High risk occupations for non-Hodgkin's lymphoma in New Zealand: case-control study.

OBJECTIVES: Previous studies into occupational risk factors for non-Hodgkin's lymphoma (NHL) in New Zealand have indicated that farmers and meat workers are at increased risk for these neoplasms. A new nationwide case-control study was conducted to assess whether previously observed associations persist and to identify other occupations that may contribute to the risk of NHL in the New Zealand population. METHODS: A total of 291 incident cases of NHL (age 25-70 years) notified to the New Zealand Cancer Registry during 2003 and 2004, and 471 population controls, were interviewed face-to-face. The questionnaire collected demographic information and a full occupational history. The relative risk for NHL associated with ever being employed in particular occupations and industries was calculated by unconditional logistic regression adjusting for age, sex, smoking, ethnicity and socioeconomic status. Estimates were subsequently semi-Bayes adjusted to account for the large number of occupations and industries being considered. RESULTS: An elevated NHL risk was observed for field crop and vegetable growers (OR 2.74, 95% CI 1.04 to 7.25) and horticulture and fruit growing (OR 2.28, 95% CI 1.37 to 3.79), particularly for women (OR 3.44, 95% CI 0.62 to 18.9; OR 3.15, 95% CI 1.50 to 6.61). Sheep and dairy farming was not associated with an increased risk of NHL. Meat processors had an elevated risk (OR 1.97, 95% CI 0.97 to 3.97), as did heavy truck drivers (OR 1.98, 95% CI 0.92 to 4.24), workers employed in metal product manufacturing (OR 1.92, 95% CI 1.12 to 3.28) and cleaners (OR 2.11, 95% CI 1.21 to 3.65). After semi-Bayes adjustment the elevated risks for horticulture and fruit growing, metal product manufacturing and cleaners remained statistically significant, representing the most robust findings of this study. CONCLUSIONS: This study has confirmed that crop farmers and meat workers remain high risk occupations for NHL in New Zealand, and has identified several other occupations and industries of high NHL risk that merit further study.

Microalbuminuria in a middle-aged workforce. Effect of hyperglycemia and ethnicity.

OBJECTIVE: To determine the prevalence of microalbuminuria in a mixed, ethnic population and to find the extent that ethnic variation in microalbuminuria can be explained by abnormal glucose metabolism, obesity, hypertension, hypertriglyceridemia, and life-style factors. RESEARCH DESIGN AND METHODS: Urinary albumin concentrations were measured in 5467 middle-aged Maori, Pacific Islander, and European workers who participated in a health-screening survey of 46 New Zealand companies. Participants provided a first-voided, morning urine sample; had a 75-g oral glucose tolerance test; had weight, height, and blood pressure measured; and completed a self-administered questionnaire about past medical history and sociodemographic status. RESULTS: A significantly higher prevalence of microalbuminuria was found in individuals with new cases of diabetes mellitus (24.1%), in cases of diabetes mellitus previously diagnosed (20.6%), and in those with impaired glucose tolerance (16.1%) compared with nondiabetic individuals (4.0%). Moreover, in the general population, a piecewise linear relationship was detected between albuminuria and plasma glucose with significant changes of slope corresponding with 2 h plasma glucose concentrations (95% confidence interval) of 6.7 (6.4-7.0) and 9.2 (8.6-9.8) mM, respectively. After adjusting for sex, obesity, hypertension, hypertriglyceridemia, cigarette smoking, and heavy alcohol consumption in a multivariate model, glycemia was the most significant determinant of urinary albumin concentrations in all three ethnic groups. However, blood glucose concentrations did not completely explain the higher relative risk (95% confidence interval) of microalbuminuria in Maori (5.97; 4.48-7.78) and Pacific Islander (5.33; 4.13-6.87) workers compared with European workers. CONCLUSIONS: Of the variables investigated, hyperglycemia was the most important factor explaining the high prevalence of microalbuminuria in Maori and Pacific Islander workers compared with the European workers. However, only 14.9% of the variation in urinary albumin concentrations was found in our multivariate model, and we have speculated on the contribution of other factors such as diet and coexisting renal diseases.

Serum 25-hydroxycholecalciferol concentration in newly detected hypertension.

