoxicity.
•Corticosteroids may cause cataracts.
•Methanol may damage of optic nerves
Hepatotoxicity
Hepatotoxicity is the toxicity to the liver, bile duct a
The liver is particularly susceptible to xenobiotics
Supply and its role in metabolism.Thus it is expos
Toxicant or its toxic metabolites. The primary form
Steatosis: Lipid accumulation in hepatocytes
Chemical hepatitis: Inflammation of the liver
Hepatic necrosis: Death of the hepatocytes
Intrahepatic cholestasis: Back of the bile salts in
Ototoxicity
•It is basicallly a damage to the ear
•ANTIBIOTICS, such as gentamicin,
can cause a lose of hearing, or
tinnitus ("ringing in the ears") .
• Ototoxicity is usually temporary with
antibiotics, but permanent hearing
damage, while rare, has been
reported
Immunotoxicity
Immunotoxicity is the toxicity of the immune system. It ca
Hypersensitivity (allergy and autoimmunity),immunodefic
Proliferation (leukemia and lymphoma). The normal funct
Is to recognize and defend against foreign invaders. This
Of cells that engulf and destroy the invaders or by antibo
Materials. e.g
•Contact dermatitis due to exposure to poison ivy
•Systemic erythematous in workers exposed to hydrazine
•Immunosuppresion by cocaine
Nephrotoxicity
The kidney is highly susceptible to toxicants for two
A high volume of blood flows through it and it filtrates
Of toxins which can concentrate in the kidneys. It ca
Toxicity causing:
•Decrease ability to excrete body wastes
•Inability to maintain body fluid and electrolyte balan
•Decreased synthesis of essential hormones ( e.g. e
•Inability to maintain PH balance
Neurotoxicity
Neurotoxicity represents toxic damage to cells of the
System( brain and spinal chord) and the peripheral n
(nerves outside the CNS).
fluoroquinolones can cause neurotoxicity by directl
receptors
Respiratory toxicity
Respiratory toxicity relates to effects on the upper re
(nose,pharynx, larynx, and trachea) and the lower re
(bronchi, brochioles and lung alveoli). The primary ty
Toxicity are:
Pulmonary irritation
The primary types of neurotoxicities
are:
Neuronopathies
Axonopathies
Demyelination
Interference with neurotransmission
Reproductive toxicity
Reproductive toxicity involves
toxic damage to either male or
female reproductive system.
Toxic effects may cause
Decrease libido and impotence
Infertility
Interrupted pregnancy ( abortion,
fatal death, or premature
delivery)
Infant death or childhood
Table 2. Organ Systems Often Affected by Toxic Exposure
Organ/System
Exposure Risks
respiratory
asbestos, radon, cigarette smoke, glues
Skin
dioxin, nickel, arsenic, mercury, cement
(chromium), polychlorinated biphenyls
(PCBs), glues, rubber cement
Liver
carbon tetrachloride, methylene chloride,
vinyl chloride
Kidney
cadmium, lead, mercury, chlorinated
hydrocarbon solvents
cardiovascular
carbon monoxide, noise, tobacco smoke,
physical stress, carbon disulfide, nitrates,
methylene chloride
reproductive
lead, carbon disulfide, methylmercury,
ethylene dibromide
hematologic
arsenic, benzene, nitrates, radiation
neuropsychological
tetrachloroethylene, mercury, arsenic,
toluene, lead, methanol, noise, vinyl
chloride