On the Substitution for Carcinogens in the Working Environment

The ultimate solution in prevention of occupational cancer risks would be to remove carcinogens from the working environment. Elimination of carcinogenic substances can be achieved by replacement of the carcinogen with non-carcinogen(s) having the same functionality, or by using a different process that produces adequate results without the use of carcinogenic agents. This paper presents selected methods and tools, which have been used for substitution purposes in practice. These are: 1. a strategy for substitution, 2. a tool for creating ideas on how to substitute, 3. a software package, SUBTEC, for solving some technical and industrial hygiene problems, and 4. a proposal for a strategy to deal with organizational and psychological barriers encountered when changes are to be introduced.     

Primary thrombosis of pulmonary artery in a child with tetralogy of Fallot.

A 34-month-old child with tetralogy of Fallot developed an acute, primary thrombosis of the pulmonary trunk. A greatly increased haematocrit was most probably a predisposing factor. An unusual postmortem finding was the large number of extremely dilated myocardial capillaries. In a review of a series of 394 consecutive necropsy cases with many kinds of cardiac anomalies, there was only one case (a 28-year-old man) with occluding thrombus formation in the pulmonary artery. This case also belonged to the Fallot group but a subacute glomerulonephritis seemed to be the major cause of death.     

Risk of fatal industrial accidents and death from other external causes among asphalt workers

Overall, no evidence was found supporting the hypothesis that asphalt workers are at increased risk of fatal industrial or road accidents. Mortality from other external causes did not increase in this population as a whole, but increased risks among short term workers deserve further attention.     

Effects of tibolone and continuous combined hormone replacement therapy on mammographic breast density

OBJECTIVE: Our purpose was to compare the effects of tibolone, continuous combined hormone replacement therapy, and placebo on mammographic breast density. STUDY DESIGN: A prospective, randomized, double-blind placebo-controlled study was performed. A total of 166 postmenopausal women were equally randomized to receive tibolone 2.5 mg, estradiol 2 mg/norethisterone acetate 1 mg (E(2)/NETA), or placebo. Mammograms were performed at baseline and after 6 months of treatment. Mammographic density was quantified according to the Wolfe classification and by the percentage area of the breast that had a dense pattern. RESULTS: An increase in mammographic density was much more common among women receiving continuous combined hormone replacement therapy (46%-50%) than among those receiving tibolone (2%-6%) and placebo (0%) treatment. The difference between E(2)/NETA and placebo was highly significant (P <.001). Treatment with tibolone did not differ from that with placebo. The relative risk of an increase in breast density for E(2)/NETA versus tibolone was found to be 8.3 (95% CI 2.7-25.0). CONCLUSION: An increase in mammographic density should be regarded as an unwanted side effect of hormone replacement therapy. In contrast to estrogen/progestogen treatment, tibolone seems to exert little stimulation of breast tissue.     

Comparison of preoperative simultaneous stereotactic fine needle aspiration biopsy and stereotactic core needle biopsy in ductal carcinoma in situ of the breast

PURPOSE: To compare the preoperative results of stereotactic fine needle aspiration biopsy (S-FNAB) with stereotactic core needle biopsy (S-CNB) performed simultaneously in breast lesions with the postoperative histopathological diagnosis of ductal carcinoma in situ (DCIS) of all histological grades. MATERIAL AND METHODS: 733 consecutive stereotactic biopsies were performed between May 1993 and June 1999. In 72 patients with mammographic findings suspicious of malignancy who were subjected to breast surgery, postoperative histopathology showed DCIS. Preoperatively, S-FNAB and S-CNB had been done simultaneously in all patients, S-FNAB with spinal needle 0.7 or 0.9 mm and S-CNB was performed with an automated 2.1-mm biopsy gun. An average of 3 S-FNABs and 3 S-CNBs were performed in each patient. RESULTS: In 56 (78%) of the 72 patients S-CNB showed DCIS. In 3 patients (4%) the S-CNB revealed "probable carcinoma", in 7 patients (10%) "atypia" and in 6, the lesions were benign. In 34 (47%) of the 72 women S-FNABs showed carcinoma, not otherwise specified. In 6 cases (8%) the S-FNABs showed "probable carcinoma" and in 12 patients (17%) "atypia"; 8 lesions were benign and 12 not diagnostic. CONCLUSION: S-CNB was superior to S-FNAB in diagnosing DCIS. Only 6 patients (8%) received a benign or non-diagnostic preoperative diagnosis with S-CNB compared to 20 patients (28%) with S-FNAB. S-CNB was superior to S-FNAB for preoperative diagnosis of DCIS, but S-FNAB could further increase the sensitivity of the biopsy since it diagnosed cancer in 4 cases where S-CNB showed benign material.     