Although blood concentrations of the active metabolite 1,25-dihydroxyvitamin D are raised in hypertension, concentrations of 25-hydroxyvitamin D, the main vitamin D metabolite, do not appear to have been reported in newly detected hypertension. Serum levels of 25-hydroxycholecalciferol were measured in 186 newly detected hypertensive patients (blood pressure > 160/95 mm Hg and never on antihypertensive medication) and normotensive controls individually matched by sex, age (+/- 2 years), ethnicity, and date of interview. Serum 25-hydroxycholecalciferol levels were similar in cases (mean (SD) = 64 (21) nmol/L) and controls (67 (28) nmol/L, P = .20). We conclude that serum 25-hydroxycholecalciferol, a marker of body vitamin D, is normal in hypertension.

Serum 25-hydroxyvitamin D3 levels decreased in impaired glucose tolerance and diabetes mellitus.

A cross-sectional survey was carried out in a New Zealand Polynesian and Caucasian workforce of 5677 staff aged 40-64 years to determine whether serum concentrations of 25-hydroxyvitamin D3 are altered in people with newly diagnosed diabetes mellitus and impaired glucose tolerance (IGT). Serum 25-hydroxyvitamin D3 concentration was significantly lower in newly detected cases with diabetes and IGT (n = 238) compared with controls individually matched by sex, age (+/- 2 years), ethnicity, and date of interview (mean (S.D.): 69 (31) vs. 76 (34) nmol/l; P = 0.0016). Among controls, serum concentrations were significantly lower in Maori (mean (S.E.) = 65 (5) nmol/l; P = 0.0013) and Pacific Islanders (59 (4) nmol/l; P = 0.0001) compared with Europeans (82 (3) nmol/l), after adjusting for age, sex, and time of year. We conclude that diabetes and IGT are associated with low serum concentrations of 25-hydroxyvitamin D3 and that low concentrations of this hormone in New Zealand Polynesians may partly explain their increased prevalence of diabetes/IGT compared with Europeans.

Organic solvent induced chronic toxic encephalopathy: extent of recovery, and associated factors, following cessation of exposure.

AIMS: to determine extent and nature of recovery of solvent induced chronic toxic encephalopathy (CTE). METHOD: 21 confirmed cases had repeat neuropsychological and clinical assessments 6-42 (mean 27) months after ceasing exposure. An exposure score was calculated for each. RESULTS: less than half (42.8%) showed evidence of improvement, which showed no association with time away from solvents or exposure score. The more severely affected at first diagnosis were nearly four times more likely to improve (RR 3.85 (95%CI 1.03, 14.38), p = 0.03). Those with no subjective improvement were five times more likely to have been on antidepressants (RR 5.25 (95%CI 0.83, 33.2), p=0.02). CONCLUSIONS: The largely irreversible nature of Type 2 CTE is confirmed. The study results suggest that severity of effect and partial recovery are not dose related but multifactorial, with individual susceptibility probably important. Concomitant depression may also adversely influence recovery.

Contrast sensitivity in organic-solvent-induced chronic toxic encephalopathy.

This is a study of visual contrast sensitivity in a series of subjects with previously diagnosed occupational organic-solvent-induced chronic toxic encephalopathy. Contrast sensitivity was measured for 16 subjects using the Vistech VCTS 6500 chart. The results were compared with age-stratified normal data. Six of the 16 subjects (37.5%) recorded abnormal contrast sensitivity results. Monocular abnormalities were found for two (33%) of these subjects. Statistically significant abnormalities in contrast sensitivity were observed at the intermediate spatial frequencies of three cycles per degree (cpd; P < .0005), 6 cpd (P < .025), and 12 cpd (P < .01). We conclude that contrast sensitivity is abnormal in some cases of occupational organic-solvent-induced chronic toxic encephalopathy. Intermediate spatial frequency channel neurones in the visual system may be more vulnerable to solvent toxicity than those of low or high spatial frequency. Contrast sensitivity testing may be a useful adjunct in the diagnostic process for this disease. Further research involving larger numbers of subjects is recommended.

Asymptomatic bacteriuria in a multiracial workforce.

