[An epidemiological study on reproductive effects in female workers exposed to acrylonitrile]

Four hundred and seventy-seven female workers exposed to acrylonitrile and 527 controls were studied by retrospective cohort method. Results showed incidence rates of pernicious vomiting and anemia, preterm delivery, and birth defects in exposed women were obviously higher than those in controls, with statistical significance. Logistic regression analysis revealed exposure to acrylonitrile in pregnant workers caused increasing risk of preterm delivery and birth defects. In addition, illness, medicine taking and X-ray irradiation during pregnancy related to the increase of incidence of preterm delivery in exposed women.

[Acrylonitrile and chemotaxis: in vitro experiments]

We have verified that chemotaxis of isolated human polymorphonuclear leukocytes (PMN) was a target of in vitro toxicant effect of acrylonitrile (ACN). This toxicant induced a significant dose dependent decreasing of chemotaxis with 50% inhibition (IC50) occurring at 15 mM. We assume that PMN from workers exposed to ACN reacts vivo in a similar way to PMN exposed in vitro to ACN. We propose therefore to use chemotaxis assay as a biomarker of early biological effect of ACN in workers, since for their monitoring there are so far only internal dose indicators but no suitable effect indicators.

Cancer occurrence among workers exposed to acrylonitrile

A MEDLINE search identified 12 published epidemiologic studies that have reported incidence or mortality experience among workers exposed to acrylonitrile. Many of the studies contain scanty descriptions of subject ascertainment, and most do not have good information on exposure assessment. Many also may have suffered from incomplete follow-up, as evinced by an overall deficit in the number of deaths observed, compared with the number expected from general population mortality rates. Such problems are not unique to studies on acrylonitrile, and to some extent they reflect the difficulties of conducting retrospective cohort studies. Despite these drawbacks, a simplified meta-analysis of the mortality experience reported for these cohorts revealed little evidence for carcinogenicity. Approximately the same number of cancer deaths was observed as was expected according to general population mortality rates (standardized mortality ratio 1.03, 90% confidence interval 0.92-1.15). The combined information from these studies is insufficient to support confidence about a lack of carcinogenicity at all sites. Nevertheless, despite the flaws in some of the individual studies, the summarized findings offer reassurance that workers exposed to acrylonitrile face no striking increases in mortality for all cancers or for respiratory cancer.

Mortality from tumours in workers in an acrylic fibre factory

A retrospective epidemiological cohort study of mortality was undertaken in 671 workers with at least 12 months' exposure to acrylonitrile (AN) in an acrylic fibre factory at Porto Marghera, Venezia; 571 subjects had simultaneous exposure to dimethylacetamide (DMA). Observed mortality in the cohort was compared with expected mortality, calculated on the basis of the mortality rates of the general population in the Veneto region. A statistically significant excess was found in the mortality rate from intestinal and colon tumours (SMR = 10.5, 4 observed). However, this finding was significant only in subgroups with 1 to 4 years exposure or 1 to 9 years latency. It is therefore concluded that there is no relationship between AN and/or DMA exposure and mortality from tumours of the colon and intestine.

[Hygienic evaluation of working conditions of acrylonitrile fiber processing at textile factories]

Main unfavourable factors of working environment in acrylonitrilic fibres processing are high concentrations of dust, high noise levels, considerable share of hard manual operations. Complex of unfavourable factors leads to reduction of muscular endurance to static effort, prolongation of motor reaction to light irritation, decrease of cellular and humoral immunity of working women. Suggested effective measures reduced dust content in working zone air.

