title: Pesticide residues in food--acute dietary exposure.
abstract: 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.
authors.affiliation: Animal and Plant Health Service, Department of Primary Industries, Brisbane, Qld, Australia. denis.hamilton@dpi.qld.gov.au
authors.forename: Denis
authors.initials: D
authors.lastname: Hamilton
authors.forename: Arpád
authors.initials: A
authors.lastname: Ambrus
authors.forename: Roland
authors.initials: R
authors.lastname: Dieterle
authors.forename: Allan
authors.initials: A
authors.lastname: Felsot
authors.forename: Caroline
authors.initials: C
authors.lastname: Harris
authors.forename: Barbara
authors.initials: B
authors.lastname: Petersen
authors.forename: Ken
authors.initials: K
authors.lastname: Racke
authors.forename: Sue-Sun
authors.initials: SS
authors.lastname: Wong
authors.forename: Roberto
authors.initials: R
authors.lastname: Gonzalez
authors.forename: Keiji
authors.initials: K
authors.lastname: Tanaka
authors.forename: Mike
authors.initials: M
authors.lastname: Earl
authors.forename: Graham
authors.initials: G
authors.lastname: Roberts
authors.forename: Raj
authors.initials: R
authors.lastname: Bhula
mesh_terms: D000818:Animals; D005506:Food Contamination / Q000032:analysis*; D006801:Humans; D008954:Models, Biological; D010573:Pesticide Residues / Q000032:analysis*; D018570:Risk Assessment / Q000706:statistics & numerical data
chemical_list: D010573:Pesticide Residues