Prevalence of asymptomatic bacteriuria was determined in the first morning urine specimens from 5669 people who participated in a health screening survey of a local workforce. Higher age-standardized prevalences were observed in Maori women (18.0%), compared with Pacific Island women (9.8%) and European women (8.7%). Similarly, higher prevalences were observed in Maori men (3.2%), compared with Pacific Island men (0.7%) and European men (1.3%). After controlling for age and gender, the relative risk for asymptomatic bacteriuria in Maori people was estimated to be 2.22 times that for non-Maori people (associated 95% CI: 1.54-3.18). Significant associations of bacteriuria included a past history of myocardial infarction, a past history of kidney disease, absence of tertiary education, and impaired glucose tolerance. The most common pathogens, isolated from a subsample of 1660 participants, were Escherichia coli, 27 cases (50.9%), and Streptococcal sp, 14 cases (26.4%).

The distribution of occupations in two populations with upper limb pain.

Occupations of two geographically distinct populations of patients with upper limb pain were examined. Relative risks for being in an occupation were calculated for subjects with epicondylitis, carpal tunnel syndrome, and pain syndromes in one population and nonspecific occupational overuse syndrome (OOS) in the other. Population A subjects (806 female, 154 male Auckland clinic referrals) with epicondylitis and carpal tunnel syndrome had higher rates of manual occupations compared with the Auckland employed population, consistent with previous research. Both Population A and Population B subjects (1,188 female, 499 male national notifications to the Department of Labour) with pain syndrome or nonspecific OOS had increased rates of clerical occupations. Relative risks ranged from 2.24 (95% CI 1.69,2.97) to 3.92 (3.50 ,4.40). Word processor operators, data-entry operators, and mail sorters were overrepresented in both populations. An unexplained association between nonspecific upper arm pain and being in some clerical occupations requires further research.

Stress and some associated factors in a representative sample of the New Zealand workforce.

Prevalence of self-reported stress was measured in a sample workforce of 1342 men. About 8% at all ages reported being "often stressed", while the peak was 11% at age 45-54 years. The socioeconomic profile of the workers approximated that of the New Zealand male workforce and it is suggested that the prevalence rate for the total workforce will be similar to that of the sample. In addition, information was obtained on blood pressure, alcohol intake, smoking, obesity, and exercise. There is a statistically significant positive association between stress and mild hypertension (p less than 0.001) and smoking (p less than 0.005) and a negative association between stress and exercise (p less than 0.025). This has implications for occupational health workers.

Exposure to fumes in typical New Zealand welding operations.

Sixteen welders, welding under typical New Zealand conditions, had ambient air within their welding helmets sampled and analysed for ozone, nitrogen oxides, fluoride, carbon monoxide, aluminium, chromium, iron, nickel, zinc and total dust. Postshift urinary metals were also analysed, and a respiratory questionnaire completed for each welder. Levels above the New Zealand Workplace Exposure Standard (WES) were found for nitrogen dioxide in four welders (two TIG, one MMA and one plasma cutter), and for total chromium in one plasma cutter, who also had a nickel level of 24% of the WES. Dust levels were highest in the plasma cutters, with one reaching 8.67 mg/m3 (WES = 5 mg/m3). Urinary levels however did not indicate excessive short or long term uptake. Where efficient fume extraction was in use, levels of air contaminants were lower than with natural ventilation. Respiratory symptoms were reported by 67% of welders, 38% meeting criteria for chronic bronchitis (relative risk = 2.0). Smoking welders reported more symptoms than nonsmoking welders.

Chronic solvent neurotoxicity in New Zealand: notified cases between 1993 and 1997.

AIM: To report on cases of chronic solvent neurotoxicity notified to the Department of Labour between 1993 and 1997. METHODS: Previously published diagnostic criteria were used to classify notified cases as "verified", "not verified" or "not proven". Verified cases were further classified as Type 1 or 2(2) and analysed according to occupation, solvent type and length of exposure. RESULTS: Of 193 notified cases, 76 were classified as "verified". The majority were male (74/76) and European (69/76). Mean length of exposure to solvents for Type I cases was 10.6 years (SD 4.7) and for Type II cases 19.8 years (SD 8.4). Forty-three cases were classified as "mild" and 33 as "moderate". The most frequent occupation was spraypainting (39%), followed by printing (16%) and boatbuilding (9%). There was no correlation between severity of symptoms and type of solvent. There was a non-significant trend of increasing severity of symptoms with length of exposure. CONCLUSION: Exposure to solvents is an important health hazard in New Zealand workplaces.

