Association of prolonged occupational co-exposures to electromagnetic fields, noise, and rotating shift work with thyroid hormone levels.

The purpose of this study was to determine the association of prolonged occupational co-exposure to extremely low-frequency electromagnetic fields (ELF-EMFs), noise, and rotating shift work with the levels of thyroid hormones (triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH). From 2016 to 2017, we enrolled all male workers without a history of thyroid disorders and followed them until 2020. To measure ELF-EMFs and noise exposures, we calculated the 8-hour equivalent sound pressure levels (Leq) and the 8-hour average of ELF-EMFs, respectively. Shift work schedules involved 8-hr fixed day and 8-hr clockwise 3-rotating night schedules. The participant's thyroid hormone levels were obtained from blood test results in their medical records. The percentage change in the levels of T3, T4, and TSH was estimated by using different mixed-effects linear regression models. The TSH levels were significantly elevated per a 10-dB increment of noise. The levels of T4 hormone were significantly changed per a unit increase in the levels of ELF-EMFs. Compared to the fixed-day workers, we observed workers exposed to shift work had a significantly lower T4 level. For T4 and TSH hormones, we found significant interactions among noise, ELF-EMFs, and shift work variables. In summary, this study warranted that prolonged exposure to ELF-EMFs, noise, and rotating shift work might be associated with thyroid dysfunction.

Epidemiology of musculoskeletal disorders among iranian adults: results from a non-communicable disease cohort study.

BACKGROUND: Persistent pain and reduced mobility and dexterity are the typical characteristics of Musculoskeletal disorders (MSDs). We aimed to determine the prevalence of back and joint pain, back, and joint stiffness, arthritis, and osteoporosis among adults and their distribution according to sociodemographic characteristics and comorbidities. METHODS: This cross-sectional study was conducted on 9,520 participants aged 35-65 years from baseline data of the Ravansar Non-Communicable Disease (RaNCD) cohort study, in the west of Iran. MSDs were evaluated by the RaNCD cohort study physician using a standard questionnaire. Binary logistic regression was used to determine associations and reported by odds ratios (OR) and 95% confidence intervals (CI). RESULTS: The MSDs in women were significantly more than in men (59.06% vs. 40.94%, P < 0.001). Skeletal muscle mass (SMM) was significantly lower in subjects with MSDs, and waist circumference (WC) and visceral fat area (VFA) were higher than in the non-MSDs (P < 0.001). MSDs were significantly more common in urban men and women (OR = 1.33; 95% CI: 1.14-1.50 and OR = 1.59; 95% CI: 1.39-1.82, respectively). Obesity increased the odds of MSDs in women (OR = 1.57; 95% CI: 1.33-1.84), whereas there was no association between BMI and MSDs in men. Men with high socioeconomic status (SES) had lower odds of MSDs than men with weak SES (OR = 0.77; 95% CI: 0.64-0.92). CONCLUSION: The MSDs were more prevalent among older people, women, obese people and urban dwellers. Lifestyle modification, especially weight loss may be helpful in reducing and controlling MSDs.

The burden of unintentional drowning: global, regional and national estimates of mortality from the Global Burden of Disease 2017 Study.

BACKGROUND: Drowning is a leading cause of injury-related mortality globally. Unintentional drowning (International Classification of Diseases (ICD) 10 codes W65-74 and ICD9 E910) is one of the 30 mutually exclusive and collectively exhaustive causes of injury-related mortality in the Global Burden of Disease (GBD) study. This study's objective is to describe unintentional drowning using GBD estimates from 1990 to 2017. METHODS: Unintentional drowning from GBD 2017 was estimated for cause-specific mortality and years of life lost (YLLs), age, sex, country, region, Socio-demographic Index (SDI) quintile, and trends from 1990 to 2017. GBD 2017 used standard GBD methods for estimating mortality from drowning. RESULTS: Globally, unintentional drowning mortality decreased by 44.5% between 1990 and 2017, from 531 956 (uncertainty interval (UI): 484 107 to 572 854) to 295 210 (284 493 to 306 187) deaths. Global age-standardised mortality rates decreased 57.4%, from 9.3 (8.5 to 10.0) in 1990 to 4.0 (3.8 to 4.1) per 100 000 per annum in 2017. Unintentional drowning-associated mortality was generally higher in children, males and in low-SDI to middle-SDI countries. China, India, Pakistan and Bangladesh accounted for 51.2% of all drowning deaths in 2017. Oceania was the region with the highest rate of age-standardised YLLs in 2017, with 45 434 (40 850 to 50 539) YLLs per 100 000 across both sexes. CONCLUSIONS: There has been a decline in global drowning rates. This study shows that the decline was not consistent across countries. The results reinforce the need for continued and improved policy, prevention and research efforts, with a focus on low- and middle-income countries.

Epidemiology of injuries from fire, heat and hot substances: global, regional and national morbidity and mortality estimates from the Global Burden of Disease 2017 study.

