Validity of ten analytical heat stress indices in predicting the physiological parameters of people under various occupational and meteorological conditions

Until now, only a few comprehensive studies have validated analytical heat stress indices in different conditions. The present study aims to investigate the validity of these indicators in predicting the physiological parameters of workers. This cross-sectional study was conducted with 194 male employees working in warm environments. First, demographic information was collected. After participants rested for 30 min, their heart rate and tympanic temperature were measured. The subjects then performed their routine tasks. At the end of 90 min, their heart rate and tympanic temperature were again measured. Additionally, their metabolism rate and clothing thermal insulation were estimated. Environmental parameters were also measured at 30-, 60-, and 90-min time points. Additional information required to compute the indices was recorded. Then, the values of each of the indices were computed. Finally, the validity of the indices was assessed under different conditions. The results indicated that the highest regression coefficients with tympanic temperature were assigned to modified physiologically equivalent temperature (mPET) (0.7515), predicted heat strain (PHS) (0.7201), and predicted mean vote (PMV) (0.7082), index, respectively. Also, the greatest regression coefficients with heart rate belonged to mPET (0.7773), PMV (0.7624), and PHS (0.6479) index, respectively. Based on the results, the highest diagnostic accuracies of receiver operating characteristic (ROC) curves for tympanic temperature were related to indices of mPET, PHS, and PMV with the area under the ROC curve (AUC) of 0.945, 0.931, and 0.930, respectively. Of the studied indices, it was observed that mPET, PHS, PMV, and PPD showed more validity compared to others.

Noise exposure and the risk of cancer: a comprehensive systematic review

The association between noise exposure and increased risk of cancer has received little attention in the field of research. Therefore, the goal of this study was to conduct a systematic review on the relationship between noise exposure and the incidence of cancer in humans. In this study, four electronic bibliographic databases including Scopus, PubMed, Web of Science, and Embase were systematically searched up to 21 April 2022. All types of noise exposure were considered, including environmental noise, occupational noise, and leisure or recreational noise. Furthermore, all types of cancers were studied, regardless of the organs involved. In total, 1836 articles were excluded on the basis of containing exclusion criteria or lacking inclusion criteria, leaving 19 articles retained for this study. Five of nine case-control studies showed a significant relationship between occupational or leisure noise exposure and acoustic neuroma. Moreover, four of five case-control and cohort studies indicated statistically significant relationships between environmental noise exposure and breast cancer. Of other cancer types, two case-control studies highlighted the risk of Hodgkin and non-Hodgkin lymphoma and two cohort studies identified an increased risk of colon cancer associated with environmental noise exposure. No relationship between road traffic and railway noise and the risk of prostate cancer was observed. In total, results showed that noise exposure, particularly prolonged and continuous exposure to loud noise, can lead to the incidence of some cancers. However, confirmation of this requires further epidemiological studies and exploration of the exact biological mechanism and pathway for these effects.

Determination and prioritization of factors affecting the occurrence of needle stick injuries among healthcare workers using techniques of Delphi and fuzzy analytical hierarchy process (FAHP)

INTRODUCTION

Needlestick injuries (NSIs) are a major hazard in the workplace for healthcare workers. To prevent these injuries, it is essential to determine the important factors affecting the occurrence of them. This study aimed to identify, classify and prioritize these factors using techniques of Delphi and fuzzy analytical hierarchy process (FAHP).

METHODS

This descriptive-analytical study was conducted in 2022. Firstly, the factors affecting the occurrence of needlestick injuries were identified by the literature review. Moreover, the Delphi technique was used to identify the factors. 20 experts (physicians, nurses, and occupational health experts) participated in the steps of the Delphi method. Then, these factors were grouped into six groups. In the next step, the fuzzy analytical hierarchy process (FAHP) was applied to prioritize the factors. For this purpose, the pairwise comparison questionnaire was designed and filled out by 20 experts. Finally, data were analyzed using MATLAB software (version 2018a).

RESULTS

42 factors (31 factors extracted from the literature review and 11 factors obtained from the Delphi technique) were identified in this study. These factors were categorized into six groups. Based on the results, the relative weight of non-demographic personal factors, tool and technology factors, job factors, organizational factors, demographic personal factors, and environmental factors were computed by 0.200, 0.185, 0.184, 0.157, 0.142, and 0.133, respectively.

CONCLUSION

These results determined the importance of the factors affecting the occurrence of needlestick injuries. These findings can be useful for planning preventive measures.

Noise-Related Hearing Disorder Among Vector Control Workers in Kuala Lumpur

Introduction Noise-related hearing disorder (NRHD) is the second most common sensorineural hearing loss, right after age-related hearing loss (presbycusis). It is the highest reported occupational disease and a major compensable occupational hazard in Malaysia. With the increase in dengue cases, the need for vector control workers to control the spread of dengue at the expense of being exposed to noisy fogging machines is critical. Methods This was a cross-sectional study of vector control workers conducted by a local authority in Kuala Lumpur. Participants were categorised as either vector control workers who were directly involved in fogging activities or those who were not. A self-administered questionnaire was used to collect sociodemographic, medical and occupational information. NRHD was confirmed by an audiogram test. Results This study found a high prevalence of NRHD among vector control workers exposed to fogging activity (occupational noise hazards), with 51.4% of them experiencing this condition. The predictors of NRHD include fogging status adjusted odds ratio (aOR) 1.94 (95% CI: 1.19 - 3.17), sex 18.28 (95% CI: 2.33 - 143.16) and age 2.03 (95% CI: 1.27 - 3.25). Conclusion The findings of this study imply that vector control workers are at risk of NRHD. The predictors of NRHD are fogging status, sex and age. These findings emphasise the major impact of occupational noise hazards on NRHD and emphasise the importance of addressing this issue to preserve employees' health; especially among male and older employees with chronic noise exposure.

Prevalence hearing loss of truck and bus drivers in a cross-sectional study of 65533 subjects

Background

Noise pollution is one of the most important occupational pollutants in heavy-vehicle drivers. Therefore, this epidemiological research was conducted with the aim of determining the prevalence of hearing loss in heavy-vehicle drivers in Iran.

Methods

This cross-sectional research was conducted on 65,533 heavy-vehicle drivers including truck and intercity bus drivers from February 2006 to March 2016. The air and bone threshold of pure tone was measured for each ear at 0.5, 1, 2, 3, 4, 6, and 8 kHz by a skillful radiology expert. The obtained data from this research was analyzed in SPSS software using statistical tests such as descriptive analysis and paired t test.

Results

Mean (standard deviation) of hearing loss in left and right ears of all people was 23.02 (8.25) and 22.48 (7.86), respectively. Paired t test showed that hearing loss difference in left and right ears was significant (P < 0.001). Mean and standard deviation of paired t test showed that hearing loss difference in left and right ears was significant in all frequencies except 1000 Hz (P < 0.001).

Conclusion

The findings of this research generally showed that 26.8% of the studied drivers have hearing loss. Hearing loss in the left ear was more than right ear.