Health risk assessment of occupational exposure to heavy metals among green space workers in Iran.

Exposure to heavy metals can result in various adverse health effects. Tehran is rated as one of the world's most polluted cities. Green space workers are continuously exposed to such pollutants in this city. Thus, this study aimed to estimate the health risks caused by exposure to heavy metals among green space workers. Eighty-eight workers and office personnel in two regions with different air quality levels were chosen for sampling. Air samples were collected using the NIOSH-7300 method and analyzed using an Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) instrument. The hazard quotient (HQ) and the lifetime cancer risk (LTCR) were calculated to assess carcinogenic and non-carcinogenic risk levels. The results revealed that the rank order of heavy metals was determined as Zn, Pb, Mn, Ni, Co, and Cd. Workers were subjected to higher concentrations of Ni, Pb, Zn, and Co than office personnel. Furthermore, the Cd, Co, and Zn exposure levels stood significantly higher in region 6 than in region 14. Non-carcinogenic risk levels for all participants fell within the acceptable range. Moreover, no employee had a carcinogenic risk level within the acceptable range when exposed to Cd. Also, 2.3% of individuals demonstrated Ni's acceptable carcinogenic risk level. Owing unacceptable risk levels, proper interventions are required to minimize occupational exposure to heavy metals. These interventions include optimizing shift schedules, using personal protective equipment, and conducting regular health assessments.

Prevalence and difference of COVID-19 symptoms, post-COVID conditions and duration of illness among the vaccinated and unvaccinated population: a cross-sectional study in Peshawar.

Studies on coronavirus disease 2019 (COVID-19) symptoms, post-coronavirus disease (COVID) conditions, and vaccination outcomes in Pakistan are limited and inconsistent. The study investigated differences in symptoms and post-COVID conditions between vaccinated and unvaccinated individuals and the impact of vaccination on illness duration based on existing literature. Methods: The study was a 3-month cross-sectional study conducted in Peshawar, Pakistan. It targeted individuals aged 16 and above who had contracted COVID-19 at least once during the recent pandemic, regardless of gender, and confirmed through reverse transcriptase polymerase chain reaction testing. The sample size was 250, determined using the WHO sample size calculator. Data were collected through questionnaires after obtaining verbal consent and analyzed using IBM SPSS version 26, taking into account their vaccination status along with other important variables. Results: Among the 250 respondents, 143 (57.2%) were unvaccinated, while 107 (42.8%) were vaccinated at the time of contracting COVID-19. Unvaccinated subjects developed a greater variety of symptoms that lasted for longer durations (P<0.001) with symptoms like dyspnea [55 (38.5%, P=0.011)], anosmia [76 (53.1%, P=0.001)], and chest pain [24 (16.8%, P=0.029)] occurring at greater percentages. Sixty-one (42.7%) unvaccinated subjects reported post-COVID conditions as opposed to 29 (27.1%) among the vaccinated group [P=0.011; odds ratio (OR)=0.5; 95% CI=0.29-0.86]. Conclusion: The study found that COVID-19 vaccination can reduce the duration and frequency of symptoms, as well as post-COVID conditions. This is the first research of its kind conducted in Peshawar, Pakistan, and may serve as a foundation for future research in this demographic.

Fabrication and characterization of TiO2 and MWCNT coated electrospinning nanofibers for UV protection properties.

This paper aimed to fabricate UV protective nanofibers by the use of specific nanoparticles. The DMF/TiO2 (Titanium dioxide), DMF/MWCNT (Multi-Walled Carbon Nano Tubes), and DMF/MWCNT+TiO2 (MWCNT: TiO2 mass ratio= 1:1) solutions were transferred into a syringe with a stainless steel needle with gauge 21. The electrospinning process was performed for 3 h at the optimized conditions. The surface morphology of nanofibers was characterized by field emission scanning electron microscopy (FESEM). Fourier transform infrared spectroscopy (FTIR) was utilized to characterize functional groups of oxidized MWCNTs and investigate the successful load of nanoparticles at the fiber surface. The UV protection property of nanofibers was investigated by measuring UV rays' transmittance through the composite web. The data of Spectroscopy was used to compute the UV protection factor (UPF). (1) The effect of CNT,TiO2, and CNT+TiO2 nanoparticles on ultraviolet protection property was analyzed separately and simultaneously. (2) The different concentrations of nanoparticles, including 1,5,10, & 15 wt%, were used to fabricate UV protective nanocomposites. (3) The electrospinning condition was optimized as a 15 cm distance between the needle tip and collector, 20 KV voltage, 250 RPM drum rotation, and 1.2 ml/h feeding rate to access the best nanofibers.

