Hematotoxocity among Chinese workers heavily exposed to benzene

Abstract

Benzene is a well‐established hematotoxin. However, reports of its effects on specific blood cells have been somewhat inconsistent and the relative toxicity of benzene metabolites on peripheral blood cells in humans has not been evaluated. We compared hematologic outcomes in a cross‐sectional study of 44 workers heavily exposed to benzene (median: 31 parts permillion [ppm] as an 8‐hr time‐weighted average [TWA] and 44 age and gender‐matched unexposed controls from Shanghai, China. All hematologic parameters (total white blood cells [WBC], absolute lymphocyte count, platelets, red blood cells, and hematocrit) were decreased among exposed workers compared to controls, with the exception of the red blood cell mean corpuscular volume (MCV), which has higher among exposed subjects. In a subgroup of workers who were not exposed to more than 31 ppm benzene on any of 5 sampling days (n = 11, median 8 hr TWA = 7.6 ppm, range = 1–20 ppm), only the absolute lymphocyte count was significantly different between exposed workers (mean [sd] 1.6 [0.4] x 103 μL) and controls (1.9 [0.4] x 103 μL, p = 0.03). Among exposed subjects, a dose‐response relationship with various measures of current benzene exposure (i.e., personal air monitoring, benzene metabolites in urine) was present only for the total WBC count, the absolute lymphocyte count, and the MCV. Correlations between benzene metabolites and hematologic parameters were generally similar, although hydroquinone was somewhat more strongly associated with a decrease in the absolute lymphocyte count, and catechol was more strongly associated with an increase in MCV. Morphologic review of peripheral blood slides demonstrated an excess of red blood cell abnormalities (i.e., stomatocytes and target cells) only in the most heavily exposed workers, with no differences in granulocyte, lymphocyte, or platelet morphology noted. Although benzene can affect all the major peripheral blood elements, our results support the use of the absolute lymphocyte count as the most sensitive indicator of benzene‐induced hematotoxicity. © 1995 Wiley‐Liss, Inc.

Decreased levels of CXC-chemokines in serum of benzene-exposed workers identified by array-based proteomics

“…Although they are also secreted by other cells, platelets remain the most abundant and the most rapidly available source for these CXC-chemokines (17,18). It is well established that benzene lowers peripheral platelet counts (7)(8)(9), raising the possibility that our finding could be explained entirely or in part by a decrease in platelet counts among the exposed subjects. However, we determined that the absolute platelet count did not significantly impact on the difference in expression of PF4 and CTAP-III between benzene exposed and unexposed subjects by using linear regression on the natural logarithm of each protein adjusted and unadjusted for platelet count (Table 3).…”

“…Benzene is an established cause of acute myeloid leukemia and myelodysplastic syndromes and may play a role in lymphocytic leukemias and non-Hodgkin lymphoma in humans (1)(2)(3)(4)(5)(6). Additionally, changes in blood and bone marrow consistent with hematotoxicity are recognized in humans and experimental animals (7)(8)(9). Benzene also produces immunosuppressive effects in exposed animals and humans and has been shown to increase susceptibility to tuberculosis and other infectious agents (10,11).…”

Hematologic Evaluation of Painting Hall Workers in an Automobile Manufacturing Company

“…Reduction in complete blood cell (CBC) count to levels below the normal limit is termed as pancytopenia, leading to aplastic anemia (16). Some authors have proposed hemoglobin (17,18), mean corpuscular volume (MCV) (19,20), absolute lymphocyte count (21)(22)(23), and CBC count (24)(25)(26) as appropriate tests for the detection of toxic effects.…”

Biomarkers of leukemia risk: benzene as a model.

“…In peripheral blood, the cells that can most readily be stimulated to divide are the T lymphocytes; therefore, the most common technique used is cytogenetic analysis of metaphases from these cells. Peripheral T lymphocytes, though a target of the hematotoxic effects of benzene (108,109), are clearly not the target of genotoxic damage responsible for the development of AML and MDS. Thus, the validity of measuring AML-specific chromosome aberrations in peripheral T cells might be questioned.…”