Document RakyGBLLzqw7y2v6Qzy5Nn84k

FILE NAME Talc TALC DATE 1967 DOC TALC009 DOCUMENT DESCRIPTION Article from Industrial Hygiene Review - Mortality Among Talc Miners & Millers in NY State INDUSTRIA HYGIENE REVIEW VOLUME 9 NUMBER In This Issue PA Mortality Among Tale Miners and Millersin New York State and M. Zaki M.D. oo cence ~ . Mortality Experience in a Group of Asbestos Workers M. i : : Kleinfeld M.D J. Messite M.D and O. Kooyman M.D A Note on Let Current S. Moskowitz Ph.D. P.E. ..... DIVISION OF INDUSTRIAL HYGIENE DEPARTMENT OF LABOR STATE OF NEW YORK DIVISION OF INDUSTRIAL HYGIEN REAPPUNT REAPPUNT 6 8S DEPARTMENT OF LABC STATE OF NEW YO INDUSTRIAL HYGIENE REVIEW NEW YORK STATE STATE DEPARTMENT OF LABOR 80 Centre Street New York New York 10013 NELSON A. ROCKEFELLER ROCKEFELLER Governor M. CATHERWOOD Industrial Commissioner Division of Industrial Hygiene Editorial Committee Jacqueline Messite M.D Assistant Director Jack Bali P.E Chief Engineering Section Edward Stein Ph.D. Chiet Laboratory Section Mouis Kleinfeld M.D. Charman Editor Robert Ratajack 10.67 21T1 3M MORTALITY AMONG TALC MINERS AND MILLERS IN NEW YORK STATE MORRIS KLEINFELD MD JACQUELINE MESSITE MD OLIVE KOOYMAN MD AND MAHFOUZ H ZAKI MD Since 1940 the Division of Industrial Hygiene has carried out a number of studies on tale miners and millers in the northern part of New York state The prime purpose of these studies was to ascertain the health hazards associated with the exposure to dust in tale mining and milling In 1940 a chest ray survey of 221 tale miners and millers employed in several plants in this region disclosed pulmonary fibrosis in 32 workers 18 of whom had had no other occupational dust exposure This survey clearly indicated that exposure in these tale mines and mills was capable of producing a fibrogenic type of pneumoconiosis In 1954 a follow study of the 32 workers with pulmonary fibrosis disclosed that the pneumoconiosis was progressive and disabling but that the progression was slow and the disability occurred primarily in the older age group A report on the clinical roentgenographic and pathological findings in six patients who had an average exposure exposure to tale dust of 26 years with a range of 20 to 33 years was reported in 1963. The major clinical features were chronic productive cough dyspnea diminished breath sounds limited chest expansion diffuse rales and clubbing The chest roentgenogram disclosed pulmonary infiltration both basally and in the midlung fields In some instances obscuration of the cardiac borders or costophrenic sinuses or both were present The most frequent pathological change was a diffuse fibrosis containing macrophages with absorbed dust particles A pattern of endarteritis with intimal hyperplasia was frequently noted Distension of bronchi and bronchioles with formation of cystic spaces was common Rather characteristic was the presence of elongated terminally elubbed bodies indistinguish- able from asbestos bedies as seen in stosis The pleura showed dense fibrotic thickening Cor pulmonale was the major complica- tion in four of the six cases and was the mechanism of death in From the Division of Industrial Hygiene New York Drs Kleinfeld Mes- e site and Kooyman and the State University of New York Downstate wen Medical Center Brooklyn NY Dr Zaki Reprinted from the Archives of Environmental Health May 1967 Volmne 14. 668-667 Copyright 1967. Amertean Medical Association 181 three A comparative clinical roentgenographie and physiologic physiologic study of workers exposed to fibrous and granular tale dust was made in 1964. The two groups were similar with regard to age sex degree of exposure and smoking habits There were no sig nificant differences in the clinical and roentgenographic findings between the two groups However the number of abnormal values for each parameter of pulmonary function measured VC VC MBC TLC RV TLC and DL was appreciably greater in those exposed to fibrous than to the granular variety of tale In 1965 pulmonary function tests were performed on 43 workers en gaged in the milling of the fibrous variety of tale The mean duration and weighted average of exposure was 19 years and 62 million particles per cubic foot respectively An appreciable num ber of the workers had abnormal pulmonary function measure ments This was partienlarly evident in the vital capacity total lung capacity and diffusing capacity There were 16 who showed pulmonary infiltration on their chest roentgenograms as compared to 27 without such evidence Those with positive radiologic findings had a proportionately greater number of respiratory symptoms and signs and abnormal pulmonary function values as compared to those without In general the correlation between the degree of pulmonary function impairment and the clinical and roentgenographic findings was poor The purpose of the present follow study was twofold 1 to obtain an estimate of the