Tags

Type your tag names separated by a space and hit enter

The effects of simultaneous exposure to methyl ethyl ketone and toluene on urinary biomarkers of occupational N,N-dimethylformamide exposure.
Toxicol Lett. 2005 Mar 15; 155(3):385-95.TL

Abstract

General regulations and risk assessment regarding toxicants are single-compound oriented even though humans are exposed to multi-chemicals in the general environment. This study investigated the effects of different levels of N,N-dimethylformamide (DMF) and co-exposure levels of methyl ethyl ketone (MEK) and toluene (TOL) on two biomarkers of DMF exposure: non-metabolized urinary (U-)DMF and the DMF metabolite urinary N-methylformamide (NMF). Thirty-five workers were selected from a two-stage field investigation strategy and were classified into four groups based on DMF exposure and co-exposure levels. Breathing-zone air concentrations of DMF, MEK, and TOL as well as dermal DMF exposure were determined. Post-shift U-DMF and U-NMF levels were determined for each individual. U-DMF concentrations were significantly higher in high-DMF groups than in low-DMF groups, but U-NMF concentrations were significantly (P<0.05) lower in the high-DMF-high-co-exposure group than in the high-DMF-low-co-exposure group; there were no significant differences between two low-DMF groups. The ratio of U-NMF to U-DMF showed the biotransformation from DMF to NMF was significantly suppressed at high co-exposure (P<0.001) for high-DMF exposure groups, possibly because of competitive inhibition of CYP2E1, the responsible enzyme involved. Due to the ubiquity of MEK/TOL in DMF-exposed occupational settings, the biological exposure index for occupational DMF exposure should be re-evaluated at high co-exposure levels.

Authors+Show Affiliations

Department of Environmental and Occupational Health, Medical College, National Cheng Kung University, 138 Sheng-Li Road, Tainan 70428, Taiwan. h7154@mail.ncku.edu.twNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15649622

Citation

Chang, Ho-Yuan, et al. "The Effects of Simultaneous Exposure to Methyl Ethyl Ketone and Toluene On Urinary Biomarkers of Occupational N,N-dimethylformamide Exposure." Toxicology Letters, vol. 155, no. 3, 2005, pp. 385-95.
Chang HY, Yun YD, Yu YC, et al. The effects of simultaneous exposure to methyl ethyl ketone and toluene on urinary biomarkers of occupational N,N-dimethylformamide exposure. Toxicol Lett. 2005;155(3):385-95.
Chang, H. Y., Yun, Y. D., Yu, Y. C., Shih, T. S., Lin, M. S., Kuo, H. W., & Chen, K. M. (2005). The effects of simultaneous exposure to methyl ethyl ketone and toluene on urinary biomarkers of occupational N,N-dimethylformamide exposure. Toxicology Letters, 155(3), 385-95.
Chang HY, et al. The Effects of Simultaneous Exposure to Methyl Ethyl Ketone and Toluene On Urinary Biomarkers of Occupational N,N-dimethylformamide Exposure. Toxicol Lett. 2005 Mar 15;155(3):385-95. PubMed PMID: 15649622.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The effects of simultaneous exposure to methyl ethyl ketone and toluene on urinary biomarkers of occupational N,N-dimethylformamide exposure. AU - Chang,Ho-Yuan, AU - Yun,Yuan-Der, AU - Yu,Yi-Chun, AU - Shih,Tung-Sheng, AU - Lin,Ming-Song, AU - Kuo,Hsien-Wen, AU - Chen,Kuo-Ming, PY - 2004/06/09/received PY - 2004/11/07/revised PY - 2004/11/15/accepted PY - 2005/1/15/pubmed PY - 2005/3/5/medline PY - 2005/1/15/entrez SP - 385 EP - 95 JF - Toxicology letters JO - Toxicol Lett VL - 155 IS - 3 N2 - General regulations and risk assessment regarding toxicants are single-compound oriented even though humans are exposed to multi-chemicals in the general environment. This study investigated the effects of different levels of N,N-dimethylformamide (DMF) and co-exposure levels of methyl ethyl ketone (MEK) and toluene (TOL) on two biomarkers of DMF exposure: non-metabolized urinary (U-)DMF and the DMF metabolite urinary N-methylformamide (NMF). Thirty-five workers were selected from a two-stage field investigation strategy and were classified into four groups based on DMF exposure and co-exposure levels. Breathing-zone air concentrations of DMF, MEK, and TOL as well as dermal DMF exposure were determined. Post-shift U-DMF and U-NMF levels were determined for each individual. U-DMF concentrations were significantly higher in high-DMF groups than in low-DMF groups, but U-NMF concentrations were significantly (P<0.05) lower in the high-DMF-high-co-exposure group than in the high-DMF-low-co-exposure group; there were no significant differences between two low-DMF groups. The ratio of U-NMF to U-DMF showed the biotransformation from DMF to NMF was significantly suppressed at high co-exposure (P<0.001) for high-DMF exposure groups, possibly because of competitive inhibition of CYP2E1, the responsible enzyme involved. Due to the ubiquity of MEK/TOL in DMF-exposed occupational settings, the biological exposure index for occupational DMF exposure should be re-evaluated at high co-exposure levels. SN - 0378-4274 UR - https://www.unboundmedicine.com/medline/citation/15649622/The_effects_of_simultaneous_exposure_to_methyl_ethyl_ketone_and_toluene_on_urinary_biomarkers_of_occupational_NN_dimethylformamide_exposure_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0378-4274(04)00507-7 DB - PRIME DP - Unbound Medicine ER -