Classification of left main coronary obstruction--feasibility of surgical angioplasty and survival after coronary artery bypass surgery

Angiographies of 384 patients who had coronary artery bypass surgery because of left main coronary artery (LMCA) obstruction during 1970-1989 were reviewed by analysing the pathology, feasibility of surgical angioplasty and survival. Complete LMCA occlusion was found in 2%, proximal ostial stenosis in 9%, mid-shaft stenosis in 24%, circular stenosis in 25% and distal bifurcation stenosis in 40% of the patients. Patients with an ostial stenosis were younger, more often women with less coronary artery disease and less calcified obstructions. Surgical angioplasty could have been an option in 22% of the patients. Early mortality was higher in patients with (4.7%) than in those without (1.9%) LMCA obstruction. The relative risk (RR) of early death was 1.9 (95% CL 1.1-3.5) after adjustment for patient characteristics. Similarly, the RR at 10 years was 1.3 (95% CL 1.0-1.6). LMCA obstruction was associated with an early and long-term increased mortality after surgery compared to patients without LMCA obstruction.     

Mortality from obstructive lung diseases and exposure to polycyclic aromatic hydrocarbons among asphalt workers

Work in the asphalt industry has been associated with nonmalignant respiratory morbidity and mortality, but the evidence is not consistent. A historical cohort of asphalt workers included 58,862 men (911,209 person-years) first employed between 1913 and 1999 in companies applying and mixing asphalt in Denmark, Finland, France, Germany, Israel, the Netherlands, and Norway. The relations between mortality from nonmalignant respiratory diseases (including the obstructive lung diseases: chronic bronchitis, emphysema, and asthma) and specific chemical agents and mixtures were evaluated using a study-specific exposure matrix. Mortality from obstructive lung diseases was associated with the estimated cumulative and average exposures to polycyclic aromatic hydrocarbons and coal tar (p values of the test for linear trend = 0.06 and 0.01, respectively). The positive association between bitumen fume exposure and mortality from obstructive lung diseases was weak and not statistically significant; confounding by simultaneous exposure to coal tar could not be excluded. The authors lacked data on smoking and full occupational histories. In conclusion, exposures to polycyclic aromatic hydrocarbons, originating from coal tar and possibly from bitumen fume, may have contributed to mortality from obstructive lung diseases among asphalt workers, but confounding and bias cannot be ruled out as an explanation for the observed associations.     

Tuberculosis diagnosed in a surgical department during 1974-93: a report of 32 cases

During the period 1974-93, 32 patients (18 males, 14 females) with previously undiagnosed tuberculosis were admitted to the department of surgery and the surgical outpatient department of Buskerud Central Hospital. Of these, 26 were native Norwegians and 6 immigrants of Asian origin with an average age of 65 and 26 years, respectively. Of the native Norwegians, 14 patients had a past history of tuberculosis and 7 cases were associated with concomitant cancer. With 1 exception, all immigrants had extrapulmonary tuberculosis. Cultural identification of Mycobacterium tuberculosis occurred in 28 cases and Mycobacterium bovis in 1 (immigrant). A total of 30 patients were cured, whereas 2 of 3 patients with miliary dissemination died.