Assessing the health impact of interventions for baker’s allergy and asthma in supermarket bakeries: a group randomised trial

  • F. M. Al Badri
  • R. Baatjies
  • Mohamed F. JeebhayEmail author
Original Article



To assess the impact of an intervention for baker’s allergy and asthma in supermarket bakeries.


A group randomised trial conducted in 31 bakeries (n = 337 bakers) that were randomly assigned to one of two intervention groups (n = 244 bakers) and a control group (n = 93 bakers). Health data collected prior to and 1-year after the intervention included information obtained from an ECRHS questionnaire; tests for atopy and serum-specific IgE to cereal flours; fractional exhaled nitric oxide (FeNO). Data from the two intervention groups were combined to form one intervention group for purposes of the statistical analysis.


At 1 year of follow-up, the incidence and level of decline of work-related ocular–nasal and chest symptoms, sensitisation status and elevated FeNO (FeNO > 25 ppb) was similar in both intervention and control groups. The mean FeNO difference was also similar across both groups (2.2 ppb vs 1.7 ppb, p = 0.86). In those with FeNO > 25 ppb at baseline, the decline was greater in the intervention compared to control group (16.9 ppb vs 7.7 ppb, p = 0.24). Multivariate logistic regression models (adjusting for smoking, baseline sensitisation to cereal flour, baseline FeNO > 25 ppb) did not demonstrate an appreciable FeNO decline (≥ 10%) in the intervention compared to control group. However, stratification by the presence of work-related ocular–nasal symptoms in bakers at baseline demonstrated a significant FeNO decline (≥ 10%) in the intervention compared to the control group (OR 3.73, CI 1.22–11.42).


This study demonstrates some evidence of an intervention effect on FeNO 1 year after an intervention, particularly in bakers with work-related ocular–nasal symptoms.


Bakers Allergy Asthma Exhaled nitric oxide Workplace interventions 



We would like to acknowledge the special contribution of Dr Tanusha Singh of the National Institute for Occupational Health for the laboratory analysis, as well as research nurse assistants Dawn Venter and Faieza Desai from the Centre for Environmental and Occupational Health Research (CEOHR) for conducting the fieldwork. We would also like to acknowledge the staff and employees of the bakeries that contributed to the successful completion of this study.

Author contributions

MFJ was responsible for the overall conceptualisation and design of the study, ensuring the development of the intervention. RB was responsible for overseeing the fieldwork, data management and analysis. FM was responsible for conducting the data analysis and preparing the manuscript under the supervision of MFJ and RB. All investigators contributed to and reviewed the manuscript prior to submission.


There was no additional funding required for this sub-study. However, the data collection of the larger study was originally funded through research scholarship grants from the Center for Asthma in the Workplace (Montreal, Canada), South African Medical Research Council, National Research Foundation FA2006040700028 (Republic of South Africa), Fogarty International Centre (Bethesda, Maryland, USA)-National Institutes of Health (2 D43 TW000812-06), Allergy Society of South Africa (Cape Town) and University of Cape Town Research Committee (Cape Town) and the baking industry (Cape Town). The funders had no role in study design; in the collection, analysis and interpretation of the data; in the writing of the report; and in the decision to submit the paper for publication. The contents of this publication are solely the responsibility of the authors and do not necessarily reflect the official views of these agencies.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no competing interests.

Ethics approval

The original study received ethical approval from the Research Ethics Committee of the University of Cape Town (reference no. 272/2002). Informed consent was obtained from all study subjects as per the protocol. The protocol can be accessed on-line (!ApmArVMYxI4B4V-9TiBgKsTKGPMp).