incidence of disease among this select group of tale workers and 2 to compare the observed mortality experience from specific diseases with the expected mortality among a similar basic population Materials and Methods All tale miners and millers employed in 1910 who had 15 or more years of exposure to tale dust as well as those who achieved minimum of 15 years of such exposure between 1940 and 196 were included in this study The group totalled 220 workers and is believed that the overall number of 220 constituted the total work force in the category under stndy Souree of Data data were obtained from a number of sources Plant records were examined and the work history of each individual was detailed to include changes of job and specific years of employment Death certificates were studied in all instances he available The records of the physicians attending the work- ers privately were reviewed Substantial medical information on the majority of the workers was available in the Division's files and was used as an additional source of data Hospital records including autopsy reports and histological specimens were examined wherever available Autopsy records were obtained in 35 of the 91 deaths Statistical Analysis The total number of deaths was distributed the following categories malignancies cardiac pneumoconiosis or complications or both accidents or suicides and all other causes The proportions of mortality from cancer of the lung and pleura and of the gastrointestinal tract and peritoneum out of the total mortality were compared with the expected mortalities due to the above causes in the various age groups The expected mortality represents the proportion of deaths among white men the United States due to the specific causes in the year 1957. This particular year was chosen as standard because is the median year of death among the 91 deaths Differences between observed and expected frequencies were tested for significance using th normal curve with large numbers and the Fisher's exact probability test for small frequencies Findings Total Deaths There were 91 deaths in the group of 220 tale workers The causes of death in the various categories are shown in Table 1. A breakdown of the deaths according to age group showed that two workers under 40 died 38 workers who were between 40 and 50 years died 47 between 60 and 79 years and four died who were 80 years and over Table 2 The average age at death of the 91 fale workers was 60.4 years with a range of 35 to 84 years Malignancies Of the 91 deaths the observed and expected mm- ber of deaths due to cancers of the lung pleura gastrointestinal fract and peritoneum are shown in Table 2 of the ten malig- hun pleura lung the mands mands the and 111ZIN 111 varomomas of the and one was a fibrosarcoma of the pleura Of the seven malignan- cies of the gastrointestinal tract and peritoneum two were cancers of the stomach and one each of carcinoma of the colon rectum and pauereas There was one primary hepatoma of the liver and the remaining case was a peritoneal mesothelioma The malignan- cies involving other sites included one case of retroperitoneal retie- ulum cell sarcoma and one of chronic lymphatic leukemia leukemia S Table Comparative Dust Counts in Talc Mines and Mills Northern New York Work Type Before 1945 1946-1965 Low Medium High Average Low Medium High Average Average Mines Drilling Mucking 83 413 2800 - : 2 30 475 - 818 0 _ 120 3 3 10 5 _ 7 59 5 Scraping : ; Mills : Crushing Crushing No Dust Counts Made up to 1948 - : 22 fl- 690 180 Screening 43 61 136 69 Milling Garners and separators 7 Pulverizers 32 75 271 92 a - - i 58 70 728 278 No Dust Counts Made 5 8 13 ? 1949-1965 1949-1965 _ / 3 13 13 360 42 7 8 37 68 37 5 20 70 25 : _ 4 27 60 22 - 25 28 31 28 Bagging RR cal and truck load 520 . a : - 7 _ No Dust Counts Made 18 63 169 73 Room 1196 Discontinued chutes 83 Discontinued 2 Concentration in millions of particles per cubic feet of ai Comment Malignancies The data on carcinoma of the lung and pleura shows an overall mortality from carcinoma of the Jung and pleura to be approximately four times that expected However the sig- nificant increase appears to occur in the age group of 60 to 79 years rather than in the 10 to 59 year age group This is at variance to what we have observed among workers exposed to asbestos dust where the observed values in the 40 to 59 as well as 60 to 79 year age groups were significantly different from the expected values Table ) The asbestos proup consisted of 152 asbestos insulators who had 15 or more years of exposure in 1945 or achieved 15 years between the period of 1945 to 1965. The overall mortality was 46 or 30.36 The reason for the earlier occurrence of an increased incidence of lung or pleural cancers in the asbestos workers compared to the tale workers may be partly due to the greater carcinogenicity of asbestos dust or to an increased level of exposure