Document 3QNqadvj58L4GkVxo6Ea109G0

FILE NAME Kent KNT DATE 1950 May 4 DOC KNT115 DOCUMENT DESCRIPTION Book Excerpt - The Arsenic Content of Tobacco and of Tobacco Smoke 173 -182 THE ARSENIC CONTENT OF TOBACCO AND OF TOBACCO SMOKE M. E. DAFF AND E. L. KENNAWAY From the Pathological Department St. Bartholomew's Hospital London E.C.1 Received for publication May 4 1950 PREVIOUS INVESTIGATIONS Two recent investigations both from the United States upon the arsenic content of tobacco and the volatilization of this arsonic when tobacco is smoked have been reported The work of these authors differs from our own in that they used artificial methods of combusting the tobacco which may or may not repro- . duce the conditions present when smoking is carried out in the ordinary way and they found no brands of tobacco containing only minimal quantities of arsenic The Arsenic Content of Tobacco 1 Gross and Nelson 1934 employed a method which consisted of digestion in nitric and sulphuric acids precipitation of magnesium ammonium arsenate solution in hydrochloric acid and estimation by the Gutzeit method " The analyses were made on analytical units composed of either 1 cigar 5 cigarettes or g smoking tobacco Five such analytical groups were analysed for each brand studied They found the content of pooled groups of 4 cigarettes of 5 brands to range from 7 to 36.3 p.p.m. Table I while individual cigars showed a wider range 8-3 to 48-4 and pipe tobacco a smaller one 26.0 to 50-0 2 Thomas and Collier 1945 using a modified Wichmann method found that individual cigarettes and cigars of a given brand varied widely in arsenic content which ranged in pools of 2 to 4 cigarettes from 2 packs of 20 presumably of the same brand from 35.4 to 114 p.p.m. while cigars 13-2 to 29.5 and pipe tobaccos 22-7 to 42.8 showed a lower range Table I Thus the cigarettes used in these two investigations showed nearly a 12fold range 9-7 to 114 p.p.m. in mean values Gross and Nelson 1934 attribute the rather narrower range found in cigarettes and in pipe tobacco compared with cigars to the mixing which the former receive but this difference is not seen in the results for cigarettes and cigars of Thomas and Collier 1945 The Arsenic Content of Tobacco Smoke Apparently the first estimates of the arsenic volatilized from tobacco were made by Remington 1927 who found 6 to 30 p.p.m. in American pipe and chewing tobaccos ; using suction by a pump he concluded that we can say roughly that half of the arsenic is evolved in the smoke . . " Gross and Nelson 1934 used an apparatus drawing about 50 ml of air through a cigarette cigar or pipe at the discharge of a syphon which took place 174 M. E. DAFF AND E. L. KENNAWAY TABLE Arsenic Content of Tobacco Gross and Nelson 1934 Collier 1945. Thomas and Gross and Nelson : Cigarettes Cigars Pipe tobacco Brand 12345 12345 As p0arts per million Means of brands Range in 5 pooled batches of 4 cigarettes each : 20t- o 27 5.6 21.1 " 26.7 . 22.9 : 24.1 25.3 " 36.3 : 33.2 9.7 13.0 . 11.6 . 22.9 " 26.1 : 24.7 Range in 5 single cigars from each of 5 brands : 8.3 to 48.4 11.6 to 26-6 Range in 5 samples from each of 4 brands 26.0 to 50.0 31 45 Thomas and Collier Cigarettes " A single pack of 20 . Groups of 2 to 4. 35.4 40 40-5 47-2 60-0 61 66 Another pack . Cigars about 1-4 . 61 67 71 84 114.0 13.2 22.5 26.2 29.5 10 cut off at onds Pipe tobacco 1-5 . 39-6; 26-5; 22.7 34-5 42.8 * These figures represent the actual analyses in p.p.m. on pooled groups of 2 to 4 cigarettes and hence are not calculated means though each figure represents the mean composition of the cigarettes in one pool three times a minute Cigars and 1/2 in to 3/4 in . . . " the smoke was absorbed and estimated " cigarettes were smoked down to about " " arsenic in the puffed and unpuffed separately The mean distribution of the arsenic recovered in the smoke ash and butts is shown in Table II Pipe tobacco was combusted until no residue but ash was left while about 22 per cent of the cigars and cigarettes remained in the butts The fraction in the puffed as against the unpuffed smoke is high in the case of pipe tobacco which difference is attri buted to " the dying down of the ember between puffs Table Arsenic Content of Tobacco Smoke Gross and Nelson 1934 Thomas and Collier 1945. Mean distribution of arsenie recovered Arsonic volatilized A Gross and Nelson ; Cigarettes brands Cigars 5 brands . Pipe tobacco 4 brunds Unpuffed Puffed smoke smoke I. 2 % 70 . 