Cases of accidental chemical contamination of food sources are occurring with increasing frequency. Measurement of consumer welfare losses in such cases has presented difficult problems. Direct consumer questionnaires are unreliable because of strategic bias (consumers may overstate losses if they think it has possibilities for improving their situation). On the other hand, assessing losses by estimating the number of individuals that will be affected and multiplying by an average loss per person (estimating actual ex post losses) is a highly tentative approach because scientific and medical research estimates regarding the number of people actually affected (e.g., contracting cancer) are highly inaccurate. Also, the many means of estimating loss per person actually affected (implicit value of life from other comparisons, cost of treatment, and value of work time lost) produce conflicting results.