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Biomedical subjects

R T Gun

Publications and source records attributed to R T Gun.

At least 19 recordsLinked to original sources
PubMed2006

Update of mortality and cancer incidence in the Australian petroleum industry cohort.

OBJECTIVES: To update the analysis of the cohort mortality and cancer incidence study of employees in the Australian petroleum industry. METHODS: Employees of Australian Institute of Petroleum member companies were enrolled in the cohort in four industry-wide surveys between 1981 and 1999. Mortality of 16,547 males and 1356 females was determined up to 31 December 2001 and cancer incidence to 31 December 2000. Cause specific mortality and cancer incidence were compared with those of the Australian population by means of standardised mortality ratios (SMRs) and standardised incidence ratios (SIRs). Associations between increased incidence of specific cancers and employment in the petroleum industry were tested by trends according to period of first employment, duration of employment, latency, and hydrocarbon exposure, adjusting for personal smoking history where appropriate. RESULTS: There was a significant elevation of the incidence of mesothelioma (SIR 1.77, 95% CI 1.05 to 2.79), melanoma (SIR 1.37, 95% CI 1.19 to 1.58), and prostate cancer (SIR 1.18, 95% CI 1.04 to 1.34). The SIRs of all leukaemias and of acute non-lymphocytic leukaemia (ANLL) were not significantly different from unity, but all 11 ANLL cases were clustered in the middle to high hydrocarbon exposure categories. Tanker drivers had a significantly elevated incidence of kidney cancer (12 cases v 5.84 expected, SIR 2.05, 95% CI 1.06 to 3.59). Lung cancer incidence was significantly reduced (SIR 0.69, 95% CI 0.57 to 0.83) CONCLUSIONS: Most cases of mesothelioma are probably related to past exposure to asbestos in refineries. No occupational cause has been identified for the excess of melanoma, or prostatic or bladder cancer. The possibility of a causal relationship between cancer of the kidney and hydrocarbon exposure warrants further study. It is uncertain whether benzene exposures, particularly past levels of exposure, have been high enough to cause ANLL.

Australia↗
PubMed2004

Update of a prospective study of mortality and cancer incidence in the Australian petroleum industry.

AIMS: To update the analysis of the cohort mortality and cancer incidence study of employees in the Australian petroleum industry. METHODS: Employees from 1981 to 1996 were traced through the Australian National Death Index and the National Cancer Statistics Clearing House. Cause specific mortality and cancer incidence were compared with those of the Australian population by means of standardised mortality ratios (SMRs) and standardised incidence ratios (SIRs). Associations between increased incidence of specific cancers and employment in the petroleum industry were tested by trends according to period of first employment, duration of employment, latency, and hydrocarbon exposure, adjusting for personal smoking history where appropriate. Total follow up time was 176 598 person-years for males and 10 253 person-years for females. RESULTS: A total of 692 of the 15 957 male subjects, and 16 of the 1206 female subjects had died by the cut off date, 31 December 1996. In males, the all-cause SMR and the SMRs for all major disease categories were significantly below unity. There was a non-significant increase of the all-cancer SIR (1.04, 95% CI 0.97 to 1.11). There was a significant increase of the incidence of melanoma (SIR 1.54, 95% CI 1.30 to 1.81), bladder cancer (SIR 1.37, 95% CI 1.00 to 1.83), and prostate cancer (SIR 1.19, 95% CI 1.00 to 1.40), and a marginally significant excess of pleural mesothelioma (SIR 1.80, 95% CI 0.90 to 3.22), leukaemia (SIR 1.39, 95%CI 0.91 to 2.02), and multiple myeloma (SIR 1.72, 95% CI 0.96 to 2.84). CONCLUSIONS: Most cases of mesothelioma are probably related to past exposure to asbestos in refineries. The melanoma excess may be the result of early diagnosis. The excess bladder cancer has not been observed previously in this industry and is not readily explained. The divergence between cancer incidence and cancer mortality suggests that the "healthy worker effect" may be related to early reporting of curable cancers, leading to increased likelihood of cure and prolonged mean survival time.

Australia↗
PubMed1998

A cluster of haematuria cases in a pesticide-manufacturing plant.

In a pesticide manufacturing and formulating facility, 10 employees out of 48 were shown to have haematuria on dipstick testing. They included seven of the 27 production workers, all of whom had worked in both of two particular areas prior to the commencement of the routine urine testing. Five of the seven production workers with haematuria underwent further investigations, and in all five the haematuria was glomerular in origin. Two underwent renal biopsy, which showed irregular attenuation of the glomerular basement membrane (GBM) but no abnormality by light microscopy. Immunofluorescence studies were negative. This case series of glomerular haematuria is not readily explained by chance, false positive dipstick testing, or a recognizable non-occupational cause. Thin GBM disease, which is a benign condition, appears the likely explanation. Thin GBM disease is usually an autosomal dominant condition, but clustering of these genotypes in this small population is improbable.