12.3 . 5.6 11.0 11.0 5.5 5.5 . 4.6 25.9 25.9 Total smoke 3 % 23.3 11 30.5 Ash 4 % Butts 5 % 28.1 28.3 .. Range Moan Thomas and Collier : Cigarettes 6 brands : 1st sories - 2nd 3rd Cigars 4 brands 1st series 2nd . 3rd " Pipe tobacco 4 brands ARSENIC CONTENT OF TOBACCO 175 Gross and Nelson 1934 devote a good deal of attention to the arrest of volatilized arsenic in the butts indicated by the amounts assumed to be present in the corresponding portion of the original cigar or cigarette By such calculations they arrive at the figures given in the 6th and 7th columns of Table II which are of course higher than those in Column 3. The pipe smoker who smokes all the tobacco does not therefore have the protection afforded by the butts of cigars and cigarettes From the present point of view this question is not of great interest ; the important datum is the amount of arsenic inhaled and in this country only about one smoker in ten smokes a pipe Hansard 1945 Thomas and Collier 1945 used an apparatus similar to that of Gross and Nelson 1934 which pumped 10 to 50 ml air during 1-2 seconds at second intervals In their first series Table II cigarettes of 7 cm length were smoked down to 1 cm in a later series only 2/3 was burned At first < . . the arsenic found was compared with analyses of whole cigarettes from the same pack but in view of the large differences they later cut off about 0.8 cm for analysis ; apparently they failed to discover that this method also can be fallacions The first and second series show very little difference in the percentages although in the first 10-20 ml and in the second 50 ml was drawn through at each puff The results are in general agreement with those of Gross and Nelson 1934 whose cigarettes contained considerably less arsenic Table I METHODS Gulzeit Method Our earlier results Table IV were obtained by the Gutzeit method which depends upon the brown and yellow colours produced in paper impregnated with HgCl ; it is fitted for the measurement of amounts of As bOetween 10 and 1 g and shows differences most clearly in the range of 8 to 3 g There may be considerable differences in the matches made by different persons ; in these experiments the mean was taken of the readings made independently by two persons unaware of the nature of the unknowns The iodometric method of Thomas and Collier 1945 was adopted later Tables III V and VI in view of the difficulty of determining the small amounts of arsenic lost in smoking The method has the advantage that whatever may be its errors in other respects there is less disagreement over the very sharp point titration of iodine and starch about which two observers usually do not differ by more than 0.05 c.c. 0-5 g while in the Gutzeit method greater differences are common . Before we had observed the differences in arsenic content which may be found within a single cigarette three successive pieces were cut from a cigarette of Brand -- weighing 0.1499 g B 1527 g and C 0.1429 g To the middle piece B was added I ml of the standard solution = 10 ug As O Gutzeit estimations upon the whole of A and C and upon 1/2 of B gave about 7 gin each one hence if this cigarette happened to be of fairly uniform composition about 14 ug or 82 per cent out of 17 ...gwas recovered Another test of the Gutzeit method is described under " Other Brands " below Method of Thomas and Collier 1945 The estimations upon Brands P and C were usually carried out upon amounts of 20 to 30 gas a method which is sufficiently accurate within this range 176 M. E. DAFF AND E. L. KENNAWAY allows of duplicate estimations upon single cigarettes containing 40 to 60 g The method and apparatus of Thomas and Collier 1945 were tested using the standard solution of As O10 gin 1 ml either alone or added to an aliquot 38 part ofa solution containing a combusted cigarette or ash and stump Table III TABLE Percentage Recovery of Arsenic by Method of Thomas and Collier 1945 Arsenic pg ; 100 50 30 20 10 : Standard solution alone : Number of estimations . Range . . . Mean , . . . . 11 . 90-2-99.0 . 94.6 2 | 4 : 6 . 4 .85.0 94.0 4 92.-4 90-0 107-5. 98-0 105 . 89-5 89-5 90.3 . 97.5 : 100-25 Standard solution -+ combusted cigarette or ash and stump : Number of estimations . . : an : . : 6 . i Range : : . . .. . oe . os 77.5-88.5 . 74-0-100.0 Mean . ' . . . .- : . : . : 83-2 . 