Prevalence of diabetes mellitus and impaired glucose tolerance in a New Zealand multiracial workforce.

A cross sectional survey was carried out among a multiracial workforce of 5677 staff aged 40 to 64 years at worksites in Auckland and Tokoroa to determine the prevalence of diabetes mellitus and impaired glucose tolerance (IGT). The prevalences of diabetes mellitus and IGT were both similar for men and women, but increased with age. The relative risks for diabetes mellitus and for IGT were both inversely associated with gross annual household income, independent of age and ethnicity, being 1.61 (95% Cl = 1.10, 2.37) and 1.80 (95% Cl = 1.21, 2.67) respectively, in the lowest income group (less than $30,000) compared with the highest (greater than $40,000). Compared with Europeans, the relative risk of diabetes mellitus was significantly increased among Maori (3.63; 95% Cl = 2.48, 5.32), Pacific Islanders (2.34; 95% Cl = 1.50, 3.66) and Asians (5.97; 95% Cl = 2.61, 13.65), after controlling for age, income and body mass index. The increased prevalence of diabetes mellitus among Maori and Pacific Islanders, but not in Asians, could be partly attributed to their increased levels of obesity compared with Europeans. However, other factors, in addition to obesity, explain the increased diabetes prevalence in nonEuropean groups.

Hypertension and its treatment in a New Zealand multicultural workforce.

AIMS: To investigate ethnic variations in blood pressure levels and the likelihood of hypertension being treated in a multicultural New Zealand workforce. METHODS: An employed population of 5651 staff aged 40 to 64 years at worksites in Auckland and Tokoroa, who recorded their current prescribed medication, were measured for blood pressure, weight and height. Body mass index (BMI) was calculated. RESULTS: Mean blood pressure levels were higher in men than women, and increased with age and BMI. Compared with Europeans, mean systolic and diastolic blood pressures were higher in Maori (by 5 to 6 mmHg), Pacific Islanders (by 4 to 6 mmHg) and Asians (by 1 to 5 mmHg) after controlling for age and blood pressure treatment. This increase in Maori and Pacific Islanders, compared with Europeans, was approximately halved after also controlling for BMI, but still remained statistically significant (p < 0.05). In contrast, ethnic differences in BMI did not explain any of the blood pressure increase in Asians. In analyses restricted to hypertensive participants, the likelihood of hypertension being treated was higher in women than men (odds ratio (OR) = 3.42; 95% CI 2.13, 5.47), and lower in Maori (OR 0.33; 95% CI 0.19, 0.58), Pacific Islanders (OR 0.27; 95% CI 0.16, 0.47) and Asians (OR 0.29; 95% CI 0.10, 0.86) than Europeans. CONCLUSION: These results suggest that the likelihood of hypertension being treated is related to sex and ethnic group; and that other unknown factors, in addition to increased BMI levels, explain the higher blood pressure levels in Polynesians compared to Europeans.

Serum lipid levels in a New Zealand multicultural workforce.

AIMS: To examine ethnic variations in serum lipid levels and to determine whether lipids are related to lifestyle variables in a New Zealand multicultural workforce. METHODS: Fasting blood samples were collected from 5671 employed people for determination of serum total and HDL cholesterol, triglycerides, and LDL cholesterol. Individual exposures over the previous three months to smoking, alcohol, leisure time physical activity were recorded, and weight and height were measured to calculate body mass index (BMI). RESULTS: Maori and Pacific Islanders had lower age-adjusted total and LDL cholesterol levels than Europeans, and these differences were increased by controlling for BMI. In contrast, age-adjusted mean (SE) HDL cholesterol levels were also lower in Maori (men = 1.17 (0.02); women = 1.38 (0.03) mmol/L) and Pacific Islanders (men = 1.17 (0.01); women = 1.30 (0.02) mmol/L) compared with Europeans (men = 1.20 (0.01); women = 1.47 (0.01) mmol/L), but when BMI, smoking and other variables were controlled, levels were significantly higher in Maori and Pacific Islanders. With serum triglycerides, the pattern was not consistent in Maori and Pacific Islanders. Age-adjusted mean levels in Maori (men = 2.25 (0.07) mmol/L; women = 1.53(0.07) mmol/L) were significantly higher (p < 0.05) than in Pacific Islanders (men = 1.82 (0.06); women = 1.34(0.05) mmol/L) of the same sex. After controlling for BMI and other variables, triglyceride levels were also significantly lower in Pacific Islanders than in Europeans and Asians. BMI and smoking were positively associated with total and LDL cholesterol and triglycerides, and negatively with HDL cholesterol, after controlling for alcohol and physical activity. CONCLUSION: Lifestyle risk factors, particularly BMI and smoking, are strongly related to serum levels of all major lipids. Ethnic variations in coronary heart disease mortality rates in New Zealand are more consistent with ethnic variations in triglycerides than with variations in the other serum lipids.

