Chapter 20 — Self-Check Quiz

20 questions. Answers with explanations at the end. Aim for 16+.

Questions

1. Organic certification primarily regulates:

• a) The nutritional content of the finished food
• b) The production process — permitted inputs, land history, animal welfare, record-keeping
• c) Pesticide residue levels in the finished food
• d) Retail pricing

2. Which of these is permitted in certified organic production?

• a) Copper sulfate
• b) Synthetic nitrogen fertilizer
• c) Genetically engineered seed
• d) Sewage sludge

3. Copper compounds in organic farming are a genuine concern because they:

• a) Are synthetic
• b) Do not degrade, accumulate in soil, and are toxic to soil organisms
• c) Are carcinogenic to consumers
• d) Reduce crop yields

4. The history of rotenone demonstrates that:

• a) Organic standards never change
• b) "Natural" and "safe" are unrelated properties
• c) Botanical pesticides are always safer
• d) Regulators ignore organic inputs

5. National residue monitoring programmes consistently find:

• a) Most samples exceed legal tolerances
• b) The great majority of samples are below tolerance, and where detected, residues are typically a small fraction of it
• c) Organic samples always have zero residues
• d) Testing is too unreliable to interpret

6. The number of foods with "detectable pesticide residues" has risen over decades mainly because:

• a) More pesticide is being applied
• b) Analytical detection limits improved by orders of magnitude
• c) Regulations were relaxed
• d) More crops are grown

7. The Dirty Dozen ranking is criticized because it:

• a) Uses fabricated data
• b) Ranks largely by detection frequency and number of compounds, without weighting by toxicity or dose relative to reference doses
• c) Only includes imported produce
• d) Is published irregularly

8. A possible negative consequence of the Dirty Dozen framing is that it:

• a) Increases organic prices
• b) May discourage conventional produce purchase among people who can't afford organic
• c) Reduces pesticide regulation
• d) Encourages overconsumption of fruit

9. The Stanford (2012) review found:

• a) Organic food is substantially more nutritious
• b) No strong evidence of nutritional superiority, but lower pesticide residues and lower antibiotic-resistant bacteria in organic meat
• c) Organic food is less safe
• d) No differences of any kind

10. The Newcastle (2014) meta-analysis reported:

• a) Higher antioxidants/polyphenols and lower cadmium in organic crops
• b) Lower protein in organic crops
• c) No differences
• d) Higher pesticide residues in organic crops

11. No study has demonstrated:

• a) Any compositional difference between organic and conventional produce
• b) A health outcome difference from eating organic versus conventional produce
• c) That organic farming uses pesticides
• d) That residues can be measured

12. The NutriNet-Santé organic-cancer association is difficult to interpret because:

• a) The sample was too small
• b) Organic purchasing is close to a direct proxy for health-conscious affluence
• c) It was industry funded
• d) Cancer was not measured

13. Compared with conventional farming, organic farming generally has:

• a) Higher yield per hectare
• b) Lower yield per hectare and higher land use per unit of food
• c) Identical yields
• d) Lower biodiversity

14. The NASEM 2016 report on genetically engineered crops concluded:

• a) GE crops pose substantially higher risks
• b) No substantiated evidence of a difference in risks to human health versus conventional counterparts
• c) The evidence was too limited to assess
• d) GE crops should be banned

15. The Séralini 2012 rat tumour study was:

• a) Independently replicated
• b) Retracted by the journal in 2013, on grounds including sample size and the tumour-prone strain
• c) Never published
• d) The basis of current EFSA policy

16. Which of these is not a safety objection to GM crops?

• a) Herbicide-tolerance changing herbicide use patterns
• b) Corporate concentration and seed patents
• c) Labelling and consent
• d) All three are non-safety objections

17. IARC Group 2A, which includes glyphosate, also contains:

• a) Nothing else
• b) Red meat consumption, very hot beverages, and shift work involving circadian disruption
• c) Only pesticides
• d) Water

18. The Bt irony is that:

• a) Bt is banned everywhere
• b) The same insecticidal protein is permitted as an organic spray and prohibited as a plant trait
• c) Bt does not work
• d) Bt is synthetic

19. Ranked by demonstrated population burden, the largest food safety risk among these is:

• a) Pesticide residues at monitored levels
• b) Foodborne pathogens
• c) GM ingredients
• d) Food additives

20. "Clean eating" receives ❌ because:

• a) Eating whole foods is unhealthy
• b) It has no definition or criteria, uses purity framing, and is associated with disordered eating
• c) It is too expensive
• d) It excludes vegetables

Answers

1. b) The production process. ⚠️ The USDA has been explicit that the organic seal certifies how food is produced, not that it is safer or more nutritious. That's the correct thing for a production standard to do — and it means every health claim attached to organic food is an inference from the standard, not a statement of it. §20.2.

2. a) Copper sulfate. ⚠️ Organic certification permits a defined pesticide list — copper, sulfur, pyrethrins, spinosad, Bt, neem, horticultural oils. It prohibits most synthetic pesticides. §20.3.

3. b) Persistent, accumulating, toxic to soil organisms. ⚠️ It doesn't degrade, it's heavily used in organic viticulture and orchards, and the EU has been progressively restricting it. A genuine environmental problem inside the system marketed as the environmental choice. §20.3.

