1. Chemical Hazards: How Do We
Translate Presence to Risk?
An Overview of Risk Analysis
James R. Coughlin, PhD CFS
President, Coughlin & Associates
Aliso Viejo, California
jrcoughlin@cox.net
www.linkedin.com/in/jamescoughlin
IAFP / Charlotte / July 29, 2013
SYMPOSIUM
“Chemical Risk Assessment 101:
A Better Understanding of a Complex
Subject Made Easier”

2. Objectives/Outline
 Why is toxicology and risk assessment of
chemicals important for foods and food
ingredients?
 General toxicology considerations, toxicity
evaluation and risk assessment
 Key determinants of human risk
 Consider “Risk-Benefit” Evaluation:
 Acrylamide as case example
 California Proposition 65

3. Paracelsus (1493-1541)
THE basic
tenet of all
Toxicology:
“The dose
alone
makes the
poison.”

4. Toxicology – A Multidisciplinary Science
 Chemistry
 Biology
 Pathology
 Physiology
 New Fields:
 Genomics
 Proteomics
 Toxicogenomics
 Nutrigenomics
 Nutrition
 Immunology
 Public Health
 Pharmacology
 Statistics
 Epidemiology
 Newest:
The Microbiome

6. Acute / Chronic Exposure and
Health Effects
 “Acute” Exposure
A single exposure to a chemical that can result
in some form of toxicity or illness
 “Chronic” Exposure
Usually a lower-dose exposure
for longer periods of time,
associated with
chronic/delayed effects

7. Factors That Influence Toxicity
 Dose / duration / frequency of intake
 Species / strain / age / sex
 General state of health
 Genetic & epigenetic factors
 Nutritional status
 Individual susceptibility (child, pregnant
woman, elderly, immune compromised)
 Synergism / antagonism
 Adaptation to the effect

8. Fate of Toxicants in Living Systems
“ADME”
 Absorption - how much is absorbed by the body?
 Distribution - what organs/body fluids does the
toxicant go to?
 Metabolism - is it modified by enzymes in the body,
and to what extent? Activation to more toxic
compound vs. Detoxification
 Excretion - how much of the toxicant (or its
metabolites) is retained and/or removed from the
body?

9. Specialized Toxicity Tests
1. Reproductive (multigeneration)
2. Teratogenicity (birth & developmental)
3. Mutagenicity (short-term, in vitro & in vivo)
4. Neurobehavioral
5. Immuno-toxicological
6. Endocrine effects
7. Potentiation / Promotion
8. Carcinogen Bioassays

10. Human Relevance of Rodent Cancer Bioassays
 Some eminent toxicologists have questioned the human relevance
of tumors seen in lifetime rodent bioassays, and they believe it’s
time to STOP doing chronic rodent bioassays at the “Maximum
Tolerated Dose”
 We toxicologists make two possibly flawed assumptions about
chronic cancer bioassays…
 Dose Extrapolation – effects seen at high rodent doses will also
occur at much lower human doses
 Species Extrapolation – if cancer is seen in rodents, then cancer
probably occurs in humans
 BUT…we need to understand Mechanisms and Modes of Action for
a chemical before we can use bioassay tumor results for regulatory
or warning purposes.

11. Risk Assessment Paradigm
 Hazard Identification - Determination of adverse effects
caused by high intakes of the chemical (epidemiology, clinical,
animal, short-term and specialized studies)
 Dose-Response Assessment
 Selection of critical data set and toxic effect levels
 Determination of Uncertainty or Safety Factors
 Derive an Acceptable Daily Intake (ADI)
 Exposure (Intake) Assessment
 Evaluation of the range and distribution of human intakes
 Risk Characterization
 Estimation of the fraction of the population exceeding ADI
 Evaluation of the magnitude of potential excess intakes.

12. Methods for Oral “RfDs”
 RfDs - U.S. EPA’s Reference Dose (similar to other agencies’
Acceptable Daily Intake or “ADI”)
 NOAEL - “No Observed Adverse Effect Level” – dose found
experimentally where there is an absence of adverse effects
 LOAEL - “Lowest Observed Adverse Effect Level” – the lowest
experimental dose which increases the frequency or severity of
toxic effects
 Uncertainty Factors - in risk assessment of chemical toxicants,
generally 10-fold increments with 100-fold as the default
 Modifying Factors - magnitude depends on study weaknesses,
severity of effects, bioavailability, susceptible subpopulations
(such as diseased people, kids).