Determination of hemoglobin adducts in humans occupationally exposed to acrylamide

Hemoglobin (Hb) adduct determinations were used to monitor occupational exposure to acrylamide (AA) and acrylonitrile (AN). Forty-one workers in a factory in the People's Republic of China who were involved in the synthesis of AA by catalytic hydration of AN and the manufacturing of polyacrylamides were studied. Ten nonexposed workers in the same city served as controls. AA and AN exposures were monitored using the modified Edman degradation procedure for the determination of their respective Hb adducts to N-terminal valine. The adduct levels in the exposed workers were 0.3-34 nmol/g Hb for AA and 0.02-66 nmol/g Hb for AN, as determined by gas chromatography-mass spectrometry (GC-MS). The formation of glycidamide (GA), the epoxide metabolite of AA, in humans was demonstrated by GC-MS analysis of its Hb adduct to N-terminal valine following acid hydrolysis, ion-exchange chromatography, and derivatization. The GA adduct was detected in samples from the exposed persons with levels of 1.6-32 nmol/g Hb. There was a linear relationship between the AA and GA adduct levels (r = 0.96) and the ratio of the in vivo doses of GA and AA was 3:10. These results suggest that AA is metabolized to GA in humans, as had previously been shown in the rat. The high AA adduct levels in the exposed workers, as compared to those expected from air concentrations, indicate that dermal exposure may contribute significantly to the total uptake of AA. The average daily in vivo doses of AA and GA in the highest exposed workers were comparable to the in vivo doses in rats injected with 3 mg/kg AA. Since a regimen of 2 mg/kg/day is known to cause a significant increase of tumors in rats, preventive measures may be necessary for humans exposed to high levels of AA in industrial settings.

Biological monitoring of acrylonitrile exposure through a new analytical approach to hemoglobin and plasma protein adducts and urinary metabolites in rats and humans

A new, simple and fast procedure of measuring acrylonitrile (ACN) in ACN derived mercapturic acids such as S-(2-cyanoethyl)-L-cysteine(CyEC), and in hemoglobin (Hb) and plasma protein adducts and urinary metabolites in rats and humans exposed to ACN was developed. ACN in mercapturic acids or proteins was analyzed by capillary gas chromatography (GC) by liberating ACN at a high-temperature in the injector port of GC with or without oxidizing sulfur atoms of the ACN-bound cysteines into sulfoxide form by hydrogen peroxide in vitro. At 350 degrees C, more than 90% of ACN in authentic CyEC was recovered by this method. Increasing a single ip dose of ACN from 5 to 50 mg/kg produced proportional increases in ACN bound to Hb 24 hr after the treatment. The alkylation of plasma protein with ACN was about 1/10 as low as that of Hb. After repeated daily ip doses of 1-10 mg/kg, ACN in Hb decreased with a half-life of about 9 days. ACN was also detected in the blood of workers exposed to ACN for 1 to 10 years at a Siberian synthetic rubber factory.

Role of bradykinin in anaphylactoid reactions during hemodialysis with AN69 dialyzers

In vitro experiments have related anaphylactoid reactions in patients treated with angiotensin-converting enzyme (ACE) inhibitors during dialysis with AN69 membranes to excessive bradykinin generation using this negatively charged dialysis membrane. In the present clinical trial plasma bradykinin levels were followed during the early phase of dialysis in 10 patients, not being treated with ACE inhibitors, using AN69, cuprophane, and polysulfone membranes. Bradykinin was measured after extraction by radioimmunoassay. During this study one episode of anaphylaxis occurred during dialysis with the AN69 membrane. Blood samples were collected during the first 5 min of the adverse reaction and showed a more than 100-fold increase in the venous effluent of the AN69 dialyzer (baseline 40 +/- 3 vs. 4,900 +/- 130 fmol/ml after 5 min). Even though none of the patients received ACE inhibitors, there were 4 more asymptomatic individuals who displayed a more than two-fold increase in their plasma bradykinin concentrations in the venous effluent of the AN69 dialyzer. When these patients were treated either with cuprophane or with polysulfone dialyzers, no significant bradykinin formation was detected, nor were there any adverse events. Taken together, these findings show that anaphylactoid reactions with the AN69 membrane are due to excessive bradykinin generation which even may occur in the absence of ACE inhibitors.

