Occupational health in Australia.

Australia is a developed country in the Asia-Pacific Region with a large land area but a small population. Its main economic activities are mining, agriculture and manufacturing, with its service and high-technology industries being the fastest growing sectors in recent years. The regulation and enforcement of Occupational Health and Safety policies are mainly administered by the Industrial Relations Departments of eight State and Territory jurisdictions in the country. A National Occupational Health and Safety Commission coordinates occupational health and safety at the Commonwealth level. In 1987 the six occupational health and safety priorities in Australia were listed as occupational back pain, management of chemicals used at work, occupational noise-induced hearing loss, occupational skin disorders, occupational cancer and mechanical equipment injury. Australia has probably the highest incidence of malignant mesothelioma in the world, although the use of asbestos has been largely phased out. There was an almost explosive "epidemic" of repetition strain injury in the 1980s. Approximately 500 work-related fatalities and 10,000 work-related injuries are notified for workers' compensation every year. In addition, it is estimated that there are several thousand cases of work-related diseases every year, many of which go unreported. Occupational physicians undergo 4 years of specialisation training. Occupational hygienists, nurses and ergonomists receive training supervised by their respective professional organisations.

Hypertonic saline challenge in an adult epidemiological survey.

Bronchial provocation tests using pharmacological agents such as methacholine or histamine are used in epidemiological studies to identify asthma despite recognition of limitations in specificity, positive predictive value and availability of reagents. Hypertonic saline (4.5%) bronchial challenge (HSBC), although less sensitive than pharmacological challenges, is reportedly highly specific in diagnosing current asthma. Added advantages are that reagents are cheap, stable and recognized by participants. Thus, HSBC may offer benefits over pharmacological tests in epidemiological surveys. This paper reports on the second field survey using the test, a study of 99 adults from the timber industry in Western Australia. The test is described and critically appraised as a practical epidemiological tool for assessing asthma prevalence. At a cutoff point of 20% FEV, fall, HSBC was positive in 8% of subjects, appeared specific for asthma, was safe, well-accepted and easy to use in the field.

Risk factors for birth defects in Singapore: a case control study.

To explore possible risk factors for birth defects, a matched case-control study was carried out at Kandang Kerbau Hospital in Singapore from January 1986 to December 1988. Cases and controls were selected from livebirths born in that hospital during that period. Cases were babies who were clinically detected as having defects at birth and the diagnosis reconfirmed at 6 weeks post partum. Each case was matched to a control by maternal age, ethnic background of mother, the same class of maternity ward and time of delivery. Five hundred and seventy-two matched pairs were accrued for the study. The parents of both cases and controls were interviewed at 6 weeks post partum. Information on the medical and birth history of both mother and baby was obtained from medical records. Using conditional logistic regression analysis to adjust for potential confounders, the strongest risk factors for birth defects were family history of birth defects (OR 3.3; 95% CI 1.8-6.4) and parents having a previous abnormal baby (OR 2.4; 95% CI 1.1-5.3). Other notable risk factors included drug history during pregnancy (OR 1.2; 95% CI 0.8-2.0), the ingestion of traditional medicine during pregnancy (OR 1.4; 95% CI 1.0-2.0), injuries or accidents during pregnancy (OR 2.2; 95% CI 1.5-3.2) and maternal diabetes mellitus (OR 1.3, 95% CI 0.3-7.1). Mothers in professional occupations (OR 1.4, 95% CI 0.7-2.6) and those in production occupation (OR 1.2, 95% CI 0.9-1.7) had an increased risk for birth defects compared to housewives.(ABSTRACT TRUNCATED AT 250 WORDS)

Descriptive profile of birth defects among livebirths in Singapore.

A case-control study of birth defects was carried out in Kandang Kerbau Hospital in Singapore for a three-year period from January 1986 until December 1988. This paper presents the descriptive profile of birth defects among livebirths seen in that hospital. Out of 44,842 livebirths, 678 babies were found to have birth defects, giving a prevalence of 15.13 per 1000 livebirths (95% CI 14.0-16.2). The musculoskeletal system was the most frequently affected system accounting for 161 cases with a prevalence of 3.59 per 1,000 livebirths (95% CI 3.06-4.19), followed by 111 cases with defects of the gastrointestinal system (2.47 per 1,000 livebirths 95% CI 2.04-2.98), 88 cases of chromosomal disorders (prevalence of 1.96 per 1,000 livebirths 95% CI 1.57-2.42), 78 cases with defects of the cardiovascular system (1.74 per 1,000 livebirths 95% CI 1.38-2.17), 73 cases with defects of the urogenital system (1.63 per 1,000 livebirths 95% CI 1.28-2.05), and 52 cases with defects of the central nervous system (1.16 per 1,000 livebirths 95% CI 0.87-1.52). The prevalence of cleft lip, cleft palate in isolation, and cleft lip and palate combined was 1.72 per 1,000 livebirths and the occurrence of Down's syndrome was 1 in 700 livebirths. When reviewed 6 weeks postpartum, the rate of false positives at birth was 4%. In a control group of 709 "normal" cases at birth, the rate of cases not detected at birth but detected at 6 week follow-up, false negatives was 0.84%.

