Skip Navigation


Occupational Medicine Advance Access originally published online on January 22, 2007
Occupational Medicine 2007 57(2):149-151; doi:10.1093/occmed/kql156
This Article
Right arrow Abstract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
57/2/149    most recent
kql156v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (1)
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Gudziol, V
Right arrow Articles by Hummel, T
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gudziol, V
Right arrow Articles by Hummel, T
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2007. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org

Short Reports

Sense of smell in workers exposed to agricultural odours

V Gudziol1, D Mackuth1, B Hauswald1, J Knothe1, K Scheuch2, T Zahnert1 and T Hummel1

1 Smell and Taste Clinic, Department of Otorhinolaryngology, University of Dresden Medical School, Fetscherstr. 74, 01307 Dresden, Germany
2 Department of Environmental Medicine, University of Dresden Medical School, Fetscherstr. 74, 01307 Dresden, Germany

Correspondence to: Thomas Hummel, Smell and Taste Clinic, Department of Otorhinolaryngology, University of Dresden Medical School, Fetscherstr. 74, 01307 Dresden, Germany. Tel: +49 351 458 4189; fax: +49 351 458 4326; e-mail: thummel{at}mail.zih.tu-dresden.de


   Abstract
Top
 Abstract
Introduction
 Methods
 Results
 Discussion
 Conflicts of interest
 References
 
Aim To investigate the effect of occupational exposure to agricultural odours on sense of smell.

Methods Olfaction was investigated in 60 employees of dairy and pig-breeding farms and compared to 60 non-farm controls living in the same rural area. Both groups were matched for age, sex and smoking habits. All participants underwent standardized, validated tests for olfactory function and were tested before and after the first day of a working cycle. In addition, farm subjects were also tested in the evening of Day 5 of this period.

Results There was no difference in overall olfactory function between the two groups. Olfactory function was not related to duration of exposure to the odorous environment.

Conclusion These results suggest that occupational exposure to strong agricultural odours has no major impact on the sense of smell.

Keywords      Environment; nose; odour; smell


   Introduction
Top
 Abstract
 Introduction
Methods
 Results
 Discussion
 Conflicts of interest
 References
 
Odours are an important part of our environment. Based on the concept of cross-adaptation it can be assumed that presence of certain odours would also influence the responsiveness to other odours [1,2]. In this context, however, it is unclear whether and if so, how such odorous environments impact on the olfactory sensitivity of individuals who are exposed to these environments. To our knowledge, there is only one publication [3] on effects of long-lasting exposure to manure odour; these authors observed no significant effect of this condition on an olfactory screening test. In another study, subjects working in perfume retail outlets did not demonstrate different test results of odour identification but better odour discrimination abilities than controls. Thus, the aim of the present study was to investigate whether people exposed to manure odours would exhibit different test results for odour identification, discrimination and for n-butanol odour thresholds compared to subjects without such exposure to odours.


   Methods
Top
 Abstract
 Introduction
 Methods
Results
 Discussion
 Conflicts of interest
 References
 
We compared olfactory function of employees of dairy and pig-breeding farms to that of non-farm controls matched for age, sex and smoking habits who did not work in such odorous environments but lived in the same rural area. Olfactory tests were performed on farm workers in the morning and evening of a full working day (generally a 8-h working day). In addition, they were tested during the evening of the last day of a 5-day working cycle. The sequence of the three tests was randomized across all farm workers. Controls were tested only in the morning and evening of the first working day of a week. Testing was performed in the same area where subjects went to work in quiet, well-ventilated rooms.

Subjects were instructed to refrain from smoking, drinking anything but water and eating for an interval of at least 30 min before testing. Exclusion criteria were employment for <3 months, or severe diseases, e.g. multiple sclerosis. Prior to examination of olfactory sensitivity subjects were asked to fill in a questionnaire with questions related, for example, to general olfactory abilities.

For assessment of olfactory function pen-like odour dispensing devices (‘Sniffin’ Sticks') were employed [4,5]. This validated kit consists of three tests of olfactory function, namely tests for n-butanol odour threshold, odour discrimination and odour identification.

Data were investigated using SPSS 12.0 for Windows®. Differences between farm workers and controls were analysed using repeated measures (rm)-ANOVAs [analyses of variance, general linear model, repeated measures design, ‘test’ (threshold, discrimination, identification) or ‘session’ (morning, evening) as within-subject factors and ‘group’ (farm workers, controls) as between-subject factors]. In the case where the main effects of the factor group or its interaction with the factor test were significant, post hoc comparisons between groups were performed using t-tests. In addition, rm-ANOVAs were used to investigate effects of the time of day/effects of the day of week [within-subjects factors tests (threshold, discrimination, identification) or session (Day 1, morning; Day 1, evening; Day 5, evening)]. Finally, partial correlations controlling for age were performed. Degrees of freedom are indicated in brackets following F- or t-values.

The study was performed according to the Declaration of Helsinki. It was approved by the Ethics Committee of the Medical Faculty of the University of Dresden Medical School. All subjects provided written informed consent.


