Occupational and Environmental Medicine

Baxter, P J; Anthony, P P; Macsween, R N; Scheuer, P J

doi: 10.1136/oem.37.3.213pmid: 7191719

The annual occurrence of angiosarcoma of the liver (ASL) in Britain from 1963 to 1977 was studied, including clinical and occupational details for those cases agreed as ASL by a panel of histopathologists. Thirty-five cases (28 men, six women, and one infant girl) were agreed as ASL. The increase in the incidence of ASL observed in recent years was attributable to Thorotrast (thorium dioxide) usage (eight cases) and exposure to vinyl chloride (two cases) in the past. In its clinical presentation and prognosis ASL resembled primary liver carcinoma, except that extrahepatic metastases were found in only eight (23%) cases, and haemoperitoneum ws more common in those cases due to Thorotrast. The results suggested a possible increased risk of ASL in the electrical and plastics fabrication industries, but information on exposure was inadequate to implicate specific chemicals. The clinical features of one case were indicative of arsenical intoxication, but medications in the other patients did not appear to be of aetiological importance.

Cecchi, F; Buiatti, E; Kriebel, D; Nastasi, L; Santucci, M

doi: 10.1136/oem.37.3.222pmid: 7426471

Adenocarcinoma of the nose and paranasal sinuses has been associated with occupational exposure to wood and leather dust. Strong evidence has been found for such an association in Florence, Italy, from 1963 to 1977. Sixty-nine cases of primary cancer of the nose and paranasal sinuses were identified from hospital records. There were 13 cases of adenocarcinoma, 11 of which were successfully traced and interviewed (patient or relative). Of the 11 cases, three were woodworkers with substantial exposure to wood dust (17 years' average employment) and seven were shoemakers, mostly trimmers. When matched to either of two separate sets of controls (non-cancer hospital patients, and non-adenocarcinoma nose or paranasal sinus cancer patients), the association with occupation was statistically significant. Smoking was ruled out as a source of bias.

Cochrane, A L; Moore, F

doi: 10.1136/oem.37.3.226pmid: 7426472

A survey carried out in 1957 by the Medical Research Council's Pneumoconiosis Unit was based on a private census, with brief industrial histories of men aged 55-64 and 25-34. Four groups were established in this way--"non-dusty," "pure coal-mining," "pure foundry," and "other and mixed." In the 55-64 age group all 387 men have been followed up except for one man, about whom we have no information, and another man, for whom we know the date of death but not the certified cause. The mortality from all causes is similar in all four groups, but there is a slight suggestion of a past or present dust problem, or both, in the foundry population. It is suggested that Staveley is, so far, the bet area we have found for studying simple pneumoconiosis of coal-miners. If this suggestion is accepted the mortality rates for miners and ex-miners with simple pneumoconiosis seem similar to those of the same age not exposed to industrial dusts, living in the same area, with similar smoking habits.

Cochrane, A L; Moore, F

doi: 10.1136/oem.37.3.230pmid: 7426473

A 20-year follow-up of a population sample of men aged 25-34 has been completed in Staveley, Derbyshire. The sample was based on a private census, with brief industrial histories, that enabled four groups to be established--"non-dusty," "pure coal-mining," "pure foundry," and "other and mixed." The similarity of the mortality rates of non-dusty, coal-mining, and foundry groups is satisfactory, but there is, however, a surprisingly high mortality rate in the other and mixed group. We were unable to explain this on the basis of their industrial exposure, and only to a very limited extent by their smoking habits. We suggest that there is a small group of uncooperative men, overweight for their height and heavy smokers, who self-select themselves into jobs that are classified in a study such as this as other and mixed.

Cherry, N; Waldron, H A; Wells, G G; Wilkinson, R T; Wilson, H K; Jones, S

doi: 10.1136/oem.37.3.234pmid: 6107122

A group of men exposed to styrene in a factory building glass-fibre boats performed a series of behavioural tests at the beginning and end of their shift, and the results were compared with those of a referent group from the same factory. Changes in mood were noted in both groups of workers but were greater in the exposed men; moreover, the change in mood was correlated with blood styrene concentration. In the styrene workers the morning reaction time was slower than that for the referents. During the day the reaction time of the men with low blood styrene concentration (less than or equal to 5.4 mumol/l) speeded up and in the afternoon was similar to that of the referents; the reaction time for the men with high blood styrene concentration (greater than or equal to 5.5 mumol/l) was unchanged. Data taken from a questionnaire indicated that the men exposed were much more likely than was the referent group to report feeling unduly tired. They also reported feeling more tired on Friday night than Monday night, suggesting that the styrene might have a cumulative effect through the week.