PIP: A case-control study of birth defects was carried out in Kerdang Kerbau Hospital in Singapore over a 3-year period from January 1986 to December 1988. This paper presents the descriptive profile of birth defects among live births seen in that hospital. Of 44,842 live births, 678 babies were found to have birth defects, which gives a prevalence of 15.13/1000 live births (95% CI 14.0-16.2). The musculoskeletal system was the most frequently affected system, accounting for 161 cases with a prevalence of 3.59/1000 live births (95% CI 3.06-4.19), followed by 111 cases with gastrointestinal system defects (2.47/1000 live births, 95% CI 2.04-2.98), 88 cases of chromosomal disorders 1.96/1000 live births, 96% CI 1.57-2.42), 78 cases with cardiovascular system defects (1.74/1000 live births, 95% CI 1.38-2.17), 73 cases with urogenital system defects (1.63/1000 live births, 95% CI 1.28-2.05), and 52 cases with central nervous system defects (1.16/1000 live births, 95% CI 0.87-1.52). The prevalence of cleft lip, cleft palate in isolation, and cleft lip an palate combined was 1.72/1000 live births and the occurrence of Down's syndrome was 1 in 700 live births. When reviewed 6 weeks postpartum, the rate of false positives at birth was 4%. Among a control group of 709 normal cases at birth, the rate of cases not detected at birth but at the 6-week followup showed a rate of 0.84% false negatives.

Cardiovascular diseases in Chinese, Malays, and Indians in Singapore. II. Differences in risk factor levels.

STUDY OBJECTIVE: The aim of the study was to examine cardiovascular risk factors to see how these might explain differences in cardiovascular disease mortality among Chinese, Malays, and Indians in the Republic of Singapore. DESIGN: The study was a population based cross sectional survey. Stratified systematic sampling of census districts, reticulated units, and houses was used. The proportions of Malay and Indian households were increased to improve statistical efficiency, since about 75% of the population is Chinese. SETTING: Subjects were recruited from all parts of the Republic of Singapore. SUBJECTS: 2143 subjects aged 18 to 69 years were recruited (representing 60.3% of persons approached). There were no differences in response rate between the sexes and ethnic groups. MEASUREMENTS AND MAIN RESULTS: Data on cardiovascular risk factors were collected by questionnaire. Measurements were made of blood pressure, serum cholesterol, low and high density lipoprotein cholesterol, fasting triglycerides and plasma glucose. In males the age adjusted cigarette smoking rate was higher in Malays (53.3%) than in Chinese (37.4%) or Indians (44.5%). In both sexes, Malays had higher age adjusted mean systolic blood pressure: males 124.6 mm Hg v 121.2 mm Hg (Chinese) and 121.2 mm Hg (Indians); females 122.8 mm Hg v 117.3 mm Hg (Chinese) and 118.4 mm Hg (Indians). Serum cholesterol, low density lipoprotein cholesterol and triglyceride showed no ethnic differences. Mean high density lipoprotein cholesterol in males (age adjusted) was lower in Indians (0.69 mmol/litre) than in Chinese (0.87 mmol/litre) and Malays (0.82 mmol/litre); in females the mean value of 0.95 mmol/litre in Indians was lower than in Chinese (1.05 mmol/litre) and Malays (1.03 mmol/litre). Rank prevalence of diabetes for males was Indians (highest), Malays and then Chinese; for females it was Malays, Indians, Chinese. CONCLUSIONS: The higher mortality from ischaemic heart disease found in Indians in Singapore cannot be explained by the major risk factors of cigarette smoking, blood pressure and serum cholesterol; lower high density lipoprotein cholesterol and higher rates of diabetes may be part of the explanation. The higher systolic blood pressures in Malays may explain their higher hypertensive disease mortality.

Motorcyclist traffic accidents and risk factors: a Singapore study.

Motorcyclist accidents cause significant morbidity and mortality in Singapore. To elucidate personal and environmental factors associated with such accidents, we studied 198 motorcyclists who were hospitalized in Singapore General Hospital between April 1986 and June 1987. The patients were mostly young and almost exclusively male with a high proportion of Malays. Most accidents occurred on Sundays and at night. Ten percent of the victims took alcohol before the accident. Most had low injury severity scores (ISS). Less experienced drivers had a significantly higher ISS than those with one year or longer of driving experience. Vigorous control of drunken driving, through public education and intensive breath testing, should reduce the incidence of traffic accidents.

Driving experience and the risk of traffic accident among motorcyclists.

In a case-control study on the risk of traffic accidents among motorcyclists in Singapore, we demonstrated an inverse monotonic relationship between accident risk and driving experience. As compared to drivers with less that 1 yr of driving experience, the odds ratios (adjusted for race, age and frequency of riding) for those with driving experience of 1-4, 5-9 and 10 yr or more were 0.60, 0.50 and 0.36, respectively. We propose that intensive in-circuit training of learner motorcyclists should replace the conventional on-the-road training on the basis that the former serves to increase their driving experience without subjecting the learner motorcyclists to the risk of sustaining road accident.

