| Formaldehyde (FA) is a simple one-carbon molecule that can be rapidly metabolized. It is endogenously produced and also formed through the metabolism of many xenobiotic agents. Acute exposure to formaldehyde can cause irritation in many organs, while prolonged exposure can lead to chronic toxicity and even cancer. Formaldehyde was nominated for possible reclassification in the 12th'Report on Carcinogens'based on the 2004 review by the International Agency for Research on Cancer, which concluded that there was sufficient evidence for the carcinogenicity of formaldehyde in humans.The predominant use of formaldehyde is in the production of industrial resins (mainly urea-formaldehyde) that are used to manufacture products such as adhesives and binders for wood products, and it is also used as a chemical intermediate. China is the largest formaldehyde producer and consumer in the world. With the large amount of use, formaldehyde pollution increasingly impacts millions of people, and the adverse health effects are of escalating concern in Chinese society and require further investigation. The biomonitoring of FA exposed workers and the investigation of sensitive biomarkers is an important and useful method to evaluate the formaldehyde-induced heath effect.Typical biological indices of exposure, such as levels of formaldehyde or its metabolites in blood or urine, have proven to be ineffective measures of exposure. Some researchers demonstrated that formaldehyde binds human serum albumin covalently, giving rise to a molecular adduct (FA-HSA) having the formaldehyde as hapten. The finding suggests that the humoral immune response to the adduct FA-HSA would provide a biological marker of formaldehyde exposure and of effective dose. In this research, we used 215 workers employed in two plywood industries as our object of study, all subjects were interviewed with questionnaire and blood samples were collected. Air sampling and formaldehyde analysis were performed through HPLC according to the National Institute for Occupational Safety and Health (NIOSH) method in selected workshops, and serum FA-HSA were detected among all workers. The average concentration of FA in the low FA exposed workshop (0.58±0.20 mg/m3) is much lower than in the high FA exposed workshop (1.48±0.61 mg/m3), and the average concentration of serum FA-HSA is (69.22±15.37) pg/ml and (136.29±89.49) pg/ml respectively. As the rising of air formaldehyde concentrations, the concentrations of FA-HSA in serum also increase.Formaldehyde can cause cytogenetic damage in exposed workers. In this study, KCL-SDS assay and single cell gel electrophoresis were used to investigate DNA-protein crosslinks and DNA strand breaks in human peripheral blood lymphocytes, and cytokinesis-block micronucleus assay was used to detect chromosome damage. The results didn't show any significant difference of cytogenetic damage among low-exposure, intermediate-exposure and high-exposure groups (P>0.05), but it did show a positive correlation between working years and CBMN‰(rs=0.339, P<0.001) and OTM (rs=0.239, P=0.003). The workers whose working years were longer than 4.4 years had a higher CBMN‰risk as well as a higher OTM risk compared to the workers whose working years were shorter than 1.5 years (Ptrend<0.001).In summary, we selected 215 occupational FA exposed workers as our study object and investigate the association of FA exposure and cytogenetic damage in peripheral lymohocytes. The results suggested that FA-HSA in serum can be a biomarker of FA exposure and of effective dose. With the increase of working years, the DNA damage of the workers also increases. CBMN‰and OTM can be used as effect biomakers to evaluate the accumulation of cytogenetic damage caused by FA exposure. |
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