BACKGROUND: Past research has shown how fires, heat and hot substances are important causes of health loss globally. Detailed estimates of the morbidity and mortality from these injuries could help drive preventative measures and improved access to care. METHODS: We used the Global Burden of Disease 2017 framework to produce three main results. First, we produced results on incidence, prevalence, years lived with disability, deaths, years of life lost and disability-adjusted life years from 1990 to 2017 for 195 countries and territories. Second, we analysed these results to measure mortality-to-incidence ratios by location. Third, we reported the measures above in terms of the cause of fire, heat and hot substances and the types of bodily injuries that result. RESULTS: Globally, there were 8 991 468 (7 481 218 to 10 740 897) new fire, heat and hot substance injuries in 2017 with 120 632 (101 630 to 129 383) deaths. At the global level, the age-standardised mortality caused by fire, heat and hot substances significantly declined from 1990 to 2017, but regionally there was variability in age-standardised incidence with some regions experiencing an increase (eg, Southern Latin America) and others experiencing a significant decrease (eg, High-income North America). CONCLUSIONS: The incidence and mortality of injuries that result from fire, heat and hot substances affect every region of the world but are most concentrated in middle and lower income areas. More resources should be invested in measuring these injuries as well as in improving infrastructure, advancing safety measures and ensuring access to care.

Validation of a temperature-humidity index (Humidex) in evaluating heat stress at a tile factory in Iran.

BACKGROUND: Several heat indices have been developed in industrial health, but each has its limitations. OBJECTIVE: The objective of this article is to determine the validity and applicability of a temperature-humidity index, named Humidex compared with the Standard Wet-Bulb Globe Temperature (WBGT) index (ISO 7243). METHOD: This cross-sectional study was conducted in the summer of 2019, in a tile factory in the west of Iran. 59 measurements were performed in 8 different workstations. Environmental parameters including natural wet bulb temperature (Tnw), dry bulb temperature (Ta), globe bulb temperature (Tg), and heat stress (WBGT) were measured. Humidex was calculated according to an equation. SPSS software (version 16) was used for data analysis. RESULTS: There was a high correlation between Humidex and WBGT in the estimation of heat stress (R=0.912, P<0.001). The Kappa Coefficient between Humidex and WBGT was 0.298, P=0.001. CONCLUSION: Humidex is highly correlated with WBGT. Humidex can be used instead of the WBGT index, especially in hot and humid environments.

Independent, modified, and interacting effects of long-term noise, extremely low-frequency electromagnetic fields, and shift work exposures on liver enzymes.

To quantify long-term independent, modified, and interacting effects of noise, extremely low-frequency electromagnetic fields (ELF-EMFs), and shift work exposures on liver enzymes, a four-year repeated measures study was performed among male workers in a thermal power plant industry from 2016 to 2020. The 8-h equivalent sound pressure levels (Leq) were measured at weighting channels of Z, A, and C for octave-band frequencies. The 8-h time-weighted average of ELF-EMFs levels was measured for each participant. Shift work schedule was determined based on job titles, including 3-rotating night shift work and fixed day shift work schedules. The fasting blood samples were taken to determine liver enzymes (AST, Aspartate transaminase; ALT, Alanine transaminase). The percentage change (PC) and 95% confidence interval (CI) of AST and ALT enzymes were estimated by the different bootstrapped-mixed-effects linear regression models. Per 10-dB noise increase, we found a significantly higher PC (95% CI) of AST and ALT (only LAeq) levels in all regression models with the highest changes for LAeq. For the octave-band noise analysis, there was an upward trend from 31.5 Hz to 1 kHz frequencies and a downward trend from 1 to 8 kHz frequencies. Per 1 mG ELF-EMFs increase, we observed a significantly higher PC (95% CI) of AST and ALT enzymes in the main adjusted and the main adjusted + shift work models. The 3-rotating night than fixed day shift workers had a significant PC in the unadjusted model for AST enzyme and the fully adjusted and the main adjusted + ELF-EMFs models for ALT enzyme. Significant negative two-way or/and three-way interaction effects among the noise, ELF-EMFs, and shift work were observed for both AST and ALT enzymes. Our findings indicated long-term noise, ELF-EMFs, and 3-rotating night shift work exposures may be significantly associated with changes in the levels of liver enzymes.

A Comprehensive Evaluation of Occupational Epidemiology in Western Iran: A Cohort Study in Ravansar Noncommunicable Diseases.

OBJECTIVE: The present study aims to evaluate the prevalence of noncommunicable diseases (NCDs), biochemical and anthropometric indicators, and lifestyle among 10 occupational groups. METHOD: The sample included 4818 men aged 35 to 65 years. The occupational group is based on the International Standard Classification of Occupations. RESULT: The highest prevalence of cardiovascular diseases and type 2 diabetes mellitus was observed in managerial occupational groups (18.62%) and technicians and associate professionals ( 14 %), respectively. Musculoskeletal disorders were more in skilled agricultural, forestry, and fishery workers, as well as craft-related trades workers, and elementary occupations. The highest body mass index was related to the managers. CONCLUSIONS: Noncommunicable diseases were higher in managers, while musculoskeletal disorders belonged to farmers and workers. Finally, lifestyle modification can help reduce NCDs and improve biochemical markers by increasing physical activity.