Effects of occupational cobalt exposure on the heart in the production of cobalt and cobalt compounds: a 6-year follow-up.

OBJECTIVE: It has been suspected that cobalt is toxic to the heart. It can cause cardiotoxicity in heavily exposed humans and in experimental systems. The issue of interest for this study is whether cobalt also affects the myocardium at occupational exposure levels. METHODS: To study the effect of occupational cobalt exposure on the heart, we conducted a follow-up of workers at a cobalt production plant. The workers' hearts had been examined by echocardiography in 1999-2000. Altogether 93 exposed and 49 non-exposed workers examined in 1999-2000 were re-examined in 2006. Occupational history and health data were collected with a questionnaire. Blood pressure was measured, and electrocardiography (ECG), laboratory tests, Holter registration, and echocardiography were conducted for all participants. Analysis of covariance (ANCOVA) was used to analyse the data. RESULTS: No differences were found between the exposed and unexposed groups for any of the echocardiographic parameters in 2006. There were no differences in the laboratory values, the ECG parameters, or the results of the Holter registration of the exposed and unexposed workers. CONCLUSIONS: Although the previous results in 2000 suggested an association between cumulative exposure to cobalt and echocardiographic findings, the results of this new cross-sectional study with a tissue Doppler 6 years later did not confirm the association in the present cohort. If cobalt exposure affects heart muscle functions at this exposure level, the effects are smaller than those caused by physiological changes due to ageing, medication, and traditional cardiovascular risk factors, such as elevated blood pressure.

Effects of growth and aging on the reference values of pulmonary nitric oxide dynamics in healthy subjects.

The lung just like all other organs is affected by age. The lung matures by the age of 20 and age-related changes start around middle age, at 40-50 years. Exhaled nitric oxide (FENO) has been shown to be age, height and gender dependent. We hypothesize that the nitric oxide (NO) parameters alveolar NO (CANO), airway flux (JawNO), airway diffusing capacity (DawNO) and airway wall content (CawNO) will also demonstrate this dependence. Data from healthy subjects were gathered by the current authors from their earlier publications in which healthy individuals were included as control subjects. Healthy subjects (n = 433) ranged in age from 7 to 78 years. Age-stratified reference values of the NO parameters were significantly different. Gender differences were only observed in the 20-49 age group. The results from the multiple regression models in subjects older than 20 years revealed that age, height and gender interaction together explained 6% of variation in FENO at 50 ml s-1 (FENO50), 4% in JawNO, 16% in CawNO, 8% in DawNO and 12% in CANO. In conclusion, in this study we have generated reference values for NO parameters from an extended NO analysis of healthy subjects. This is important in order to be able to use these parameters in clinical practice.

Prediction of obeche wood-induced asthma by specific skin prick testing.

BACKGROUND: It has previously been shown that a positive skin prick test (SPT) result is a good predictor of a positive specific inhalation challenge (SIC) in patients with occupational asthma (OA) related to wheat or rye flours. This association has not been previously studied in OA attributable to obeche wood. AIMS: To describe a clinical series of patients with OA induced by obeche wood. To investigate if the SPT result can be used as a predictor for the outcome of SIC tests. METHODS: OA was diagnosed according to patient history, lung function examinations and SIC tests, as well as the determination of obeche SPTs. We analysed sensitivity, specificity and positive (PPV) and negative predictive values (NPV) at different wheal sizes of the SPTs and drew receiver-operating characteristic plots using the SIC test result as the gold standard. RESULTS: Obeche wood SIC tests were performed on 34 symptomatic workers. Of these, 27 workers had a positive test result and were diagnosed as having OA. The minimal cut-off value with a PPV of 100% was an SPT wheal of 3.5 mm from obeche wood. This means that all workers with a wheal size of ≥ 3.5 mm from obeche wood had a positive SIC. CONCLUSIONS: Positive SPT results in symptomatic workers were good predictors of a positive SIC. SIC with obeche wood may be unnecessary in strongly sensitized workers.