  1. Al Badri FM, Jeebhay MF (2017) Factors associated with serial longitudinal changes in exhaled nitric oxide (FeNO)—a review of the literature. Curr Allergy Clin Immunol 30:98–109Google Scholar
  2. Alvarez MJ, Olaguibel JM, Garcia BE et al (2000) Airway inflammation in asthma and perennial allergic rhinitis. Relationship with nonspecific bronchial responsiveness and maximal airway narrowing. Allergy 55:355–362CrossRefGoogle Scholar
  3. American Thoracic Society (2005) ATS/ERS recommendations for standardized procedures for the online and offline measurement of exhaled lower respiratory nitric oxide and nasal nitric oxide, 2005. Am J Respir Crit Care Med 171:912–930. CrossRefGoogle Scholar
  4. Baatjies R, Jeebhay MF (2013) Sensitisation to cereal flour allergens is a major determinant of elevated exhaled nitric oxide in bakers. Occup Environ Med 70:310–316CrossRefGoogle Scholar
  5. Baatjies R, Lopata A, Sander I et al (2009) Determinants of asthma phenotypes in supermarket bakery workers. Eur Respir J 34:825–833. CrossRefGoogle Scholar
  6. Baatjies R, Meijster T, Lopata A et al (2010) Exposure to flour dust in South African supermarket bakeries: modeling of baseline measurements of an intervention study. Ann Occup Hyg 54:309–318Google Scholar
  7. Baatjies R, Meijster T, Heederik D et al (2014) Effectiveness of interventions to reduce flour dust exposures in supermarket bakeries in South Africa. Occup Environ Med 71:811–818CrossRefGoogle Scholar
  8. Basketter D, Berg N, Kruszewski FH et al (2012) Relevance of sensitization to occupational allergy and asthma in the detergent industry. J Immunotoxicol 9:314–319. CrossRefGoogle Scholar
  9. Bernstein DI, Roach DE, McGrath KG et al (1983) The relationship of airborne trimellitic anhydride concentrations to trimellitic anhydride–induced symptoms and immune responses. J Allergy Clin Immunol 72:709–713CrossRefGoogle Scholar
  10. Bjermer L, Alving K, Diamant Z et al (2014) Current evidence and future research needs for FeNO measurement in respiratory diseases. Respir Med 108:830–841. CrossRefGoogle Scholar
  11. Boulay M-E, Morin A, Laprise C, Boulet L-P (2012) Asthma and rhinitis: what is the relationship? Curr Opin Allergy Clin Immunol 12:449–454CrossRefGoogle Scholar
  12. Bousquet J, Khaltaev N, Cruz AA et al (2008) Allergic Rhinitis and its Impact on Asthma (ARIA) 2008 update (in collaboration with the World Health Organization, GA(2)LEN and AllerGen). Allergy 63(Suppl 8):8–160. CrossRefGoogle Scholar
  13. Brant A, Zekveld C, Welch J et al (2006) The prognosis of occupational asthma due to detergent enzymes: clinical, immunological and employment outcomes. Clin Exp Allergy 36:483–488CrossRefGoogle Scholar
  14. Burney PG, Luczynska C, Chinn S, Jarvis D (1994) The European community respiratory health survey. Eur Respir J 7:954–960CrossRefGoogle Scholar
  15. de Groene GJ, Pal TM, Beach J et al (2011) Workplace interventions for treatment of occupational asthma. Cochrane database Syst Rev. CrossRefGoogle Scholar
  16. Dressel H, Gross C, De la Motte D et al (2007) Educational intervention decreases exhaled nitric oxide in farmers with occupational asthma. Eur Respir J 30:545–548CrossRefGoogle Scholar
  17. Dweik RA, Boggs PB, Erzurum SC et al (2011) An official ATS clinical practice guideline: interpretation of exhaled nitric oxide levels (FENO) for clinical applications. Am J Respir Crit Care Med 184:602–615. CrossRefGoogle Scholar
  18. Foresi A, Leone C, Pelucchi A et al (1997) Eosinophils, mast cells, and basophils in induced sputum from patients with seasonal allergic rhinitis and perennial asthma: relationship to methacholine responsiveness. J Allergy Clin Immunol 100:58–64CrossRefGoogle Scholar
  19. Hashimoto S, Ten BA, Roldaan AC et al (2011) Internet-based tapering of oral corticosteroids in severe asthma: a pragmatic randomised controlled trial. Thorax 66:514–520. CrossRefGoogle Scholar
  20. Jolly Athena T, Klees Julia E, Pacheco Karin A et al (2015) Work-related asthma. J Occup Environ Med 57:e121–e129. CrossRefGoogle Scholar
  21. Malo J-L, Ghezzo H (2004) Recovery of methacholine responsiveness after end of exposure in occupational asthma. Am J Respir Crit Care Med 169:1304–1307. CrossRefGoogle Scholar
