Pesticide residues in the total diet in Canada II—1970

Composites of food representing the Canadian diet were analysed for organochlorine and organophosphorus pesticides and arsenic. Thirteen organochlorine and three organophosphorus pesticides were found. Residues were consistently low and would contribute to the diet approximately 20 μg total pesticide residues and 30 μg arsenic per person per day.     

Pesticide residues in the total diet in Canada

A total diet, representative of a Canadian's daily food intake was formulated, grouped by types of food, and prepared as for eating. Analysis of these composites for residues showed eleven organochlorine but no organophosphorus pesticides. Residues were low and would yield an average total daily intake of 24μg/person/day. The level of arsenic was determined on one-quarter of the samples and was found to be consistently below 0.1 ppm.     

Pesticide residues in the total diet in Canada. IV. 1972 and 1973

Foods, representing an average Canadian diet, were prepared for eating, made into homogenised composites, each containing one type of produce, and analysed for pesticide residues and arsenic. The amounts found were at a consistently low level which could contribute approximately 20 μg total pesticide residues and 35 μg arsenic/person/day.     

Pesticide residues in the total diet in England and Wales, 1966–1967: III.—Organophosphorus pesticide residues in the total diet

Details are given of the methods of analysis used in the determination of Organophosphorus pesticide residues in each of the food groups into which the total diet samples were divided. Residues of only 6 pesticides were detected. Malathion was the most commonly found, mainly in the cereal foods group of the diet, but all the residues were at low levels.     

Pesticide residues in the total diet in England and Wales, 1966–1967: IV.—Mercury content of the total diet

Results are given of determinations of the mercury content of each of the 7 composite food groups into which samples of the total diet were divided. In the very few sub-samples in which mercury was detected, the levels found were very low and close to the limit of detection by the colorimetric method used.     

Pesticide residues in total diet samples (VIII).

During the eighth year of the Total Diet Study, residues remained at the relatively low levels reported previously. A total of 35 market baskets were collected in 32 cities which ranged in population from less than 50,000 to 1,000,000 or more. Averages and ranges of residues found are reported for the period June 1971 through July 1972 by region and food class. Results of recovery studies within various classes of residues are also presented.     

Pesticide and other chemical residues in total diet samples (XI)

In the Total Diet study, the Food and Drug Administration has, since 1964, reported residues of pesticides and other chemicals ingested in the average diet of the Nation's largest eater, the young adult male. During the eleventh year of the study, pesticide residues remained at the relatively low levels reported previously. Twenty market baskets were collected in 20 cities which ranged in population from less than 50,000 to 1,000,000 or more. Averages and ranges of residues found are reported for August 1974 through July 1975 by food class. The individual items used in making up the dairy and meat composites in four market baskets were analyzed for pesticides and the results are included. Data for lead, cadmium, selenium, mercury, arsenic, and zinc are also included. Results of recovery studies within various classes of residues are also presented.     

Pesticide residues in foodstuffs in Great Britain. XV.—Triphenyltin residues in potatoes

An analytical method and results are given for the determination of triphenyltin residues in potatoes. Of the 44 samples analysed 35 contained residues of 0.001 ppm or less; residues in 6 of the samples were in the range 0.002–0.005 ppm and in 3 samples in the range 0.006–0.008 ppm.     

Pesticide residues in foodstuffs in Great Britain XIV.—Mercury residues in potatoes

The total mercury contents of the skin and flesh fractions of potatoes from 87 commercial crops grown in England were in the range 0.0–0.08 ppm with the majority in the range 0.01–0.04 ppm.     

Pesticide residues in foodstuffs in Great Britain: XIII.—Organochlorine residues in cereals,pulses and nuts

Results are presented for the determination of organochlorine insecticide residues in grain, pulses and nuts sampled on arrival in Britain during the 2½ years up to June 1969. BHC was detected in nearly every sample but the general level was low, most samples containing less than 0·1 ppm. DDT was found less frequently. Very few samples contained more than 1 ppm of either insecticide. DDE in trace amounts was found in about 10% of the samples of grain and nuts and TDE was found in one sample of grain. The only other organochlorine compounds detected were aldrin in one sample of pulses and hexachlorobenzene in 7 samples of wheat.     

