L4-Pesticide Residues in Food - University of Idaho

Pesticide Residues in Food

Food Toxicology Instructor: Gregory M?ller, Ph.D.

University of Idaho

Food Toxicology

Learning Objectives

? Develop an introductory understanding of pesticide use and monitoring in the human food chain.

? Know the major classes of pesticides. ? Understand the legal basis for monitoring. ? Comprehend the risk vs. benefits

analysis basis of

? FIFRA, FQPA

2

Pesticides

? Economic and public health poisons.

? Control of insects, weeds, rodents and other pest animals.

? Bacterial, fungal and viral infection in agriculture, homes and public health applications.

? Natural chemicals, synthetic chemicals, biological agents.

? Residue or = Risk

3

Food Toxicology

Pesticide Data Program

? USDA: Annual survey of target commodities for target chemicals and multi-residue screening (12,446 samples).

? Year 2004 overall results.

? Detectable residue. ? 70% of fruit & veg samples. ? >50% of drinking water samples.

? Residue exceeding tolerance. ? 0.2% of samples.

? Residue without tolerance. ? 5.2% of samples.

? 4 pdp/Summary2003.pdf

Food Toxicology

Food Toxicology

Scope of US Commercial Activity

? About 865 Active Ingredients (1996).

? 350 in food chain. ? ~20,000 products, 9000 tolerances. ? 1.25 billion pounds (AI) pesticides. ? Herbicides are >50% of volume, >50%

sales; most top 10 use.

? Retail sales.

? >$10 B (Ag, Non-Ag). ? >$8 B (Agricultural).

5

Food Toxicology

Trends in Regulation and Use

? Lower use rate. ? Low-volume application. ? Risk mitigation requirements. ? Integrated Pest Management

(IPM). ? Conditional registration

(monitoring). ? Safer chemicals. ? Biopesticide use. ? Increased exposure concerns.

? Patterns, routes and levels. 6 ? Applicator training.

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Food Toxicology

Major Classes of Pesticides

? Insecticides. ? Herbicides. ? Fungicides. ? Rodenticides. ? Bactericides. ? Biopesticides. ? Special

application.

Food Toxicology

Special Application Chemicals

? Acaracides, Algicides, Avicides, Bactericides, Piscicides, Virucides, Molluscicides.

? Insect attractants, Insect repellants, Bird repellents, Mammal repellents.

? Plant growth activators. ? Synergists.

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8

Pesticides, 1

? Antibiotic insecticides.

? Abamectin, Spinosad.

? Arsenical insecticides.

? Lead arsenate.

? Botanical insecticides.

? Nicotine, Pyrithrins, Rotenone.

O

O

O

O

O

O

Rotenone

9

Food Toxicology

Pesticides, 2

? Bacterium

? Bacillus thuringiensis (Bt)

? Carbamate insecticides.

? Aldicarb, Carbaryl, Carbofuran, Oxamyl.

? Organochlorine insecticides.

? Aldrin, Dieldrin, DDT, Endrin, Methoxychlor, Pentachlorophenol.

Food Toxicology

HN

O

S

N

O

10 Aldicarb

Pesticides, 3

? Organophosphorus insecticides.

? Azinphos-methyl, Dichlorvos, Chlorpyriphos, Fenthion, Diazinon,

? Malathion, Parathion.

? Pyrethroid insecticides.

? Fenvalerate, Permerthrin, Resmethrin.

Food Toxicology

ON+ O

11 Parathion

S

O

PO O

Pesticides, 4

? Botanical rodenticides.

? Strychnine.

? Coumarin rodenticides.

? Brodifacoum, Bromodialone, Warfarin.

? Inorganic rodenticides.

? Zinc Phosphide.

? Unclassified rodenticides.

? Ergocalciferol, Sodium Fluoroacetate.

12

Food Toxicology

N H

H

H N

O

O

Strychnine

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Food Toxicology

Pesticides, 5

? Amide herbicides.

? Metolachlor.

? Dinitrophenol herbicides.

? Dinoseb.

OH

HO

P

N

H

O

? Imidazolinone herbicides.

? Imazethapyr.

? Organophosphorus herbicides.

? Glyphosate.

OH

O Glyphosate

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Pesticides, 6

? Phenoxyacetic herbicides.

? 2,4 D.

? Quaternary ammonium

N+

herbicides.

? Diquat, Paraquat.

? Thiocarbamate herbicides.

? Molinate.

? Triazine herbicides

? Atrazine.

? Sulfonylurea herbicides.

? Metsulfuron.

