Release of beryllium from beryllium-containing materials in artificial skin surface film liquids.
Stefaniak-AB; Virji-MA; Day-GA
Ann Occup Hyg 2011 Jan; 55(1):57-69
Purpose: Skin exposure to soluble beryllium compounds causes systemic sensitization in humans. Penetration of poorly soluble particles through intact skin has been proposed as a mechanism for beryllium sensitization; however, this mechanism is controversial. The purpose of this study was to investigate the hypothesis that particulate beryllium compounds in contact with skin surface release ions via dissolution in sweat. Methods: Dissolution of 11 particulate beryllium materials (hydroxide, metal, oxides and copper-beryllium fume), 3 copper-beryllium alloy reference materials (chips and solid block), and 4 copper-beryllium alloy tools was measured over 7 days in artificial sweat buffered to pH 5.3 and pH 6.5. Results: All testmaterials released berylliumions in artificial sweat. Particulate froma reduction furnace that contained both crystalline andamorphous beryllium was the most soluble compound - 40% dissolved in 8 h. Rates of beryllium release from all other particulate and reference materials were faster at pH 5.3 than at pH 6.5 (P < 0.05). At pH 5.3, values of the chemical dissolution rate constant, k [g (cm2 day)21] differed significantly for hydroxide, metal, and oxide 21.7 6 0.031027, 1.760.631028, and1.060.531029, respectively (P < 0.05). Up to 30mg of beryllium was released from the alloy tools within 1 h. Dissolution rates in artificial sweat were equal to or faster than values previously determined for these materials in lung models. Conclusions: Poorly soluble beryllium materials undergo dissolution in artificial sweat, suggesting that skin exposure is a biologically plausible pathway for development of sensitization. Skin surface acidity, which is regulated by sweat chemistry and bacterial hydrolysis of sebum lipids varies by anatomical region and may be an exposure-modifying factor for beryllium particle dissolution.
Beryllium-compounds; Skin; Skin-absorption; Skin-exposure; Sensitization;
Author Keywords: beryllium sensitization; bioaccessibility; particle dissolution; skin
Aleksandr Stefaniak, Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505, USA
7440-41-7; 1304-56-9; 13327-32-7
Annals of Occupational Hygiene