Two rare complications of chronic benzene poisoning: myeloid metaplasia and paroxysmal nocturnal hemoglobinuria. Report of two cases

Benzene--a review of the literature from a health effects perspective

A literature review of the impact on human health of exposure to benzene was conducted. Special emphasis in this report is given to the health effects reported in excess of national norms by participants in the Benzene Subregistry of the National Exposure Registry--people having documented exposure to benzene through the use of benzene-contaminated water for domestic purposes. The health effects reported in excess (p < or = .01) by some or all of the sex and age groups studied were diabetes, kidney disease, respiratory allergies, skin rashes, and urinary tract disorders; anemia was also increased for females, but not significantly so.

Leukaemia and lymphoma risks derived from solvents

Results of epidemiologic studies indicating an association between solvent exposure and the development of malignancies affecting haematopoietic and lymphatic tissues are reviewed. Clinical and cytogenetic data supporting this association are discussed. A variety of malignant disorders have been associated with solvent exposure, i.e. acute leukaemia, Hodgkin's disease (odds ratio 2.8-6.6), non-Hodgkin's lymphoma (odds ratio 3.3) and myeloma, and there are some indications that solvent exposure may be a risk factor for myelofibrosis. The carcinogenic effect of benzene is epidemiologically and experimentally well documented and there are some indications that other solvents may also be hazardous. Possible mechanisms bringing about malignant transformation are discussed. The need for further epidemiologic, cytogenetic and clinical studies on the association between solvent exposure and malignant diseases is emphasised.

Chemical of current interest--benzene

Benzene is one of the world's major commodity chemicals. It is derived from petroleum and coal and is used both as a solvent and as a starting material in chemical syntheses. The numerous industrial uses of benzene over the last century need not be recounted here, but the most recent addition to the list of uses of benzene is as a component in a mixture of aromatic compounds added to gasoline for the purpose of replacing lead compounds as anti-knock ingredients. The best known and longest recognized toxic effect of benzene is the depression of bone marrow function seen in occupationally exposed individuals. These people have been found to display anemia, leucopenia, and/or thrombocytopenia. When pancytopenia, i.e., the simultaneous depression of all three cell types, occurs and is accompanied by bone marrow necrosis, the syndrome is called aplastic anemia. In addition to observing this decrease in humans and relating it to benzene exposure, it has been possible to establish animal models which mimic the human disease. The result has been considerable scientific investigation into the mechanism of benzene toxicity. Although the association between benzene exposure and aplastic anemia has been recognized and accepted throughout most of this century, it is only recently that leukemia, particularly of the acute myelogenous type, has been related to benzene. The acceptance of benzene as an etiological agent in aplastic anemia in large measure derives from our ability to reproduce the disease in most animals treated with sufficiently high doses of benzene over the necessary time period. Unfortunately, despite extensive efforts in several laboratories, it has not been possible to establish a reproducible, reliable model for the study of benzene-induced leukemia. The recent demonstration that several animals exposed to benzene either by inhalation or in the drinking water during studies by Drs. B. Goldstein and C. Maltoni suggests that such a model may be forthcoming. Nevertheless, at this time it is not clear whether bone marrow damage of the type that leads to aplastic anemia is required for the development of leukemia. Most studies of benzene toxicity have involved dosing animals with benzene either by inhalation or by injection, using high doses to ensure a toxic response. Very few studies have concentrated on the oral route of administration and none have concentrated on administering benzene by mouth at the low doses occasionally detected in drinking water.(ABSTRACT TRUNCATED AT 400 WORDS)

Malignancies due to occupational exposure to benzene

There is no doubt about the leukemogenic effect of benzene in man. The evidence is as follows: (1) The incidence of leukemia in shoeworkers exposed to benzene in a period of 8 years in Istanbul was 13.6/100,000, which is significantly higher than that for leukemia in the general population. (2) Following the phase-out of benzene in Istanbul, the number of leukemic workers decreased and none were reported in the subsequent 3 years. (3) The development of leukemia in pancytopenic patients with benzene exposure was observed in 13 out of 51 patients. (4) The differences in the distribution of the types of leukemia in individuals exposed and in nonexposed groups were as follows: acute leukemia 96.1% in the former group, and 46% in the latter group. The high percentages of acute erythroleukemia and preleukemia were other interesting findings in the exposed group. (5) Two cases of leukemia were observed in a 6-year period at a tire cord manufacturing plant with 550 workers. At one location in the plant the concentration of benzene measured by gas chromatography was nearly 110 ppm. Additionally, we have studied 12 cases of malignant lymphoma, four cases of multiple myeloma, and six cases of lung cancer, all of whom were chronically exposed to benzene. The possible role of benzene in the etiology of these malignancies is discussed.