to asbestos dust or both as compared to commercial tale which is mixture of silicates and carbonates with a small amount Theortical 56 3.9 Peritonum and G and Mortaliy Observd 19 13 152 ProptinalPleura Workes and Lung Asbetos Theortical 7.4 38 31 the in of Age Observd Cancer to From Relatd 23.8 26.1 26.1 groupstatistically staistcaly in Peritonum Peritonum Mortaliy and From sitaiscaly number Expectd Tract Deaths values smal and Malignrt of Deaths Gastroinel Pleura 12 theoricatheoretica theoretica because and perfomd Table Ccaths observd Total 21 observed 46 observed not betwr anlysi Difernc Staiscl AgeGroup 69-07 6079 Total 10 of free silica In the absence of adequate smoking data one cannot assess the role played by smoking in the causation of the pulmonary carcinomas in both series In three of the ten tale workers where smoking history was obtainable two smoked at least one pack daily for over 20 years and one smoked ten cigars daily for 55 years With regard to carcinoma of the gastrointestinal tract and peritoneum among the tale workers we did not find any significant difference between the observed and expected values in the overall and specific age groups studied However in the asbestos group Table ) a significant difference between the observed and expected values was found in the overall categories Our findings in the asbestos workers are similar to what has been reported by Selikoff Churg and Hammond If a clear etiological . relation ship is subsequently established between exposure to asbestos and carcinoma of the gastrointestinal tract then one may attribute the differences in incidence between the asbestos and fale groups to the reasons given for carcinoma of the lung and pleura Deaths Due to Paumoconiosis of Complications or Both -Previons studies have reported that cor pulmonale is a major complication of tale pneumoconiosis and is a major cause of death among iale workers The findings in this study are consistent with the previous reports Peptic Ulcer Among the death group of 91 cases there were ten subjects who had a duodenal ulcer and in one of the ten the aleer was the cause of death In the 129 workers who are still alive 19 had a diagnosis of duodenal ulcer This is a total of 29 or 13.2 According to the health statistics of the 1. Depart- ment of Health Education and Welfare the prevalence of peptic uleer found between 1957 to 1959 for males of all ages is 21 4 per thousand population of 2.1 * Despite the fact that the figures obtained through the National Health Survey represent point proval proval proval ae ee proval Oe in in contrat contrat contrat to the poopind providence providence lignes of om study it appears that the incidence of peptic ulcers among tale workers is higher than among the general population A significant in- crease in incidence of peptic ulcer varying between 20 to 25 has been found in patients with chronic obstructive pulmonary . disease Since the tale workers have primarily a restrictive rather than an obstructive lung disorder one may speculate that both types may be associated with an increased incidence of peptic ulcer [ Correlation of Carcinoma of Lung With Age Duration of Ex posure or Pucumoconiosis or Both Relating caremoma of the lung with duration of exposure it might be relevant that all the indi viduals with carcinoma of the lung or pleura had their initial ex posure prior to the institution of wet drilling The average duration of exposure prior to the introduction of wet drilling was 14,6 years Although this was a period of heavy exposure Table 3 there is no evidence to indicate that there was a direct relationship between the duration of exposure prior to the onset of wet drilling and the occurrence of pulmonary carcinoma The mean age of the group of ten workers who developed carcinoma of the Inng of pleura was 63.6 years with range of 45 to 75 years This is slightly above the mean age of 60.4 years with a range of 38 to years for the overall group of 91 death cases Since the life expectancy of white men born in the United States in 1920 is given as 544 years and since these workers were born in 1920 or earlier there does not seem to be a reduction in the life span from the exposure With regard to carcinoma of the lung and pneumoconio sis our data indicated that eight of the ten persons with carcinoma of the lung had clearent evidence of an associated pneumoconiosis No confirmatory evidence was obtained in the remaining two OBE of whom had fibrosarcoma of the pleura and the other a bilatera massive pleural effusion Summary and Conclusions Mortality data on 91 tale miners and millers in New York state who had 15 or more years of exposure to tale dust by 1940 or hac achieved 15 years between 1940 and 1965 were reviewed The average age at death was 60 4 years with a range of 38 to 84 years Proportional mortality from carcinoma of the lung and pleura among tale workers was four times that