Risk assessment of chemicals in food: Human based tolerable intake

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Risk assessment of chemicals in foodHuman based
tolerable intake

• Dr. Nantika Soonthornchaikul
• Faculty of Public Health
• Thammasat University
• Thailand

http//www.codexalimentarius.org/
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- HQ ??? - Cancer risk
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Chemical risks in food
1. ???????????

• Industrial chemicals
• Agricultural chemicals
• food manufacturing and processing
• Household chemicals
• veterinary drug residues
• others

2. ?????????????
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Food additive intake (JECFA)
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• Contaminants
• Pesticides (JMPR)
• Veterinary drugs
• pollutants

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Safe levels of intake

• Acceptable daily intake ADI, ARfD Food
  additives
• Tolerable intake Contaminants
• Tolerable daily intake (TDI)
• Provisional tolerable weekly intake (PTWI)

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• ???????? Dietary exposure
• ????????????????? Safety level

 
Ci concentration of chemical in food item
(µg/g) Fi food consumption (g/day) BW
Body weight (kg)
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Codex
US EPA

• ??????????????? (Food consumption)
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HQ Cancer risk
ADI,ARfD PTWI
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?????????????? Dietary exposure assessment

• ??????? Dietary intake
• Toxicology endpoint, type of chemical, possible
  population subgroups, data used
• ??????????? International dietary exposure
  ???????????????????????????????? National level
• ?????? Consumption data ??? concentration
  ??????????????

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1. Acceptable daily intake (ADI)

• generally estimated by dividing the
  no-observed-effect level (NOEL)
• expressed in mg additive per kg (mg/kg) body
  weight of humans.
• To protect against the most sensitive adverse
  effect, it also protects against other adverse
  effects

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• Chlopyrifos
• ADI 00.01 mg/kg bw
• ARfD 0.1 mg/kg bw

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2. Acute reference dose (ARfD)

• ??????????????????????????????????
• ?????????????
• ??????????????? 24 ???????
• ????? mg/kg BW

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3.Tolerable Daily Intakes (TDI)

• the total intakes by ingestion, to which it is
  believed that a person can be exposed daily over
  a lifetime without deleterious effect.
• They are based on non-carcinogenic effects.
• expressed on a body weight basis (e.g., mg/kg/day)

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4. Provisional tolerable weekly intake (PTWI)

• Expressed on a weekly basis to emphasize that
  long-term exposure is important (for contaminants
  that cumulate in the body)
• Provides a bright line for the risk manager
  against which intake can be compared
• Adverse effects are seen with many contaminants
  in the range of exposure for some population
  groups - difficult to separate risk assessment
  from risk management
• Ex Methyl mercury 1.6 mcg/kg/wk

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• ???????????? safety levels
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Aggregate exposure
cummulative exposure
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Potential uses of food consumption surveys
Food insecurity
Nutrient adequacy estimation
Diet-disease relationships
Food consumption surveys
Food pattern analysis
Exposure assessment
Additional indicators e.g. - anthropometry -
health indicators
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Dietary Assessment data types

• FFQ
• 24-hour recall
• Duplicate diet
• Food records
• Diet history

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Dietary vs. exposure assessment
Dietary assessment Exposure assessment
Purpose To determine nutritional adequacy dietary-disease relationship - RDI - dietary guidelines - population groups at risk - basis of nutrition policies and programmes, incl. fortification To determine - if dietary exposure is below toxicological thresholds - main contributing foods or food group(s) - population groups at risk basis for risk managers to take action basis of national regulatory and food control systems
Data needed - food consumption/supply data - food composition data - food consumption/supply data - occurrence data
Formula I ?(W1C1 W2C2 ...WnCn)i where I intake of the nutrient, W1 weight consumed of food 1, C1 content of the nutrient in food 1, iindividual E ?(W1C1 W2C2 .... WnCn)i where E Dietary exposure, W1 weight consumed of food 1, C1 content of the e.g. contaminant in food 1, iindividual
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Dietary vs. exposure assessment
Dietary assessment Exposure assessment
Expressed in g/mg/mcg per d g/mg/mcg per d/week/month per kg bodyweight
Compared to RDI, UL MPL, ML, ADI
Concern lt RDI or gtUL gt MPL/ML/ADI
Special methodology Total diet Studies (TDS) selection of foods based on food consumption survey data representing a large portion of a typical diet, preparation of food as consumed and pooling of related foods into distinct food groups before analysis. Model diets screening methods to assess if worse case scenarios are still under toxicological thresholds, e.g. budget method, model diet for veterinary drug residues 500 g meat (300g muscle, 100g liver, 50g kidney, 50g fat) 1.5 liter milk 100g egg per day
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• ????????????????????? 500 ????/???, ????????? 5
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• ???????????????? 60 ??
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