Biomonitoring results and cytogenetic markers among harbour workers with potential exposure to river silt aerosols.

BACKGROUND: Workers on dredgers and lighters on rivers are potentially exposed to a variety of substances. AIMS: To determine the internal load of heavy metals and arsenic as well as levels of cytogenetic markers in workers exposed to river silt aerosols. METHODS: One hundred exposed workers were examined up to eight times within three years. Additionally, 100 control workers were studied once. Blood samples were analysed for lead, mercury, and cadmium. Additionally, micronuclei frequency and sister chromatid exchange (SCE) rates were determined. Urinary samples were analysed for cadmium, mercury, nickel, chromium, and arsenic. Information on potential confounders, such as smoking habits and consumption of fish were assessed. RESULTS: Apart from some increased concentrations of mercury in blood (maximum 14.6 microg/l) and arsenic in urine (maximum 356.5 microg/l) all measurements were within reference values. None of the exposure and effect markers were found to be significantly increased in exposed workers compared to non-exposed controls. In multiple linear regression models, mercury levels in blood as well as the concentration of arsenic in urine were strongly related to fish consumption. Cadmium levels in blood as well as urinary cadmium concentrations were strongly related to smoking habits. After adjusting for smoking habits, SCE rates were associated with cadmium levels in blood. CONCLUSION: Increased exposure levels or enhanced levels of cytogenetic markers were not found in workers exposed to river silt aerosols. However, cadmium exposure in blood was related to SCE frequency.

Lung function and work-related exposure in pig farmers with respiratory symptoms.

The present study was conducted to evaluate characteristics of pig houses that are associated with the development of respiratory morbidity in 100 swine producers with work-related respiratory symptoms. A standardized questionnaire for farm characteristics was used, and lung function was assessed immediately before and after feeding the pigs. Exposure to dust and endotoxin was determined by personal sampling. Among these farmers, baseline lung function results were shown to be negatively associated with duration of employment, number of pigs on the farm, manual feeding, and ventilation. The decrease in forced vital capacity and forced expiratory volume in 1 second over the feeding period was negatively correlated with air velocity, whereas respirable dust concentrations were shown to be significant predictors of maximal midexpiratory flow (MMEF25/75) decline. In conclusion, among symptomatic pig farmers, those with higher numbers of pigs and longer duration of employment are at highest risk for developing functional impairment.

[Quantitative computed tomography of the lung in the early diagnosis of asbestosis: initial results in asbestos-exposed navy personnel]. / Die quantitative Computertomographie der Lunge in der Frühdiagnostik der Asbestose: Erste Erfahrungen an asbestexponierten Marinesoldaten.

AIM: To evaluate the diagnostic role of respiratory gated quantitative CT of the lung with regard to the early detection of asbestos-induced lung fibrosis. MATERIAL AND METHODS: 29 navy personnel with a mean asbestos exposure of 21.3 years and exclusively low profusion stages with regard to plain film X-ray (0/1 and 1/0, ILO 1980) were examined using high resolution CT and respiratory gated quantitative CT of the lung. RESULTS: A low but significant increase of the global lung density with -816 HU (range -844 to -749 HU) was found in comparison with the age-matched reference values of -829.8 HU (range -834 to -819 HU). In individual cases the histogram analysis demonstrated a shift of the density distribution towards higher density intervals without corresponding findings in HRCT. No alterations in lung function were observed. There was no correlation between the latency period or length of exposure and density values. CONCLUSION: The respiratory gated quantitative CT of the lung may potentially develop into an accessory parameter for monitoring dust exposed personnel.

Arsenic species excretion in a group of persons in northern Germany--contribution to the evaluation of reference values.