Predicting the probability of occupational fall incidents: a Bayesian network model for the oil industry.

Purpose. The probability of being injured or killed from an occupational incident is much higher than a process mishap in the oil and gas industry. The aim of this study was to establish a model for predicting the probability of occupational fall incidents using Bayesian networks. Methods. The study was performed in a selected number of oil refineries. Bayesian network variables (n = 18) were identified using literature as well as expert knowledge. These contributing factors were categorized into four layers (organizational, supervisory, preconditions and unsafe acts) according to the Swiss cheese model. Causal relationships among contributing factors were determined using expert judgment in combination with Dempster-Shafer theory. The conditional probability table of each contributing factor was measured using a questionnaire. Results. The prior probability of fall events was 5.34% (53 cases per 1000 operational workers in 12 months). The posterior probability predicted that using fall protection devices and safe working platforms will decrease more than half (58%) of fall occupational incidents. Conclusion. Bayesian network features including graphical representation, easy belief updating, performance testing and sensitivity analysis facilitate the process of predicting occupational incident probability including fall events. The proposed approach is a step toward quantitative risk analysis of occupational incidents.

Comparative Study of Resting Metabolic Rate and Plasma Amino Acid Profile in Patients Who Underwent Laparoscopic Roux-en-Y Gastric Bypass and Laparoscopic Sleeve Gastrectomy: 6-Month Follow-up Study.

PURPOSE: Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG) are the most common techniques for treatment of morbid obesity. However, a few studies have compared the energy expenditure and plasma amino acid profile after LRYGB and LSG. The present study was conducted to assess the resting metabolic rate (RMR) and plasma amino acid profile in obese patients who underwent LRYGB and LSG before and 6 months after the surgery in order to compare these changes from baseline between the two procedures. MATERIALS AND METHODS: Forty-three adult obese patients participated in this study (LRYGB = 22 and LSG = 21) and were followed up for 6 months. RMR was measured by indirect calorimetry. The plasma amino acid profile was determined using high-performance liquid chromatography (HPLC). RESULTS: Mean percent excess weight loss (%WL) were 22.8 ± 4.5% and 23.3 ± 5.7% in LRYGB and LSG, respectively. RMR reduced significantly from baseline by - 459 ± 202 kcal/day in LRYGB and - 500 ± 262 kcal/day in LSG. RMR reduced beyond the expected decrease in both procedures. A decreasing trend was observed in the plasma concentration of branched-chain amino acids (BCAA), aromatic amino acids (AAA), and amino acid index (AAI) in both techniques. There was no significant difference in weight, RMR analysis, and amino acid change from baseline between LRYGB and LSG. CONCLUSION: Our results showed that the effects of LRYGB and LSG on RMR and amino acid profile were comparable.

Evaluation of Respiratory Symptoms among Workers in an Automobile Manufacturing Factory, Iran.

BACKGROUND: This study estimated the prevalence of respiratory symptoms and disorders among workers exposed to exposure to volatile organic compound (VOCs) in an automobile manufacturing factory in Tehran, Iran in 2016. METHODS: Subjects of this case-control research were included 80 samples including 40 workers exposed to different level of BTEX as well as 40 unexposed individuals were considered as control group. Methods 1501 and 7602 presented by the National Institute of Occupational Safety and Health (NIOSH) were used for the sampling and analysis of compounds in the air. Gas Chromatography-Flame Ionization Detector (GC-FID) was used for analysis of compounds of interest. Six silica samples were collected during the campaign. Silica analyses were performed by using visible absorption spectrophotometry system. Lung functions were evaluated for 80 workers (40 exposed, 40 nonexposed) using spirometry system. RESULTS: The average amount of total dust and free silica measured in factory were 7.3±1.04 mg.m-3 and 0.017±0.02 mg.m-3 respectively. Average benzene, toluene, ethyl-benzene and xylene exposure levels in exposed subject's median were 0.775±0.12, 1.2±2.08, 45.8±8.5, and 42.5±23.9 ppm respectively. Statistical tests showed significant difference between pulmonary function tests (except PEF) of exposed and non-exposed individuals before and after employment (P<0.05). Workers exposed to VOCs presented lower levels of FVC, VC, and PEF than the control group except FEV1/FVC%, FEV1, FEF2575 and FEV1/VC%. CONCLUSION: Decline in lung volumes and respiratory symptoms, significant difference associated with the exposure to dust or gas, duration of exposure, and smoking habit. Therefore, lung function tests should be performed before and after the employment to identify sensitive workers candidates.

