The aim of the study was to investigate cancer risk following employment in the asphalt industry.Cancer incidence was studied among 22 362 male asphalt workers employed for more than one season in jobs entailing exposure to bitumen (mainly road pavers) in Denmark, Finland, Norway, and Sweden. These workers are part of a European cohort of asphalt workers, for which results on mortality have been reported. The follow-up was almost complete, and reference rates were obtained from national cancer registries.The incidence of cancer was reduced in all four countries [overall standardized incidence ratio (SIR) 0.89, 95% confidence interval (95% CI) 0.86-0.94]. Lung cancer incidence was increased in all four countries, yielding an overall SIR of 1.21 (95% CI 1.07-1.36), but no trend was detected according to time since first employment. No overall increased incidence of bladder cancer was observed, but there was a suggestion of a tendency towards higher risk with longer time since first employment, with a relative risk of 1.85 (95% CI 0.90-3.78) for more than 30 years versus 1-14 years (P-value for trend 0.1). The incidence of lip and stomach cancer was nonsignificantly increased, and the excess was present mainly in Denmark. No increased incidence was detected for other neoplasms, notably malignant melanoma, nonmelanoma skin cancer, and kidney cancer.The results of this study confirm the pattern of cancer risk detected in the mortality analysis of the European cohort; in addition, they provide suggestive evidence of an excess risk of bladder cancer among asphalt workers.
OBJECTIVES: The cancer incidence among 2957 boiler welders was investigated. The subjects were registered electrical welders from 1942 to 1981. A subcohort of 606 stainless steel welders was studied separately. METHODS: The investigation was a historical prospective cohort study based on a national registry. The loss of follow up was 4.9%. RESULTS: There were 625 deaths (659 expected). There were 269 cancer cases (264 expected). An excess of lung cancer was found; 50 cases v 37.5 expected. There were three cases of pleural mesotheliomas v 1.1 expected. The subcohort of stainless steel welders had six cases of lung cancer v 5.8 expected, and one case of pleural mesothelioma v 0.2 expected. CONCLUSIONS: The welders in the study were assumed to represent a qualified work force. These welders had a small excess risk of lung cancer. The excess risk did not seem to be associated with stainless steel welding. Smoking and asbestos exposure were potential confounders.
Abstract The physical and chemical characteristics of chromium and some of its compounds are summarized. The term chromium is derived from the Greek word for color, because most chromium compounds are brightly pigmented. The element chromium was discovered in Europe in 1798 by N. L. Vauquelin, but it had already been used in swords by the Hittites about 1300 BC . Chromium occurs in nature in bound‐form chromite ore, which is the only chromium ore of any importance, and it makes up 0.1–0.3 ppm of the earth's crust. The red color of rubies and green color of emeralds, serpentine, and chrome mica are produced by chromium. Chromium metal is prepared by reducing the ore in a blast furnace with carbon (coke) or silicon to form an alloy of chromium and iron called ferrochrome, which is used as the starting material for the many iron‐containing alloys that employ chromium. Chromium to be used in iron‐free alloys is obtained by reduction or electrolysis of chromium compounds. Chromium is difficult to work in the pure metal form; it is brittle at low temperatures, and its high melting point makes it difficult to cast. The U.S. National Occupational Exposure Survey estimated that a total of about 200,000 workers, including about 30,000 women, were potentially exposed to hexavalent chromium compounds. The typical airborne concentrations in various industrial operations are given; however, the combustion of coal and oil is the largest single source of air pollution. The use of chromium in stainless steel (SS) (+18%) is a major use of the element. Chromium in the trivalent form is an essential trace element to humans. It is involved in the metabolism of glucose. Chromium deficiency may result in impaired glucose tolerance, peripheral neuropathy, and elevated serum insulin, cholesterol, and triglycerides, similar to those symptoms observed in diabetic patients. Accumulated molybdenum in euxinic shales has been of great importance for understanding the stepwise oxygenation of the earth atmosphere. Mo is incorporated into metal cofactors by complex machineries, and is an essential trace element for microorganisms, plants, animals, and humans. As Mo in trace amounts are quite abundant in nature today, deficiency due to low intake from food and drinking water is hardly known in humans. Deficiency is reported after prolonged total parenteral nutrition with clinical signs characterized by tachycardia, headache, mental disturbances, and coma. XO deficiency is relatively benign, still patients with isolated deficiencies of SO or Mo cofactor exhibit mental retardation, neurological problems, and ocular lens dislocation. Symptoms of intoxication may be general, such as flulike and CNS symptoms, fever, coughing, nausea, vomiting, diarrhea, anemia, and neuropathy. Tungsten has the highest melting point of all the metals (3400°C) and it retains its strength at high temperatures. Tungsten carbide is second to diamond in hardness. The prime uses of tungsten are in cemented carbides, mills products, and steel/alloys. Exposure to tungsten‐containing compounds may occur during production and uses of tungsten, its alloys, and compounds. Toxicological information on tungsten and its compounds is limited in comparison to other metals. There is a need for more systematic studies of the behavior and effects of tungsten and its various compounds in different animal species. The early determinations of toxicity of tungsten and its compounds showed a difference between soluble and insoluble forms. Soluble compounds (tungstate) were distinctly more toxic than the insoluble forms (oxide), resulting in two separate permissible limits for industrial exposure (1 and 5 mg/m 3 TWA, respectively). Most existing data concern the toxicity and health effects of cemented WC and its constituents, particularly in humans. The most significant exposure‐related health effects are an interstitial lung disease (hard metal disease) and an increased risk of lung cancer. Experimental studies have also reported a worrying carcinogenic activity of tungsten containing alloys.
Currently, the gap between the demand for treatment of cases of illness and the available resources for curative medicine has become so wide in Norway that it is time to introduce a new comprehensive system for preventive medicine in order to reduce human suffering and the cost of curative medicine. The authors propose a new system of preventive medicine which involves systematic collection of personal data on disease determinants, and concentrated intervention directed at individuals at high risk of illness and accident. Implementing a new system of prevention requires the establishment of units for intervention and screening, one unit per 100,000 to 300,000 persons. These units should collect personalized data on exposure to risk, particularly among high risk groups, to enable screening of groups of subjects according to their exposure to disease determinants and subsequent a priori disease risks. Based on systematic collection of such data, individualized risk-determined intervention is proposed among identified risk groups, to be carried out within the existing primary health care system.