Cobalt asthma--a case series from a cobalt plant.

BACKGROUND: Cobalt has been shown to induce mainly asthma, allergic contact dermatitis and hard metal disease. The data on cobalt asthma are mainly based on case reports. AIMS: To characterize all the cases of occupational cobalt asthma encountered in a cobalt plant at the time of diagnosis and 6 months later. We also evaluated the incidence of cobalt asthma in different departments on the basis of data on occupational exposures. METHODS: We identified cases of cobalt asthma confirmed with specific bronchial challenge tests in the Kokkola cobalt plant in Finland where exposure levels have been regularly monitored. RESULTS: Between 1967 and 2003, a total of 22 cases of cobalt asthma were diagnosed in the cobalt plant. On challenge tests, mostly late or dual asthmatic reactions were observed. The incidence of cobalt asthma was the highest in the departments with the highest cobalt exposure levels. All cases of cobalt asthma were encountered in departments where irritant gases were present in the ambient air in addition to cobalt. At the time of the follow-up examination 6 months later, non-specific hyperreactivity had mostly remained at the same level or increased. CONCLUSIONS: The incidence of cobalt asthma correlated with the exposure levels of cobalt in corresponding departments. An irritating effect of gaseous compounds may enhance the risk of cobalt asthma and even the smallest amounts of cobalt may be harmful to susceptible workers. Symptoms of asthma may continue despite the fact that occupational exposure to cobalt has ceased.

The effects of asthma on the quality of life and employment of construction workers.

Relatively little is known about the consequences of asthma for patients' work ability. In particular, the relationship between asthma and construction work has not been studied previously. The aim of this study was to determine how asthma affects construction workers' work ability and quality of life, and the most important conditions that cause respiratory symptoms in construction work. A questionnaire was sent to all construction workers examined in the pulmonary clinic of Tampere University Hospital between 1991 and 1995 who were diagnosed as having 'asthma bronchiale' (n = 104). In addition, 206 non-asthmatic construction workers were recruited from the register of the local trade union. Altogether, 73% of the asthmatic construction workers and 70% of the controls completed the questionnaire. Of the asthmatics, 48% were retired, whereas only 24% of the controls were receiving a pension. The asthmatics evaluated their work ability and general health as significantly worse than did the controls. The asthmatics had more limitations in their work and everyday life than the controls. Asthmatic construction workers had often changed work tasks and also occupation because of their illness. Building renovation, cleaning and insulation with mineral fibre materials were the most common causes of respiratory symptoms in the workplace, among both the asthmatics and the controls. Cold air, physical exercise and all types of dust and smoke caused the asthmatics to experience symptoms. It was concluded that asthma limits the work and everyday life of construction workers. Exposure to dusty, non-sensitizing agents is associated with asthmatic symptoms among construction workers.

Asbestos exposure: a potential cause of retroperitoneal fibrosis.

The etiology of retroperitoneal fibrosis is unknown in 70% of the cases. The aim of our study was to examine the possible association between occupational asbestos exposure and retroperitoneal fibrosis; only two cases have been reported in the literature. We gathered all the cases of retroperitoneal fibrosis diagnosed in the Tampere University Hospital between 1987 and 1995. We examined their hospital records to evaluate the possible etiology of the disease. We also sent a structured questionnaire to all living patients (10/13) to obtain information on their asbestos exposure. The chest radiographs of the patients were re-read to evaluate possible changes resulting from asbestos exposure. We found 13 cases of idiopathic retroperitoneal fibrosis. Seven patients (all male) had been exposed to asbestos in the past. The chest radiographs of the four most-exposed patients showed characteristic asbestos-related abnormalities, including bilateral pleural plaques, round atelectasis and small irregular lung opacities. In our study, we found that asbestos exposure and asbestos-induced changes in the lung and pleura were common among male retroperitoneal fibrosis patients. We suggest that occupational exposure to asbestos may be an important etiological factor for retroperitoneal fibrosis.