title: Quantitative plasma biomarker analysis in HDI exposure assessment.
abstract: Quantification of amines in biological samples is important for evaluating occupational exposure to diisocyanates. In this study, we describe the quantification of 1,6-hexamethylene diamine (HDA) levels in hydrolyzed plasma of 46 spray painters applying 1,6-hexamethylene diisocyanate (HDI)-containing paint in vehicle repair shops collected during repeated visits to their workplace and their relationship with dermal and inhalation exposure to HDI monomer. HDA was detected in 76% of plasma samples, as heptafluorobutyryl derivatives, and the range of HDA concentrations was < or =0.02-0.92 microg l(-1). After log-transformation of the data, the correlation between plasma HDA levels and HDI inhalation exposure measured on the same workday was low (N = 108, r = 0.22, P = 0.026) compared with the correlation between plasma HDA levels and inhalation exposure occurring approximately 20 to 60 days before blood collection (N = 29, r = 0.57, P = 0.0014). The correlation between plasma HDA levels and HDI dermal exposure measured on the same workday, although statistically significant, was low (N = 108, r = 0.22, P = 0.040) while the correlation between HDA and dermal exposure occurring approximately 20 to 60 days before blood collection was slightly improved (N = 29, r = 0.36, P = 0.053). We evaluated various workplace factors and controls (i.e. location, personal protective equipment use and paint booth type) as modifiers of plasma HDA levels. Workers using a downdraft-ventilated booth had significantly lower plasma HDA levels relative to semi-downdraft and crossdraft booth types (P = 0.0108); this trend was comparable to HDI inhalation and dermal exposure levels stratified by booth type. These findings indicate that HDA concentration in hydrolyzed plasma may be used as a biomarker of cumulative inhalation and dermal exposure to HDI and for investigating the effectiveness of exposure controls in the workplace.
authors.affiliation: Department of Environmental Sciences and Engineering, The University of North Carolina at Chapel Hill, Rosenau Hall, NC 27599, USA.
authors.forename: Sheila L
authors.initials: SL
authors.lastname: Flack
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Fent
authors.forename: Linda G
authors.initials: LG
authors.lastname: Trelles Gaines
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Thomasen
authors.forename: Steve
authors.initials: S
authors.lastname: Whittaker
authors.forename: Louise M
authors.initials: LM
authors.lastname: Ball
authors.forename: Leena A
authors.initials: LA
authors.lastname: Nylander-French
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis / Q000378:metabolism* / Q000633:toxicity; D000418:Albumins / Q000032:analysis; D001336:Automobiles; D015415:Biomarkers / Q000097:blood; D003485:Cyanates / Q000032:analysis / Q000378:metabolism* / Q000633:toxicity; D003627:Data Interpretation, Statistical; D003959:Diamines / Q000097:blood*; D004784:Environmental Monitoring; D008401:Gas Chromatography-Mass Spectrometry; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D006868:Hydrolysis; D019570:Inhalation Exposure / Q000032:analysis*; D017953:Isocyanates; D016014:Linear Models; D008297:Male; D016273:Occupational Exposure / Q000032:analysis*; D010150:Paint; D011482:Protective Devices / Q000706:statistics & numerical data; D012869:Skin Absorption; D013997:Time Factors; D017132:Workplace / Q000592:standards
chemical_list: D000395:Air Pollutants, Occupational; D000418:Albumins; D015415:Biomarkers; D003485:Cyanates; D003959:Diamines; D006454:Hemoglobins; D017953:Isocyanates; C015262:1,6-hexamethylene diisocyanate; C007297:1,6-diaminohexane