Effects of aqueous extracts of PM(10) filters from the Utah valley on human airway epithelial cells.
We hypothesized that the reduction in hospital respiratory admissions in the Utah Valley during closure of a local steel mill in 1986-1987 was attributable in part to decreased toxicity of ambient air particles. Sampling filters for particulate matter < 10 micrometer (PM(10)) were obtained from a Utah Valley monitoring station for the year before (year 1), during (year 2), and after (year 3) the steel mill closure. Aqueous extracts of the filters were analyzed for metal content and oxidant production and added to cultures of human respiratory epithelial (BEAS-2B) cells for 2 or 24 h. Year 2 dust contained the lowest concentrations of soluble iron, copper, and zinc and showed the least oxidant generation. Only dust from year 3 caused cytotoxicity (by microscopy and lactate dehydrogenase release) at 500 microgram/ml. Year 1 and year 3, but not year 2, dust induced expression of interleukin-6 and -8 in a dose-response fashion. The effects of ambient air particles on human respiratory epithelial cells vary significantly with time and metal concentrations. (+info)
Pulmonary fibrosis in a steel mill worker.
We report a case of pulmonary fibrosis in a 32-year-old man, who had worked at a steel mill and who died of respiratory failure due to interstitial fibrosis despite vigorous treatment. He showed SLE-associated symptoms, such as pleural effusion, malar rashes, discoid rashes, arthritis, leukopenia, and positive antinuclear antibody and anti-histone antibody. However, he did not present anti-DNA antibody. A thoracoscopic lung biopsy showed interstitial fibrosis, chronic inflammation and a small non-caseating granuloma in lung tissues, which could be induced by external agents such as metals. The manganese concentration in the lung tissue was 4.64 microg/g compared to 0.42-0.7 microg/g in the controls. The levels of other metals, such as iron, nickel, cobalt and zinc in patient's lung tissue were higher than those in the controls. The patient was probably exposed to Si and various metal dusts, and the lung fibrosis was related to these exposures. Exposure to Si and metal dusts should be sought in the history of any patient with SLE, especially in a male with pulmonary signs, and if present, exposure should be stopped. In the meantime, steps should be taken to ensure that workers exposure to Si and metal dusts in all environments have adequate protection. (+info)
Increased risk of restenosis after placement of gold-coated stents: results of a randomized trial comparing gold-coated with uncoated steel stents in patients with coronary artery disease.
BACKGROUND: Gold is a highly biocompatible material. Experimental evidence suggests that coating the stent with a gold layer may have a beneficial influence. In this randomized trial, we assessed whether gold-coated stents were associated with a better clinical and angiographic outcome after coronary placement. METHODS AND RESULTS: Patients with symptomatic coronary artery disease were randomly assigned to receive either a gold-coated Inflow stent (n = 367) or an uncoated Inflow stainless steel stent (n = 364) of identical design. Follow-up angiography was routinely performed at 6 months. The primary end point of the study was the occurrence of any adverse clinical event (death, myocardial infarction, or target-vessel revascularization) during the first year after stenting. At 30 days, there was no significant difference in the combined incidence of adverse events, with 7.9% in the gold-stent group versus 5.8% in the steel-stent group (P = 0.25). The incidence of angiographic restenosis (> or =50% diameter stenosis) was 49.7% in the gold-stent group and 38.1% in the steel-stent group (P = 0.003). One-year survival free of myocardial infarction was 88.6% in the gold-stent group and 91.8% in the steel-stent group (P = 0.14). One-year event-free survival was significantly less favorable in the gold-stent group (62.9% versus 73.9% in the steel-stent group; P = 0.001). CONCLUSIONS: Coating steel stents with gold had no significant influence on the thrombotic events observed during the first 30 days after the intervention. However, gold-coated stents were associated with a considerable increase in the risk of restenosis over the first year after stenting. (+info)
Non-fatal work related injuries in a cohort of Brazilian steelworkers.
OBJECTIVES: Workers in the steel industry are exposed to various severe hazards. This study investigated risk factors for non-fatal injury occurring in the workplace and during travel to and from work in steelworkers in Brazil. METHODS: Non-fatal work related injuries during employment from January 1977 to September 1992 were analysed in a cohort of 21 732 male workers in the steel plant of USIMINAS, Brazil. RESULTS: There were 14 972 non-fatal injuries during follow up, with 10 891 injuries in the workplace and 4081 during travel to and from work (travel to work injury). The rate of injury in the workplace was 5.6/100 person-years and that of travel to work injury was 2.1/100 person-years. The most common injuries were to hands, arms, and eyes, with 90% of the eye injuries caused by a foreign body. Both rates of workplace and travel to work injury increased significantly with the number of injuries previously experienced, and decreased with number of years in employment and calendar period. The rates of travel to work injury also seemed to decrease with age, but age was not an independent predictor of workplace injury when we controlled for duration of employment. The rate of workplace injury was increased eightfold for workers who had experienced more than six previous injuries compared with those with no previous workplace injuries after adjusting for duration of employment and calendar period. Labourers were most at risk of workplace injury, with about eight injuries per 100 person-years. Travel to work injury was most common among support workers, with nearly half of the travel to work injuries affecting the eyes. CONCLUSION: The rate of injury was high in these steelworks, both for workplace and travel to work injuries. Characteristics of the work areas and the employees can identify high risk groups; protective measures, safety, health training, and injury programmes should concentrate particularly on these groups. Prevention of eye injury needs special attention in steelworks. (+info)
Studies on plasma lipids in industrial workers in central Trinidad and Tobago.
