title: Cobalt skin dose resulting from short and repetitive contact with hard metals.
abstract: BACKGROUND
  Many daily contacts with metallic items are short and repetitive, and result in metal release; material, sweat, friction and wear may all be important.
  
  
  OBJECTIVE
  To study cobalt release and skin deposition as a result of many short and repetitive contacts with two cobalt-containing materials.
  
  
  METHODS
  Study participants (n = 5) handled two types of hard metal disc (Co 6% and Co 15% Cr 0.6%) for 30 min. Deposited cobalt skin doses were measured with acid wipe sampling and chemical analysis. Cobalt release from the hard metal discs in artificial sweat was measured under conditions simulating those present during the handling of discs.
  
  
  RESULTS
  Average cobalt skin doses from discs containing 6% Co and 15% Co 0.6% Cr were 1.1 µg/cm(2) [standard deviation (SD) 0.4 µg/cm(2) ] and 0.7 µg/cm(2) (SD 0.5 µg/cm(2) ), respectively. More cobalt was released from hard metal discs containing 6% Co [11.4 µg/cm(2) (SD 1.2 µg/cm(2) )] than from discs containing 15% Co 0.6% Cr [4.8 µg/cm(2) (SD 0.6 µg/cm(2) )]. 10% to 15% of the potentially available cobalt was deposited on the skin during handling.
  
  
  CONCLUSIONS
  It is likely that the cobalt deposited as a result of short and repetitive contact with hard metals may cause harm. Research regarding cobalt exposure, metal release and the deposition of skin-sensitizing metals resulting from short and repetitive contact is needed for a better understanding of the allergy risk.
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, SE 171 77, Stockholm, Sweden.
authors.forename: Klara
authors.initials: K
authors.lastname: Midander
authors.forename: Anneli
authors.initials: A
authors.lastname: Julander
authors.forename: Lizbet
authors.initials: L
authors.lastname: Skare
authors.forename: Carola
authors.initials: C
authors.lastname: Lidén
mesh_terms: D000497:Alloys / Q000032:analysis*; D003035:Cobalt / Q000032:analysis*; D004781:Environmental Exposure / Q000032:analysis*; D006801:Humans; D012867:Skin / Q000737:chemistry*; D013542:Sweat / Q000737:chemistry; D014414:Tungsten / Q000032:analysis*
chemical_list: D000497:Alloys; C080121:hard metal; D003035:Cobalt; D014414:Tungsten
keywords: acid wipe sampling; artificial sweat; cemented carbide; cobalt; cobalt release; risk assessment; skin dose