It will be an appropriate source for you to understand about the food toxicology. Further, the impacts of genetically modified are discussed in detail. the effects of toxicity in human and other living organisms are included in this document with examples.

1. Food Toxicology &
Biological Contamination
V.Vijitha
Lectrurer (Prob.)
Dept. of Biosystems Technology
FoT, UoJ

2. Acceptable Daily Intake (ADI)
&
Non Observed Effect Level (NOEL)

3. • ADI is an estimate of the amount of a substance in food
or drinking water that can be consumed daily over a
lifetime without presenting an appreciable risk to health.
• ADI is usually expressed as mg per kg body weight per
day.
• It is applies to chemical substances such as,
• food additives
• pesticide residues
• veterinary drugs

4. ADI of each sweetener
approved by the FDA

5. • The ADI is established through toxicity testing
• on different animal species
• at different life stages and
• in several generations and
• by determining the absorption, digestion, metabolism, and
excretory capacity in humans
• ADIs are set by using information obtained from
toxicological studies, including data from studies on
various laboratory animals.
• From these studies, NOEL is established.

6. What is NOEL???
• It is the highest dose level that produces no observable
toxic effect in the most sensitive test species.
• It is expressed in mg per kg of body weight per day.

7. Safety Factor Approach
• Safety factor approach was introduced in the US in the mid-
1950s by the FDA.
• It is intended to provide an adequate margin of safety for
consumers.
• It defines the legislative guidelines for food additives and
environmental contaminants.
• The safety factor attempts to account for,
• differences between animals and humans
• differences in sensitivity among humans

8. • A safety factor of 100-fold is commonly applied to
animal data to derive the ADI of food additives
• The ADI is derived by applying a safety factor to the
NOEL.

9. What is on your food???

10. GM foods & Health risks

11. GMOs
• Genetically modified organisms (GMOs): Organisms that
have been altered using genetic engineering methods.
• Key steps involved in genetic engineering are
1. Identifying a trait of interest
2. Isolating that trait
3. Inserting that trait into a desired organism
4. Propagating that organism

13. • Genetically engineered foods can pose serious risks to
farmers, human health, domesticated animals, wildlife
and the environment.
• It has been estimated that upwards of 75% of processed
foods on supermarket shelves contain genetically
engineered ingredients.

14. Effects and health risks
by genetic engineering
• Toxicity
• Allergic Reactions
• Antibiotic Resistance
• Immuno-suppression
• Cancer
• Loss of Nutrition

15. Toxicity
• Genetically engineered foods are inherently unstable.
• Long term toxicological tests be required prior to the
marketing of GE foods.
• Eg: consumption of Calgene Flavr Savr tomato (Flavr
Savr), resulted in stomach lesions in laboratory rats.

16. Allergic Reactions
• The genetic engineering of food creates serious health risks involving
allergenicity
• Each genetic engineered foods contains a number of novel proteins
which have never been part of the human diet.
• Eg: Altered genes, bacteria, viruses, promoters, marker systems, and
vectors.
• Each of these novel proteins could create an allergic response in some
consumers.
• Marketing of these foods without mandatory testing causes allergenicity
for millions of unsuspecting consumers.

17. Immuno-suppression
A study on the effect (on rats) of the consumption of potatoes
genetically engineered to contain the biopesticide Bacillus
Thuringiensis
• Result: The rats consuming genetically altered potatoes had
significant detrimental effects on,
• organ development
• body metabolism
• immune function
• Conclusion: Genetically engineered foods leads to immuno-
suppression.

18. Cancer
• Genetically engineered recombinant Bovine Growth
Hormone (rBGH), used to induce dairy cows to
produce more milk
• Canada and Europe have rejected this drug, due to
health concerns on animal and human.
• Finding: The levels of a hormone called insulin-like
growth factor-1 (IGF-1) are increased in dairy products
produced from cows treated with rBGH
• IGF-1 is an important factor in the growth of breast
cancer, prostate cancer, and colon cancer.

19. Antibiotic Resistance
• GE foods could make disease-causing bacteria resistant to current
antibiotics.
• It resulted in a significant increase in the spread of infections and
diseases in the human population .
• Virtually all GE foods contain “antibiotic resistance markers”.
• It helps the producers to identify whether the new genetic material
has actually been transferred into the host food.

20. • Ex: GE maize plant from Novartis includes an ampicillin
resistance gene
• Ampicillin is a valuable antibiotic used to treat a variety of
infections in people and animals.
• A number of European countries refused to permit the Novartis Bt
corn to be grown.
• Because the ampicillin resistance gene could move from the corn
into bacteria in the food chain.
• It makes ampicillin far less effective in fighting a wide range of
bacterial infections.

21. Loss of Nutrition
• GE can alter the nutritional value of food.
• In 1992, the FDA examined the problem of nutrient loss
in GE foods.
• Result: The genetic engineering of foods could result in
“undesirable alteration in the level of nutrients” of
such foods.