of the control population However the significant increase in incidence appeared in the 60 to 79 year age group rather than in the 40 to 59 year group Thi was at variance with our findings in asbestos workers who had Similar durarinn of axposin woring a simiba period where the increase in observed incidence was present in both age categories The earlier occurrence in the asbestos workers was attributed to the greater carcinogenicity and possibly to exposure to asbesto dust of greater concentration as compared to commercial tal Carcinoma of the gastrointestinal tract and peritoneum showe no significant difference m the tale and control populations How ever in the ashesfos workers gastrointestinal and peritoneal malig 1:22 nanciesis were elevated significantly Death due to JOCORTOSIS or its complications or both was recorded in 28 individuals 19 of whom died from cor pulmonale The cause of death in the remaining nine was tuberculosis 5 or bronchopneumonia 4 The lapsed time from first tale expositre to death from pneumocomosis or complications or both averaged 25.9 years with a range from 15 to 39 years Excluding cor pulmonale there were 25 cardiac deaths 19 of which were due to coronary artery disease three to hypertensive heart disease and three to rheumatic heart disease Of the 91 death cases data on environmental exposure were avail able in 80. The mean duration of exposure for this group was 24.7 years with a range of to 47 years Previous studies have indicated that cor pulmonale was a major cause of death among tale miners and millers This was also found in the present study However what has not been previously brought out is the increase in observed incidence of carcinoma of the lung among these workers as demonstrated in this study References Siegal W Smith A. R and Greenbung Themolite Take Mining Including Roentgenological Amer Rochten 19:11 20 Jan 1943 foe The Findings Dust Hazard in in Lake Worker 2, Kleinfeld M. Messite .. and Tabershaw 1. Arch Industr Health 12:66 July 1955 Tale Pneumocomio i , 3 Kleinfeld M. et al Tale Pneumoconiosis A Report of Six PatientS With Postmortem Findings Arch Earoon Health 101 175 July 1963 4. Kleinteil M. et al Lang Function in Tale Workers A Compnative Physiologic Study of Workers Exposed to Filions and Grannia Tall Dusts Arch Eneton Health 109 566 Nov 1964 5. Kleinteld M. al Ellert of Tale Dust Inhalation on Lung Function Arch Environ Health 431-437 March 1965 6. Selikoff J. Churg J. and Hammond E. ( Asbestos Exposure and Neoplasia / | 137 22-26 ( April 6 1964 7. Peptic Ulcers Reported in Interview- m 1. 8. National Health Survey Survey Washington D. C U. S. Department of Health Education and Weltare Public Health Service 1960 Chronic Obstinctive Pulmonary Discuse in Manual for Physicials National Tuberculosis Association 1966 71 Ql Statistical Abstract of the United States U. eau of the Census 1966 7 Washington 1 } mo MORTALITY EXPERIENCE IN A GROUP OF ASBESTOS WORKERS MORRIS KLEINFELD MD JACQUELINE MESSITE MD AND OLIVE KOOYMAN MD " The term asbestos is used to identify a group of fibrous sili cates Prolonged inhalation of significant amounts of asbestos dus over an extended period of time can produce in certain individual respiratory disorder known as asbestosis It is characterized primarily by congh dyspnea basal crepitations and reticulonodu lar shadowing of chest roentgenograms Clubbing and cyanosi are usually seen in the more advanced stage of this disorder Chronic bronchitis and emphysema are associated with this disease the emphysema being more of a localized than a diffuse obstructive type Cor pulmonale is the major compheation and usual caus of death from this disease This is particularly true in those with excessive dust exposure There is an increased incidence of lung carcinoma and mesothelioma of pleura and peritoneum associated with sustained asbestos exposure The most consistent pathologica finding is a dense fibrosis containing macrophages with absorber dust particles which in many areas obliterates the pulmonary archi tecture A pattern of endarteritis with intimal hyperplasia hyperplasia con sistent with pulmonary hypertension and bronchiolectasia and associated major findings Rather striking is the presence of elon gated terminally clubbed bodies both segmented and unsegmented m the respiratory bronchioles or imbedded in the fibrous tissue or both The pleura often shows dense fibrotic thickening an not infrequently there are calcified pleural plaques over the pleura Surfaces The clinical and pathological features are indicative of a pronounced dysfunction of the respiratory mechanism This ha been confirmed by studies of pithmonary function which have shown a disturbance in both ventilatory function and diffusion capacity The main physiologie alteration is a reduced diffusion capacity The purpose of the present study was to obtain mortality data in gram of asbestos workers and to