  22. Malo JL, Cartier A, Ghezzo H et al (1988) Patterns of improvement in spirometry, bronchial hyperresponsiveness, and specific IgE antibody levels after cessation of exposure in occupational asthma caused by snow-crab processing. Am Rev Respir Dis 138:807–812. CrossRefGoogle Scholar
  23. Merget R, Sander I, van Kampen V et al (2015) Serial measurements of exhaled nitric oxide at work and at home: a new tool for the diagnosis of occupational asthma. Environment Exposure to Pollutants. Springer, United States, pp 49–52Google Scholar
  24. Merget R, Sander I, van Kampen V et al (2016) Triticale allergy in a farmer. Am J Ind Med 59:501–505CrossRefGoogle Scholar
  25. Moscato G, Vandenplas O, Gerth Van Wijk R et al (2008) Occupational rhinitis. Allergy 63:969–980. CrossRefGoogle Scholar
  26. Moscato G, Pala G, Barnig C et al (2012) EAACI consensus statement for investigation of work-related asthma in non-specialized centres. Allergy 67:491–501. CrossRefGoogle Scholar
  27. Munoz X, Viladrich M, Manso L et al (2014) Evolution of occupational asthma: does cessation of exposure really improve prognosis? Respir Med 108:1363–1370. CrossRefGoogle Scholar
  28. Park HS, Lee SK, Lee YM et al (2002) Longitudinal study of specific antibodies to toluene diisocyanate (TDI)-human serum albumin (HSA) conjugate in patients with TDI-induced asthma. Korean J Intern Med 17:249–251. CrossRefGoogle Scholar
  29. Perfetti L, Cartier A, Ghezzo H et al (1998) Follow-up of occupational asthma after removal from or diminution of exposure to the responsible agent: relevance of the length of the interval from cessation of exposure. Chest 114:398–403CrossRefGoogle Scholar
  30. Piirila PL, Nordman H, Keskinen HM et al (2000) Long-term follow-up of hexamethylene diisocyanate-, diphenylmethane diisocyanate-, and toluene diisocyanate-induced asthma. Am J Respir Crit Care Med 162:516–522. CrossRefGoogle Scholar
  31. Rees D, Phillips JI (2014) Investigating the effectiveness of occupational health interventions in the workplace. Occup Environ Med 71:809–810. CrossRefGoogle Scholar
  32. Rolla G, Guida G, Heffler E et al (2007) Diagnostic classification of persistent rhinitis and its relationship to exhaled nitric oxide and asthma: a clinical study of a consecutive series of patients. Chest 131:1345–1352. CrossRefGoogle Scholar
  33. Soyseth V, Kongerud J, Aalen OO et al (1995) Bronchial responsiveness decreases in relocated aluminum potroom workers compared with workers who continue their potroom exposure. Int Arch Occup Environ Health 67:53–57CrossRefGoogle Scholar
  34. Tarlo SM, Malo J-L, de Blay F et al (2017) An official american thoracic society workshop report: presentations and discussion of the sixth jack Pepys workshop on asthma in the workplace. Ann Am Thorac Soc 14:1361–1372. CrossRefGoogle Scholar
  35. Toren K, Blanc PD (2009) Asthma caused by occupational exposures is common—a systematic analysis of estimates of the population-attributable fraction. BMC Pulm Med 9:7. CrossRefGoogle Scholar
  36. Tsolakis N, Malinovschi A, Nordvall L et al (2018) Absence of serum IgE antibodies indicates non-type 2 disease in young asthmatics. Clin Exp allergy. CrossRefGoogle Scholar
  37. Vandenplas O, Dressel H, Wilken D et al (2011) Management of occupational asthma: cessation or reduction of exposure? A systematic review of available evidence. Eur Respir J 38:804–811CrossRefGoogle Scholar
  38. Vandenplas O, Dressel H, Nowak D, Jamart J (2012) What is the optimal management option for occupational asthma? Eur Respir Rev 21:97–104. CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2020

Authors and Affiliations

  1. 1.Occupational Medicine Division and Centre for Environmental & Occupational Health Research, School of Public Health and Family MedicineUniversity of Cape TownCape TownSouth Africa
  2. 2.Occupational Medicine DepartmentArmed Forces Medical ServicesMuscatOman
  3. 3.Department of Environmental and Occupational StudiesCape Peninsula University of Technology (CPUT)Cape TownSouth Africa

Personalised recommendations