Reference values for four arsenic species (inorganic As(III); inorganic As(V); dimethylarsinic acid DMA; monomethylarsonic acid MMA) in urine were evaluated for 101 male persons in northern Germany (46.9 +/- 10.5 y) applying anion exchange chromatographic species separation with on-line hydride-technique atomic absorption spectrometry (between-days imprecision 6.8-10.1%; 11.0-50.0 micrograms/l; n = 30; detection limits d. l. 1; 10; 2; 2 micrograms/l). DMA was found in 88.1% of the persons (x +/- s = 7.21 +/- 9.64 micrograms/g creatinine; median 4.02 micrograms/g; 95% < 22.5 micrograms/g) followed by As(III) (11.3%; median < d. l.; 95% < 0.54 microgram/g) whereas no MMA and As(V) could be found. Seafood consumption within the last 2 days led to higher DMA levels compared to having seafood more than 6 days ago (n = 43 vs. n = 42; 10.04 +/- 11.58 vs. 3.47 +/- 3.55 micrograms/g; p < 0.01).

[Clinical picture and pathology of the so-called vinyl chloride disease]. / Klinik und Pathologie der sog. Vinylchlorid-Krankheit

About 26 years ago symptoms of liver and spleen were described for the first time by Tribukh et al. in laborers exposed to vinyl chloride. Besides these symptoms sclerodermia, acroosteolysis and Raynaud's phaenomenon are known to be typical for the VC disease. Rather high concentrations of VC seem to be necessary to cause this disease. After cessation of exposure the symptoms may improve partly. Haemangiosarcoma of the liver may occur as the most serious effect of prolonged exposure to vinyl chloride. Presently 48 cases induced by VC exposure are observed all over the world. Diagnosis is difficult, the prognosis of this cancer is practically always fatal. The improvement of working places by the chemical industries should further reduce the risk of acquiring VC disease as well as haemangioma of the liver due to VC exposure.

Lung function decline in 4-monthly repeated spirometric measurements: due to silt aerosol exposure or decreasing effort?

BACKGROUND: Workers on dredgers and lighters on rivers are exposed to the inhalation of aerosols and dusts. OBJECTIVE: The aim of this study was to investigate effects of river silt aerosol and dust exposure on the respiratory health of dredging employees. METHODS: Six examinations were performed over a period of 2 years at 4-monthly intervals in 54 seamen with higher silt aerosol exposure and 36 controls of the same employer. RESULTS: No significant differences could be observed between the groups at any time of the study but there was an unexpected significant decrease in the age-corrected expiratory vital capacity (FVC), forced expiratory volume in 1 s (FEV(1)) and midexpiratory flow rate (MMEF(25/75)) over the six series in both groups. This may indicate a loss of effort of the participants in re-examinations since biological and technical influences were highly unlikely to be the cause of these findings. CONCLUSIONS: Ignoring this possible decline of effort in frequently repeated measurements may result in overestimating potential effects of occupational exposure.

Lack of combined effects of exposure and smoking on respiratory health in aluminium potroom workers.

OBJECTIVE: To investigate the combined influence on respiratory health of smoking and exposure in an aluminium potroom. METHODS: In a cross sectional study of 75 potroom workers (23 never smokers, 38 current smokers, 14 ex-smokers) and 56 controls in the same plant (watchmen, craftsmen, office workers, laboratory employees; 18 non-smokers, 21 current smokers, 17 ex-smokers), prevalences of respiratory symptoms and spirometric indices were compared. RESULTS: Smokers in the potroom group had a lower prevalence of respiratory symptoms than never smokers or ex-smokers, which was significant for wheezing (2.6% v 17.4% and 28.6% respectively, both p < 0.01), whereas respiratory symptoms in controls tended to be highest in smokers (NS). No effects of potroom work on the prevalence of respiratory symptoms could be detected. In potroom workers, impairment of lung function due to occupational exposure was found only in non-smokers, with lower results for forced vital capacity (FVC) (98.8% predicted), forced expiratory volume in one second (FEV1) (96.1% predicted) and peak expiratory flow (PEF) (80.2% predicted) compared with controls (114.2, 109.9, and 105.9% predicted; each p < 0.001). Conversely, effects of smoking on lung function were only detectable in non-exposed controls (current smokers v non-smokers: FVC 98.8% v 114.2% predicted; p < 0.01; FEV1 95.5 v 109.9% predicted; p < 0.05). CONCLUSIONS: In a cross sectional survey such as this, the effects of both smoking and occupational exposure on respiratory health may be masked in subjects with both risk factors. This is probably due to strong selection processes which result in least susceptible subjects continuing to smoke and working in an atmosphere with respiratory irritants.