cough sre the abserved mor tality experience from specific diseases with the expected mortality among a similar basic population From the Division of Industrial Hygiene New York Dis Kleinfeld Mes Site and Kooyman Reprinted hom the Archives of Environmental Health August 1967 Volume 15 pp 177-180 Copyright 1967. American Medical Association hand 11 Material and Method The study group consisted of 152 asbestos workers who had 15 or more years of asbestos exposure by 1945 or had achieved 15 years of exposure to asbestos dust between 1945 and 1965 Source of Personal data were obtained from union records and the occupational history obtained for each man included operations performed and dates and places of employment For those who had died records of the health and welfare fund pro- vided date and place of death Copies of death certificates were examined in all instances when available The records of the physiciaus attending the workers privately were reviewed Hospital records and histological specimens were examined whenever avail able Autopsy records were obtained in 17 of the 46 deaths Statistical Analysis number of deaths were distributed in the following categories malignancies cardiac pneumoconiosis or complications or both accidents and all other causes The observed mortality from cancer of the lung and pleura and of the gastrointestinal tract and peritoneum were compared with the expected mortalities due to the above causes in the various age groups The expected mortality represents the proportion of deaths among US white mates due to the specific causes in the year 1948 This particular year was chosen as standard because it is the me- dian year of death among the 46 deaths The differences between the observed and the expected frequencies were detailed for sig nificance using the normal curve for large numbers and the Fish- er's exact probability test for small frequencies Table Causes of Death in 46 Asbestos Workers From 1945 to 1965 Cause of Death Malignancies Lung and pleura Gastrointestinal and peritoneum All other malignancies Cardiac deaths other than cor pulmonale Asbestosis and complications Accidente All other causes No. 23 12 7 4 13 3220 3220 3220 Total 46 o 50 26.1 15.2 8.7 28.3 43 40 13.1 100 Findings Total Deaths -There were 46 deaths in the group of 152 asbestos insulators The causes of death in the various categories are shown 15 in Table 1. A distribution of the deaths according to age group showed that there was 1 less than 40 years 21 between 40 and 39 years 23 between 60 and 79 years and 1 over 80 years Table 2 The average age of death of the 46 asbestos workers was 60.3 years with a range of 33 to 81. The average age for the overall group of 152 asbestos workers was 53.7 years with a range of 33 to 81 Malignancies Of the 46 deaths the observed and expected mumber of deaths due to cancer of the lung and pleura gastrointestinal tract and peritoneum are shown in Table 2. Of the 12 malignancies of the lung and pleura ten were carcinomas of the hung and two were pleural tumors one a mesothelioma and the other a fibrosarcoma of the seven malignancies of the gastrointestinal tract and peritoneum two were cancers of the stomach one a lymphocoma of the small intestine one a cancer of the colon and three were peritoneal tumors two of which were mesotheliomas and one a mesentrie sarcoma The malignancies involving other sites included one case of chronic lymphatic leukemia and one retroperitoneal reticulum cell sarcoma and one metastatic car cinoma primary site unknown Cardiar Deaths Of the 13 cardiac deaths excluding cor pul monale eight had coronary artery disease three had hypertensive heart disease one rheumatic heart disease and one syphilitic heart disease Asbestosis or Complications in Both Of the 46 deaths two had asbestosis complicated by cor pulmonale All Other Causes the six in this category there was one each of the following cerebrovascular accident pulmonary tuber enlosis acute peritonitis chronic arthritis gangrenous appendicitis with peritonitis and Laemmer cirrhosis Environmental Exposure Exposure The mean duration of exposure for the 152 asbestos workers was 26 years with a range of 15 to 50 years while that for the 46 dayth gysgo wae 31.8 years with 21 Tat of 15 to 47 years Although fiberglass was introduced into the industry during the past ten years it is fairly certain that all of these asbestos insulators had a minimum of five years exposure to asbestos dust Even though fiberglass eventually became the primary component of the insulating material some asbestos was nevertheless incorporated Expectd 5.6 3.9 Peritonum and 15.2 GI 13 61 61 and Mortaliy ProptinalPleura and Workes 7.4 38 AsbetosLung the Pleura in of and 10 Age Cancer to Lung From Relatd P. 23 26.1 26.1 signfcat Peritonum 2 staicly Mortaliy Gord Gord Gord and From Cause is Proptinal Tract Deaths values Malignt and expcted Pleuraand 153 71 Lung