Arsenic Content of American Cod Liver Oil ARTHURD. HOLMES, The E. L. Patch Co., Boston, Mass., AND ROE REMINGTON, Medical College of the State of South Carolina, Charleston, S. C. U R I K G recent years of the British Isles. Table I1 Twenty samples of crude, medicinal, American much attention has been has been r e c a l c u l a t e d f r o m cod liver oils have been examined for arsenic. given to the role of the analyses of domestic sea food The samples represented typical oils f r o m the i n o r g a n i c constituents of the made in the laboratories of the various American centers producing cod liver oil. dietary. Saturally the elements, U. S.Food and Drug AdminisThe arsenic content was found to vary f r o m 1.4 such as calcium and phosphorus, tration and reported by White which are found in the body (24). The values reported by to 5.1 p . p . m., with an average value of 2.6 * in relatively large amounts were White are lower for most forms 0.13. These values are materially higher than first studied. In the course of than those of Chapman but are f o r common fruits and vegetables, about the same these i n v e s t i g a t i o n s i t was in agreement, in that crustaceans as for American marine fish and shelljish, and learned that other elements such contain more arsenic than other decidedly lower than f o r crustaceans. as iodine, m a n g a n e s e , copper, sea a n i m a l s . A c c o r d i n g to fluorine, etc., which are often Fellenberg ( 7 ) ,dried edible seaData are not available concerning the nutripresent only as mere traces, freweed from Japan contains from tional or therapeutic value of the arsenic conquently have profound influence 20 to 30 p. p. m. of arsenic, and tributed to the dietary by the regular consumption on metabolism and physical wella sample of ground dried kelp of cod liver oil. It is believed lo be present in a being. Arsenic is one of those from the Pacific Coast of the f o r m of low or no toxicity. elements which occur in traces. United States (sold for human Nevertheless F o r d v c e . Rosen. c o n s u m p t i o n ) c o n t a i n e d 66 and Myers, using a"modification of the Marsh method sensi- p. p. m. (23). When compared on the fresh basis, vertebrate tive to 0.001 mg. of arsenic (8) found arsenic to be present in fish from the sea contain on the order of ten times as much normal urine in about 75 per cent of 40 cases, and in normal arsenic as agricultural products of the land, and crustaceans blood in 50 per cent of 130 cases (9). Billeter (6) examined up to one hundred times as much. organs and tissues of seventeen cadavers, ranging from new- TABLE 11. ARSENICCONTENT OF AMERICAN MARINEFOODS (24) born to 70 years of age (without arsenical medication) and VARIETY .hBENIC VARIETY ARSENIC found arsenic always present, increasing in amount with age. P. p . m. P. p . m. Guthmann and Grass (11) found arsenic always present in the Cod 1.5-4.1 Irish moss 1.5- 6 . 4 Eels 1.9 Clams 1.1- 1 . 9 venous blood of women, averaging 0.64 p. p. m. and increasing Haddock (smoked fillet) 4.2 Crab meat 1.5- 8.3 1.5 Lobsters 1.7-13.6 about 50 per cent during menstruation. It seems quite cer- Mackerel (fresh) Prawns 13.5 Oysters 1.1- 1 . 8 tain that, whether or not its presence in traces is of use to the Sardines (canned) 1.1-2.2 Shrimp 1.8- 8 . 3 body, arsenic, like zinc, aluminum, iodine, copper, etc., is I n view of the widespread use of cod liver oil, particularly always present. by babies and young children, and the firm scientific foundaIt has long been believed that small amounts of arsenic are of value in the treatment of leucemias, anemias (especially tion on which this use rests, it seemed of interest to determine pernicious anemia), and syphilis (16, 22) ; consequently, the arsenic content of typical oils produced along the eastern arsenic in various forms has been used in the treatment of shore of Xorth America. Little information exists as to the is used as an alterative and arsenic content of cod liver oil. Sadolin (21) examined two these diseases. The oxide (AsPO3) tonic (19) and Fowlers solution (17) is widely prescribed. In samples of cod, finding, respectively, 0.4 and 0.8 p. p. m. of view of the important place of arsenic in medicine and its arsenic in the flesh, 0.7 and 3.2 p. p. m. in the liver, and 3.0 general occurrence in the normal human body, the prevalence and 4.5 p. p. m. in the liver oil. Fat extracted from muscular tissue of eels and herrings contained most of the arsenic of the of this element in food becomes a matter of interest. Myers (16) examined a large number of samples of vegetable tissue; hence Sadolin concluded that the arsenic of fish is in food purchased in city markets. Table I summarizes his fat-soluble form (20). Fellenberg ( 7 ) , on the other hand, values which are recalculated to the "fresh basis." These found about twenty times as much arsenic in dried codfish results are in general agreement with the earlier work of meal as in cod liver oil. Bertrand (3) and of Jadin and Astruc (12). TESTS ON CODLIVEROIL TABLE I. ARSENIC CONTENT OF VEGETABLE FOOD(15) Since oils are somewhat resistant to oxidation by nitric and