Two volunteers were exposed to various airborne concentrations of triethylamine. Levels of 18 mg/m3 for eight hours caused subjective visual disturbances (haze and halos) and objective corneal oedema. The effects faded within hours after the end of exposure. The visual disturbances are unpleasant and may cause accidents at work and in traffic after the end of work.

Fifty eight coal miners attended the Royal Gwent Accident and Emergency Department with serious hand injuries over a three year period. The commonest cause of the injuries was falling rock or coal from the pit roof crushing the hand and the commonest type of injury was the crushed, compound fracture of the terminal phalangeal area of the digit, with or without pulp loss. Records of the time off work with the injury were obtained in 52 miners. Only seven (13%) returned to work within one month. Of 40 individual distal phalangeal injuries reviewed after one year, only four (10%) had normal sensation and full movement at the distal joint. Nevertheless, only seven miners (13%) had to alter their initial occupation at the mine and move to lighter duties.

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An inquiry into the relation between exposure to silica dust, the presence of silicosis, and progressive systemic sclerosis was conducted in white South African gold miners by means of a case-control study. Seventy nine cases of progressive systemic sclerosis were matched by year of birth with an equal number of control miners selected randomly but bearing in mind the administrative channel through which the case had come to be identified. Analysis showed no association between silicosis and PSS but did show that the cumulative life time silica exposure was significantly higher in the cases compared with controls. This difference was due to a difference in the intensity of exposure to silica during mining service rather than a difference in duration of service. The results are discussed in the context of current thought on the aetiology of progressive systemic sclerosis, particularly in relation to autoimmune and genetic factors.

The concentrations of smoke, polycyclic aromatic hydrocarbons (PAHs), and some gaseous air pollutants have been measured in two London Transport diesel bus garages and compared with observations made in the same garages over 20 years earlier. The main feature of the results was a large reduction in the background concentrations of smoke and polycyclic aromatic hydrocarbons from sources such as coal fires, attributable to the implementation of the Clean Air Act. Contributions from the buses to the benzo(a) pyrene content of the air inside the garages were of the same magnitude as before, being small in relation to former coal smoke contributions.

In Armadale, a town in central Scotland, the standardised mortality ratios (SMRs) for lung cancer were exceptionally high during 1968-74. A large cluster of cases was found in a residential zone downwind from a foundry. In the present study death certificates in the mortality registers of three town parishes were analysed for 1961-82 and the time trends of mortality from major categories of disease were examined. The distribution of mortality from lung cancer within Armadale's six residential zones was compared with that of the other diseases for the periods 1968-75 and 1976-82; the zone of particular interest was that containing the original cluster of lung cancer. The distribution of lung cancer was also compared with the pattern of air pollution by metals, collected by Sphagnum moss bags. The annual numbers of deaths from respiratory cancer in Armadale rose to a plateau in 1968-77; after a fall during 1978-80, the numbers returned in 1981 and 1982 to their previous high values. Between 1968-75 and 1976-82 the mean SMRs for all the disease categories except respiratory cancer rose. The SMR for total mortality in 1976-82 was the same as in preceding years when the standardised death rate for Armadale was the highest for Scotland in the annual reports of the Registrar General. In the zone with the highest mortality from lung cancer in 1968-75 the SMR for that disease continued to be higher than expected. That zone also showed the highest SMRs for cancer of the upper alimentary tract, cerebrovascular disease, hypertension, and coronary heart disease; its SMR for bronchitis was the second highest in the town. Pollution studies indicated that zones with high SMRs for respiratory and non-respiratory cancer were exposed to air pollution by metals. The temporal and spatial patterns are consistent with the view that the problem of mortality from cancer and non-malignant diseases in Armadale remains.

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After the catastrophic losses of three Hull deep sea trawlers in 1968, the Committee of Inquiry into Trawler Safety (CITS) was established. Fourteen months later, CITS reported on factors affecting the safety of deep sea trawlers and their crews. Pre-CITS (1961-70) and post-CITS (1971-80) crude mortality rates for accidents at work are compared for "deep sea" fishermen (those working on vessels greater than or equal to 24.4 m (80 feet) registered length) and "inshore" fishermen (those working on vessels less than 24.4 m). The ratio of deep sea to inshore fishermen had changed from 1:1.5 (1961) to 1:7.0 (1980), reflecting the radical restructuring of the fishing fleet that began in the early 1970s. Between 1961 and 1980, there were 909 recorded deaths at sea of United Kingdom fishermen. Of these, 711 (78%) were due to accidents (either from vessel losses or personal accidents) and 198 (22%) were due to unspecified disease, homicide, and suicide. Comparison of pre-CITS and post-CITS mean death rates showed an increase (+39%) for deep sea fishermen, a decrease (-4%) for inshore fisherman, and an increase (+2%) for both combined. For deep sea fishermen, there were synchronous increases in mortality from vessel losses (+32%) and from personal accidents (+49%, p less than 0.05) whereas the overall rate for inshore fishermen reflected a decrease (-33%, p less than 0.01) in deaths from personal accidents but an increase (+52%) in deaths from vessel losses. Although pre-CITS mortality rates exhibited no statistically significant difference between deep sea fisherman was significantly greater (p< 0.02). Compared with coal miners, fishermen were, on average, four times more likely to die from accidents at work. If CITS had reasonable cause for concern in 1969, the grounds for similar concern did not diminish because the evidence suggests that deep sea fishermen were at no lesser risk of death from accidents after CITS reported than before. Overall, both groups of fishermen experienced an accident mortality rate between 1961 and 1980 that showed no indication of improvement.

