FAO Meeting Report No. PL/1965/10/1 WHO/Food Add./27.65 EVALUATION OF THE TOXICITY OF PESTICIDE RESIDUES IN FOOD The content of this document is the result of the deliberations of the Joint Meeting of the FAO Committee on Pesticides in Agriculture and the WHO Expert Committee on Pesticide Residues, which met in Rome, 15-22 March 19651 Food and Agriculture Organization of the United Nations World Health Organization 1965 1 Report of the second joint meeting of the FAO Committee on Pesticides in Agriculture and the WHO Expert Committee on Pesticide Residues, FAO Meeting Report No. PL/1965/10; WHO/Food Add./26.65 ALDRIN Chemical name 1,2,3,4,10,10-hexachloro-1,4,4a,5,8,8a-hexahydro-endo-1,4-exo- 5,8-dimethanonaphthalene; 1,2,3,4,10,10-hexachloro-1-4-4a,5,8,8a-hexahydro-exo-1,4,endo-5,8- dimethanonaphthalene. Synonyms HHDN, Octalene Empirical formula C12H8Cl6 Structural formulaBIOLOGICAL DATA Biochemical aspects Following the feeding of aldrin to animals it is stored in the tissues, especially in the fat (Bann et al., 1956; Ivey et al., 1961; Lehman, 1956; Street et al., 1957; Treon & Cleveland, 1955). At low levels of intake (1 ppm) the storage ratio is large (about 60 times) (Lehman, 1956), but this storage ratio decreases rapidly to less than one with an intake of 50 ppm. Aldrin is largely and readily converted in the animal body, especially in the liver, to dieldrin (Bann et al., 1956; Ivey et al., 1961; Treon & Cleveland, 1955). The rate of change has not been fully established, and is independent of the site of entrance into the body. The dieldrin is stored without further change and may be recovered as such from animal products and tissues, including the eggs of fowls and the milk of dairy cows within 24 hours after ingestion (Bann et al., 1956). Fifteen minutes after an intravenous injection of 14C aldrin, aldrin and its metabolites were found in the bile (Morsdorf et al., 1963). Acute toxicity Animal Route LD50 mg/kg Reference body-weight Mouse Oral 44 Borgmann et al., 1952 Council of Europe, 1962 Rat, male Oral 38-54 Borgmann et al., 1952 Council of Europe, 1962 Gaines, 1960 Lehman, 1951 Treon & Cleveland, 1955 Rat, female Oral 46-67 Borgmann et al., 1952 Council of Europe, 1962 Gaines, 1960 Lehman, 1951 Treon & Cleveland, 1955 Rat, female Intravenous 18 Council of Europe, 1962 Guinea-pig Oral 33 Borgmann et al., 1952 Council of Europe, 1962 Rabbit Oral 50-80 Borgmann et al., 1952 Council of Europe, 1962 Treon & Cleveland, 1955 Dog Oral 65-95 Borgmann et al., 1952 Council of Europe, 1962 Man. A 23-year-old man intentionally drank a quantity of aldrin equivalent to 25.6 mg per kg of body-weight. The following symptoms were noticed: generalized convulsions, E.E.G. changes, haematuria and albuminuria. Recovery was complete (Spiotta, 1951). Short-term studies Rat. Groups of 12 rats (6 male and 6 female) were fed diets containing 0.5, 2.5, 75 and 150 ppm aldrin for 90 days. The liver weight was increased at the two higher dosages. The mortality rate was increased at the 150 ppm level. In a feeding study lasting from 6 to 7 months, dosage levels of 5, 10 and 25 ppm aldrin were used with groups of 5 females. No enlargement of the liver or other gross change was noted. Histological data are not described. In a 9-month feeding experiment, with 20 female rats per group, the dosage levels were 5, 15, 25 and 45 ppm of aldrin. There was an increase in the liver body-weight ratio at 45 ppm (Borgmann et al., 1952). Groups of 25 female rats were fed diets 5, 10 and 20 ppm of recrystallized aldrin for 64 weeks. The group on 20 ppm showed an increase in weight over the controls which was correlated with an increased food intake. At the 10 ppm and 20 ppm levels the oestrus cycle was disturbed (Ball et al., 1953). Groups of 5 animals of each were given 2.5, 5, 25, 75 or 300 ppm of either purified or technical aldrin in the diet for 26 weeks. Two rats of each group were killed before the end of the treatment, and the last three were killed before the thirty-seventh week. All the animals receiving 300 ppm died in 2 weeks. At 75 ppm the survival rate was