22. Effect of toxicity
in human & living organisms

23. Chronic kidney disease of
unknown aetiology
• CKDu is an increasing health concern in Sri Lanka.
• The first case was reported in Sri Lanka's North Central
Province (NCP).
• Various possible causes for CKDu in have been
investigated in Sri Lanka.
• Eg: Poisoning from metals, cyanobacteria toxins,
agrochemicals, heat stress
• But no definite causes have been identified so far.

24. • Potential causes include,
• dehydrating working conditions
• genetic susceptibility
• various lifestyle factors
• Possible environmental exposures:
Drinking water
Exposure to metals

25. • Drinking water
87% of the population in dry zone regions use and consume
groundwater
Elevated fluoride levels and distribution patterns in potable
water have been detected in the drinking water of CKDu
prevalent areas
Fluoride is an important causal component of CKDu due to its
tendency to accumulate in the kidneys
Anyhow, several villages that have implemented drinking
water regulations seemed to have lower cases of CKDu

26. • Exposure to metals
• The widespread use of agrochemicals containing various heavy
metals can be the potential causes of CKDu.
• People can be exposed to these metals through water and diet
• Arsenic: Combined with water hardness and leads to calcium
arsenate crystal formation.
• Aluminum: Combined with fluoride and become into aluminum-
fluoride complexes.
• It could potentially move through biological membranes easier than
aluminum and fluoride can individually.
• Poor quality aluminum pots which can leach out aluminum during
cooking also can be a potential sources .

27. Carcinogens
• These are the substances and exposures that can lead to
cancer.
• Environmental factors can include a wide range of
exposures
• Lifestyle factors: nutrition, tobacco and alcohol use, physical
inactivity
• Naturally occurring exposures: UV light, infectious agents
• Medical treatments: radiation and drugs that suppress the
immune system
• Workplace exposure

28. • They may cause cells to divide at a faster than normal rate.
• It could increase the chances that DNA changes will occur.
• Substances labelled as carcinogens can have different levels of
cancer-causing potential.
• Some might increase cancer risk after only a short exposure.
• But others might only cause cancer after prolonged and high levels
of exposure.
• For any particular person, the risk of developing cancer depends on
many factors
• How they are exposed to a carcinogen
• The length and intensity of the exposure
• The person's genetic makeup

29. Mutagen
• That may cause changes in normal cell division in organisms.
• Approximately, 90% of the carcinogens are mutagens.
What is the difference between mutagen & carcinogen???
• Mutagen causes a heritable change in the genetic
information of an organism.
• Carcinogen causes or promotes cancer in animals and
humans.
What is the difference between mutagenesis & carcinogenesis?
• Mutagenesis: Mechanism by which the change in the
genetic material occurs
• Carcinogenesis: Mechanism by which the formation of
tumours occurs due to mutagenic events

30. Mutagen Carcinogen

31. Teratogen
• It is a substance that interferes with normal fetal development and
causes congenital disabilities.
• Effects: Visibly abnormal, internally abnormal, or chemically abnormal
• Factors determine how dangerous the teratogen exposure is during
pregnancy:
• The drug, substance or type of toxin
• How long the pregnant person was exposed
• The amount of exposure
• The gestational age of the fetus at exposure
• Hereditary factors
• It’s best to avoid teratogens at all times during pregnancy

32. Examples of teratogens
• Alcohol, cigarettes and recreational drugs
• Medications
• Infections and viruses
• Environmental toxins, chemicals or other physical agents
• Health conditions

33. Alcohol, cigarettes and recreational drugs
• Alcohol affects the fetus’s central nervous system
• Drinking alcohol during pregnancy increases the fetus’s
risk for fetal alcohol syndrome.
• It causes abnormal facial features, a small head and
brain and other physical and behavioural disabilities.
• Cigarette smoking is associated with fetal growth
restriction and premature birth

34. Medications
• Examples of teratogenic medications:
• Antimicrobials
• Anticoagulants (blood thinners)
• Antithyroid medications
• Vitamin A (ingredient in skincare products)
• Hormonal medication

35. Infections and viruses
• Infections, viruses, parasites and other bacterial illnesses
can pose serious threats to a pregnant person & the foetus.
• Eg:
• Toxoplasmosis (an infection that spreads through cat feces)
• Rubella
• Chickenpox
• HIV

36. Environmental toxins, chemicals
or other physical agents
• Certain chemicals and substances may cause congenital
abnormalities.
• These birth disorders include spina bifida (incomplete
development of the fetus’ spine) or neurological
problems.
• Radiation exposure
• Mercury (found in certain types of fish)
• Lead (found in paint and pipes in older homes)

37. Health conditions
• Certain chronic illnesses can increase the fetus’s risk of
congenital abnormalities.
• Ex: Diabetes, thyroid conditions & autoimmune diseases
• The increased risk for teratogenic exposure typically
comes from the medication used to treat these conditions.

38. Thank You