title: Role of dermal exposure in systemic intake of methylenediphenyl diisocyanate (MDI) among construction and boat building workers.
abstract: The causal relationship between inhalation exposure to methylenediphenyl diisocyanate (MDI) and the risk of occupational asthma is well known, but the role of dermal exposure and dermal uptake of MDI in this process is still unclear. The aims of this study were to measure dermal exposure to and the dermal uptake of MDI among workers (n=24) who regularly handle MDI-urethanes. Dermal exposure was measured by the tape-strip technique from four sites on the dominant hand and arm. The workers with the highest exposure (n=5) were biomonitored immediately after their work shift, in the evening and the next morning, using urinary 4,4´methylenedianiline (MDA) as a marker. Dermal uptake was evaluated by comparing workers' MDA excretions both when they were equipped with respiratory protective devices (RPDs) and when they did not use them. The measured amounts of MDI on their hands varied from below 0.1 to 17 μg/10 cm(2) during the test. MDI concentrations were in the range of 0.08 to 27 μg m(-3) in the breathing zone outside the RPDs. MDA concentrations varied from 0.1 to 0.2 μmol mol(-1) creatinine during the test period. The decreasing effect of RPDs on inhalation exposure was absent in the next morning urine samples; this excretion pattern might be an indication of dermal uptake of MDI.
authors.affiliation: Finnish Institute of Occupational Health, Lemminkäisenkatu 14-18 B, FI-20520 Turku, Finland. Electronic address: maj-len.henriks-eckerman@ttl.fi.
authors.forename: Maj-Len
authors.initials: ML
authors.lastname: Henriks-Eckerman
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland.
authors.forename: Erja A
authors.initials: EA
authors.lastname: Mäkelä
authors.affiliation: Finnish Institute of Occupational Health, Kuopio, Finland.
authors.forename: Juha
authors.initials: J
authors.lastname: Laitinen
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland.
authors.forename: Katriina
authors.initials: K
authors.lastname: Ylinen
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland.
authors.forename: Katri
authors.initials: K
authors.lastname: Suuronen
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland.
authors.forename: Aki
authors.initials: A
authors.lastname: Vuokko
authors.affiliation: Finnish Institute of Occupational Health, Tampere, Finland.
authors.forename: Riitta
authors.initials: R
authors.lastname: Sauni
mesh_terms: D004784:Environmental Monitoring; D004785:Environmental Pollutants; D017575:Gloves, Protective; D006801:Humans; D017953:Isocyanates / Q000008:administration & dosage / Q000633:toxicity*; D016273:Occupational Exposure; D012869:Skin Absorption / Q000502:physiology*; D001559:Benzhydryl Compounds
chemical_list: D004785:Environmental Pollutants; D017953:Isocyanates; C005969:4,4'-diphenylmethane diisocyanate; D001559:Benzhydryl Compounds
keywords: Dermal exposure; Isocyanate; MDI