Adult↗
PubMed1998

Carbon monoxide exposures in Australian workplaces could precipitate myocardial ischaemia in smoking workers with coronary artery disease.

BACKGROUND: Quite low levels of carbon monoxide (CO) exposure have been shown experimentally to induce myocardial ischaemia in subjects with coronary artery disease. This study examines the actual exposure levels in Australian workplaces under normal operating conditions, to assess whether the resulting carboxyhaemoglobin (COHb) levels are high enough to present a risk of myocardial ischaemia in any workers who may have recognised or unrecognised coronary artery disease. METHODS: A total of 84 workers took part in the study, 60 of whom were working in an environment where a combustion process was taking place indoors and were therefore classified as exposed to CO. Ambient CO levels and end-expiratory CO levels (the latter as a predictor of COHb) were measured two-hourly and the number of cigarettes smoked over an eight-hour shift recorded. RESULTS: Mean workplace CO levels throughout the shift ranged between three and 12 ppm. Mean COHb ranged between 0.7% and 2.1% in non-smokers and 2.1%-7.6% in smokers, except for a single reading of 12.5% in forklift operations (one smoker). Exposed workers had significantly higher COHb levels than the non-exposed, both for smokers and non-smokers. Smoking also had an important independent effect on COHb. CONCLUSION: Under workplace conditions prevailing in industries where combustion processes are occurring indoors, CO exposures are unlikely to be high enough to cause myocardial ischaemia in non-smokers. However in a worker whose COHb is already raised from smoking, an increment from such occupational environments could be sufficient to induce myocardial ischaemia in workers with coronary artery disease.

Australia↗
PubMed1997

Occupational risk factors for Alzheimer disease: a case-control study.

There is evidence to support the role of a number of environmental factors in Alzheimer disease (AD). This study examines the role of chemical and physical exposures in the occupational environment. The sample included 170 patients with AD and 170 medical-practice-based controls, matched for age and sex, who were assessed for histories of occupational exposures to a range of chemical and physical agents, including hydrocarbon solvents, lead, mercury, organophosphates, aluminum, asbestos and other silicates, vibration, and physical underactivity. Occupational histories were obtained from informants for both patients and controls. Exposure was assessed by a panel of occupational hygienists, blinded to the case or control status of each subject, using the occupational histories and the Job-Exposure Matrix of the U.S. National Institute for Occupational Safety and Health. No statistically significant associations were found between any of the exposures and the occurrence of AD, either in the overall study group or in patients with a family history of AD. The findings suggest the absence of any occupational cause for AD.

Aged↗
PubMed1995

Mesothelioma: is asbestos exposure the only cause?

BACKGROUND: Although a causal association between mesothelioma and occupational exposure to asbestos is beyond dispute, nearly all population-based studies of mesothelioma have found some proportion of cases with no history of asbestos exposure. DATA: Incidences of mesothelioma in men and women not occupationally exposed to asbestos for the period 1980-1985 were generated from: (i) estimates of occupational exposure to asbestos in the general male population, obtained from population-based controls in a case-control study of incident cancer in South Australia; and (ii) National Mesothelioma Surveillance Program data. The incidence in men not occupationally exposed was 8.5 per 1,000,000 person-years, compared with 2.6 per 1,000,000 person-years in women, a difference of 5.9 per 1,000,000 person-years (90% confidence interval, 4.8-7.2). CONCLUSION: Mesothelioma without a history of asbestos exposure may be caused by asbestos in the general environment, but this fails to explain why such cases occur more commonly in men. Alternative explanations include the existence of another independent cause of mesothelioma, or of a co-factor which, combined with "environmental" levels of asbestos exposure, constitutes a sufficient cause. Such a risk factor is likely to be occupational, in which case mesothelioma may be expected to occur even after occupational asbestos exposures have been eliminated.

Asbestos↗
PubMed1995

Effects of thermal, personal and behavioural factors on the physiological strain, thermal comfort and productivity of Australian shearers in hot weather.

Multiple-regression analyses were used to evaluate the separate and combined effects of factors that are commonly expected to influence strain and productivity in a hot workplace. Forty-three men were studied throughout 54 man-days of shearing sheep and pressing wool bales, in air temperatures 19-41 degrees C and Wet-bulb Globe Temperature index (WBGT) 16-29 degrees C; 43% of the observations of WBGT exceeded 26.7 degrees C, the Threshold Limit Value (TLV) for the subjects' work rate of 400 W. Subjects were men of age 18-59 years, fat-free mass 44-77 kg, and body fat content 11-26%, who had drunk an estimated 0-207 g alcohol the previous evening. Afternoon mean values of rectal temperature (Tre) exceeded 38.0 degrees C (maximum 38.4 degrees C) in 4 of the 15 observations made when WBGT > TLV, and in none of those made when WBGT < TLV. Over the 10 h work day the subjects sweated 2.4-9.9 kg, but they replaced their sweat losses so successfully that warmer weather and heavier sweating were not accompanied by significantly greater dehydration. Surprisingly, the fatter men felt cooler, and those who had drunk more alcohol the previous evening had lower Tre and tended to be more productive. Age was not associated with any measured response. All factors together explained barely half the observed variation in Tre and thermal comfort, and almost none of the variation in productivity. The findings highlight the uncertainty inherent in attempts to define safe limits for occupational heat stress; they show how such uncertainty could restrict the usefulness in the shearing industry of the current heat-stress guidelines; and they demonstrate the effectiveness of the behavioural responses that permit shearers to perform sustained strenuous work in a hot environment without excessive physiological strain.

