Total body burden arising from a week’s repeated dermal exposure to N,N-dimethylformamide
- 1Department of Environmental and Occupational Health, Medical College, National Cheng Kung University, Tainan, Taiwan
- 2Institute of Occupational Safety and Health, Council of Labor Affairs, Taipei, Taiwan
- 3Department of Applied Cosmetics Sciences, Chia-Nan University of Pharmacy and Science, Tainan, Taiwan
- Correspondence to: Dr H-Y Chang Department of Environmental and Occupational Health, Medical College, National Cheng Kung University, 138 Sheng-Li Road, Tainan 704, Taiwan; h7154mail.ncku.edu.tw
- Accepted 21 October 2004
Abstract
Background: Hazardous chemicals and their metabolites may accumulate in the body following repeated airborne exposures and skin contact.
Aims: To estimate the contribution of skin absorption to total body burden of N,N-dimethylformamide (DMF) across a working week in two groups with similar levels of respiratory exposure but dissimilar skin contact.
Methods: Twenty five workers in a synthetic leather (SL) factory, 20 in a copper laminate circuit board (CLCB) factory, and 20 age and sex matched non-DMF exposed subjects, were recruited. Environmental monitoring of DMF exposure via respiratory and dermal routes, as well as biological monitoring of pre-shift urinary N-methylformamide (U-NMF), were performed for five consecutive working days.
Results: Environmental and biological monitoring showed no detectable exposure in controls. The average airborne DMF concentration (geometric mean (GM) 3.98 ppm, geometric standard deviation (GSD) 1.91 ppm), was insignificantly lower for SL workers than for CLCB workers (GM 4.49, GSD 1.84 ppm). Dermal DMF exposure and U-NMF values, however, were significantly higher for SL workers. A significant pattern of linear accumulation was found across a five day work cycle for SL workers but not for CLCB workers.
Conclusions: Dermal exposure to DMF over five consecutive days of occupational exposure can result in the accumulation of a significant DMF body burden. The long term exposure response under both repeated and intermittent conditions of substantial skin exposure is worthy of note.
- CLCB, copper laminate circuit board
- DMF, N,N-dimethylformamide
- GM, geometric mean
- GSD, geometric standard deviation
- NMF, N-methylformamide
- SL, synthetic leather
Footnotes
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Competing interests: none declared
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The study protocol was approved by the Institutional Review Board of the Medical College, National Cheng Kung University, before the research started. Each participant read and signed the consent forms before the study began.
