title: Letter to the editor.
authors.affiliation: a Division of Environmental Health Sciences, School of Public Health, University of Minnesota , Minneapolis , Minnesota.
authors.forename: Gurumurthy
authors.initials: G
authors.lastname: Ramachandran
authors.forename: Jooyeon
authors.initials: J
authors.lastname: Hwang
authors.forename: Peter C
authors.initials: PC
authors.lastname: Raynor
authors.forename: Bruce H
authors.initials: BH
authors.lastname: Alexander
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Mandel
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis*; D007501:Iron; D008906:Mining; D016273:Occupational Exposure / Q000032:analysis*; D052638:Particulate Matter / Q000032:analysis*; D017640:Silicates
chemical_list: D000395:Air Pollutants, Occupational; D052638:Particulate Matter; D017640:Silicates; D007501:Iron