Clinical analysis of 43 cases of chronic benzene poisoning.

Benzene can result in bone marrow suppression. Chronic benzene poisoning (CBP) can be found among workers with excessive benzene exposure. CBP could give the appearance of different types of disorders such as leukopenia, agranulocytosis, anemia, pancytopenia, aplastic anemia (AA), myelodysplastic syndrome (MDS), and leukemia. This paper describes 43 CBP cases with the patients' ages ranging from 18 to 36 years (average: 23 years). Among them, 13 (30%) were male and 30 (70%) were female. Their job titles were furniture maker, shoemaker, industrial painter and metal shop worker. Their work durations ranged from 1.5 to 72 months (average: 14 months). Benzene levels in these workplaces exceeded 30 mg/m3. Ten of the 43 cases (23%) were diagnosed as mild cases of CBP, another 10 (23%) were moderate, and 23 (53%) were severe. Treatment for CBP included the following: cessation of benzene exposure, general supportive therapy, antibiotics, vitamins, corticosteroids, androgens, colony-stimulating factors (G-CSF, GM-CSF), blood component therapy, and traditional Chinese medicine. Thirty-three (77%) of the cases recovered completely, nine (21%) cases improved, and one (2%) died. In general, prognosis of CBP cases is optimistic when appropriate treatment is given. However, a few of the benzene-induced AA cases showed no response to treatment, which raises questions about the traditional view of the pathogenesis of the illness. Furthermore, only a part of the population with the same level of benzene exposure would suffer from the disease. Still, CBP cases with the same benzene exposure level exhibited different extents of severity of the illness. This evidence suggests strongly the existence of individual susceptibility. Detection of the biological markers regarding the individual susceptibility would be valuable for screening workers who are not suitable to be exposed to benzene.