Health profiles of workers exposed to acrylonitrile

The objective of this study was to reveal the health effects of acrylonitrile (AN) in seven Japanese acrylic fiber manufacturing factories. The study subjects were 157 AN-exposed male shift workers who had been exposed to AN for 17 years on the average and 537 control workers whose working conditions were similar to those of the AN-exposed workers. The seven factories were classified into two groups according to their AN exposure levels in 1987, and also into three groups on the basis of 1976 exposure levels. The most highly exposed group of subjects showed a mean AN concentration of 1.13 ppm by personal sampling. Medical examination failed to detect any health effects attributable to long-term exposure to AN, although the existence of some symptoms of acute irritation could not be completely ruled out. The results of this study may provide a "no observed effects level" for human on-the-job exposure with regard to the health effects examined here.

Unusual occupational toxins

Occupational and environmental medicine affords encounters with many unusual toxins, ranging from exotic metals to rocket fuels. Twelve of the most unusual industrial toxins are reviewed here and their clinical manifestations and treatments explored: acetonitrile, acrylonitrile, boron hydrides, dimethylaminopropionitrile, dimethylformamide, hydrazines, methyl isocyanate, 2-nitropropane, phosphine, Stalinon, tellurium, and vanadium.

Effect of chronic exposure to acrylonitrile on subjective symptoms

A cross-sectional study was performed to clarify the relationship between exposure to acrylonitrile (AN) and its effect on subjective symptoms by using a modified Cornell Medical Index (CMI) health questionnaire. The 7 acrylic fiber manufacturing factories surveyed were classified into 3 groups, namely, group L with a mean environmental acrylonitrile concentration of 1.8 ppm, group M with 7.4 ppm, and group H with 14.1 ppm. The total number of workers engaged in acrylic fiber manufacturing processes (acrylonitrile workers) and reference workers analyzed were 504 and 249, respectively. These consisted of 92 acrylonitrile workers and 108 reference workers in group L, 304 and 102 respectively in group M, and 108 and 39 respectively in group H. The mean values for length of exposure to acrylonitrile were 5.6 years in group L, 7.0 years in group M, and 8.6 years in group H. Neurotic status as determined by Fukamachi's criteria and Cornell Medical Index profiles did not show any AN-related differences between AN workers and reference workers in any of the groups. The subjective symptoms with significantly high prevalences in AN workers were "headache", "tongue trouble", "choking lump in throat", "fatigability", "general malaise", "heavy arms", and "heavy sweating". Except for "choking lump in throat" there was no relationship between the prevalence of symptoms and the length or level of exposure to acrylonitrile. These results suggested that long-term exposure to acrylonitrile at levels up to 14.1 ppm did not induce neurotic effects in acrylonitrile workers, but might cause some reversible subjective symptoms.

Assessment of blood compatibility of haemodialysis membranes using a miniature flat sheet dialyser

Available pre-clinical techniques of assessing severity of untoward reaction by blood following contact with haemodialysis membranes do not account for the effects of dialysate and flow characteristics in the observed blood changes. A miniature flat sheet dialyser that considered these effects was prepared and tested in both in-vitro and ex-vivo circuits. Changes in platelets and leucocytes in heparinised human blood in-vitro tests did not distinguish regenerated cellulose (Cuprophan 150PM) membrane from a synthetic membrane, a copolymer of acrylonitrile and sodium methyl sulphonate (AN69S). Ex-vivo tests using rats showed more marked leucocyte (41.3%) and platelet (43.1%) depletion by Cuprophan 150PM than AN69S after 90 minutes of dialysis. Leucocyte and platelet loss due to AN69S were 26.9% and 13.4% respectively. In addition, Cuprophan 150PM membranes exhibited high affinity for leucocytes and platelets in both in-vitro and ex-vivo tests compared to AN69S membranes which were primarily covered with erythrocytes. Application of simulated in-use techniques in preclinical evaluation of blood compatibility membranes that are used in extra-corporeal treatment are recommended.