87.0 With the pure solution the results were less accurate with the higher amounts with ) latter 30 to 100 gthan the lower 10 to 20 g though with the the titra- - of of Cassil tion error is course considerable as 0.05 ml 0.5 g and Wichmann 1939 claim an average recovery of 99.5 per cent of amounts from 5 to 500 g In the presence of the combusted products the recovery is less complete between 80 and 90 per cent Gross 1933 has drawn attention to the occurrence of such errors in the estimation of arsenic in tobacco which are attributed to uncombusted residues of pyridine and nicotine ; we failed to obtain satisfactory results by the method which he devised to overcome this difficulty Fortunately the defect was of the same order with both the smoked and unsmoked material so that the measurement of the arsenic volatilized was not affected ARSENIC CONTENT OF CIGARETTES AND OF ASH AND STUMP In the previous investigations summarized above artificial methods of smoking were employed air being drawn through a pipe cigar or cigarette by means of a pump This process might be fallacious as there is no warrant that the apparatus reproduces the conditions present when tobacco is smoked in the usual way We have confined our experiments wholly to cigarettes smoked by one or other of three persons accustomed to this form of smoking and they were asked to do this in their ordinary way ; the two brands used P and C are in common use in this country The ash and stump were dropped into separate weighing bottles in our earlier experiments but latterly the two have been analysed together ; the amount of arsenic found if less than that in the cigarette should indicate the amount volatilized in the smoke of which a part must have been inspired But actually the problem is by no means simple the difficulty being to ascertain the arsenic content of the cigarette originally Table IV The data in Table IV show that the amount of arsenic As ug.g. ug.g. in whole cigarettes or in portions of these from 5 packages of one brand P ranges from 24 to 106 and in one from 56 to 106 while Brand C shows a smaller package infer range 28 to 61 Henceit is impossible to the arsenic content of cigarettes about to be smoked unless the average of a very large number is ascertained Before this width of range was realized we obtained many contradictory results showing amounts in the ash and stump which were sometimes less and sometimes more than that thought to be present originally ARSENIC CONTENT OF TOBACCO 177 TABLE Range of Arsenic Content in Two Brands of Cigarettes Method See also Tables V and VI Gulzeit Package and As O 3 g number of moe . ; po ; Brand P. cigarettes Range Mean s Whole cigarettes . . . . - 100 49-5-76.6 . 67-8 Cigarettes 7 wholes and 2 halves . : ~~ B 20 : 55.9 106.2 . 82.3 from 5 Pieces Piece from 3 cigarettes . : : . C 10 . each of 4 cigarettes . . D 20 27.2-34.3 35.8-59.7 . 30.7 49.6 6 Successive picces cut from 1 cigarette . . D 20 . 58 51 41 58.4 . 46.1 58-7 38-8 13 Estimations on mixed tobacco of 10 cigarettes | 10 23.9-31.9 . 27.5 Range in 5 packages of Brand P . Lae . 23.9 106.2 ts Brand C. 10 Pieces from 5 cigarettes : : : . A 20 . 33.4-61.5 . 51.3 5 Successive pieces cut from 1 cigarette . . A 20 54.2 43-1 51-8 30-6 2 46.J 51.0 11 Estimations on mixed tobacco of 10 cigarettes 20 Range in two packages of Brand C and 40 38.5 These results are reckoned as gig in order to give a uniform basis of comparison But as the weight of most cigarettes does not differ very much from one gram the figures give a rough mousure the arsenic in one cigarette which is of more obvious practical interest A quantity expressed gig is numerically the same as parts per million 70- 60- 709 ae N mS AY So Be 10- | I FIG Consecutive analyses of cigarettes Cigarette Ash an. d - s~ tump and of ash and stump Brand P. cigarette The Gutzeit method enables an estimation to be made upon 1/5 to 1/10 of a cigarette such as those of Brands P and C. We therefore cut off such portions ' for analysis from cigarettes of which the remainder was smoked in the manner described The results were again contradictory and we found that such suc- cessive portions may show a range of 38-8 to 58-7 or 100 151 in P and of 30-6 54-2 or 100 177 C Table IV ~ In the hope of obtaining more uniform material the papers were removed from the cigarettes of a package of 10 or 20 and the tobacco mixed by hand and 178 M. E. DAFF AND E. L. KENNAWAY a minced with scissors Cigarettes were made by rolling this tobacco in