Takeuchi, Y; Ono, Y; Hisanaga, N; Kitoh, J; Sugiura, Y

doi: 10.1136/oem.37.3.241pmid: 7426474

The neurotoxicity of n-pentane, n-hexane, and n-heptane have been studied in Wistar strain male rats after exposure to 3000 ppm of n-pentane, n-hexane, or n-heptane for 12 hours a day for 16 weeks. The nerve conduction velocity and the distal latency were measured before the beginning of the exposure and after exposure for four, eight, 12, and 16 weeks. The experiment showed that n-hexane disturbed the conduction velocity of the motor nerve and the mixed nerve and prolonged the distal latency in the rat's tail, but that n-pentane and n-heptane did not. The light and electron microscopic examination showed that the peripheral nerve, the neuromuscular junction, and the muscle fibre of the rats exposed to n-hexane were severely impaired, but those of the rats exposed to n-pentane or n-heptane showed no particular changes even after 16 weeks of exposure. These results show that n-hexane is far more toxic to the peripheral nerve of the rat than n-pentane or n-heptane. It is necessary to study the neurotoxicity of other petroleum hydrocarbons, since some reports suggest that petroleum solvents might possibly contain neurotoxic hydrocarbons other than n-hexane.

Harries, M G; Burge, P S; O'Brien, I M

doi: 10.1136/oem.37.3.248pmid: 7426475

Thirty-seven patients with asthma or alveolitis thought to result from exposure to materials commonly encountered at their work were tested by inhalation of an aerosol of these materials. Twenty-four (65%) developed an immediate asthmatic reaction, which was followed by a non-immediate reaction in 10, of whom six developed the signs and symptoms of alveolitis. Eighteen (76%) patients with asthmatic reactions to test material were prick test positive to that material while only two our of 13 with a negative inhalation test were prick test positive (15%). Precipitating antibody to test material was measured in 23 and was present in nine (39%) of those with positive inhalation tests, and one (12%) of those with negative tests. It was present in five of the six with a reaction in the gas exchanging portions of the lung.

Lees, R E M

doi: 10.1136/oem.37.3.253pmid: 7426476

ABSTRACT Seventeen men were studied during the cleaning of bottom ash from the boiler of an oil-fired electricity generating station. The men were exposed to a time weighted average respirable dust (<10 μ) of 523 μg/m3, containing 15·3% vanadium. Sixteen of the men wore respirators, subsequently found to have peak leakages of up to 9%, while one volunteer had a one-hour exposure wearing only a compressed paper oronasal mask. Symptoms experienced by the men were recorded, urine samples were collected for assessment of vanadium concentration 24 hours after the first exposure, and spirometry was performed daily for four days and on the eight day. Pronounced reductions in forced vital capacity (mean 0·5 l), forced expiratory volume (mean 0·5 l), and forced mid-expiratory flow (mean 1·16 l/s) had occurred within 24 hours of first exposure to the dust, and had not returned to pre-exposure levels by the eight day. Four weeks after exposure no residual deficits were present. A urinary vanadium concentration of 280 μg/l was found in the volunteer, but none of the others had concentrations above the test-threshold of 40 μg/l. Symptoms and signs of airway irritation were noted. The timing, duration, and quality of changes in lung function, however, indicated that the response could not be attributed solely to a reflex bronchial reaction to irritation by an inert dust.

Liddell, F D; McDonald, J C

doi: 10.1136/oem.37.3.257pmid: 7426477

Two cohorts of chrysotile miners and millers in Quebec were selected to study the extent to which chest radiographs taken while still employed predict mortality. The paper presents mainly findings in much the larger cohort, which consisted of 4559 men (two-thirds past workers) whose latest radiograph had been assessed by one of six experienced readers into what became the UICC/Cincinnati (U/C) classification; by the end of 1975 there had been 1543 deaths in this cohort. The findings were generally confirmed in the other cohort, comprising 988 current male workers, who had been examined in 1967-8 by questionnaires on respiratory symptoms and smoking and by lung function tests, and for whom all six readers had assessed their 1966 radiographs into the U/C classification; 130 men had died by the end of 1975. Men with any radiographic abnormality, heavy dust exposure, or a history of cigarette smoking had relative risks (RRs) of total mortality greater than unity. Death from pneumoconiosis was associated with small parenchymal opacities, usually irregular, of profusion l/l or more, and with heavy dust exposure but not with smoking. Most who died from lung cancer had smoked cigarettes, or had been heavily exposed to dust, or both. Small parenchymal opacities were present in most but not all the excess deaths due to lung cancer. Deaths from other malignant diseases showed no consistent dust or x-ray patterns. RRs of deaths from most other causes were raised for certain radiographic features. Failures in forecasting mortality were primarily due to deaths in which asbestos-related disease was not the primary cause but may have been a contributing factor. The main findings validated the U/C classification convincingly, particulary as the films had been taken as routine and were of modest quality. Despite objective rules for the reading and the fact that all six readers were contributing to the development of the classification, there was inevitably some observer variation. The importance of radiographic technique and the need for careful control of the reading is evident. Our results provide support for the use of the chest radiograph for surveillance of asbestos workers, and for environmental monitoring. Its protective value for individual workers, however, is limited to the extent that radiological progression continues after withdrawal from exposure, and by the carcinogenic risk associated with dust already retained.

McMillan, G H; Pethybridge, R J; Sheers, G

doi: 10.1136/oem.37.3.268pmid: 7426478

In follow-up studies of samples of employees at two of Her Majesty's Dockyards the prevalence of asbestos-related lesions in smokers and ex-smokers was statistically significantly higher than in non-smokers even when differences in age and exposure risk were considered.