RESUMEN
Objective To explore the biological exposure limit of blood system damage caused by long-term exposure to polycyclic aromatic hydrocarbons (PAHs) in non-occupational population by using the benchmark dose method, and to provide relevant reference for further improving the assessment of PAHs-induced health damage effects. Methods Adult residents living in downwind direction of a coke-oven plant in Shanxi Province were selected as the research subjects, and the information collected from baseline was used as the control. The metabolites of PAHs in urine were used as exposure biomarker, and the abnormal rate of red blood cell index was used as response biomarker. The relationship between urinary OH-PAHs and the erythrocyte damage rate was analyzed, and the benchmark dose (BMD) and the lower confidence limitation for the benchmark dose (BMDL) were calculated using Bayesian dose-optimizing software. Results The urinary PAH metabolites were mainly naphthalene and fluorene. The detection concentrations of 2-OHFlu and 1-OHPhe in the final year were higher than those in the baseline (P<0.05). With the increase of exposure years, the abnormal rate of red blood cells in the final year was higher than that in the baseline (P<0.05). In addition, the abnormal rate of red blood cells increased with the increase of the concentrations of five metabolites of PAHs in urine, and the chi-square trend test was significant (P<0.05). The benchmark dose (BMD) of OH-PAHs was 0.67 μmol/mol Cr, 0.82 μmol/mol Cr, 1.40 μmol/mol Cr and 0.78 μmol/mol Cr, respectively. The BMD of 2-OHNap in people with barbecue diet habits was 0.23 μmol/mol Cr. The BMD of 2-OHNap in people without barbecue diet habits was 1.44 μmol/mol Cr. Conclusion There is a dose-response relationship between the concentration of PAHs metabolites in urine and the damage of red blood cells. Long-term exposure to PAHs can lead to hematological damage. It is suggested that targeted public health interventions should be formulated to reduce the exposure of the general population to PAHs.
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We evaluated the toxicity of hepatic, hematological, and oxidative effects of glyphosate-Roundup(®) on male and female albino Swiss mice. The animals were treated orally with either 50 or 500 mg/kg body weight of the herbicide, on a daily basis for a period of 15 days. Distilled water was used as control treatment. Samples of blood and hepatic tissue were collected at the end of the treatment. Hepatotoxicity was monitored by quantitative analysis of the serum enzymes ALT, AST, and γ-GT and renal toxicity by urea and creatinine. We also investigated liver tissues histopathologically. Alterations of hematological parameters were monitored by RBC, WBC, hemoglobin, hematocrit, MCV, MCH, and MCHC. TBARS (thiobarbituric acid reactive substances) and NPSH (non-protein thiols) were analyzed in the liver to assess oxidative damage. Significant increases in the levels of hepatic enzymes (ALT, AST, and γ-GT) were observed for both herbicide treatments, but no considerable differences were found by histological analysis. The hematological parameters showed significant alterations (500 mg/kg body weight) with reductions of RBC, hematocrit, and hemoglobin, together with a significant increase of MCV, in both sexes of mice. In males, there was an important increase in lipid peroxidation at both dosage levels, together with an NPSH decrease in the hepatic tissue, whereas in females significant changes in these parameters were observed only at the higher dose rate. The results of this study indicate that glyphosate-Roundup(®) can promote hematological and hepatic alterations, even at subacute exposure, which could be related to the induction of reactive oxygen species.