determine whether violation rates, frequency of occurrence of residues, and residue
levels obtained from such a sampling regimen differ from those obtained through the
FDA’s traditional surveillance approach.Total Diet StudyThe FDA’s Total Diet Study (TDS) is designed to estimate dietary intakes of pesti-
cide residues by men and women of various age groups, from infants to senior citi-
zens. FDA personnel purchase foods from supermarkets or grocery stores four times
per year, once from each of four geographical regions of the country. Each collection
contains 261 food items (234 items prior to 1992) that are selected on the basis of
information obtained through nationwide dietary surveys. The 261 foods are repre-
sentative of more than 3,500 different foods in the national surveys; for example,
apple pie represents all fruit pies and fruit pastries. Each of the four collections is a
composite of similar foods purchased in three cities in that region. The foods are pre-
pared and then analyzed for pesticide residues (as well as industrial chemicals, toxic
elements, trace and macro elements, vitamin B6, and folic acid). The levels of pesti-
cides found are used in conjunction with food consumption data to estimate the die-
tary intakes of pesticide residues.
Total Diet Studies are the primary sources of information on the levels of contami-
nants and nutrients in foods for human consumption. In addition, TDS results can be
an indicator of environmental contamination by chemicals, such as Persistent Organic
Pollutants (POPs), and can be used to assess the effectiveness of specific risk manage-
ment measures. As the presence of toxic chemicals in our world and their potential
presence in our food increase, it is increasingly important to assess human exposure to
background concentrations of a large number of chemicals in the diet. The responsibi-
lity and obligation to make these assessments usually rests with national health author-
ities. Total Diet Studies are internationally recognized as the least expensive way to
estimate the average dietary intakes of toxic and nutritional chemicals for a range of
population groups.^17Organic Foods: Fewer Pesticide ResiduesDo organically grown foods contain fewer residues of toxic pesticides than conven-
tionally grown foods? The answer is an emphatic yes, according to a scientific study
published in the peer-reviewed journalFood Additives and Contaminantsin May- In this detailed analysis of pesticide residues in foods, more than 94,000 con-
ventional and organic food samples were studied by three organizations.
The USDA’s data reported the following:1) 73 percent of conventionally grown
foods had one or more pesticide residues; 2) 23 percent of organically grown samples
of the same crops had any residues; 3) more than 90 percent of conventionally grown
apples, peaches, pears, strawberries, and celery had residues; and 4) conventionally
grown crops were six times as likely as organic crops to contain multiple pesticide
residues.
78 | Pesticides