GastroinelDeaths tractand Table gastroinelobservd Total we 917 betwn betwe nbetween Diferncindcates Age Group 40 40-59 60-79 - 08 Total GI ' Comments Malignancies The data on carcinoma of the lung and pleura show an overall mortality from carcinoma of the lung and pleura to be approximately nine times that expected Selikoff et al who studied a similar group of asbestos insulators found that the death rate from cancer of the lung and pleura was approximately seven times as high among the asbestos group as in the US white male population As shown in Table 2 the increase is significant both in the 40 to 59 and 60- to year age groups This is at variance with what was observed among fale workers exposed to mixed silicate dusts where the significant increase in cancer of the lung and pleura occurred in the 60 to 79 year age group rather than in the ' 10. to year age group The tale group consisted of 220 tale millers or miners or both who had 15 or more years of exposure in 1940 or achieved 15 years between the period of 1940 and 1965. The overall mortality in the tale workers was 41.4 The reason for an increased incidence of lung or pleural cancers in the younger age group among the asbestos workers as compared to the tale workers may be partly due to the greater caremogenicity or longer duration of exposure to asbestos or both The asbestos workers with lung or pleural cancers were exposed on the average for 28.2 years while the tale workers had an average exposure of 23.3 years In addition it is possible that other components such as the metallic cations present in the asbestos dust may also ae count for the difference in incidence of lung or pleural cancers between the two groups In view of the meager history available on smoking one cannof assess the role played by this factor in the causation of pulmonary carcinomas among either the tale or asbestos workers In four of the 122 asbestos workers where a smoking history was obtainable one smoked two packs per day for 20 ; years one one pack a day for 24 years one half a pack a day for over 20 years and one smoked only two cigars per day for 18 years With regard to carcinoma of the gastrointestinal tract and Ve weet year stses pee veesavew Prony z tds sane auberton auberton auberton wo ude wo soe ora Ce) veresriael ad liye was found between the observed and expected frequencies in the overall specific age groups studied The present findings among the asbestos workers are similar to those reported by Selikoff al No significant differences was found between the observed and expected frequencies in the overall and specific age groups among the tale workers If a clear etiological relationship is subse quently established between exposure to asbestos dust and ca- cinoma of the gastrointestinal tract then one may attribute the difference in incidence between the asbestos and fale groups to the reasons given for carcinoma of the lung and pleura Deaths Due to Asbestosis and Complications --Previous studies have reported that cor pulmonale is a major complication of as- + bestosis and a major cause of death among asbestos workers The findings in this study however are not consistent with the previous reports and this may be explained by a lower concentration of asbestos dust exposure over a prolonged period of time The mean duration of exposure of those who developed lung or pleural cancer was 28.2 years with a range of 15 to 40 years This is consistent with the observation of Gilson who recently pointed out that a reduction in asbestos dust exposure is less likely to produce chronic lung disease but the risk of neoplasia inereases with sustained exposure to relatively lower concentrations In 26 of the deaths where roentgenographie data were available 12 showed changes consistent with asbestosis only two of the 12. death was related to the asbestosis cor pulmonale being the primary cause in both Of the 12 that died of malignancy of the hung or pleura five had asbestosis and three did not and no information was available on the remaining four Correlation of Carcinoma of Lung or Pleura With Age Dura tion of Exposure or Asbestosis The mean age of the group of 12 workers who developed carcinoma of the lung or pleura was 56.5 years with a range of 33 to 71 years This is slightly below the mean age of 60.3 years with a range of 33 to 81 years for the overall group of 46 death cases The mean duration of exposure exposure of those that had cancer of the lung and pleura was 28.2 years with a range of 15 to 40 years The average years from onset of exposure to death in this group was 29.5 years with a range of 15 to 40 years The mean duration of exposure for the overall group of 46 deaths was 31.8 years with a range of 15 to 47 years The differences in mean age and mean duration of exposure for the 46 deaths cases and the group that developed cancer of the Jung or pleura are not statistically significant With regard