The relationship between body mass index and socioeconomic status in New Zealand: ethnic and occupational factors.

AIMS: the relationship between body mass index (BMI) and socioeconomic status (SES) was examined in a multiracial New Zealand workforce in order to investigate ethnic variations. METHODS: an employed population of 5673 people were measured for weight and height and BMI calculated. Socioeconomic status was assigned using the UK Registrar General's scale. RESULTS: both European women and men showed an inverse relationship of increasing BMI with decreasing SES which is typical of developed societies. Maori, Pacific Islanders and Asians did not, but neither did they show the direct relationship of developing societies. Examination of the components of SES showed that combined family income did not influence BMI in any ethnic group but that education was strongly associated with BMI in Europeans (p = 0.0001) and weakly associated in Maori (p = 0.0603), and occupation was strongly associated with BMI in Europeans (p = 0.0001) and weakly associated in Pacific Islanders (p = 0.0148) independently of education. CONCLUSIONS: ethnic variations are partly explained by educational levels and occupation, but not by income. Increased education may decrease prevalence of obesity. Some occupational factors are discussed.

Hazards associated with the boat building industry in New Zealand: an OSH audit.

AIM: To randomly audit the boat building industry in New Zealand to assess the occupational health status and level of knowledge of employees. METHODS: A survey was conducted using a nurse and inspector administered questionnaire. 151 workers from 120 randomly selected firms participated in the survey. RESULTS: 31.5% respondents thought they had had some sort of work related health problem since working in that job. 22% reported wheezing during the last twelve months. 14-16% met criteria for occupational causation, and 4% met a measure of severe wheezing related to work. 25.6% of workers had dermatitis. Only a quarter of these met criteria for occupational causation. No respondents reported symptoms suggestive of chronic solvent neurotoxicity. Solvents and epoxy resins comprised the majority of chemicals with which there was contact. Observation suggested little use of Material Safety Data Sheets as a source of knowledge about toxicity of the chemicals used. Although 94.3% reported wearing gloves, this did not correlate with numbers reporting dermatitis suggesting non-compliance or glove failure. CONCLUSION: New Zealand boat builders and their employees remain at risk for occupational health problems by virtue of their employment.

Dietary intakes of middle-aged European, Maori and Pacific Islands people living in New Zealand.

AIM: To compare dietary intakes of Maori, Pacific Islands and European men and women in New Zealand. METHODS: A food frequency questionnaire was used to calculate nutrient intakes of 5523 New Zealand workers aged 40 years and over (3997 men, 1524 women) from a cross-sectional survey carried out between 1988 to 1990. RESULTS: Compared with European men and women, Maori women and Pacific Islands men and women consumed larger amounts of total energy per day. Age-adjusted nutrients expressed as percentage contribution to total energy intakes showed that Maori and Pacific Islands men and women consumed less carbohydrate, fibre and calcium, and more protein, fat, saturated fat and cholesterol than European men and women, respectively. These results were consistent with fewer servings of cereal and cheese per month, and more servings of red meats, fish and eggs in Maori and Pacific Islands participants compared with Europeans, after adjusting for age and total energy intakes. Pacific Islands men and women also consumed more servings of chicken, fewer cups of milk and fewer servings of fruit per month compared to Europeans. Maori men and women consumed more slices of bread and fewer servings of vegetables per month compared to European men and women. CONCLUSIONS: There were striking differences in dietary habits, food selections and cooking practices between European, Maori and Pacific Islands participants. Dietary intakes of Maori workers were closer to those of Europeans than those of Pacific Islands participants. Ethnic differences were due to larger portion sizes and increased frequency of most foods in Maori and Pacific Islands participants.