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15. Acrylamide Snapshot: Chemistry and Toxicology
 Occupational neurotoxin; genotoxic / mutagenic in cell cultures
 Known rat carcinogen, classified as “probable human carcinogen”
 Metabolized to glycidamide (an epoxide), also an animal carcinogen
 Acrylamide & glycidamide can bind to DNA, amino acids and proteins
 DNA adducts  carcinogenic potential
 Blood hemoglobin adducts  biomarker of exposure
 Dietary proteins may reduce acrylamide uptake in humans
 Protective enzymes can detoxify acrylamide and glycidamide
 Discovered by the Swedes in 2002 in hundreds of heat-processed
food products, making up about 40% of our calories.
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16. Swedish Discovery of Acrylamide in Foods
(announced April 2002)
Tareke et al., J. Agric. Food Chem. 50: 4998-5006 (2002)
 Discovered after illness investigations of tunnel workers
exposed to acrylamide as a grouting agent in 1997;
background levels of Hemoglobin-acrylamide adducts of non-
smoking Swedes were found to be elevated
 Higher temperature / time / surface area increase levels:
 Carbohydrate-rich foods high: 150 - 4,000 ppb
 Protein-rich foods low, e.g. meats: 5 - 50 ppb
 Not detected in unheated or boiled foods; 120 C is needed
 Swedish adult acrylamide intake estimated to be 100 μg/day,
but now known to be much lower in most populations.
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17. Ammonia
Alkyl amines
Amino acids
Proteins
Phospholipids
Aldehydes
Ketones
Sugars
Carbohydrates
Lipids
Carbonyls
Esters
Amides (Acrylamide)
Heterocyclic Compounds
Amine
Carbonyl
Amino-Carbonyl
Interaction
(Amadori Products)
HEATHEAT
Furans Oxazoles
Pyrroles Imidazoles
Thiophenes Pyridines
Thiazoles Pyrazines
Melanoidins
(pigments)
Volatile Compounds
(aroma chemicals)
General Scheme of Maillard Browning Reaction

18. Food Acrylamide Range (ppb)
Baby food/biscuits ND - 442
Breads/bakery products ND - 364
Cereals 11 - 1057
Chocolate products ND - 909
Coffee (roasted, not brewed) 37 - 374
Coffee (brewed) 5 - 11
Cookies/crackers 26 - 1540
Dairy drinks ND - 43
Dried foods/mixes ND - 1184

19. Food Acrylamide Range (ppb)
French fries 117 - 1325
Fruits/vegetables (canned) ND - 83
Gravies/seasonings ND - 151
Infant formulas ND
Nuts/nut butters ND - 457
Potato chips 117 - 4080
Snacks (other salty) 12 - 1340
Olives 123 - 1925
Prune juice 53 - 326

