Iranian Journal of Public Health
Year:2023 | Volume:52 | Issue:12|Papers Count:2

Background: Working in hot environments can cause diseases and reduce performance by upsetting the balance of physiological parameters of workers' bodies. Bakers are among the people exposed to heat stress continuously and daily. This review study aimed to investigate the effect of heat stress on bakers. Methods: In this review study, the related articles based on keywords were reviewed using “IranMedex”, “Science Direct”, “PubMed”, “Scopus”, “Web of Science”, “SID”, “Google Scholar”, and “Magiran” databases from the years 2000 to 2021. The used search terms were "Heat stress", "Heat strain", "Heat exposure", "Heat waves", "Workplace", "Baker", and "health effects". In order to extract the required data, all parts of the articles have been reviewed. Results: Out of the 16 studies reviewed in this study, 43. 75% were cross-sectional, 25% were descriptive cross-sectional, and 31. 25% were performed according to other study designs. In all of the studies, the WBGT index was used to assess ambient heat stress. In most studies, the mean exposure temperature was higher than the WBGT-ACGIH limit, especially among traditional bakery workers. The findings showed that exposure to thermal stress significantly affects some hematological parameters of blood, oxidative stress, heart rate, and body temperature. Conclusion: The situation of heat stress in the bakery environment is worrying in terms of health and reduced productivity of employees. Therefore, it is essential to take the necessary preventive and control measures to reduce heat stress and the resulting strain.

Background: Cardio-respiratory fitness (CRF) is a strong predictor of overall health and is considered a key physiological measure in health care settings. Maximal oxygen uptake (VO2max) is considered the gold standard for measuring CRF. Non-exercise VO2max regression equations provide a safe, simple and relatively accurate means of measuring CRF in the general population. This study aimed to develop first native regression equations to predict of CRF without exercise test in Iranian healthy boys. Methods: Laboratory gold standard CRF and anthropometric variables were measured in 597 healthy boys (8-17 yr) in Hmadan City, Iran in 2019. Multiple regression analysis was used to generate CRF regression equations. Cross validation of the CRF regression equations was assessed using PRESS statistics, Pearson correlation, Bland-Althman plot and paired t-test. Results: CRF regression equations based on age, body mass index, body fat and resting heart rate were developed (R2=0. 602 – 0. 639, SEE = 3. 42 – 3. 73 ml/kg/min). PRESS statistics show that, shrinkage of the R2 (0. 04 – 0. 06) and the increment of SEE (0. 18 – 0. 25 ml/kg/min) is minor. There was strong correlation (R =0. 847–0. 883, P<0. 001) and no significant difference (min diff= 0. 09–0. 18 ml/kg/min, P>0. 05) between measured and predicted CRF. The Bland-Altman plot illustrates the strong agreement between the two values. Conclusion: We introduced simple and satisfactorily accurate CRF regression equations based in healthy boys. Prediction of CRF of the boys by regression equations would provide a simple tool for assessing cardiorespiratory fitness in large studies including Iranian boys.