Pesticide residues in foodstuffs in Great Britain. Pesticide residues in raspberries and strawberries

Over the period 1968/70 147 samples of raspberries and 124 samples of strawberries were analysed for organochlorine insecticide residues. DDT was found in 30% of the samples but only one sample contained as much as 1.4 parts/million. No residues were detected in the raspberries during the last year of the survey which coincided with the discontinued use of DDT on this crop. 184 of the above samples were also analysed for residues of organophosphorus insecticides and the fungicide dichlofluanid. Malathion was found in one sample of raspberries. Approximately 40% of the strawberries contained detectable amounts of dichlofluanid and its metabolite with combined residues ranging from 0.1 to 7.5 parts/million. Only two samples of raspberries contained residues of either dichlofluanid or its metabolite. It is considered that the residues of these various pesticides should not present a hazard to consumers.     

Pesticide and mercury residues in commercially grown catfish.

In 1970, 54 commercial catfish farms in Arkansas and Mississippi were sampled for pesticide and mercury residues. Pesticide residues above FDA action levels were detected in 15 percent of the fish samples. Data on residues in sediment, fish feed, and source water suggest that fish were not being contaminated from these sources. Average fish residue per county was, however, strongly correlated with the percent of total acres planted in cotton and soybeans. Results strongly suggest that cotton production was the primary source of contamination. Actual routes of movement have not been clearly defined but aerial transport seems most probable.     

Pesticide residues in food--acute dietary exposure

Consumer risk assessment is a crucial step in the regulatory approval of pesticide use on food crops. Recently, an additional hurdle has been added to the formal consumer risk assessment process with the introduction of short-term intake or exposure assessment and a comparable short-term toxicity reference, the acute reference dose. Exposure to residues during one meal or over one day is important for short-term or acute intake. Exposure in the short term can be substantially higher than average because the consumption of a food on a single occasion can be very large compared with typical long-term or mean consumption and the food may have a much larger residue than average. Furthermore, the residue level in a single unit of a fruit or vegetable may be higher by a factor (defined as the variability factor, which we have shown to be typically x3 for the 97.5th percentile unit) than the average residue in the lot. Available marketplace data and supervised residue trial data are examined in an investigation of the variability of residues in units of fruit and vegetables. A method is described for estimating the 97.5th percentile value from sets of unit residue data. Variability appears to be generally independent of the pesticide, the crop, crop unit size and the residue level. The deposition of pesticide on the individual unit during application is probably the most significant factor. The diets used in the calculations ideally come from individual and household surveys with enough consumers of each specific food to determine large portion sizes. The diets should distinguish the different forms of a food consumed, eg canned, frozen or fresh, because the residue levels associated with the different forms may be quite different. Dietary intakes may be calculated by a deterministic method or a probabilistic method. In the deterministic method the intake is estimated with the assumptions of large portion consumption of a 'high residue' food (high residue in the sense that the pesticide was used at the highest recommended label rate, the crop was harvested at the smallest interval after treatment and the residue in the edible portion was the highest found in any of the supervised trials in line with these use conditions). The deterministic calculation also includes a variability factor for those foods consumed as units (eg apples, carrots) to allow for the elevated residue in some single units which may not be seen in composited samples. In the probabilistic method the distribution of dietary consumption and the distribution of possible residues are combined in repeated probabilistic calculations to yield a distribution of possible residue intakes. Additional information such as percentage commodity treated and combination of residues from multiple commodities may be incorporated into probabilistic calculations. The IUPAC Advisory Committee on Crop Protection Chemistry has made 11 recommendations relating to acute dietary exposure.     

Pesticide residues: Food surveys in the United Kingdom

The development of food surveys for levels of pesticide residues, toxic metals and polychlorobiphenyls and related compounds is outlined. The role of the surveys in monitoring the effect on the levels of compounds in specific foods following changes in pesticide usage is explained. Studies over 8 years on levels in the total diet show they are well below the acceptable daily intakes recommended by the Food and Agriculture Organisation/World Health Organisation for organchlorine and other pesticides. During this period the levels found have in general declined.