Document x55Np2dNJkn5gNojeZBORmRjG

A. M. A. ARCHIVES O F Industrial Hygiene and Occupational Medicine EDITORIAL BOARD PHILIP DRINKER, Chief Editor '55 Shaituch Street, Boston 15 THEODORE F. HATCH, Pittsburgh FENN E. POOLE, Glendale, Calif. ROBERT A. KEHOE, Cincinnati FRANK A. PATTY, Detroit FRANK PRINCE Denver WILLIAM A. SAWYER, Rochester, N. Y. JAMES H. STERNER, Rochester, N. Y. RICHARD J. PLUNKETT, M.D., Chicago, Managing Edlior Volume 3 1951 PUBLISHERS AhlERICAN MEDICAL ASSOCIATION CHICAGO iO, ILL. LIBRARY UNIVERSITY OF CALIFORNIA DAVIS PLTEXP009305 WATER PCB-SD0000054580 OCCURRENCE OF DDT IN HUMAN FAT AND MILK EDWIN P. LAUG, Ph.D. FRIEDA M. KUNZE, B.S. AND C. S. PRICKETT, M.S. WASHINGTON, D. C, TJEFORE it is possible to evaluate any chronic occupational DDT exposure it is necessary to determine a base line, i. e., what exposure, if any, is suffered by the general population. DDT has had widespread use. Investigations conducted by the Food and Drug Administration indicate that this has resulted in traces of DDT appearing in some truck crops, dairy and meat products, and more recently, even in flour. To evaluate DDT exposure by repeated analyses of individual dietaries of a large number of persons would be technically very difficult. However, experiments conducted in our laboratories *1 have shown that the storage of DDT in adipose tissue is an extremely sensitive ``biological magnifier" of trace amounts of ingested DDT. For example, we have shown that 0.1 p.p.m. DDT in the diet of the rat leads to the storage of about 10 to 15 p.p.m. DDT in the fat. On the assumption that human fat would respond by storage of DDT consumed in traces, an attempt has been made to use this sensitive indicator as a gage of DDT exposure in the general population. Seventy-five samples of human fat were analyzed for DDT. The specimens were furnished through the cooperation of Dr. Francis Pottenger of Monrovia, Calif. The samples were all abdominal fat obtained at autopsy, biopsy or abdominal surgery. Since it appeared likely that traces of ingested DDT might be excreted in human milk, 32 samples from 32 different Negro women outpatients of a District of Columbia Hospital were analyzed for DDT. The specimens were furnished through the cooperation of Dr. E. A. Clark. It must be emphasized that none of the subjects were occupationally employed as pesticide operators. Protocols of all cases examined were kept. These indicated that the greatest pos sible amount of DDT to which they were exposed must have come from the diet, although in a few instances the inhalation of DDT.-containing sprays and dusts incidental to their use in and about the home could not be excluded. DDT analyses were made by a modified Schechter procedure,2 sufficiently sensitive to detect and quantitate 5 Ag. of DDT in 100 ml. milk or-1 Ag. DDT in 1 Gm. of fat. The modified Schechter procedure was found to give the same results as the standard Schechter procedure, using the method of Clifford,3 in which the isolation of the ortho and para isomers of DDT is used to establish the identity of DDT. For additional discussion of this method, reference should be made to the paper by Laug and associates.1 Special care was taken to separate the DDT from the fat before attempting its colorimetric determination. From Division of Pharmacology, Food & Drug Administration, Federal Security Agency. 1. Laug, E. P.; Nelson, A. A.; Fitzhugh, 0. G., and Kunze, F. M.: Liver Cell Alteration and DDT Storage in the Fat of the Rat Induced by Dietary Levels of 1 to 50 P.P.M. DDT, J. Pharmacol. & Exper. Therap. 98:268, 1950. 2. Prickett, C. S.; Kunze, F. M., and Laug, E. P.: Modification of the Schechter Method for the Determination of Methoxychlor or DDT in Biological Materials, J. A. O. A. C. 33:880, 1950. 3. Clifford, P. A.: Determination of DDT, Particularly in Milk and Fats, by the Schechter Procedure, J. A. O. A. C. 30:337, 1947. 245 PLTEXP009306 WATER PCB-SD0000054581 246 INDUSTRIAL HYGIENE AND OCCUPATIONAL MEDICINE RESULTS The results of analyses of 75 samples of human fat are given in table 1. This shows the number of cases in which DDT was found in each of six ranges of concentration. Approximately one fourth of the specimens examined contained no DDT, or only traces (0.1 to 1.0 p.p.m.). The two values in the high concentra tion range were respectively 26 and 34 p.p.m., the latter from an infant. The average for all samples was 5.3 p.p.m. An explanation for the skew distribution pattern of the samples at the low DDT concentration range was sought in the possible effect of sex on the fat storage of DDT.' Males and females, however, were equally represented, and statistical analyses showed no significant difference between the sexes (p = 0.05). Table 1 .--Range of Concentration of DDT in Seventy-Five Samples of Hitman Fat Range, p.p.m. DDT Gases 0.0 ............................................................... .......................................... 15 1.1. 5.0 ..................................... .......... 5.1*10.0 ......................................................... Average concentration = 6.3 p.p.m. * Actual values were 26 and 84 p.p.m. Table 2.--Range of Concentration of DDT in Thirty-Two Samples of Human Milk Range, p.p.m. DDT' 0.00 ............................................................... 0.01-0.05 .............................................. ....... 0.11-0.16 ......................................................... Average concentration = 0.13 p.p.m. * Actual values were 0.25, 0.28, 0.42 BDd 0.77 p.p.m. Gases o .. o. ' Table 2 shows the range of concentration of DDT found in 32 samples of human milk. These results give a normal distribution pattern, with a frequency maximum coincident with the average concentration of 0.13 p.p.m. for all 32 subjects. This concentration of DDT is of the same order as that found within the past year in a number of market milks analyzed by the Food and Drug Administration. The four samples of human milk in the high concentration range showed 0.25, 0.28, 0.42 and 0.77 p.p.m. Tn none of these cases could the high values be correlated with any extraordinary known exposure to DDT. In summary, this preliminary survey shows that DDT occurs in human fat and milk, presumably as the result of the widespread use of DDT with consequent con tamination of a number of important foodstuffs. On the basis that man stores DDT in his fat at the same rate as the rat it may be assumed that traces of DDT in the average human dietary are of the order of 0.05 p.p.m. As yet clinical data are not available to assess whatever danger may be associated with the DDT stored in the fat or excreted in human milk in the quantities reported. PLTEXP009307 WATER PCB-SD0000054582