Non-fatal injuries among motorcyclists treated as in-patients in a general hospital.

In a study of the injury pattern among 198 motorcyclists who sustained road traffic accidents from 1986-1987, it was found that the following body regions, in decreasing order of frequency, were involved: external region (surface or integumentary lesion of any body region) with 285 injuries, extremities and bony pelvis with 118 injuries, head and face with 94 injuries, chest with 10 injuries, abdomen with 3 injuries, and spine with 2 injuries. Despite the extensive use of crash helmets, head injuries were still a common and severe form of injury resulting from traffic accidents, indicating the need for improvement of safety standards of crash helmets. Lower limb injuries, mostly fractures of bones and dislocation of joints, are also amenable to prevention through design of leg protection devices. Injuries to other body regions are difficult to prevent and other measures such as legal and administrative means, should be fully exploited in accident prevention.

Epidemiological transition in Asian countries and related health policy issues.

The transition in morbidity and mortality from largely communicable diseases to largely non-communicable diseases has been effected in many Asian countries, particularly those which are newly-industrializing. Consequently, significant changes in national health policies have been made to cope with new problems such as the increasing numbers of old people, occupational diseases, accidents and cancer. AIDS, hepatitis B and the "tropical diseases" should, however, remind un that communicable diseases are still very important in Asian countries.

History of blood transfusion, tattooing, acupuncture and risk of hepatitis B surface antigenaemia among Chinese men in Singapore.

To determine whether a history of blood transfusion, tattooing, and acupuncture is associated with an increased risk of hepatitis B surface antigenaemia, a study of 6,328 Chinese men between 35 and 65 years of age was undertaken in Singapore. The age-adjusted odds ratios were 1.44 (95% CI: 1.14, 1.83) for blood transfusion, 1.14 (95% CI: 0.80, 1.63) for tattooing, and 0.88 (95% CI: 0.71, 1.11) for acupuncture. Using no history of any of the three percutaneous procedures as reference, the age-adjusted odds ratio for blood transfusion only was 1.40, 95% CI: 1.07, 1.84, and for blood transfusion plus tattooing was 2.59, 95% CI: 1.18, 5.70. The proportion of HBsAg positive cases attributable to blood transfusion and tattooing, as measured by the population attributable risk, are 4.1 and 0.7 per cent, respectively.

Mercury in scalp hair of healthy Singapore residents.

Two hundred and twenty-five hair samples (150 Chinese, 44 Malays and 31 Indians) from healthy residents not occupationally exposed to mercury were analyzed by cold vapour atomic absorption spectrophotometry to determine their total, inorganic and organic mercury levels. The arithmetic means of total mercury levels in hair were 6.1, 5.2 and 5.4 ppm for the Chinese, Malays and Indians, respectively. Factors contributing to the amount of mercury in hair, including consumption of fish and marine products, use of traditional ethnic medicines, artificial hair waving, age, sex and ethnicity were analyzed. Fish consumption, sex and ethnicity are factors found to contribute significantly (p less than 0.05) to mercury levels in hair.

Atomic absorption spectrophotometric microdetermination of total mercury in undigested biological samples.

The influence of reaction time upon stannous (II) chloride as a reductant in the cold-vapor atomic absorption spectrophotometric method was investigated. In this comparative study, virtually all operating conditions, including volumes and chemicals used, were made identical except for the redesigning of the reaction vessels. The use of a reaction mixing time of 2 minutes (TR method), rather than immediate bubbling with aspiration (IL method) of total mercury from undigested biological samples, has several advantages. There is an average 4.5-fold increase in sensitivity of peak height readings with virtually no loss of mercury vapor from the reaction vessel by diffusion. Using the TR method also eliminated interaction of mercury with the matrices investigated, viz., undigested blood, undigested saliva, undigested urine, and digested hair samples. The average recovery for the TR method was superior to the IL method, 99.3 +/- 3.2% vs. 84.7 +/- 3.3%, p less than 0.05. In addition, mercury concentrations determined with the TR method were identical using either peak area or peak height readings. It was also found that concentrations determined using either the formulae given by Magos and Clarkson (4) and Farant et al. (5) or an aqueous calibration curve were equivalent. Only 0.2-1.0 mL of biological samples was needed for each analysis in the study.

Toluene in blood after exposure to toluene.

Analysis of the postshift toluene levels in the blood of 50 assembly line workers indicates that toluene levels in blood were correlated with the time-weighted average (TWA) exposure levels of the same day (r = 0.90). Toluene concentrations in 10 laboratory technicians not exposed to toluene at their work gave an average level of 0.002 microgram/mL of blood. Significant levels of residual toluene were found in the preshift blood of workers exposed to 57 to 146 ppm of toluene as compared to the unexposed. The blood toluene values determined from capillary blood taken from finger tips are higher than the reported values from venous blood. The method described is useful for large-scale screening and epidemiological surveys.