20. U.S. National Toxicology Program (NTP) –
Carcinogen Bioassay of Acrylamide
 U.S. FDA nominated acrylamide and glycidamide for complete toxicology
testing in November 2002 for future risk assessment purposes
 2-year cancer bioassay in rats and mice fed acrylamide in drinking water
(untreated control + 4 treatment doses), with ancillary studies on
metabolism, genotoxicity and toxicokinetics
 NTP Technical Report No. 575 was peer-reviewed in April 2011; Panel
accepted conclusions that there was “Clear Evidence of Carcinogenicity”
in male & female rats and male & female mice
 For consideration: the observed NTP tumor findings and cancer potencies
may be useful in increasing acrylamide’s acceptable risk level.
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22. Acrylamide Risk Assessment Considerations Based
on NTP Cancer Bioassay
 FAO/WHO Joint Expert Committee on Food Additives (JECFA)
acrylamide risk assessment (2010) used preliminary NTP data
on benign tumors in the rat mammary gland and mouse
Harderian gland, but these endpoints are not biologically
relevant to human risk assessment
 JECFA and national authorities should reevaluate acrylamide’s
potential for human risk based on the lower incidences of
more relevant NTP malignant rat and mouse tumor endpoints
 Lack of human cancer risk must be factored into any risk
assessment and risk management plans adopted by national
regulatory agencies (FDA, Health Canada, EFSA) and global
public health authorities (JECFA, Codex).
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23. Recent Dietary Epidemiology Studies of
Acrylamide (Human Studies)
 Pelucchi et al. 2011. “Exposure to Acrylamide and
Human Cancer - A Review and Meta-analysis of
Epidemiologic Studies.” Annals Oncology 22: 1487-1499.
 “Conclusions: Available studies consistently suggest
a lack of an increased risk of most types of cancer
from exposure to acrylamide.”
 Lipworth et al. 2012. “Review of Epidemiologic Studies
of Dietary Acrylamide Intake and the Risk of Cancer.”
Eur. J. Cancer Protection 21: 375-386.
 Concluded no increased human risk, and urged that
no further epidemiology studies even be initiated.
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24. “Acrylamide in Foods: A Review of the Science and
Future Considerations”
David R. Lineback, James R. Coughlin and Richard H. Stadler,
Ann. Rev. Food Sci. & Technol. 3: 15-35 (April 2012)
 Most countries have advised consumers to follow the dietary
recommendations for a balanced diet issued by their food
regulatory and public health agencies.
 The data available to date have been insufficient to warrant any
recommendation for a significant change in the dietary
recommendations because of acrylamide.
 Current epidemiological and toxicological evidence are
insufficient to indicate that the amounts of acrylamide consumed
in the normal diet are likely to result in adverse human health
effects, particularly cancer.
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25. No Significant Risk Level [NSRL] = (1 x 10-5)
Over 500 Carcinogens
MADL = No Observable Effect Level
1000
Over 300 Reproductive Toxicants [DARTs]
Exposure (µg/day), Not Concentration!

26. Acrylamide Battleground under California Prop 65
 Listed in 1990 as a carcinogen; “Safe Harbor” level = 0.2 μg/day; must
stay below this level to avoid cancer warnings; if you can detect it, even a
1-ounce serving of any food exceeds this level
 French fries: Attorney General sued and settled case (2008) against
frozen fries/tater tots demanding a 50% reduction in levels; fast-food
restaurant fries have had cancer warnings posted for years
 Potato chips: AG settled (2008) the case against chip manufacturers;
agreement to cut levels to 275 ppb by end of 2011 (20 - 85% reductions) to
avoid warnings; no warnings currently being given
 Cereals: Private “bounty hunter” lawyers sued cereal manufacturers in
2009; case is still pending
 Coffee: “Bounty Hunter” sued coffee shops in 2010 over brewed coffee;
10 x 10-inch cancer warning placards have been posted; another case
now in court against over 120 coffee roasters for packaged roast coffees.
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27. Benefit-Risk Evaluation –
The “Holistic Approach”
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28. Food and Chemical Safety Issues
 We usually test individual food chemicals, not the whole
foods or beverages (except with epidemiology)
 For whole foods, we must identify biologically active toxic
component(s)
 Must determine appropriate mechanism of action of
specific chemicals (carcinogens, reproductive toxicants)
 Key importance of dose-response relationships
 Interactions with diet/nutrients, environment & drugs
 Explore sensitive segments of population (young, aged)
 Risk/Benefit Assessment is crucial need:
 Goal: NO “significant or unreasonable” risk!!

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31. “Benefit-Risk Evaluation” to Assess the Safety of
Foods Containing Toxicants and Carcinogens
I believe we’ve been doing it the WRONG WAY for
decades, by simply evaluating the risk of individual
chemicals one by one in a food
Going forward, I believe the RIGHT WAY is to evaluate
the safety of the whole food by comparing its risks vs.
benefits using the “Holistic Approach”
Various “Benefit-Risk Evaluations” and regulatory
guidance documents have recently been published in
the U.S. [FDA’s “Mercury in Fish” evaluation] and
Europe [EFSA, ILSI Europe].
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