Journal of Occupational Health and Epidemiology

12-19

Authors: D Shahimoradi , R Vazirinejad *

Background: Today application of computer in the life of people is very common and those who work with computer in especially long – term are faced with musculoskeletal pains. The aim of this study was to investigate risk factors of musculoskeletal and Joint pains among computer users in Rafsanjan city in the years 2012-13. Materials and Methods: In this descriptive study, 420 computer users were recruited in Rafsanjan city between 18 April 2012 and 19 January 2013. The data were collected by a checklist, in face to face interview sessions. Data were analyzed in SPSS and parametric and nonparametric tests were used where appropriate. Results: Cervical pain was associated with position of desk, chair and keyboard. There were significant association between shoulder pain and position of the keyboard, low back pain and chair position, carpal tunnel syndrome and mouse usage. The prevalence of cervical pain, shoulder pain, arm pain, wrist pain, hand pain, low back pain, elbow pain, back pain, and carpal tunnel syndrome, among respondents were 38.3%, 38.3%, 27.1%, 21.2%, 18.8%, 24.5%, 15.7%, 26.4% and 21.2%, respectively. In this study, there was significant association between exercise and all variables of carpal tunnel syndrome, elbow pain, back pain, low back pain and shoulder pain. Conclusions: It can be concluded that prevalence of musculoskeletal pain in computer users in our study were very common. Improving the position of desk, chair, mouse and keyboard could help with reducing cervical pain, shoulder pain, back pain, low back pain and carpal tunnel syndrome.

27-36

Authors: H Vivien , Z Hashim * , P Ismail , S Md Said , D Omar , S Bahri Mohd Tamrin

Background: This study has used biomarker of exposure-effect continuum to examine the biological characteristics of organophosphate (OP) toxicity and its genotoxic effect among rice farmers. Materials and Methods: A cross-sectional study was conducted among 160 pesticide exposed rice farmers and 160 adults from the fishing village as the unexposed group. They share the common socio-economical background for inter-individual comparison in human toxicology assessment. In this study depression of blood cholinesterase is used as a biomarker of exposure to OP toxicity. Two genotoxic assays (micronuclei and comet assay) were conducted as a biomarker of genotoxic effect among the adult population. In this context, micronuclei assay is used to indicate the chromosome breakage and comet assay to estimate the possible DNA damage. Results: The study showed a significant difference of blood cholinesterase level (p=0.001) between the exposed-unexposed groups. Besides, the results showed that farmers had at least 2-2.5 folds of significant increase (p=0.001) in MN frequency (in 1000 cells) and comet tail length (µm) compared to the unexposed group. In addition, regression analysis among farmers showed that blood cholinesterase level decreased with the genotoxic effects. A small variation (R2=0.148) of MN frequency could be explained by the depression of blood cholinesterase level; however, a significant reduction (p=0.001), with strong changes (R2=0.712) in comet tail length was attributed to the depression of blood cholinesterase levels. Risk factors like age, body mass index, smoking status and years of working showed the different strength of the relationship with these genotoxic effects. Conclusions: This study suggests that chronic exposure to OP shows an inhibition to blood cholinesterase level, which is associated with the potential DNA breakage as indicated by comet assay. Age, smoking and years of working are the contributing factors influencing the biomarker of effects.

44-53

Authors: A Ahmadi Orkomi * , B Tavakoli , A Noorpoor

Background: Cement industry has many process units. Basically all of these units can be considered as a source of noise. Since noise pollution is defined based on its offensive hearing effects, the importance of the noise sources depends directly on the number of workers in the unit. Materials and Methods: An experimental study has been done at Tehran cement factory to recognize and analyze the major noise pollution source machineries. In this survey, first, the mean A-weighted sound pressure level and the number of workers in each unit have been measured and the obtained data has been analyzed in Microsoft Excel. Afterwards, based on the mentioned ISO, some experiments have been done to calculate the A-weighted acoustic power level of the crusher which emits the highest level of noise. Results: The noisiest units have been recognized and some applicable suggestions have been offered to reduce the sound exposure level. Also by calculating the sound power levels and considering the design parameters which affect the sound power generated by the crusher, an empirical equation has been presented to calculate the acoustic power level as a function of horsepower, number of hammers and the weight of each hammer. Conclusion: The acoustic measurement results show that the crusher, cement mill and row mill units are the three major noise emission sources. In another experiment, based on ANSI S1.36 and ISO 3746 guidelines, the sound power level of the crusher unit has been measured indirectly. Afterwards, by using a multiple regression algorithm and minimizing the mean square error, an empirical equation has been proposed to correlate the acoustic power level as a function of the horsepower and the mass of all hammers of the crusher.

60-66

Authors: Z Zamanian , K Nikeghbal * , H Ebrahimi , S Purshahidi

Background: It has been prover that the prevalence of experiencing job related stress is very high among the dentists. This stress can be the result of factors such as poor lightening of dental office and noise. This stress can cause emotional distress and threaten dentists’ physical health and affect the quality of their life. This study is conducted to determine dentists’ professional quality of life and job-related stress and two important workplace factors that can affect them which are lighting and noise. Materials and Methods: In this cross-sectional study the researchers visited the dental offices in Shiraz city and measured lighting and noise of the places, also dentist's quality of life and job stress were determined using McGill quality of life questionnaire and job-stress questionnaire. Results: The relationship between quantitative variables was determined by using regression test and the multiple regression test was used for the modeling process. The average of local noise caused by dental drills and other parameters was 75.5 and 74.5 in public and private offices. In 2.2% of dental offices lightening condition was below the standard levels. Results show that 58.9% of dentists participating in this study experience good or fairly good quality of life. Conclusion: The results suggest that workplace environmental situation and dentists’ professional stress and quality of life are correlated. So adjusting effective workplace parameters to the standard levels can lead to increase in the dentists’ quality of life.

76-81

Authors: M Rezaeian *

Background: The most common method of collecting data in any area of human health research is to apply a questionnaire. However, if extreme cautiousness is not taking into account while designing a questionnaire, the gathered data might be ineffective. Therefore, the aim of the present article is to discuss some of the most important set of guidelines in designing a questionnaire. Materials and methods: To fulfil the aim of the study, it has been tried to search the relevant literature by looking at different search engines and also carry out hand searching. It has also been tried to elaborate any selected guidelines by examples relevant to occupational epidemiology. Results: The literature highlights that there are at the very least ten common-sense guidelines that one should take into account for designing a valid and reliable questionnaire. Conclusions: By following the proposed guidelines it is hoped that a deigned questionnaire is able to elicit the responses that one might need.