Respiratory health and fluoride exposure in different parts of the modern primary aluminum industry.

OBJECTIVE: The aim of this cross-sectional study was to investigate possible acute and long-term respiratory health effects of work at different working places in the primary aluminum industry. METHOD: A cross-sectional study was carried out on 78 potroom workers, 24 foundry workers, and 45 carbon-plant workers (n = 147, exposed group), and 56 control workers (watchmen, craftsmen, office workers, laboratory employees) of a modern German prebake aluminum plant. The survey consisted of pre- and postshift spirometric and urinary fluoride measurements. RESULTS: Potroom workers had significantly lower preshift results with regard to forced vital capacity (FVC, 99. 5% versus the 107.2% predicted; P < 0.05) and peak expiratory flow (PEF, 85.2% versus the 98.4% predicted; P < 0.01) as compared with controls. In a multiple regression model a small but significant negative correlation was found between postshift urinary fluoride concentrations and FVC, FEV(1), and PEF. Across-shift spirometric changes were observed only in FVC among carbon-plant workers (103.0 +/- 13.3% predicted preshift value versus 101.2 +/- 13.6% predicted postshift value; P < 0.05). CONCLUSIONS: The results suggest that lung function impairment in the modern primary aluminum industry may be only partly due to fluoride exposure and that working in aluminum carbon plants may cause acute lung function changes.

Lung function, biological monitoring, and biological effect monitoring of gemstone cutters exposed to beryls.

OBJECTIVES: Gemstone cutters are potentially exposed to various carcinogenic and fibrogenic metals such as chromium, nickel, aluminium, and beryllium, as well as to lead. Increased beryllium concentrations had been reported in the air of workplaces of beryl cutters in Idar-Oberstein, Germany. The aim of the survey was to study the excretion of beryllium in cutters and grinders with occupational exposure to beryls--for example, aquamarines and emeralds--to examine the prevalence of beryllium sensitisation with the beryllium lymphocyte transformation test (BeLT), to examine the prevalence of lung disease induced by beryllium, to describe the internal load of the respective metals relative to work process, and to screen for genotoxic effects in this particular profession. METHODS: In a cross sectional investigation, 57 out of 100 gemstone cutters working in 12 factories in Idar-Oberstein with occupational exposure to beryls underwent medical examinations, a chest radiograph, lung function testing (spirometry, airway resistance with the interrupter technique), and biological monitoring, including measurements of aluminium, chromium, and nickel in urine as well as lead in blood. Beryllium in urine was measured with a newly developed direct electrothermal atomic absorption spectroscopy technique with a measurement limit of 0.06 microgram/l. Also, cytogenetic tests (rates of micronuclei and sister chromatid exchange), and a BeLT were performed. Airborne concentrations of beryllium were measured in three factories. As no adequate local control group was available, the cutters were categorised into those with an exposure to beryls of > 4 hours/week (group A) and < or = 4 hours/week (group B). RESULTS: Clinical, radiological, or spirometric abnormalities indicating pneumoconiosis were detected in none of the gemstone cutters. Metal concentrations in biological material were far below the respective biological limit values, and beryllium in urine was only measurable in subjects of group A. Cytogenetic investigations showed normal values which were independent of the duration of beryllium exposure. In one subject, the BeLT was positive. Beryllium stimulation indices were significantly higher in subjects with detectable beryllium in the urine than in those with beryllium concentrations below the detection limit (p < 0.05). In one factory, two out of four measurements of airborne beryllium concentrations were well above the German threshold limit value of 2 micrograms/m3 (twofold and 10-fold), and all gemstone cutters working in this factory had measurable beryllium concentrations in urine. CONCLUSION: No adverse clinical health effects were found in this cross sectional investigation of gemstone cutters working with beryls. However, an improvement in workplace hygiene is recommended, accompanied by biological monitoring of beryllium in urine.