Static exposure of rats to methyl isocyanate, for one hour, led to respiratory impairment during and after exposure. The resultant changes in breathing pattern suggest that this compound is both a sensory and a pulmonary irritant. Low concentrations resulted in extensive necrosis and loss of epithelial cells in the proximal airways but widespread alveolar damage was found only after exposure to high, lethal concentrations. At high concentrations methyl isocyanate probably caused peracute death through reflex inhibition of breathing. Animals surviving the exposure exhibited signs of airway narrowing and development of (haemorrhagic) pulmonary oedema. The epithelial lesions were repaired rapidly, but residual peribronchial fibrosis and signs of renewed injury/inflammation were apparent.

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Acute toxic effects of methyl isocyanate in the rat were determined for two hour exposures to concentrations in the range 11 ppm (very slight effect) to 65 ppm (lethality: pulmonary oedema). Changes in the eye, lungs, and behaviour were noted. Eye changes were confined to erosions of the corneal epithelium and were most severe at intermediate levels of exposure. A comparison was made of the effects noted in rats with reported effects on survivors of the Bhopal disaster. Urinary thiocyanate concentrations in exposed rats were found to be reduced relative to control values.

The relation of respiratory symptoms, pulmonary function, and abnormalities of chest radiographs to estimated exposures of borax dust has been investigated in a cross sectional study of 629 actively employed borax workers. Ninety three per cent of the eligible workers participated in the study and exposures ranged from 1.1 mg/m3 to 14.6 mg/m3. Symptoms of acute respiratory irritation such as dryness of the mouth, nose, or throat, dry cough, nose bleeds, sore throat, productive cough, shortness of breath, and chest tightness were related to exposures of 4.0 mg/m3 or more, and were infrequent at exposures of 1.1 mg/m3. Symptoms of persistent respiratory irritation meeting the definition of chronic simple bronchitis were related to exposure among non-smokers. Decrements in the FEV1 as a percentage of predicted were seen among smokers who had heavy cumulative borax exposures (greater than or equal to 80 mg/m3 years) but were not seen among less exposed smokers or among non-smokers. Radiographic abnormalities were uncommon and were not related to dust exposure. Borax dust appears to act as a simple respiratory irritant and perhaps causes small changes in the FEV1 among smokers who are heavily exposed.

The job-exposure matrix described has been developed for use in population based studies of occupational morbidity and mortality in England and Wales. The job axis of the matrix is based on the Registrar General's 1966 classification of occupations and 1968 classification of industries, and comprises 669 job categories. The exposure axis is made up of 49 chemical, physical, and biological agents, most of which are known or suspected causes of occupational disease. In the body of the matrix associations between jobs and exposures are graded to four levels. The matrix has been applied to data from a case-control study of lung cancer in which occupational histories were elicited by means of a postal questionnaire. Estimates of exposure to five known or suspected carcinogens (asbestos, chromates, cutting oils, formaldehyde, and inhaled polycyclic aromatic hydrocarbons were compared with those obtained by detailed review of individual occupational histories. When the matrix was used exposures were attributed to jobs more frequently than on the basis of individual histories. Lung cancer was significantly more common among subjects classed by the matrix as having potential exposure to chromates, but neither method of assigning exposures produced statistically significant associations with asbestos or polycyclic aromatic hydrocarbons. Possible explanations for the failure to show a clear effect of these known carcinogens are discussed. The greater accuracy of exposures inferred directly from individual histories was reflected in steeper dose response curves for asbestos, chromates, and polycyclic aromatic hydrocarbons. The improvement over results obtained with the matrix, however, was not great. For occupational data of the type examined in this study, direct exposure estimates offer little advantage over those provided at lower cost by a matrix.

Synthetic pyrethroids are neurotoxic insecticides with a low mammalian toxicity. Prior investigations have found these agents to be neither cutaneous irritants nor sensitisers. Clinically demonstrable inflammation, as judged by erythema, oedema, or vesiculation, has not been apparent. Nevertheless, paraesthesia does result from cutaneous exposure. In this investigation technical grade flucythrinate was applied to the forearms of human participants twice daily for five consecutive days. Laser Doppler velocimeter measurements were made before each topical application, with histamine phosphate being intradermally injected on termination of the study. Results of both laser Doppler velocimetry and histamine induced axon reflex vasodilatation were not statistically significant at an alpha = 0.05 level. This investigation suggests that the synthetic pyrethroids have little influence on neurogenic vasodilatation on topical exposure.