   Results
Top
 Abstract
 Introduction
 Methods
 Results
Discussion
 Conflicts of interest
 References
 
We investigated 60 farm workers at six dairy and pig-breeding farms [age range 23–58 years, mean age 41.8 ± 7.9 years (mean ± standard deviation); 39 women, 21 men; duration of employment in this environment 0–41 years, mean 18.2 ± 9.9 years]. There were 20 smokers among the farm workers. Their test results were compared to a group of 60 controls matched for age, sex and smoking habits who lived in the same area as the farm workers (age range 25–61 years, mean age 42.0 ± 7.8 years; 39 women, 21 men; 20 smokers).

Comparisons between farm workers and controls did not yield any significant differences for olfactory function (Table 1; factor group: F[1,118] = 0.95, P = 0.33; factor session: F[1,118] = 1.71, P = 0.19; session x group: F[1,118] = 0.36, P = 0.55) indicating that the odorous environment had no major influence on general olfactory abilities.


View this table:
[in this window]
[in a new window]

  		Table 1. Descriptive statistics of measures of olfactory function in farm workers (n = 60) and controls (n = 60) [means, standards errors of means (SEM)]

 
In addition, there were no effects of the time of exposure to environmental odours on olfactory function in farm workers as indicated by the non-significant findings for factors session (F[2,114] = 1.27, P = 0.28) and the missing significance of the interaction session x test (F[4,228] = 0.95, P = 0.43). Finally, in farm workers there were no significant correlations between olfactory tests and the number of years working in odorous environments (r55 < 0.08, P > 0.56).


   Discussion
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
Conflicts of interest
 References
 
Our study found that the olfactory function of employees of dairy and pig-breeding farms did not differ from controls who lived in the same rural area. In addition, the duration of exposure to strong environmental odours had no major effect on general olfactory abilities.

The present results extend work by Snyder et al. [3]. Using an olfactory screening test they did not observe significant changes between farmers and non-farmers in terms of their abilities to identify odours. The present study did not reveal differences between farm workers and controls with respect to odour discrimination. In fact, employees continuously exposed to odours in perfume retail outlets exhibited an increased ability to discriminate between odours [6]. This finding can now better be explained by a training effect due to the continuous active engagement with a large variety of fragrances (compare) [7,8] than with a continuous exposure to an odorous environment

For most smokers and some passive smokers tobacco smoke is the most important environmental odour they are exposed to. Berglund et al. [9] demonstrated a decreased olfactory sensitivity in smokers only for those odours that are present in tobacco smoke. This specific desensitisation to odours may also explain why farm workers did not demonstrate decreased olfactory function compared to controls. Thus, olfactory cross-adaptation does not seem to be a major factor in these occupational conditions.

Taken together, the present data obtained in a relatively large sample of subjects using a sensitive and validated olfactory test battery indicate that environmental exposure to strong odours has no major effect on general olfactory function.


   Conflicts of interest
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Conflicts of interest
References
 
None declared


   Acknowledgements
 
This work was supported by a grant from the ‘Lieselotte und Dr Karl-Otto Winkler Stiftung für Arbeitsmedizin’, Essen, Germany.


   References
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Conflicts of interest
 References
 

  1. Cain WS. (1970) Odor intensity after self-adaptation and cross-adaptation. Percept Psychophys 7:271–275.

  2. O'Connell RJ, Stevens DA, Zogby LM. (1994) Individual differences in the perceived intensity and quality of specific odors following self- and cross-adaptation. Chem Senses 19:197–208.[Abstract/Free Full Text]

  3. Snyder MC, Leopold DA, Chiu BC, Von Essen SG, Liebentritt N. (2003) The relationship between agricultural environments and olfactory dysfunction. J Agric Saf Health 9:211–219.[Medline]

  4. Hummel T, Sekinger B, Wolf S, Pauli E, Kobal G. (1997) ‘Sniffin’ sticks': olfactory performance assessed by the combined testing of odor identification, odor discrimination and olfactory threshold. Chem Senses 22:39–52.[Abstract/Free Full Text]

  5. Kobal G, Klimek L, Wolfensberger M, et al. (2000) Multicenter investigation of 1,036 subjects using a standardized method for the assessment of olfactory function combining tests of odor identification, odor discrimination, and olfactory thresholds. Eur Arch Otorhinolaryngol 257:205–211.[CrossRef][Medline]

  6. Hummel T, Guel H, Delank W. (2004) Olfactory sensitivity of subjects working in odorous environments. Chem Senses 29:533–536.[Abstract/Free Full Text]

  7. Engen T and Bosack TN. (1969) Facilitation in olfactory detection. J Comp Physiol Psychol 68:320–326.[CrossRef][Web of Science][Medline]

  8. Rabin MD. (1988) Experience facilitates olfactory quality discrimination. Percept Psychophys 44:532–540.[Web of Science][Medline]

  9. Berglund B, Lindvall T, Nordin S. (1992) Environmentally induced changes in sensory sensitivities. Ann N Y Acad Sci 641:304–321.[Web of Science][Medline]


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?



This Article
Right arrow Abstract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
57/2/149    most recent
kql156v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (1)
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Gudziol, V
Right arrow Articles by Hummel, T
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gudziol, V
Right arrow Articles by Hummel, T
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?