Anaphylactoid reactions in hemodialysis patients treated with the AN69 dialyzer

During an 11 week period (May to July, 1990), we observed six anaphylactoid reactions (AR) in six different hemodialysis patients occurring at the onset of treatment with a new AN69 hollow-fiber dialyzer. Four patients required cardiopulmonary resuscitation and one of these expired. Four patients were also receiving an angiotensin converting enzyme (ACE) inhibitor while the other two were not on medication known to affect the renin-angiotensin system. Only patients treated with AN69 dialyzers were affected. A review of the literature indicated that out of 1087 patients reported, 72 patients were on the combination of an AN69 dialyzer and ACE inhibitor therapy and 41 (57%) demonstrated AR. Only two patients (0.4%; both from our series) treated with an AN69 dialyzer without ACE inhibitor therapy developed AR. AR did not occur in patients treated with a variety of other dialyzers during this 11 week period, with or without ACE inhibition. Possible causes for AR are discussed and include: (1.) blood-AN69 membrane interaction leading to the production of bradykinin and other vasodilators, the breakdown of which may be delayed by the presence of ACE inhibitors; (2.) hypersensitivity to ethylene oxide; (3.) passage of bacterial products from dialysate to blood; (4.) changes in membrane manufacturing specifications. Recommendations are proposed for the prevention and treatment of AR.

Occupational contact dermatitis due to acrylonitrile

Within DSM Chemicals BV, a producer of acrylonitrile, skin complaints are frequent. The majority of these are of an irritant nature, while a smaller portion is based on acquired allergies. Allergological examination revealed 5 employees with an allergy to acrylonitrile. 1 of these subjects also developed paraesthesiae in the skin sites affected, a finding not previously described for acrylonitrile. In the guinea pig maximization test (GPMT), acrylonitrile showed strong allergenic potential. For prevention and treatment of contact allergologic disorders, close cooperation between occupational health officer, dermatologist and toxicologist in chemical companies is recommended.

Testosterone in sera of workers exposed to acrylonitrile

Testosterone was measured through three consecutive years in sera from young and adult male subjects working in a chemical factory exposed to some complex chemical noxae, the major exposure being acrylonitrile (vinylcyanid). In the first yr, (group A), the blood was collected on May 1975 (no 39), the II-nd yr (group B) on March (no 109) and the III-rd yr (group C) on May (no 149). The exposure time varied in each group between 6 mos and 7-10 yrs. For comparison, blood samples were collected from 145 men of comparable age grouped in nonexposed: blood donors (no 37) (group a), new workers (no 23) (group b) and exposed to other chemical noxae in the same factory: Na cyanid (group c, no 23), cyan derivatives (group d, no 22) and pyrolysis (group no 39). The seasonal testosterone variations being considered, the Student's 't' test applied to the hormonal levels in acrylonitrile groups A, B and C showed non significant differences. However, the comparison of the testosterone concentrations in sera of the groups A, B and C vs the control groups investigated during the same month of the year showed much lower levels of the hormone in the first groups (p less than 0.001). These data are suggesting that the exposure to acrylonitrile either by direct participation to the technological chain or by working in the same noxious environment may influence the testosterone synthesis and/or secretion.

[Granulomatous processes in the lungs]

Findings of lung granulomas are not rare but their etiology may be embarrassing in autoptic and especially in bioptic material which is shown in two such cases: a 19-year old drug addict man practising intravenous administration of Alnagon pills and a 54-year old woman working with acrylonitrile fibres. Differential diagnosis of granulomas is discussed at large.

Comparison of two hemodialysis membranes, polyacrylonitrile and cellulose acetate, on complement and coagulation systems

Two hemodialysis membranes, polyacrilonitrile (AN 69) and cellulose acetate (CA), were compared for their effects on complement and hemostasis. Two groups of 5 patients, in dialysis for more than 5 years, were successively dialysed for 4 weeks periods with each type of membrane. We measured C3a (complement activation), platelets and beta-thromboglobulin (platelet activation), thrombin-antithrombin III complexes and fibrinopeptide A (coagulation activation), using C-Reactive Protein as a control for dilution effects. As previously shown, activation of complement was more important with CA than with AN 69 (p less than 0.01). In contrast, activation of coagulation (increase in fibrinopeptide A and thrombin-antithrombin III complexes) was more pronounced with AN 69 than with CA. This study emphasizes the need to consider different biological systems when the bioincompatibility of a hemodialysis membrane is evaluated.