papers in a machine filter being inserted at one end to keep the contents from falling out But even this treatment does not give satisfactory results it is very difficult to take up samples of such material which will contain constant proportions of the coarser and finer particles as the latter tend to fall away from the former ; the tobacco would have to be ground to a powder similar to snuff to secure uniformity The analyses ranged in the ratio of 100 133 in P and of + 100 C. Moreover the minced tobacco even when moistened is not easy to smoke in the same way as ordinary tobacco Adjacent cigarettes of Brand P from a much larger package containing 100 were taken but these at first showed a wide range 49.5 to 76-6 Table IV After ' ; the adoption of the method of Thomas and Collier 1945 in place of that of <3 Gutzeit we came upon a row in this box of more uniform composition this change cannot be accounted for by the greater accuracy of the former method Successive single cigarettes or pairs were combusted as such or smoked alternately The analyses of 30 consecutive cigarettes Table V and Fig ) showed Table Consecutive Analyses of Cigarettes and of Ash and Stump Method of Thomas and Collier 1945 AsO gg Cigarette 48.3 48-6 51-3 52.7 Ash and stump 46-7 41.1 43.0 47-1 41.3 . 35.4 46.7 51.7 50.5 62.9 47-0 44.7 55.8 40.5 51.8 40.5 48.2 40.2 45.2 30.8 60.5 39.6 56-1 46.0 42.7 . 39-2 Brand P. Mean 50.5 . Loss per cent = 15-8 42.6 P = 001 that an average of 15.8 per cent of the arsenic is lost in the process of smoking and had presumably been volatilized ; this loss is statistically significant P = 0.001 The same method was applied to Brand C of which the largest boxes available contained 50 the first two rows showed in 18 cigarettes a loss of only 7-6 per cent which was not statistically significant P = 0.2 The first two rows of another box Table VI were of more uniform composition and showed in 22 cigarettes a significant loss of 13-7 per cent P = 0.01 Three cigarettes in the 3rd row taken for ashing yielded exceptionally large amounts of arsenic 180 M1 E. DAFF AND E. L. KENNAWAY The 4th row showed a loss of 18.2 per cent which is just significant P = 0.05 in spite of the small numbers 12 cigarettes involved The analyses upon the whole box showed a significant loss of 10.7 per cent P = 0-01 course of the analyses on this box is shown in Fig 2 The whole Several estimations on from 10 to 20 cigarette papers whether bought in packets or taken from cigarettes gave amounts between 0-75 and 2 ghence the quantity in a single cigarette is negligible The papers and cork from 10 C cigarettes gave 1.25 ug BRANDS OTHER THAN ENGLISH Cigarettes of thirteen other brands were examined some by the Gutzeit method and some by that of Thomas and Collier 1945 Three known American brands gave figures 25 to 47 g rather lower than the means 50 to 55 g of the English brands P and C Table VII All the eight Turkish brands showed TABLE Brands other than English American : Brand Number of cigarettes As g per g Brand A . . : : 125 F 125 " . . . iS) . ' . : . 125 : 35.2 . 41 47 30-0 25.3 26-3 26.9 31-2 Turkish : Brand R Box1 . . : . " R Box 2 . . . . Nil; ash -F stump 4 . 1.03 nil 4.3 ni ash + stump ni A . . . . 1 in two portions . 0.5 1.9 4 whole . 1.08 08 0 9 1 in two portions 2 whole 3 " French ? Rhodesian * i.c. colour not distinctly different from that of blank very low amounts nil to 4 ug./g and similar results were given by a packet brought from France and by cigarettes supposed to contain Rhodesian tobacco After these results were obtained we came upon a short note by H. Popp 1928 of Frankfurt a M. giving the following results : Arsenic p.p.m. Tobacco from the Palatinato . . . . 5.1 " " Macedonia cigarette tobacco Java " " . . : , . " " Brazil . . 0.7 0.33 4.6 He comments upon the much higher figures of Remington 1927 and suggests the possible importance of insecticides The possibility was considered that the very low results given by Turkish cigarettes were due to some constituent having an inhibiting effect on the re- 182 M. E. DAFF AND E. L. KENNAWAY REFERENCES CASSIL C. C. AND WICHMANN H. 1939 J. Ass Off agric Chem GROSS C. 1933 Ind Eng Chem Anal Ed 5 58 Idem AND NELSON O. 1934 Amer J. Publ Hlth 24 36 Hansard 1945 Parliamentary Debates 407 626 POPP 1928 Z. angew Chem 41 838 REMINGTON R. 1927 J. Amer chem Soc 49 1910 THOMAS M. D. AND COLLIER T. 1945 J. Industr Hyg Toxicol Wash 22 27 201 436