good. Liver/body-weight ratio was increased in males at 25 ppm and in both sexes at 75 and 300 ppm. Swelling of centrolobular liver cells with peripheral distribution of the cytoplasmic granules were often seen. At 2.5 and 5 ppm these changes were seen with the same frequency as in the controls. They were markedly obvious at 25 ppm and over, but regressed after the end of the treatment (Treon et al., 1951). Quail and pheasants. These animals died following concentrations of 5 ppm of aldrin in the diet (Dewitt, 1955). Dog. When dogs were fed, for 5 or 6 days per week, diets containing 10 to 30 ppm of aldrin, death occurred after periods of feeding ranging from a few days to about 7 months. Three groups of suckling puppies (11 days old), 3 each group comprising 2 males and 1 female were given 1.5, 3.0 and 4.5 mg/kg per day respectively, on 5 days per week. All the animals died within 38 days. A 2-month-old male and a female survived about 6 to 7 months when given 0.9 to 1.8 mg/kg body-weight per day for 6 days per week (Treon & Cleveland, 1955). When 3 groups of 3 dogs (both sexes) were given orally 0.2, 0.6 and 2.0 mg of recrystallized aldrin per kg of body-weight daily for one year, 5 of them produced litters but the pups died early, probably because of high quantities of aldrin or dieldrin in the milk of the dams. Histological liver changes were found in the dogs (Kitselman, 1953). Groups of 4 dogs (2 male and 2 female) were given 1 and 3 ppm of aldrin in their diet for 68 weeks. Liver damage occurred in 3 animals on the 3 ppm dosage level. There were significant increases in liver/body-weight ratios in the dogs on 3 ppm of aldrin. Kidney damage occurred in the female at the 1 ppm dosage level. An average concentration of aldrin of 0.3 ppm remained in the adipose tissue in the animals fed 3 ppm and 0.18 ppm remained at 1 ppm. Dieldrin occurred at a concentration of 25.4 ppm in the fat of a dog fed 1 ppm of aldrin (Treon & Cleveland, 1955; Treon et al., 1955). A group of 12 dogs was given aldrin orally for 2 years at the following daily doses - 0.2 mg/kg (2 dogs), 0.5 mg/kg (4 dogs), 1, 2 and 5 mg/kg (2 dogs each). The animals at 5 mg/kg and one of those given 2 mg/kg died within 24 days. The other animal at 2 mg/kg and the 2 given 1 mg/kg died in 1 year. All the others survived until the end of the experiment but for a dog at 0.5 mg/kg which died in a few days. Fatty changes in the liver and kidney, associated with "mild bone marrow changes" were observed at the highest doses. At 0.5 mg/kg one animal showed convulsions. No effects were seen at 0.2 mg/kg (Fitzhugh et al., 1964). Sheep and cattle. Heifers given 0.5-1 mg/kg/day for 64 days and cattle given 1.9 mg/kg/day for 10 days were not affected, whereas sheep given 6 mg/kg/day died within 28 days (Kitselman et al., 1950). Long-term studies Mouse. Groups of approximately 200 young C3HeB/Fe mice, equally divided by sex, were fed a diet containing 10 ppm of aldrin for their life-span (maximum 2 years). The aldrin shortened their average life-span by 2 months, as compared with an equal number of controls, and significantly increased the incidence of hepatic tumours (Davis & Fitzhugh, 1962). Rat. In a 2-year feeding experiment, groups of 20 rats (10 male and 10 female) were given 5, 10, 50, 100 and 150 ppm of aldrin. The concentrations of 100 and 150 ppm increased the mortality rate and those of 50, 100 and 150 ppm produced microscopic changes in the liver. A single rat on 10 ppm of aldrin had specific liver changes; the rats on 5 ppm of aldrin had no noticeable liver changes. Aldrin was stored in the tissues at all dosage levels (Borgmann et al., 1952). In a second 2-year feeding experiment a group of 80 rats (40 male and 40 female) was given 2.5, 12.5 and 25 ppm of recrystallized aldrin. There was a questionable increase in mortality rate at the 25 ppm level in females. Significant increase in the liver/body-weight ratio occurred in males at all levels and at 12.5 and 25 ppm in females. Histological liver changes characteristic of organic chlorine compounds occurred at all dosage levels of aldrin (Treon & Cleveland, 1955). In a third 2-year feeding experiment, groups of 24 rats (12 male and 12 female) were given 0.5, 2, 10, 50, 100 and 150 ppm of aldrin. Concentrations of 50 ppm and above in the diet increased the mortality rate in a dose-response relationship. Liver/body-weight ratio increased at all levels of feeding. Characteristic microscopic lesions occurred in the liver at all levels; these were minimal at 0.5 ppm but increased in severity with dosage. There was an increase in tumour incidence among treated animals at all feeding levels and particularly at lower levels, but no single type of tumour predominated (Fitzhugh & Nelson, 1963). Aldrin was fed to groups of 16 female rats at 2.5, 12.5 and 25 ppm for three generations: at 12.5 and 25 ppm the number of pregnancies was reduced. The incorporation of aldrin into the diets of lactating females has a "slight to moderate" effect on mortality among the offspring at 2.5 ppm. It was severe at higher doses (Treon & Cleveland, 1955). Comments on the experimental studies reported The primary mode of action of aldrin is on the central nervous system. This is the mechanism of death in acute poisoning. Symptoms of central nervous system stimulation are also seen after repeated high doses. Repeated doses at lower levels give rise to liver damage and, in this respect, young dogs are more susceptible than rats. In one long-term feeding experiment in rats there was a general increase in tumour production in the experimental animals at the lower dosage levels as compared to the controls, but the liver was not particularly affected. Liver tumours were, however, significantly increased on a dosage of 10 ppm in one strain of mice susceptible to the development of these tumours. In rats, it has been suggested (Fitzhugh et al., 1964) that the apparent tumorigenic properties of aldrin could be related to a general type of effect. EVALUATION Level causing no significant toxicological effect In the rat and the dog a no-effect level has not been demonstrated. Acceptable daily intake for man From the data presented, an acceptable daily intake for man cannot be estimated. Until further evidence is forthcoming, every effort should be made to see that the intake of aldrin for man is kept at the lowest possible level. Further work required Additional long-term toxicity studies in other species than the rat, including further reproduction studies. Determination of a no-effect level in more than one species. REFERENCES Ball, W. L., Kay, K. & Sinclair, J. W. (1953) Arch. industr. Hyg., 7, 292 Bann, J. M. et al. (1956) J. Agr. Food Chem., 4, 937 Borgmann, A. R. et al. (1952) Kettering Lab., University of Cincinnati Report, March. Council of Europe (1962) Agricultural pesticides, Strasbourg Davis, K. J. & Fitzhugh, O. G. (1962) Toxicol. Appl. Pharmacol. 4, 187 Dewitt, J. B. (1955) J. Agr. Food Chem., 3, 672 Fitzhugh, O. G. & Nelson, A. A. (1963) Unpublished data from the United States Food and Drug Administration Fitzhugh, O. G., Nelson, A. A. & Quaife, M. L. (1964) Food Cosmet. Toxic., 2, 551 Gaines, Th. B. (1960) Toxicol. Appl. Pharmacol., 2, 88 Ivey, M. C. et al. (1961) J. Agr. Food Chem., 9, 374 Kitselman, C. H. (1953) J. Amer. vet. med. Ass., 123, 28 Kitselman, C. H., Dahm, P. A. & Borgmann, A. R. (1950) Amer. J. vet. Res., 11, 378 Lehman, A. J. (1951) Quart. Bull. Assoc. Food and Drug Officials U.S., 15, 122 Lehman, A. J. (1956) Quart. Bull. Assoc. Food and Drug Officials U.S., 20, 95 Morsdorf, K. et al. (1963) Med. Exp., 8, 90 Spiotta, E. J. (1951) Arch. industr. Hyg., 4, 560 Street, J. C. et al. (1957) Proc. West. Sec. Amer. Soc. Anim. Prod.,44 (1) Treon, J. F. & Cleveland, F. P. (1955) J. Agr. Food Chem., 3, 402 Treon, J. F. et al. (1951) Unpublished report from Kettering Lab., University of Cincinnati Treon, J. F. et al. (1955) Kettering Lab., University of Cincinnati Report, February
See Also: Toxicological Abbreviations Aldrin (ICSC) Aldrin (PIM 573) Aldrin (FAO/PL:CP/15) Aldrin (FAO/PL:1967/M/11/1) Aldrin (IARC Summary & Evaluation, Supplement7, 1987) Aldrin (IARC Summary & Evaluation, Volume 5, 1974)