Mortality patterns among employees exposed to acrylonitrile

A cohort of 2671 men, 1774 of whom were exposed to acrylonitrile, was observed from 1951 through 1983 for mortality. No statistically significant excess of all-cause or cause-specific mortality was observed. Analysis of exposure duration to acrylonitrile with respiratory cancer mortality showed no trend. Men exposed to high levels of acrylonitrile had respiratory cancer rates similar to men not exposed in the workplace and to the US general male population. These study results do not support the hypothesis that acrylonitrile is a human carcinogen.

Cancer incidence of workers exposed to dimethylformamide and/or acrylonitrile

This study was to determine whether exposure to dimethylformamide (DMF) and acrylonitrile (ACN) separately or in combination, was associated with increased cancer incidence. Workers exposed to DMF and/or ACN were observed from 1956 through 1984 for cancer incidence. The workers exposed to DMF but not ACN showed significant excesses in incidence for buccal cavity and pharynx cancer and malignant melanoma. A significant excess of prostate cancer incidence was observed among workers exposed to DMF and ACN. No dose-response relationships were observed between DMF or ACN exposure and cancer incidence. The significant excesses in cancer incidence among employees exposed to DMF and/or ACN could be due to statistical chance or other factors, such as tobacco and alcohol consumption. Further studies are warranted.

Mortality study of workers exposed to dimethylformamide and/or acrylonitrile

Workers exposed to dimethylformamide (DMF) and/or acrylonitrile (ACN) were observed from 1950 through 1982 for mortality. The wage-roll workers exposed to DMF showed significant excess in total deaths attributable mainly to ischemic heart disease and external causes when compared with rates from E. I. Du Pont de Nemours & Co. However, there were no significant excesses in mortality when expected numbers were based on US or local statistics. No dose-response relationships were observed between DMF or ACN exposure and mortality. The significant excesses in mortality among employees exposed to DMF and/or ACN could be due to statistical chance or life-style factors

Cancer incidence and mortality among workers exposed to acrylonitrile

A cohort of 1,083 male employees who had potential for exposure to acrylonitrile between 1944 and 1970 at a Du Pont textile fibers plant were followed through 1981 for mortality and through 1983 for cancer incidence. In total, the 21 cancer deaths were fewer than expected based on either Du Pont or U.S. rates. No significant excesses were seen by primary site. In all, 37 cancer cases occurred as compared with 36.5 expected based on company rates. Five lung cancer cases were observed and 6.9 expected. There were 5 prostate cancer cases as compared with 1.9 expected. Of these, 4 occurred among wage employees during the 1975-1983 period, compared to 0.9 expected. This excess was statistically significant.

Epidemiology of brain tumours in man and their relationship with chemical agents

The 2000 or so deaths that result each year in England and Wales from brain tumours, as defined by ICD 191, represent approximately 0.3-0.4% of all deaths, with a slightly greater incidence in men than in women. Because of the low incidence of mortality from other causes in childhood, brain cancer accounts for 3.5% of all deaths in the 1-14-year age group. Mortality from brain cancer increased considerably between 1931 and 1961 but this is probably explained by changes in disease classification and improvements in diagnostic techniques. Because of the relatively low incidence of brain cancer in man, cohort studies need to be large in order to accrue sufficient cases for meaningful interpretation. Large cohort studies may run the risk of diluting a high-risk group of workers with lesser or non-exposed individuals. These considerations have encouraged the investigation of brain cancer by case-control studies and the interpretation of these must take into account possible sources of bias. At present the evidence for any chemical causation of brain cancer in man is inconclusive.

Epidemiologic study of workers exposed to acrylonitrile: an update

A previous report presented the cancer morbidity and mortality experience through 1976 of a cohort of 1,345 male employees with potential for exposure to acrylonitrile at a fibers-producing plant. This study has now been updated through 1983 for cancer incidence and through 1981 for mortality. Overall, 43 cancer cases have occurred, with 37.1 expected based on company rates. A previously reported excess number of cases of lung cancer remains, but is not as marked (10 observed, 7.2 expected). Prostate cancer cases were significantly in excess, with six cases observed and 1.8 expected. Mortality analyses revealed 36 cancer deaths, with 31.6 expected. Of these, 14 were from lung cancer, with 11.6 expected based on company rates. Only one death from prostate cancer occurred, with 1.0 expected. To our knowledge, prostate cancer excesses have not been reported in any other acrylonitrile studies, and hence their significance is currently difficult to assess.

