Marzieh Belji Kangarlou

This 15-year prospective cohort study aimed to examine the impact of occupational exposure to noise and respirable flour dust on the incidence of metabolic syndrome (MetS) and its components among 379 flour mill workers in Iran. The cohort was divided into an exposed group (n = 232), comprising workers with chronic exposure to noise and dust, and a non-exposed group (n = 147), including administrative and supervisory staff with minimal exposure. Annual measurements of noise and dust followed NIOSH guidelines, and cumulative exposures were calculated over time. MetS and its components were assessed based on ATP III criteria using clinical and biochemical markers such as fasting blood sugar (FBS), triglycerides (TG), HDL cholesterol, and blood pressure. The results revealed that prolonged exposure to flour dust was associated with borderline increases in the risk of hypertension and hypertriglyceridemia, while noise exposure did not show significant associations with MetS or its components. Significant risk factors for MetS components included body mass index (BMI), age, and type 2 diabetes mellitus (T2DM). Age was a strong predictor of hyperglycemia (HR = 1.08, 95% CI: 1.02–1.14, p = 0.007), and baseline TG levels were significantly associated with hypertriglyceridemia (HR = 1.003, 95% CI:1.001–1.004, p = 0.001). Stratified analyses highlighted increased risks of MetS components among workers with extended working hours and rotational shifts. These findings emphasize the need for workplace interventions to reduce cumulative exposure risks. Future research should investigate potential mechanisms and synergistic effects of multiple occupational hazards.

Co-exposure to noise and nanomaterials, such as silver nanoparticles (Silver-NPs), is a common occurrence in today’s industries. This study aimed to investigate the effects of exposure to noise and the administration of silver-NPs on the liver tissue of rats. Thirty-six adult male albino Wistar rats were randomly divided into six groups: a control group (administered saline intraperitoneally), two groups administered different doses of Silver-NPs (50 mg/kg and 100 mg/kg, 5 days a week for 28 days), two groups exposed to noise in addition to Silver-NPs (at the same doses as mentioned before), and a group exposed only to noise (104 dB, 6 hours a day, 5 days a week for 4 weeks). Blood samples were taken to assess hepatic-functional alterations, such as serum ALP, ALT, and AST levels. Additionally, biochemical parameters (MDA, GPX, and CAT) and the silver concentration in the liver were measured. Histopathological analysis, mRNA expression (P53 and NF-κB), protein expression (CYP450), and liver weight changes in rats were also documented. The study found that the administration of Silver-NPs and exposure to noise resulted in elevated levels of ALP, ALT, AST, and MDA ( p < .01). Conversely, GPX and CAT levels decreased in all groups compared with the control group ( p < .0001). There was a significant increase ( p < .05) in liver weight and silver concentration in the liver tissues of groups administered Silver-NPs (50 mg/kg) plus noise exposure, Silver-NPs (100 mg/kg), and Silver-NPs (100 mg/kg) plus noise exposure, respectively. The expression rate of P53, NF-κB, and cytochromes P450 (CYPs-450) was increased in the experimental groups ( p < .05). These findings were further confirmed by histopathological changes. In conclusion, this study demonstrated that exposure to noise and the administration of Silver-NPs exacerbated liver damage by increasing protein and gene expression, causing hepatic necrosis, altering biochemical parameters, and affecting liver weight.

Background and Objective: The development of new technology has changed the work environments of today´s world and made workers in these workplaces tolerate more visual and cognitive requirements compare with physical demands. This study aimed to investigate the quantitative and qualitative status of workplace illumination and its association with mental ...

The professional use of formaldehyde is a major occupational health concern in medical laboratory operations. Quantification of various risks associated with chronic exposure to formaldehyde may help in understanding the related hazards. This study designed to assess the health risks associated with inhalation exposure to formaldehyde involving biological, cancer, and non-cancer risks in medical laboratories. This study was performed in the hospital laboratories at Semnan Medical Sciences University. Risk assessment was performed in pathology, bacteriology, hematology, biochemistry, and serology laboratories with 30 employees, using formaldehyde in their daily routine operations. We determined area and personal exposures to airborne contaminant, applied standard air sampling, and analytical method recommended by National Institute of Occupational Safety and Health (NIOSH). We addressed formaldehyde-specific hazard by estimating peak blood level, life cancer risk, and the hazard quotient of non-cancer risks, adapted from Environmental Protection Agency (EPA) assessment method. The airborne formaldehyde concentrations in the laboratory personal samples ranged 0.0156–0.5940 ppm (mean = 0.195 ppm, SD = 0.048) and area exposure ranged 0.0285–1.0810 ppm (mean = 0.462 ppm, SD = 0.087). Based on workplace exposure, peak blood levels of formaldehyde were estimated at minimum 0.0026 mg/l to maximum 0.152 mg/l (mean = 0.015 mg/l, SD = 0.016). The mean cancer risk levels in terms of area and personal exposures were estimated respectively at 3.93 E − 8 μg/m³ and 1.84 E − 4 μg/m³, and for the non-cancer risk levels of the same exposures measured respectively at 0.03 μg/m³ and 0.07 μg/m³. Formaldehyde levels were significantly higher among laboratory employees, especially bacteriology workers. Exposure and risk could be minimized by strengthening control measures including the use of management controls, engineering controls, and respiratory protection equipment to reduce exposure levels of all workers to less than the allowed exposure limits and improve indoor air quality in the workplace.

Background and Objective: Lower back pain is one of the most common musculoskeletal disorders and an important cause of early retirement due to disability in employees in industrialized and developing countries. The present study aimed to determine the work ability index and its relationship with low back pain among employees ...