Adolescent↗
PubMed1993

A study of building structural features associated with high indoor air concentrations of organochlorine termiticides.

As part of a two-year study of post-treatment residential exposure to the termiticide, aldrin, the building structural features of ten houses with crawl-space-type floors were assessed by an independent inspector. Building attributes recorded on a checklist included the age of the dwelling, room characteristics, floor details and the nature of subfloor ventilation. At the end of each inspection, the inspector, who was blinded to data on airborne aldrin concentrations, provided a rating of expected indoor air contamination. Several of the building attributes, including the age of the house, the area of exterior subfloor vents, as well as the inspector's rating, were significantly correlated with airborne aldrin values. No single building variable, however, was highly correlated with every measure of aldrin concentration over a 12-month period. The observed data are consistent with poor subfloor ventilation and a 'leaky' floor being important contributors to indoor air pollution. It is recommended that pest control companies advise householders about any obvious floor and ventilation deficiencies before soil treatment work is undertaken. Pesticide exposure (by analogy with geological radon exposure) may be reduced by sealing gaps in floors and/or by improving subfloor ventilation.

Air Pollution, Indoor↗
PubMed1990

The incidence and distribution of RSI in South Australia 1980-81 to 1986-87.

Despite the human and financial cost of repetition strain injury (RSI), comprehensive incidence data have been lacking. A unique opportunity exists to obtain such data in South Australia, where since 1980-81 the Australian Bureau of Statistics has assigned all injuries, not explicitly diagnosed as diseases but stated as having been caused by repetitive movement, to a unique "type of accident" code, and has subclassified them according to bodily location. The statistical profile of diseases and accidents affecting the upper limb resulting from repetitive movement is not simply one of a keyboard operators' epidemic. Rather, it has revealed a problem which is endemic in sections of the blue-collar workforce, in whom both the numbers and the incidence rates are higher than in keyboard operators, and were higher even when the incidence in keyboard operators peaked in 1984-85. These conditions have been especially frequent in particular sections of the female blue-collar workforce, and interventions which have resulted in (or coincided with) benefits to keyboard operators have failed to improve the situation in the former group. It is suggested that the groups most at risk are female workers performing unfulfilling, unskilled tasks, and that interventions to benefit these workers will have to give attention to more fundamental issues than those hitherto addressed.

Accidents↗
PubMed1990

Worksafe Australia: to the McKay report and beyond.

The health and safety of workers was not the only raison d'être for Worksafe Australia. To the Hawke Government, to the ACTU hierarchy and to the employers, a federal initiative in occupational health was a vital item in the ALP-ACTU Accord which would lock the unions into wage restraint. To the already powerful Commonwealth Department of Employment and Industrial Relations the initiative was a golden opportunity to establish a new federal structure under its influence. Thus a bureaucracy, top-heavy with administrators, came into being whilst established national occupational health activities ground to a halt. Plagued by dissent from within and criticism from without, the organisation was saved from extinction only by its importance to the Accord. In 1987 the Government appointed Mr. B. V. McKay to review Worksafe Australia, following which the activities of the organisation were streamlined, with due acknowledgement now given to the key role of the States in giving effect to nationally-agreed policies and standards. However problems remain, and the future of Worksafe Australia is still uncertain.

Accident Prevention↗
PubMed1988

Ultralow volume application of organophosphate concentrate in grain terminals: a new occupational health hazard.

The introduction of ultralow volume (ULV) application of the organophosphate pesticide Fenitrothion in grain terminals presents a risk to workers of skin contact with concentrate. Blood testing, by the Ellman method, of a group of five grain terminal workers working on grain treatment showed a lowering of mean red blood cell cholinesterase (RBC ChE) activity to 23 units/gm Hb (normal value 28-40) with a range of 16-29. The probable cause was identified as percutaneous absorption of Fenitrothion concentrate by workers using ungloved hands to clean blocked drip feed nozzles. Modification of work practices was followed by a rise of mean RBC ChE to 33.6 units/gm Hb (range 32-36) during the following grain treatment season. RBC ChE activity measured during the intervening winter season--that is, a non-exposure period--showed a mean of 33.3 units/gm Hb (range 23-40).

Agricultural Workers' Diseases↗