Occupational chronic exposure to metals. I. Chromium exposure of stainless steel welders--biological monitoring.

External and internal chromate exposure of 103 stainless steel welders who were using manual metal are welding (MMA), metal inert gas welding (MIG) and both methods, were measured by ambient and biological monitoring. At the working places the maximum chromium trioxide concentrations were 80 micrograms/m3. The median values were 4 micrograms/m3 (MMA) and 10 micrograms/m3 (MIG). The median chromium concentrations in erythrocytes, plasma and urine of all welders were less than 0.60, 9.00 and 32.50 micrograms/l. For biological monitoring purposes, chromium levels in erythrocytes and simultaneously in plasma seem to be suitable parameters. According to our results, chromium levels in plasma and urine in the order of 10 and 40 micrograms/l seem to correspond to an external exposure of 100 micrograms chromium trioxide per cubic metre, the technical guiding concentration (TRK-value). Chromium concentrations in erythrocytes greater than 0.60 micrograms/l indicate an external chromate exposure greater than the TRK-value.

Work-related respiratory disorders and farming characteristics among cattle farmers in Northern Germany.

BACKGROUND: The aim of this cross-sectional study was to investigate the prevalence of respiratory symptoms among Northern German farmers in relation to cattle farming characteristics. METHODS: 1735 farmers were visited on their farms and were interviewed using a standardized questionnaire on work-related respiratory symptoms and farming details. RESULTS: 84.6% of the farmers were cattle farmers. The prevalence of work-related respiratory symptoms was 40.3%. In a multiple logistic regression model adjusting for response rate, age, gender, and smoking habits, work-related respiratory symptoms were shown to be significantly associated with the ventilation of the cattle house (OR (ventilation via the wall): 0.57), feeding management (OR (feeding once daily): 0.53), and plant crop (OR: 0. 75). Farmers, living inland, showed a significant higher prevalence of work-related respiratory symptoms (OR: 1.34). CONCLUSIONS: The use of ventilation via the wall might be recommended for new cattle houses in regions with warm winters.

Distribution of dust-mite allergens (Lep d 2, Der p 1, Der f 1, Der 2) in pig-farming environments and sensitization of the respective farmers.

BACKGROUND: The aim of the present study was to determine the distribution of mite allergens in pig-farming environments in comparison to urban homes and the relationship between exposure to mite allergens and sensitization to the respective allergens in 100 pig farmers with work-related respiratory symptoms. METHODS: The concentration of storage mite (Lep d 2) and house-dust-mite (Der p 1, Der f 1, and Der 2) allergens in dust collected from five different sampling sites (floor, wall, grain mill, transit area between confinement house and farmer's kitchen, and farmers' mattresses) was studied in relationship to the respective sensitization rates. Allergen concentrations in the mattresses were compared to those determined in mattresses from 22 urban dwellers. RESULTS: Median concentrations of Der p 1 and Der 2 in the mattresses of the farmers were significantly higher than in the urban dwellers' samples (53.4 microg/g dust vs 1.05 microg/g dust, P=0.001; 19.6 microg/g dust vs 2.2 microg/g dust, P<0.0001, respectively). Allergen concentrations in the transit areas were strongly related to bedroom exposure. In a multiple logistic regression model, a weak but significant relationship between Der p 1 exposure and sensitization to Der p 1 was found. Despite these findings, the prevalence of sensitization to mite allergens in the farmers (18%) was comparable to the prevalence in the general population. CONCLUSIONS: Allergen exposure at the workplace is strongly related to the concentration of allergens in farmers' beds. Exposure to domestic mite allergens should be taken into account when assessing occupational exposure to allergens and the respiratory health of farmers.