Effects of toxic chemicals on the reproductive system. Council on Scientific Affairs

In an effort to make physicians more aware of the hazards of the workplace to pregnant workers, the Council on Scientific Affairs' Advisory Panel on Reproductive Hazards in the Workplace prepared this third and final report reviewing the effects of chemical exposure. A total of 120 chemicals were considered for reviews based on an estimation of their imminent hazard, ie, widespread use and/or inherent toxicity. Following a brief introduction, which sets out general principles, clinical applications, and aids to the recognition of a human teratogen, the report presents reviews and opinions for three representative chemicals. Information concerning the remaining 117 compounds is available upon request.

[Production technology and use of composite materials in the aeronautics industry, risks and pathology in the manufacturing workers]

The type and applications of composite materials have increased greatly during the last forty years, particularly in the aircraft and aerospace industries. The foreseeable increase of the employment of composite materials in future needs an adequate engagement in finding out health risks involved with technological processes. Composite materials - considered as a close union between a continuous glass, aramid or carbon reinforcing fibre and a epoxy matrix - present several advantages over traditional materials. Structural epoxy adhesives are defined as complex formulated systems. By mixing a large number of ingredients a formulated resin is obtained, which represents the start of the production process for adhesive manufacture. The most important ingredients such as catalysts, accelerators, the groups of epoxy monomers and oligomers, additives most used and their role into the epoxy matrices are illustrated. Of the various technologies existing for the fabrication of aircraft structures the one so called "vacuum bag" is described. The knowledge of the chemical composition of the substances used in the production of composite materials and epoxy adhesives allows to verify the possible existence of hazard for workers health. Among the potentially dangerous chemicals, epoxy monomers and oligomers, catalysts, accelerators are to be considered. The metabolism and the mechanisms of toxicity of epoxides are summarized. However the toxic effects of most epoxides are far from being wholly investigated. In man epoxides ingestion, inhalation or absorption through the skin can lead to several toxic effects: irritation and sensitisation, alterations of liver and nervous function. Finally some epoxides are considered to be carcinogenic in animals and in man; however for many compounds, the results are not yet conclusive. From what it is said above come out the necessity of a careful sanitary control of the workers exposed to these hazards, control that is made difficult by the lack of adequate biological indices for the risks found.

A review of health risks in acrylonitrile industry

The Occupational Health Branch of the Ontario Ministry of Labour began a study in 1978 for the evaluation of health risks associated with acrylonitrile (AN) exposure. Detailed hygiene and medical investigations were conducted in fourteen plants for evaluating AN exposure in various industrial processes. For companies were also studied in relation to mixed chemical exposure representing acrylic fibres, nitrile rubber, ABS-resin, and acrylic emulsions production. The possible interaction between AN and other coexisting chemical exposures was reviewed since dimethyl formamide, styrene, and butadiene have similar pharmacokinetics and possible synergistic effects. Exposure in acrylic fibre production may be synergistic and carcinogenic. Results of air monitoring indicated exposure levels to AN below 2 ppm (TWA) in most cases. Exposure to other co-existing chemicals was evaluated. Results of medical tests indicated no significant abnormalities in chest x-rays or liver function tests in currently exposed workers.

Nasal allergy in spinning mill workers and the possibility of allergenicity of chemical fibers and cotton linters

During a three-year period from 1976, we examined fifty eight patients with nasal allergy who worked in spinning mills or handled sewing machines. Skin tests and procative nasal tests were performed on these patients with crude and fractionated extracts from cotton linters, cotton cloth and chemical fibers. The crude aqueous antigens were extracted in dextro-phenol solution and fractionated by Saphadex G-100. It was possible that the cotton and chemical fibers included components which were the cause of hypersensitivity, but there is still doubts concerning their reaction as irritant substances. Serum specific IgE antibody was found in extracts from chemical fiber. Therefore, spinning mill dust acts as an irritant of the nose add the possibility of antigenicity of the dust for immediate type nasal allergies can not be denied from the present study.