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Food Toxicology

N+ Paraquat

Food Toxicology

Legal Basis for Monitoring

? 1906 The Jungle (U. Sinclair). ? 1906 Federal Meat Inspection Act;

1906 Pure Foods and Drug Act.

? 1938 Federal Food, Drug and Cosmetic Act, FFDCA.

? 1910 Federal Insecticide Act, then ? 1947 Federal Insecticide,

Fungicide and Rodenticide Act. ? Modern amendments.

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Delaney Clause

? 1958 Delaney Clause (FFDCA)

? Zero-risk cancer standard for residues in processed foods.

Food Toxicology

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Food Toxicology

Legal Basis for Monitoring, 2

? Federal jurisdiction.

? EPA, FDA (HHS), FSIS (USDA), AMS (USDA)

? Authority.

? FIFRA, FFDCA, FMIA, PPIA, EPIA

? EPA ? Registration, RA, tolerance, environmental quality.

? FDA ? Tolerance enforcement. ? FDA, FSIS, AMS

? Food monitoring.

? State primacy for FIFRA. ? 1996 Food Quality

Protection Act.

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Food Toxicology

Legal Basis for Monitoring, 3

? SDWA - Safe Drinking Water Act.

? Maximum contaminant levels.

? CWA - Clean Water Act.

? NPDES discharge permits.

? RCRA - Resource Conservation and Recovery Act.

? Listed wastes.

? CERCLA (Superfund)

? Hazardous substances.

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Why FQPA?

? Years in the making: adopts most scientific recommendations

? Delaney Paradox

? Different regulations for processed and raw foods

? No detectable level of carcinogens allowed in processed foods

? Court decisions requiring enforcement of Delaney, 1993/95

Food Toxicology

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Motivation for Change

? NAS "Kids" Study: Pesticides in the Diets of Infants and Children, 1993.

? Minor crop pressure, streamlining. ? 1996 Election year opportunism.

? Origins in Commerce Committee: Consumers.

? Unanimous passage, House/Senate.

Food Toxicology

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Food Toxicology

NAS Kid's Study Results

? The exposure of children to pesticides is substantially different from that of adults.

? The government needs to do more to address the unique risks posed to children.

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Consumed by "Kids"

Non-nursing infant subgroup

Commodity

g /kg/day

milk

10.9

apples

6.3

oranges

2.7

peaches

2.1

soybeans*

1.6

pears

1.6

carrots

1.5

*component as soybean oil 22 NAS

Food Toxicology

Food Toxicology

Children: Not Just Little Adults

? About 300 Active Ingredients (AI) registered for top 20 commodities eaten by infants and children.

Some FQPA Changes

? Kids as the dose model. ? Additive toxicity. ? Aggregate exposure. ? Endocrine disruption. ? "Reasonable certainty of no

harm" health standard. ? Right-to-know.

Food Toxicology

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FIFRA

? Federal Insecticide, Fungicide, and Rodenticide Act.

? FIFRA is a Licensing Authority...labels are the license.

? FIFRA is one of the few risk vs. benefits statutes.

Food Toxicology

FIFRA

? FIFRA gives EPA strong authority to require any data necessary to evaluate risk to human health and the environment.

? Registration is national in scope and authority.

? Registrant-generated data used to evaluate risk.

Food Toxicology

2E5PA

26 EPA

Human Health

NAS Risk Assessment Process

1. Hazard Identification.

? Toxicity testing, adverse effects.

2. Dose-Response Assessment.

? Quantitative toxicity.

3. Exposure Assessment.

? Food, water, home, workplace.

4. Risk Characterization.

? Risk = Toxicity x Exposure.

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Food Toxicology

Food Toxicology

Agrichemical Registration

? As many as 70 specific tests may be required (> $10M cost).

? Health effects and toxicology. ? Environmental fate. ? Ecological effects. ? Residue chemistry.

? Commercial development.

? 10 yr cycle, $50M.

28 EPA

Food Toxicology

TTR: Total Toxic Residue

? Agrichemical residue plant/animal metabolism. ? Typically with radiolabeled parent compound (AI). ? Track and identify metabolic products.

? Attempt to identify >80-90% TTR.

? Separate toxicology trials for major metabolites sometimes warranted.

? Effects of food processing and use of product as animal feed.

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Human Health

? Prior to Food Use Registration. ? Ecological.

? Acute and chronic. ? Aquatic and terrestrial.

? Human Health.

? Acute and chronic. ? Populations and sub-populations. ? Special protection for children.

Food Toxicology

30 EPA

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