sulfuric acids, the combustion of the samples was made in (Parts per million, fresh basis) ARSENIC VARIETY ARSENIC VARIBTY the enclosed torch of von Kolnitz and Remington (14). The Eggplant 0.00-0.16 Broccoli l e a v e 0.02-0.50 oil ( 5 cc.) was pipetted on to a 6-inch (15.2-cm.) No. 3 abLettuce 0 00-0.13 Broccoli 0.00-0.11 Lima beans (green) 0.00-0.95 Beet greene 0.00-trace sorbent cotton roll, and the roll was burned as described in the Spinach O.O&O. 03 Cabbage 0.00-0.14 String beans (green) 0.00-0.04 Carrots 0.00-0.13 article cited. The liquid from the absorption bottles and rinsFruits 0.00-0.17 Celery 0.00-0 20 ings of the apparatus were combined, acidified with nitric and sulfuric acids, and evaporated to fumes of sulfur trioxide in a ARSENICIN MARINEPRODUCTS covered beaker. If darkening occurred, additions of 1 cc. Since marine plants and animals are known to be much each of nitric acid were made until clear. Arsenic was then richer in zinc, iodine, copper, and other elements than those determined by the official Gutzeit method of the Association of the ' w d , it is not surprising that sea food contains also of Official Agricultural Chemists ( I ) . Recovery of known much more arsenic. Chapman (6) found startlingly high amounts of arsenic by this method was satisfactory. Blank values for shellfish and crustaceans from the coastal waters tests on cotton and reagents showed no measurable stain. 573
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The oils which were studied were produced by the “direct steam method” of cooking strictly fresh cod livers. After the oils were released from the liver tissues, they were filtered through filter cloth and filter paper to remove all liver residue. Oils prepared in this manner from fresh livers are classed as crude medicinal cod liver oils; i. e., they differ from medicinal oils only in that they have not been destearinized. Samples were so selected as to represent the principal cod liver oil manufacturing localities, including both off-shore and deepsea fish. Table I11 reports the geographical location of the manufacture of the oils, their iodine numbers, free fatty acid, and arsenic content. The iodine numbers (except for sample 1466) and free fatty acid content were within the U.S.P. specifications for medicinal cod liver oil. Arsenic content varied from 1.4 p. p. m. for sample 1388 manufactured a t Gloucester, Mass., and sample 1466 manufactured at Swans Island, Maine, to 5.1 p. p. m. for sample 1278 manufactured aboard a steam trawler from deep-sea fish.
Rakestraw and Lutz (18) reports that, after a careful study of the arsenic content of sea water from Buzzards Bay, they are unable to substantiate Gautier’s theory that the concentration of arsenic in sea water increases with depth, but they corroborate the view of Atkins and Wilson that the greater portion of arsenic in sea water is present in the form of arsenite. To what extent the numerous variables may influence the arsenic content of cod liver oils obtained from codfish caught in different localities, a t different seasons, and a t different depths of water is not yet known. The arsenic content of the twenty samples of cod liver oils (average 2.6 * 0.13 p. p. m,) shows that they contained much more arsenic than fruits and vegetables, about the same amount of marine vertebrate fish of American waters, but much less than crustaceans. N o information is a t present available as to the relative toxicity of arsenic as it occurs in cod liver oil or in fish, as compared with inorganic forms. Also data are lacking concerning its dietary or therapeutic value. It is well knawn that certain synthetic organic comTABLE111. IODINE NUMBER,FREEFATTY ACID,AND ARSENIC pounds of arsenic are relatively nontoxic to higher animals. CONTENT OF AMERICAN COD LIVEROILS The fact that maritime peoples regularly consume quantities FREE of sea food’ and cod liver oil suggests that the arsenic is in an GEOQRAPAICAL LOChTIOX IODINE FATTY organic form, probably nontoxic or a t least only slightly SAMPLE OF MANUFACTURE No. ACID ARSENIC Au. toxic. Kloster ( I S ) found that fisher folk of northern Norway P.p . m. P.p . m % mere apparently unharmed by an average daily consumption 1405 Mass. Provincetown 152.7 0.505 1.7 1388 Gloucester 147.7 0.927 1.4 of one ounce of cod liver oil per person. 1447 Gloucester 150.2 0.804 1.5 1.5 1387 1279 1280 1278 1466 1398 1391 1199 1365 1362 1360 1361 1363 1318 1368 1371 1367 a
Deep seaa
Steam trawler
Maine
Swan8 Island Lockport Lock ort N o d Sidnev Gasp&,Quebec Paspebiac Percb Fox River Chlor dornes Granrfvalley Newfoundland St. Johns Nova Scotia
Fogo
172.4 167.2 175.3 142.2 135.8 161.6 164.0 148.9 145.8 143.9 143.9 143.1 143.0 158.2 152.6 154.1
0.700 1.290 1.200 1.160 0.144 0.426 0.339 0.840 0.264 0.598 0.331 0.296 0.364 0.578 0.359 0.339
2.4 2.5 3.0 5.1 1.4 2.3 3.4 3.8 2.1 3.3 2.7 2.0 2.1 2.7 2.9 3.3
ACKNOWLEDGMENT
3.3 1.4
Tests reported here were carried out with the technical assistance of Harry von Kolnitz. LITER.4TURE C I T E D
3.2
2.4
Change Island Little Fogo Island 154.1 0.357 2.1 2.8 Exact location unknown, general area of George’s and Brown’s Banks.