There are reports that 1,2-dichloropropane, a constituent of many commercial solvents and stain removers in Italy, has caused severe liver damage and, sometimes, acute renal failure. Between 1980 and 1983 three cases of 1,2-dichloropropane intoxication (1 by ingestion, 2 by inhalation) were observed. Clinical features included severe liver damage, acute renal failure (2 patients), haemolytic anaemia, and disseminated intravascular coagulation. The most surprising features were haemolytic anaemia and disseminated intravascular coagulation which have not been reported before. The clinical picture was similar despite different modes of exposure.

Nine healthy male volunteers were exposed to m-xylene for four hours a day, three hours in the morning and one hour in the afternoon, with a 40 minute break in between, at six day intervals during six succeeding weeks to explore the effects of m-xylene on the sense of balance. The atmospheric m-xylene concentrations were either fixed at 8.2 mumol/l (200 ppm) or they fluctuated (5.2-16.4 mumol/l; 135-400 ppm) with peaks of 16.4 mumol/l and duration of 10 minutes at the beginning of each exposure session. The subjects were sedentary or exercised at 100 W for 10 minutes at the time of the peaks. The two control days, with and without exercise, were similar to the exposure days but without exposure. Body sway was measured with the subjects' eyes open and closed before they entered the chamber and in the chamber immediately after the cessation of the peak exposure when blood samples for gas chromatographic analysis were also drawn. Changes in the eyes closed/open ratio of the average and maximal body sway along the sagittal and lateral axes were calculated using the morning value as a reference. Changes in the eyes closed/open ratios of both average and maximal body sway correlated positively with blood m-xylene concentrations during fixed (8.2 mumol/l) exposure at rest and during fluctuating exposure combined with exercise as analysed with linear regression analysis. The results suggest that m-xylene has a dose related effect on the sense of balance at moderate atmospheric levels.

The recent finding of cases of silicosis among jade workers in Hong Kong points to this disease being an occupational hazard. The source was found to be the silica flour that was added in a polishing process. Five cases are described together with the results of environmental investigation in a workplace. In three cases the disease was of early onset, rapidly progressive, and presented the features of galloping silicosis noted in other occupational exposures to silica flour. One patient had massive fibrosis and severe glomerulonephropathy, an association that has also been previously noted. One case showed evidence of active tubercular infection in addition to silicosis and two had healed lesions. Silica concentrations in the workplace during the suepect process were well above accepted threshold limit values.

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Cadmium induced renal effects were examined in 60 workers (58 men, 2 women) previously exposed to cadmium. Tubular damage in the form of beta 2-microglobulinuria was found in 40%, and urinary albumin and orosomucoid increased significantly with increasing urinary cadmium and increasing relative clearance of beta 2-microglobulin. It is suggested that increased albumin excretion is secondary to the tubular damage. In no case was typical glomerular proteinuria found that could be related to cadmium. Histories of renal stones were more common among the workers with high urinary cadmium concentrations. The glomerular filtration rate was measured in 17 of the workers who had pronounced tubular dysfunction. The average glomerular filtration rate for these men was less than the age adjusted predicted value (mean = 84%). Furthermore, there was a significant (p less than 0.05) correlation (r = -0.47) between tubular reabsorption loss and a decreased glomerular filtration rate.

The Association of Plastic Manufacturers in Europe maintains a register of all cases of angiosarcoma of the liver (ASL) resulting from exposure to vinyl chloride monomer (VCM). This register has recorded all known VCM related cases of the disease worldwide that have been histologically confirmed. Although likely to be incomplete, it is the most comprehensive tabulation of such cases available and, by the end of 1984, 118 men had been registered. The information from analysis of the cases currently on the register is used to make an approximate projection of the number of cases to be expected in the future. The conclusion from this projection is that the industry is reaching the halfway stage in the appearance of VCM related ASL.

Dust from the village of Karain containing the fibrous zeolite erionite, talc, and physiological saline were tested by intraperitoneal injection in 486 Swiss albino mice. Malignant tumours were found in 84 (41 mesotheliomas, 31 lymphomas, 1 peripheral epidermoid carcinoma, and 11 lymphomas and mesotheliomas together) of the 321 animals which died spontaneously within nine to 32 months after injection of Karain dust (26.1%). Three mesotheliomas and no lymphomas were found among 24 animals injected in the same way with talc during the same time (12.5%). In 46 control animals injected with physiological saline three mesotheliomas and one lymphoma were seen (8.7%). Thus Karain dust appears to be a potent carcinogen, causing both mesotheliomas and malignant lymphomas.

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In a 30 year follow up study of 8526 men aged 20 and over in the Rhondda Fach 99.9% of the population was traced. Generally, the results are similar to those found in a 20 year follow up of the same subjects. Miners and ex-miners had an excess mortality compared with non-miners, but within the former only those who had had categories B and C pneumoconiosis showed a raised mortality. Category A pneumoconiosis was not associated with any excess compared with other miners and ex-miners. Two further aspects of the data relating to gastric cancer and progressive massive fibrosis will be examined in later reports.