Luukkaala, Tiina

Neupane, Subas

Nygård, Clas-Håkan

Siukola, Anna

Virtanen, Pekka

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Physical and mental strain in the food industry : A 4 year follow-up study

Trepo - Institutional Repository of Tampere University

   This document has been downloaded from  Tampub – The Institutional Repository of University of Tampere    Publisher's version   Authors: Neupane Subas, Virtanen Pekka, Luukkaala Tiina, Siukola Anna, Nygård Clas-Håkan  Name of article: Physical and mental strain in the food industry : A 4 year follow-up study  Name of work: Age Management during the Life Course : Proceeding on the 4th Symposium on Work Ability  Editors of work: Nygård Clas-Håkan, Savinainen Minna, Kirsi Tapio, Lumme-Sandt Kirsi  Year of publication: 2011 ISBN: 978-951-44-8392-9  Publisher: Tampere University Press Pages: 170-177  Discipline: Medical and Health sciences / Public health care science, environmental and occupational health Language: en School/Other Unit:  School of Health Sciences             All material supplied via TamPub is protected by copyright and other intellectual property rights, and duplication or sale of all part of any of the repository collections is not permitted, except that material may be duplicated by you for your research use or educational purposes in electronic or print form. You must obtain permission for any other use. Electronic or print copies may not be offered, whether for sale or otherwise to anyone who is not an authorized user.   |  170  |Physical and mental strain in the food industry: A 4-year follow-up study Neupane S, Virtanen P, Luukkaala T, Siukola A, Nygård C-H School Health Sciences, University of Tampere, FinlandAbstractThis study examined the associations between working conditions and the changes in strain among food processing employees. Blue-collar (n=248) workers aged from 20 to 60 years were followed. Mental strain had increased significantly whereas physical strain remained unchanged at follow-up. The changes in mental strain for the older employees were positively correlated with the changes in physical strain (β = 0.25, p=0.05). We conclude that the increase in unfavorable ergonomics may increase physical strain but may also increase mental strain, especially among older employees.Key words: Mental strain, physical strain, physical factors, food fac-tory, follow-up study   |  171  |IntroductionFood manufacturing is a branch where the work still includes a lot of lifting and carrying, repetitive movements and other heavy physical loads. The work environment of the food processing industry is char-acterized by extreme temperatures, draught, noise and bad lighting, which are risk factors for early retirement from working life (1). The most prevalent group of work-related diseases in the food processing industry in Finland is repetitive strain injuries (2). This indicates that food industry workers are highly susceptible to strain in the hands, wrists, and elbows. The risk for sick leaves and early retirements is typically increased in such of working conditions (3-5), and food industry workers have been shown to have twice as many sick leaves as the average among industrial workers in Finland and the EU (6-8). Indeed, the branch is also at the top of the early retirement statistics (1, 3). As regards the associations of physically stressful working conditions to strain among the workers, the food processing industry serves as a good source for research material. The aim of the present study was to analyze whether changes in the work environment and ergonomics are related to changes in physical and mental strain. Materials and methodsStudy setting and dataThe study subjects were employees from four factories and from the office department of a food industry company in Finland. A question-naire survey in the company in 2003 yielded, with the response rate 77%, 1,120 respondents and the corresponding figures were 90% and 1,564 respondents in the follow-up 2007. This study concerns the blue-collar employees (N= 248) who responded to both questionnaires. Their mean age was 39 years (SD=9.5) ranging from 20 to 60 years at the beginning of follow-up. The study was approved by the ethical committee of Pirkanmaa Hospital District.  |  172  |MeasuresStrain:Mental strain was assessed by a single question (“Strain means the situation in which a person feels excited, apprehensive/concerned, nervous or distressed or she/he can’t sleep affected by the things on her/his mind. Do you feel this kind of strain nowadays?”) with reply options from 0 (not at all) to 10 (very much). The question from Borg (9), with a scale from 6 (not at all) to 20 (very much), was used to measure physical strain.Working conditions: The variable describing environmental exposure was constructed of the questions concerning draught, noise, bad indoor climate, heat, cold and blinding light by summing up the replies (scaled from 1=not at all to 5=very much) into a single variable ranging from 6 to 30. In a similar way, the variable describing ergonomics was summed up of the questions concerning repetitive movements, uncomfortable working postures and restlessness into a variable ranging from 3 to 15. Statistical methodsChanges in strain during follow-up were calculated by subtracting the values for 2003 from the values for 2007. Associations between changes in ergonomics and environmental exposure with the changes in mental and physical strain were first studied with Spearman’s correlation co-efficients. Then corresponding multifactorial analysis was conducted using linear regressions with the Enter method, with age, gender and work ability in the model. Perceived work ability was assessed on a scale from 0 (poor) to 10 (excellent) (10). Distributions of the change from 2003 and 2007 were shown as means and standard deviations and tested by paired samples t-test. We were particularly interested in studying aging workers; therefore the participants were divided into those aged 45 or under (young) and those over 45 years (old) (11). Statistical analyses were performed using SPSS for Windows version 16.0.2.   |  173  |ResultsTable 1 describes that environmental exposure and ergonomics remained almost unchanged during follow-up. Mental strain had increased sig-nificantly (p = 0.04) whereas physical strain remained unchanged. Table 1. Descriptive statistics of the participants (n=248) and means of the variables at baseline in 2003 and at follow-up in 2007.Variables Baseline Follow-up P- value1GenderMen 30 % -Women 70 % -Age All (Mean) 39 yrs  ≤45 yrs 68.5 % - >45 yrs 31.5 % -Work ability (mean, SD) (0-10) 8.39 (1.18) 8.37 (1.28) 0.60Work environment (mean, SD)Ergonomics (3-15) 9.08 (2.83) 8.95 (2.88) 0.79Environmental exposure (6-30) 17.28 (4.02) 17.15 (4.11) 0.41Strain (mean, SD)Physical  (6-20) 14.47 (2.93) 14.49 (3.05) 0.93Mental    (0-10) 3.67 (2.52) 4.07 (2.82) 0.041 P-value tested from paired sample t-testTable 2 shows the un-standardized β – coefficients with 95% confidence intervals and p-values from age, gender and work ability adjusted linear regression models. The change in mental strain was correlated with the change in physical strain among older workers (β = 0.25, p=0.05). As to the change in physical strain, statistically significant correlations were seen with the changes in ergonomics both among the young and the old workers, and there was also a significant correlation with the change in mental strain among the older employees.   |  174  |Table 2. Associations of the change in mental or physical strain, change in ergonomic and environmental factors for change in mental and physical strain from 2003 to 2007 separately for workers under 45 and older than 45 years. Adjusted linear regression models with enter method (N=248). Change in mental strain≤45 yrs (n=170)> 45 yrs (n=78) Un-standardized coefficient β(95% CI) for βP2Un-standardized coefficient β(95% CI) for βp3 Change in physical strain0.06-0.08-0.210.400.250.00-0.510.05Change in ergonomics 0.16-0.03-0.360.090.10-0.27-0.490.57Change in environmental exposure0.04-0.07-0.150.46-0.02-0.23-0.190.85Change in physical strain≤45 yrs (n=170)> 45 yrs (n=78)Un-standardized coefficient β(95% CI) for βpUn-standardized coefficient β(95% CI) for βp4 Change in mental strain0.06-0.09-0.220.400.220.00-0.450.05Change in ergonomics 0.260.06-0.46<0.010.300.04-0.740.02Change in environmental exposure0.05-0.06-0.170.340.02-0.17-0.220.82The linear regression model was adjusted for age, gender and changes in work ability2  P-value; the level of significance is 5%3 Exposure variable for outcome changes in mental strain4 Exposure variables for outcome changes in physical strain    |  175  |DiscussionIn this study we found an association between a change in unfavorable ergonomics and changes in physical strain among both the young and among the older workers, whereas the associations of environmental exposure with both the physical and the mental strain proved non-significant. In our study changes in ergonomic stress were positively correlated with the changes in physical strain. Employees in the food factory often stand for long periods and may be required to lift heavy objects or use cutting, slicing, grinding, and other dangerous tools and machines, which may be non-ergonomic. Tuomi (12) explained that people in-volved in high physical demands at work, poor physical environment and poor work postures were more physically strained than other people. Within occupations with comparable work demands for all employees, individual differences in e.g. actual working methods may finally result in a variation in working postures (13, 14) and add to the strain.The high physical strain among the employees is important. The physical strain in this study had not changed at follow-up despite the technical changes in the working environment intended to improve the ergonomics during the follow-up years, for instance modernization of the production lines. However, mental strain had increased significantly during follow-up, which could be due to changes in environmental conditions which are considered the prime cause of mental strain (15). Thus, awareness of problematic ergonomics is important, in particular because food processing work includes many females and there are also older people. It has been shown (16) that older employees experience more strain than younger employees. Our study also shows higher perceived physical strain among younger employees than their older counterparts. This study might have some bias because all the information re-garding mental and physical strain and perception of work environment was collected using a questionnaire, i.e. no objective measurements for the work environment were taken. The study concerned only the food   |  176  |processing industry, and the specific environment and homogenous employee group are one of the strengths of the study. There is a need for future research with corresponding design, as other types of workplaces may have different challenges in the physical environment and different strain-physical environment interaction. It can be concluded that the increase in unfavorable ergonomics may increase physical strain but also increase mental strain, especially among older employees. References1. Salonen P, Arola H, Nygård CH, Huhtala H, Koivisto AM. Factors associ-ated with premature departure from working life among ageing food industry employees. Occup Med (Lond) 2003; 53:65–68. 2. Karjalainen A, Palo L, Saalo A, Jolanki R, Mäkinen I and Kauppinen T. 2009.Ammattitaudit ja ammattitautiepäilyt  2007. Työperäisten sairauksien rekisteriin kirjatut uudet tapaukset. [Recognised and suspected cases of occupational diseases in 2007] Työterveyslaitos Helsinki. Vammalan Kirjapaino Oy, pages 35–363. Ilmarinen J, Tuomi K, Klockars M. Changes in the work ability of active employees over an 11-year period. Scand J Work Environ Health 1997 (suppl 1) 23:49–574. Nygård CH, Arola H, Siukola A, Savinainen M, Luukkaala T, Taski-nen H, Virtanen P. Perceived work ability and certified sickness absence among workers in a food industry. Int Congr Ser 2005; 1280:296–3005. Sell L. Predicting long-term sickness absaence and early retirement pension from self–reported work ability. Int Arch Occup Environ Health 2009; 82:1133–1138 doi: 10.1007/s00420–009–0417–66. Ilmarinen J. Aging workers in the European Union status and promotion of work ability, employability and employment. Helsinki: Finnish Institute of Occupational Health, Ministry of Social Affairs and Health, Ministry of Labour; 19997. Vahtera J, Kivimäki M. Sairauspoissaolot (Sickness absences). In: Kauppinen T, Hanhela R, Heikkilä P, Lehtinen S, Lindström K, Toikkanen J, Tossavainen A (eds) Work and Health in Finland 2003 (In Finnish, Työ ja terveys Suomessa 2003), Finnish Institute of Occupational Health, Helsinki, 2004, pp 178–182   |  177  |8. Gimeno D, Benavides FG, III, Benach J, Amick BC. Distribution of sick-ness absence in the European Union countries. Occup Environ Med 2004; 61:867–869. doi:10.1136/oem.2003.0100749. Borg G. Perceived exertion as an indicator of somatic stress. Scand J Rehabil med 1970; 2:92–9810. Tuomi K, Ilmarinen J, Seitsamo J, Huuhtanen P, Martikainen R, Nygård C-H, Klockars M. Summary of the Finnish research project (1981–1992) to promote the health and work ability of aging workers. Scand J Work Environ Health 1997; 23: 66–7711. World Health Organization. Aging and Working Capacity, Report of a WHO Study Group. WHO Technical Series no 835. WHO, 199312. Tuomi K Eskelinen L, Toikkanen J et al. Work load and individual factors affecting work ability among aging municipal employees. Scand J Work Environ Health 1991; 23 (Suppl 1):128–3413. Burdorf A. Sources of variances in exposure to postural load on the back in occupational group. Scand J Work Environ Health 1992; 18:361–36714. Kilbom Å and Persson J. Work technique and its consequences for mus-culoskeletal disorders. Ergonomics 1987; 30: 273–27915. Cooper CL and Roden J. Mental health and satisfaction among tax of-ficiers. Social Science Medicine 1985; 21:147–75116. Nygård C-H, Huuhtanen P, Tuomi K, Martikainen R. Perceived work changes between 1981 and 1992 among aging workers in Finland. Scand J Work Environ Health 1997; 23(suppl 1): 12–9

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Physical and mental strain in the food industry : A 4 year follow-up study

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