In general, the arsenic content of cod liver oil manufactured in Massachusetts and Maine appears to be lower than that of oils manufactured from deep-sea fish or a t Nova Scotia, the Gasp6 Peninsula, and Newfoundland. However, one must be exceedingly cautious in making comparisons of the arsenic content of oils manufactured a t different points along the North American shores, since a careful study (4) of the habits and habitat of the cod indicates that the codfish frequently “carries out extensive migrations.” Furthermore, the diet (4) of the cod is extremely variable and includes squid, small herring, launce, shad, mackerel, menhaden, silversides, alewives, young silver hake, haddock, cod, flounders, cunners, sea muscles, crabs, hermit crabs, lobsters, sea urchins, and shrimps. Obviously the diet of codfish caught in any given locality is infiuenced by the abundance of the different fish or crustaceans on which it feeds. Judging by the arsenic content of marine forms as reported in Table 11,it would be assumed that, when codfish were feeding largely on crustaceans, their arsenic intake would be significantly greater than when they were depending largely upon small fish of the various species for food. Gautier (10) has reported that the arsenic content of sea water increases with the depth a t which the sample is taken, and Atkins and Wilson (8)are of the opinion that most of the arsenic in sea water is presumably present as arsenite. A recent paper by
Assoc. Official Agr. Chem., Methods of Analysia, p. 306 (1930). Atkins, W. R. G., and Wilson, E. G., Biochem. J., 20, 1223 (1926); J. Marine Biol. Assoc. United Kingdom, 14, 609 (1927).
Bertrand, G., Bull. soc. hug. aliment,8,49 (1920). Bigelow, H. B., and Welsh, W. W., U. S. Bur. Fisheries, BuU. 40, Pt. 1, 414-20 (1924). Billeter, O.,and Marfurt, E., Helw. Chim. Acta,6,780 (1923). Chapman, A. C., Analyst, 51, 548 (1926). Fellenberg, Th. v., Biochem. Z., 218, 315 (1930). Fordyce, J. A,, Rosen, I., and Myers, C. N., Am. J. Med. Sci., 164. 492 (1922).
Fordyce, J.‘A . , Rosen, I., and Myers, C. N., Arch. Internal Med., 31, 739 (1923). , Gautier, A., Compt. rend., 137, 232, 374 (1903). , ,Guthmann, H., and Grass, H., Arch. Guniikol., 152. 127 (1932). Jadin, F., and Astruc, A., Compt. rend., 154, 893 (1912j, 159, 268 (1914).
Kloster. J.. Nord. .Wed. Tids.. 4. S o . 40. 745 (1932). Kolnitz; H. von, and Rerningion, R. ‘E., IND. EXG.CHEM.. Anal. Ed., 5, 38 (1933). Myers, C. N., Thorne, B., Gustafson, F., and Kingsbury, J.,
IND. EXG.CHEM.,25,
624 (1933).
National Dispensatory, Lea Brothers & Co., Philadelphia, pp .. 28-30 (1894).
Pharmacopeia of the U. S., 10th Dec. Rev., p. 222, Lippincott, Philadelphia, 1926. Rakestraw, N. W., and Luta, F. B., Biol. Bull., 65, 397 (1933). Remington, “Practice of Pharmacy,” 7th ed., p. 765, Lippincott, Philadelphia, 1926. Sadolin, E., Biochem.Z.,201, 323 (1928). Sadolin, E., Dansk. Tids. Farm., 2, 186 (1928). Sollman, T., “Manual of Pharmacology,” 3rd ed., pp. 956-7, W. B. Saunders Co., Philadelphia, 1928. South Carolina Food Research Laboratory, unpublished data. White, W. B., IND.E m . CHEM.,25, 621 (1933). RECBIVED November 29, 1933. 1 Shrimp and prawns containing sometimes aa high as 30 p. p. m. of arsenic are on sale during most months of the year in Charleston and are eaten regularly and abundantly by a considerable portion of the population.
