title: Symptoms of respiratory disease and lung functional impairment associated with occupational inhalation exposure to carbon black dust.
abstract: OBJECTIVE
  The aim of this study was to ascertain whether symptoms of respiratory disorders and lung functional impairments are associated with occupational inhalation exposure to carbon black (CB) in a group of rubber workers.
  
  
  METHODS
  The study population consisted of 72 male workers with a past history of and current exposure to CB and 69, randomly selected, healthy unexposed male office workers that served as the referent group. Subjects were interviewed and given standardized respiratory symptom questionnaires to answer. Furthermore, pulmonary function tests (PFTs) were performed before and after the work shift for exposed subjects and once during the work shift for referent subjects. Furthermore, to assess the extent to which workers were exposed to CB, using standard methods, inhalable and respirable dust fractions of CB were measured in different dusty worksites.
  
  
  RESULTS
  The levels of exposure to inhalable and respirable CB dust were estimated to be 6.2 ± 1.7 and 2.3 ± 0.29 mg/m(3) respectively (mean ± SD). Respiratory symptom questionnaires revealed that regular cough, phlegm, wheezing and shortness of breath were significantly (p<0.05) more prevalent among exposed workers. Furthermore, significant decreases in some preshift and postshift parameters of pulmonary function of exposed workers with a spirometric pattern consistent with restrictive ventilatory disorder were found.
  
  
  CONCLUSIONS
  The findings of this study provide circumstantial evidence to support the notion that exposure to CB exceeding its current TLV is associated with a significant increase in the prevalence of respiratory symptoms along with both acute, partially reversible and chronic irreversible significant decreases in some parameters of pulmonary function.
authors: Department of Occupational Health, School of Health and Nutrition and Research Center for Health Sciences.
authors: Masoud
authors: M
authors: Neghab
authors: Majid Habibi
authors: MH
authors: Mohraz
authors: Jafar
authors: J
authors: Hassanzadeh
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational / Q000032:analysis / Q000633:toxicity*; D002617:Chemical Industry; D003430:Cross-Sectional Studies; D004391:Dust / Q000032:analysis*; D004784:Environmental Monitoring; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects / Q000032:analysis; D007492:Iran; D008297:Male; D016273:Occupational Exposure / Q000009:adverse effects* / Q000032:analysis; D012129:Respiratory Function Tests; D012140:Respiratory Tract Diseases / Q000139:chemically induced* / Q000175:diagnosis; D012408:Rubber; D053260:Soot / Q000032:analysis / Q000633:toxicity*; D013997:Time Factors
chemical_list: D000395:Air Pollutants, Occupational; D004391:Dust; D053260:Soot; D012408:Rubber