title: Manganese exposure in foundry furnacemen and scrap recycling workers.
abstract: OBJECTIVE
  Cast iron products are alloyed with small quantities of manganese, and foundry furnacemen are potentially exposed to manganese during tapping and handling of smelts. Manganese is a neurotoxic substance that accumulates in the central nervous system, where it may cause a neurological disorder that bears many similarities to Parkinson's disease. The aim of the study was to investigate the sources and levels of manganese exposure in foundry furnacemen by a combined measuring of blood-manganese (B-Mn) and manganese in ambient air (air-Mn).
  
  
  METHODS
  During a period of 16 months, Air-Mn and B-Mn (denoted 'exposure values') were measured involving 24 furnacemen employed in three small size foundries and 21 scrap recycling workers from one plant. In the study period, 18 furnacemen had B-Mn measured 3-4 weeks after decreasing or stopping exposure (denoted 'post-exposure values'). The reference group for the B-Mn measurements consisted of 90 Danish male subjects.
  
  
  RESULTS
  Furnacemen who work in insufficiently ventilated smelting departments inhale, absorb, and retain significant amounts of manganese in their blood (approx. 2.5-5 microg/l above reference values) despite a generally low measured airborne level of manganese fumes (0.002-0.064 mg/m(3)). The 'exposure values' compared with 'post-exposure values' revealed a significant decrease in the B-Mn (on average 3.7 microg/l) level of the most exposed furnacemen. Two persons in our study were suspected of suffering clinically subacute manganese intoxication as both had B-Mn levels beyond the normal limit (25 and 29 microg/l, respectively). The potential problem disappeared completely after cessation of exposure, and the B-Mn levels decreased to 9.4 and 14.1 microg/l, respectively.
  
  
  CONCLUSIONS
  Risk assessment based on combined measurements of B-Mn and air-Mn seems to be valid in the interpretation of workers' hazard. Our study indicates that B-Mn may be a valuable parameter for estimating recent exposure (within 1-2 weeks). However, more knowledge is needed about the B-Mn level and its relation to neurological symptoms.
authors.affiliation: Danish Work Environment Service, Landskronagade 33, DK 2100 Copenhagen, Denmark. fla@arbejdstilsynet.dk
authors.forename: F
authors.initials: F
authors.lastname: Lander
authors.forename: J
authors.initials: J
authors.lastname: Kristiansen
authors.forename: J M
authors.initials: JM
authors.lastname: Lauritsen
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational / Q000009:adverse effects / Q000032:analysis* / Q000097:blood / Q000506:poisoning; D003247:Conservation of Natural Resources; D003718:Denmark; D004784:Environmental Monitoring / Q000379:methods*; D006801:Humans; D008297:Male; D008345:Manganese / Q000009:adverse effects / Q000032:analysis* / Q000097:blood; D020149:Manganese Poisoning / Q000097:blood / Q000209:etiology; D008452:Maximum Allowable Concentration; D008669:Metallurgy; D008875:Middle Aged; D009784:Occupational Diseases / Q000097:blood / Q000209:etiology; D016273:Occupational Exposure / Q000009:adverse effects / Q000032:analysis*; D018570:Risk Assessment; D012307:Risk Factors; D014691:Ventilation
chemical_list: D000395:Air Pollutants, Occupational; D008345:Manganese