Mortality of United Kingdom acrylonitrile polymerisation workers

The mortality of 1111 men who worked on the polymerisation of acrylonitrile and the spinning of acrylic fibre from 1950 to 1968 was surveyed up to the end of 1978. Seventy-nine deaths were identified. The population was drawn from six factories, where polymerisation started before 1968, in England, Wales, Scotland, and Northern Ireland. In the group of men exposed to acrylonitrile for at least one year the total number of deaths was smaller than expected. An excess of deaths from all cancers was found, arising mainly from cancers of the lung, stomach, colon, and brain, but the excess was not statistically significant. Significant excesses of stomach cancer overall and in those aged 55-64, and of lung cancer in those aged 15-44 were found. Consideration of deaths according to factory indicated that the excesses of stomach cancer may have been due to regional factors. The excess of lung cancer was investigated further in view of the fact that, unusually, it occurred in relatively young men, but no consistent difference between the duration of exposure to acrylonitrile of the three young patients with lung cancer and matched controls was found. The study is limited and further analysis in the future is needed. The results are not conclusive and neither add to nor detract from existing suspicions that acrylonitrile is a human carcinogen but, taken together with evidence from other studies, indicate the necessity for the continuing surveillance of the exposed population in the United Kingdom.

Epidemiologic study of workers exposed to acrylonitrile

This retrospective cohort study of 1,345 male employees with potential for exposure to acrylonitrile analyzes cancer incidence and mortality from 1956 to 1976. Expected numbers based on company and national rates have been computed on person-years. The analyses consider calendar time, payroll classification, occupation, duration of exposure, severity of exposure, and latency. Overall, 25 cases of cancer occurred, with 20.5 expected based on company rates. Of these, eight were respiratory cancer cases, with 4.4 expected. Excesses were found primarily during the 1970-76 time period among wage roll employees who had worked during plant start-up. A trend toward increased risks was seen with increased duration and severity of exposure. Twenty cancer deaths were found, with 17.4 expected according to company rates. Since many cancer cases were recently diagnosed and are living, it may be premature to evaluate mortality statistics. These findings, coupled with results from tests in laboratory animals, raise the serious suspicion that acrylonitrile may be a human carcinogen.

[Change in the blood serum amino acid spectrum in workers engaged in the manufacture of acrylonitrile and the ways for its correction via nutrition]

A group of 100 workers employed in acrylonitrile production were examined. The blood serum showed a decreased content of free sulfur-containing, mostly indispensable amino acids, free sulfhydryl groups and diminution of the activity of blood enzymes. On the basis of the data obtained a diet has been developed which includes foodstuffs rich in amino acids. After 24 days on this diet the workers were examined at the prophylactorium of the chemical works. The diet was shown to exert a favourable effect on the content of free amino acids and activity of serum enzymes.

Complications of implantation of synthetic fibers into scalps for "hair" replacement: experience with fourteen cases

Fourteen cases of complications from implantation of acrylic fibers into scalps for correction of male-pattern baldness were studied. The complications were severe enough in all of them to force attempts to remove the fibers, many of which from the nature of their knotted insertion could not be extracted. Thus, immediate complications were encountered and serious, delayed, bad effects are anticipated. Among the early complications already observed are marked edema of the face; hemorrhagic oozing; microbial infection; foreign-body reactions; scarring; acneform comedones and pustules; pain, pruritus, and numbness; and loss of natural hair. Complications in the furture are likely to be progressive sclerosis from irretrievable fragments and knots of the artificial materials and conceivably malignant degeneration of tissues of the scalp. For all of these known and possible bad effects, implantation of present-day synthetic fibers into the scalp must be judged to be a dangerous practice that must be stopped at once.

Analysis of chromosomes of workers exposed to acrylonitrile

Examination of 18 workers who had been exposed to acrylonitrile for 15.3 years on average and 18 workers who had not been exposed to acrylonitrile showed no difference in the incidence of chromosome aberrations; for each person concerned 100 metaphases were evaluated.