4. b) "Natural" and "safe" are unrelated. Rotenone was a botanical insecticide widely used in organic production and has been withdrawn or restricted in many jurisdictions on toxicity grounds. ⚠️ Chapter 18's threshold: natural buys no exemption. §20.3.

5. b) The great majority below tolerance. Typically well above 95%, with a large fraction showing no detectable residues, and detected levels usually a small fraction of the tolerance — which itself carries a safety factor of a hundredfold or more below observed-effect levels. §20.4.

6. b) Detection limits improved. ⚠️ Parts per million became parts per billion or lower. So detections rose while quantities generally fell. "Detected in 70% of samples" is a statement about instruments, not about exposure — and it is exactly the number that gets reported. This is the engine of the whole marketing apparatus. §20.4.

7. b) Ranks by detection frequency, not dose relative to reference doses. ⚠️ An item can rank high because many compounds were found at trivial levels. Published analyses applying toxicological reference doses to the same USDA data have concluded the residues are orders of magnitude below levels of concern. The data is real; the ranking omits the variable that determines toxicological significance. §20.5.

8. b) It may discourage conventional produce purchase. ⚠️ Particularly among lower-income shoppers who can't afford organic and, told "contaminated," buy neither. Claim 1 (✅) losing to Claim 3 (🟠) — which is exactly what Marisol did. §20.5.

9. b) No strong nutritional superiority; lower residues and lower antibiotic-resistant bacteria. Smith-Spangler et al., Annals of Internal Medicine, 2012. ⚠️ Both of those secondary findings are real and the second is underrated. §20.6.

10. a) Higher antioxidants/polyphenols, lower cadmium. Barański et al., British Journal of Nutrition, 2014; methodology contested. ⚠️ And Chapter 13's isolated-nutrient graveyard applies: a higher concentration of a compound in a food is not a demonstrated health benefit. §20.6.

11. b) A health outcome difference. ⚠️ Which is the endpoint anyone actually cares about. The compositional differences are real and modest — likely smaller than the variation between two conventional apples from different soils, seasons and varieties. §20.6.

12. b) Organic purchasing proxies health-conscious affluence. ⚠️ Arguably the strongest example of healthy-user bias available anywhere in nutrition (Chapter 2 §2.3) — higher income and education, less smoking, more exercise, more produce, less UPF, more preventive care. Adjustment can't fix it, for Chapter 19 §19.11's reason. §20.7.

13. b) Lower yield, higher land use. ⚠️ The yield gap is the crux — organic is generally better per hectare and often worse per kilogram. Which metric matters depends on whether land is the constraint, and if lower yields mean more land is farmed, it comes from somewhere. (Organic is generally better on nitrogen runoff, biodiversity and soil organic matter — the balance sheet has entries on both sides.) §20.8.

14. b) No substantiated evidence of a difference in health risks. ⚠️ One of the strongest consensuses in food science — NASEM 2016, plus AAAS, WHO, EFSA and numerous national academies. And note what the ✅ covers: approved products currently on the market — a claim about what has been assessed. §20.9.

15. b) Retracted in 2013. By Food and Chemical Toxicology, on grounds including inadequate sample size and the tumour-prone rat strain; later republished elsewhere. ⚠️ It continues to circulate widely. §20.9.

16. d) All three are non-safety objections. ⚠️ This is the chapter's most transferable lesson. The movement argued a factual claim (safety) that didn't hold, while holding legitimate positions — corporate seed concentration, herbicide-tolerance trajectories, monoculture, labelling and consent — that never depended on it. When the factual claim collapsed, it took the legitimate ones with it. That's what happens when a values position borrows a scientific costume. §20.10.

17. b) Red meat, very hot beverages, shift work. ⚠️ Group 2A describes evidential strength, not danger magnitude. Chapter 18 §18.13's aspartame structure exactly: IARC assesses hazard, regulators assess risk. (The genuine residual dispute is about weighting occupational versus dietary exposure — and the public argument is almost entirely about the latter, which is the weaker case.) §20.11.

18. b) Permitted as a spray, prohibited as a plant trait. ⚠️ Same protein, same mechanism, opposite regulatory status, decided by delivery method — and the plant-trait version generally requires less total application. §20.3, §20.9.

19. b) Foodborne pathogens. ⚠️ Millions of illnesses, tens of thousands of hospitalizations, and hundreds to thousands of deaths annually in the US alone. Monitored pesticide residues have no demonstrated population burden. ⚠️ And the interventions that work — handwashing, separation, temperature, prompt refrigeration — are ✅ and free. A meat thermometer costs less than one week of organic premium. §20.12b.

20. b) No definition, purity framing, disordered eating association. ⚠️ "Clean" implies its opposite — Chapter 17's shape 2 isn't incidental to the framing, it IS the framing. The underlying behaviours (more whole foods, less UPF) are real and don't need the vocabulary. ⚠️ And the framework has no stopping rule: foods are morally categorized, the boundary keeps moving, and there is always something else to eliminate. Chapter 34. §20.13.

Scoring

Three items worth checking regardless of score.

Question 6. ⚠️ If you missed this, every residue headline you ever read will mislead you, in a predictable direction.

Question 16. ⚠️ The most portable lesson in the chapter — and it applies to positions you hold, not just ones you don't.

Question 19. ⚠️ If pesticide residues ranked above pathogens in your mind, the chapter has done its main job by correcting it — and the correction is free to act on.