to carcinoma of the lung and asbestosis the data indicated that five of the 12 individuals with carcinoma of the lung had asbestosis three did not and in four no information was available The small number of cases plus the absence of information in four cases precludes the making of any correlation Summary and Conclusions Conclusions Mortality data or 46 asbestos insulators in New York state who has 15 or more years of exposure to asbestos dust by 1945 or hac achieved 15 years of exposure between 1945 and 1965 were re viewed The average age at death was 60.3 years with a range o 33 to 81 years There were 12 deaths due to malignancies of lung or pleura The differences in the mean age and mean duration o exposure for the 46 deaths and the group that developed cancer of lung or pleura were not statistically significant Proportional mortality from carcinoma of the lung and pleur among asbestos workers studied was nine times that expected in US white males The observed mortality was significantly highe in the 40- 50- as well as in the 60- to 79 year age groups Thi was at variance with authors previous findings among tale worker who had a similar duration of exposure covering a similar period but where the observed incidence increased significantly only in the 60- to year age category The occurrence of malignancy o lung and pleura in the younger age group of asbestos workers ma be attributed to the greater carcinogenicity of asbestos or th longer duration of exposure to asbestos dust or both as compared to tale dust exposure The mean duration of exposure of the as bestos workers with lung or pleural cancers was five years longe in duration than that found in the tale group with similar malig nancies In addition other components in the asbestos dust es posure such as the presence of metallic cations may also be factor to account for the difference in incidence between the tw groups Carcinoma of the gastrointestinal tract and peritoneum of which there were seven cases showed a significantly greate incidence in the observed as compared to the expected in US whit males Death due to cor pulmonale was observed in only two in dividuals The low incidence of cor pulmonale as a cause of deat as compared to the high incidence of pulmonary and gastroin testinal carcinoma may be ascribed to a lower level of asbestos dus exposure occurring over a longer period of time M. H. Zaki MD Department of Enynonmental Medicine State Universit of New York Downstate Medical Center New York assisted in the statistica , analysis of data ' 20 References 1. Kleinfeld M Messite J. and Shapir ] Clinical Radiological and Physiological Findings in Asbestosis Arch Luern Med 813 1966 2. Bader M. Bader R. .: and Selikod I. J Pulmonary Function in Asbestosis of Lung Amer J Med 235 1961 3. Selikoff I. .; Churg .; and Hammond C. Neoplasia JLW1 JLW1 188 1964 Asbestos Exposure and 4. Kleinfeld M. et al Mortality Among Tate Miners and Millers in New York State Arch Environ Health 462-667 1967 5. Heard B. E. and Williams R. The Pathology of Asbestosis With Reference to Lang Function Thorta 264 1961 16. Gilson J. C. Changing Hazards of Exposure to Asbestos Dust presented at Conference on Biological Effects ot Asbestos New York Academy of Sei- ences New York Oct. 19 21 1904 A NOTE ON LET CURI SAMUEL MOSKOWITZ PH.D. P.L In an article entitled Safety in the Use of Hand H. static Spray Coating Equipment which was writter author and published in the June 1966 issue of this join statement was made that the called let level for pound adult is a current of 60 milliamperes of 60 cycle AC was also stated that This will cause discoordination of heart ac- tion in approximately the most sensitive 1/2 of 1 of adults sub- jected to such current through the body Two readers of the article have objected to calling a flow of as much as 60 mA of 60 cycle AC a " go current since that much might be harmful This objection is well taken Roberts 1 quof- ing Alexander ) states that With continued contact and How of a 60 eyele alternating current currents over 25 mA might be har~-nfulwhereas currents of 70-90 mA could prove fatal Dalziel 3 has pointed out that 30 milliamperes of 60 cycle AC is a rea- sonable safe current for a duration may induce a freezing haz ard He also has pointed out that " Currents of the go level if they flow for an appreciable time are more than sufficient to produce deep burns and both types electric and thermal may be produced simultaneously It is hoped that this note will be used in connection with the article on electrostatic paint spraying References 1. Roberts H. Narcolepsy following following injury by electric current Arch Environ Health 33 125 1966 9. Alexander .: Electrical injuries to the central nervous system Mer Clin North Imer 663 1958 3. Dalziel C. Electric Shock The Encyclopedia of Electronics ed by Charles Susskind pp 205-208 Reinhold Publishing Co New York 1962 12741274