We assessed the plasma lipid profiles and other cardiovascular disease (CVD) risk factors in 187 (147 men, 47 women) apparently healthy employees of the Caribbean ISPAT industry in Trinidad and Tobago. Anthropometric indices and fasting plasma levels of total cholesterol (T-chol), triglyceride (TG), high-density lipoprotein (HDL), and low-density lipoprotein (LDL) were measured. The results indicate that: there was increased body mass and relative hyperlipidemia in the population studied, these CVD risk factors (increased body mass, increased blood T-chol, TG, and LDL) were more prevalent in men than women (p < 0.05), and these parameters did not differ significantly (p < 0.05) when compared among the three ethnic groups (African and Indian descendants and mixed descents). These features suggest a greater risk of CVD in men than in women. It is likely that this observation in the industrial workers might reflect the situation in the general population especially in men. Although further confirmatory studies are necessary across societal socioeconomic strata within Trinidad, we suggest that efforts should be directed at reducing excess body weight among the workers, and providing advice on increased complex carbohydrate diet in place of saturated fat. (+info)
Bacterial phosphating of mild (unalloyed) steel.
Mild (unalloyed) steel electrodes were incubated in phosphate-buffered cultures of aerobic, biofilm-forming Rhodococcus sp. strain C125 and Pseudomonas putida mt2. A resulting surface reaction leading to the formation of a corrosion-inhibiting vivianite layer was accompanied by a characteristic electrochemical potential (E) curve. First, E increased slightly due to the interaction of phosphate with the iron oxides covering the steel surface. Subsequently, E decreased rapidly and after 1 day reached -510 mV, the potential of free iron, indicating the removal of the iron oxides. At this point, only scattered patches of bacteria covered the surface. A surface reaction, in which iron was released and vivianite precipitated, started. E remained at -510 mV for about 2 days, during which the vivianite layer grew steadily. Thereafter, E increased markedly to the initial value, and the release of iron stopped. Changes in E and formation of vivianite were results of bacterial activity, with oxygen consumption by the biofilm being the driving force. These findings indicate that biofilms may protect steel surfaces and might be used as an alternative method to combat corrosion. (+info)
The percutaneous greenfield filter: outcomes and practice patterns.
OBJECTIVE: The percutaneous steel Greenfield filter (PSGF) is similar in appearance to the titanium Greenfield filter (TGF) but differs in the length and orientation of the attachment hooks and in the over-the-wire delivery system. Because these differences improve ease of insertion and attachment, they may affect patient outcomes and physician practices. The purpose of this study was to evaluate the performance of the PSGF relative to the TGF and to determine whether there had been a change in physician practices. METHODS: The Michigan Filter Registry contains data for a prospective cohort of 2188 patients with Greenfield filters. Procedural and long-term outcomes for patients with a PSGF were abstracted. These events were compared with rates for Registry patients who had a TGF. Trends for indication for placement, delivery route, and filter location were also compared with published series. RESULTS: Since 1995, 600 PSGFs have been placed in 599 patients. A 1-year mortality rate of 42% left 349 patients available for annual follow-up, and studies were completed for 231 (66%). Periprocedural events occurred in 2.5% of cases with associated morbidity in 1.5%. The rate of new pulmonary embolism was 2.6%, and vena caval patency was 98.3%. The combined rate of new venous thromboembolic events was 12.5%. Left-sided femoral vein placements increased to 20%, and the major indication for filter placement has become prophylaxis (46%). CONCLUSIONS: The PSGF is similar to the TGF with respect to patient outcomes, and it provides decreased rates of asymmetry along with excellent fixation. The flexible carrier system has allowed more frequent access through the left femoral vein. The ease of use and favorable patient outcomes have resulted in more frequent placement for prophylactic indications. (+info)
Predictors of first nonfatal occupational injury following employment in a Brazilian steelworks.
OBJECTIVES: This study investigated the influence of sociodemographic and occupational factors on the risk of 1st injury among Brazilian steelworkers. METHODS: Workers 1st employed between 1 January 1977 and 31 December 1985 and still employed on 1 December 1983 were followed from the date of hire until 30 October 1992. Occupational injuries were ascertained from a database. Kaplan-Meier curves for time to 1st injury were calculated for the total cohort and for different subgroups. A multivariate analysis of risk factors for 1st injury was carried out using the Cox proportional hazards regression model. RESULTS: Forty-one percent of the workers had > or = 1 occupational injuries, and 39% of 1st injuries occurred in the 1st year of employment. Lacerations, contusions, penetration by foreign bodies, bums, sprains, and fractures constituted the main diagnostic groups. Injuries to the hands, eyes, feet, arms, and legs dominated. Over 5% of the injured workers were on temporary disability leave (cumulative total 10,660 days). The probability for an occupational injury was 16% for the 1st year, rising to 25% in the 2nd year. The risk of nonfatal injury was highest for laborers [hazard ratio (HR) 1.76, 95% confidence interval (95% CI) 1.35-2.29] and employees in the steel mill (HR 1.40, 95% CI 1.21-1.63), and inversely related to worker age and educational level. The risk of injury decreased significantly with calendar period of employment. CONCLUSIONS: Substantial reductions in nonfatal injuries may reflect changes in work organization, increased automation, and improved safety standards. Knowledge of predictors of work-related injury may contribute to injury prevention strategies, especially among newly employed workers. (+info)