title: Environmental factors associated with baseline and serial changes in fractional exhaled nitric oxide (FeNO) in spice mill workers.
abstract: BACKGROUND
  This study evaluated the determinants of high fractional exhaled nitric oxide (FeNO; >50 ppb) and serial changes in FeNO over a 24-hour period in spice mill workers at risk of work-related allergic respiratory disease and asthma.
  
  
  METHODS
  A cross-sectional study of 150 workers used European Community Respiratory Health Survey (ECRHS) questionnaires, Phadiatop, serum-specific IgE (garlic, chilli pepper, wheat; Phadia, ImmunoCAP), spirometry and FeNO. A hand-held portable nitric oxide sampling device (NIOX MINO, Aerocrine AB) measured FeNO before and after the 8-hour shift and after 24 hours from baseline.
  
  
  RESULTS
  The mean age of workers was 33 years; 71% were male, 46% current smokers and 45% atopic. Among workers with garlic sensitisation, 13% were monosensitised and 6% were co-sensitised to chilli pepper. Baseline preshift FeNO geometric mean (GM=14.9 ppb) was similar to the mean change across shift (GM=15.4 ppb) and across the 24-hour period (GM=15.8 ppb). In multivariate linear models, smoking (β=-0.507) and atopy (β=0.433) were strongly associated with FeNO. High FeNO (>50 ppb) was significantly associated with asthma-like symptoms due to spice dust (OR=5.38, CI 1.01 to 28.95). Sensitisation to chilli pepper was more strongly correlated with FeNO (r=0.32) and FeNO>50 ppb (OR=17.04, p=0.005) than garlic. FeNO increase (>12%) across 24 hours demonstrated a strong association with elevated exposures to spice dust particulate (OR=3.77, CI 1.01 to 14.24).
  
  
  CONCLUSIONS
  This study suggests that chilli pepper sensitisation is associated with high FeNO (>50 ppb), more strongly compared with garlic, despite the low prevalence of sensitisation to chilli. Elevated inhalant spice dust particulate is associated with a delayed elevation of FeNO across the 24-hour period.
authors.affiliation: Centre for Environmental and Occupational Health Research, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa.
authors.forename: Anita
authors.initials: A
authors.lastname: Van der Walt
authors.affiliation: Centre for Environmental and Occupational Health Research, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa Faculty of Applied Sciences, Department of Environmental and Occupational Studies, Cape Peninsula University of Technology, Cape Town, South Africa.
authors.forename: Roslynn
authors.initials: R
authors.lastname: Baatjies
authors.affiliation: National Institute for Occupational Health (NIOH), NHLS, Johannesburg, South Africa Department of Clinical Microbiology & Infectious Diseases, School of Pathology, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Tanusha
authors.initials: T
authors.lastname: Singh
authors.affiliation: Centre for Environmental and Occupational Health Research, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa.
authors.forename: Mohamed F
authors.initials: MF
authors.lastname: Jeebhay
mesh_terms: D000328:Adult; D001249:Asthma / Q000139:chemically induced*; D015415:Biomarkers / Q000032:analysis; D002212:Capsicum; D003430:Cross-Sectional Studies; D004391:Dust; D005060:Europe; D005260:Female; D005737:Garlic; D006801:Humans; D007221:Industry; D019570:Inhalation Exposure / Q000009:adverse effects* / Q000032:analysis; D007407:Interviews as Topic; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis*; D016273:Occupational Exposure / Q000009:adverse effects* / Q000032:analysis; D017365:Spices / Q000009:adverse effects* / Q000032:analysis; D013147:Spirometry; D055815:Young Adult
chemical_list: D015415:Biomarkers; D004391:Dust; D009569:Nitric Oxide
keywords: Asthma; FeNO; chili pepper; garlic; work-related