Relation between Lifestyle and Socio-Demographic Factors and Body Composition among the Elderly.

BACKGROUND: Aging is accompanied by various changes that can cause changes in diet and body composition resulting sometimes in malnutrition and disability in the elderly. Changes in body composition among the elderly are mainly the result of physical inactivity and nutrition. This study was designed to examine the relationship between lifestyle and socio-demographic factors and body composition. METHOD: A cross-sectional study was carried out with 380 elderly people aged 60 and over in district 5 of Tehran, Iran. Their body composition was measured by Bioelectrical Impedance Analysis and the Actigraph device was used for assessing physical activity patterns. A three-day food recall was conducted to measure their intake of energy and macronutrients. Lifestyle and socio-demographic information were collected by interview using a pretested questionnaire. RESULTS: Overweight, obesity and central obesity were more prevalent in women than in men (p<0.001). Moreover, 57.1% and 18.7% of participants had high and very high fat mass index, respectively. High fat mass index was seen in 47% of men and 37.5% of women who had normal body mass index (BMI). Meanwhile, age, gender, physical activity, energy intake, the percentage of energy from fat and protein, educational level, job, television watching time, smoking, chronic diseases, and taking medicine were significantly associated with anthropometric measurements (p<0.05). CONCLUSION: Overweight, obesity and high body fat percentage were common among the aged. Considering the factors that are significantly associated with body composition, programs that can increase their awareness about the dietary balance and suitable physical activity should be organized to address these problems.

Evaluation of the effects of occupational noise exposure on serum aldosterone and potassium among industrial workers.

The existing literature indicates that occupational exposure to noise may have adverse effects on workers' health. The aim of this study was to evaluate the possible effects of exposure to different sound pressure levels (SPLs) on serum aldosterone and potassium concentration among Iranian blue collar workers in Golgohar Mining and Industrial Company in Sirjan, Kerman Province, Iran. This case-control study was performed on 45 workers of Golgohar Mining and Industrial Company. The subjects consisted of 30 workers from manufacturing departments and 15 office employees of the mining company. The controls, mainly with administrative jobs were exposed to 72 dBA SPL. Cases, in two separate groups, were exposed to noise levels of 88 dBA and 103 dBA, respectively. Noise intensity was measured at the desired locations. Noise measurements were performed according to the International Organization for Standardization (ISO) 9612. To measure the serum aldosterone and potassium concentrations, a 5 mL blood sample was taken from each worker at the specified time intervals and aldosterone concentration was determined using enzyme-linked immunosorbent assay (ELISA) test in the laboratory. Repeated measurement and Spearman's correlation coefficient analysis were used with α = 0.05. Exposure to the different levels of sound pressure resulted in different aldosterone concentrations and meanwhile an increase in the SPL did not affect the concentration of potassium. From 10:00 AM to 10:30 AM, as SPL increased, aldosterone concentrations did not increase significantly but from 13:30 PM to 14:00 PM, raised SPL led to a significant increase in aldosterone concentration. However, there was no correlation between the concentration of potassium and different factors. This study indicated that increases in SPLs affect aldosterone concentration but at the same time do not have significant effects on serum potassium level.

Personal Exposure to Polycyclic Aromatic Hydrocarbons in Newsagents in Tehran, Iran.

BACKGROUND: Vehicle exhaust is a major source of exposure to Polycyclic Aromatic Hydrocarbons (PAHs) found in the urban atmosphere. Newsagents usually work close to heavy traffic flow. The purpose of this study was to assess the breathing zone exposure of newsagents to PAHs found in the urban atmosphere of Tehran City during summer and autumn seasons and comparing the levels of exposure in both seasons. METHODS: Fifteen non-smoking newsagents were randomly selected from north, south, east, west, and center of Tehran. Particle and gas phases PAHs were collected on polytetrafluoroethylene (PTFE) filter and XAD-2 adsorbent. Gas chromatography-mass spectrometry (GC/MS) was used to determine PAHs concentrations in newsagent's breathing zone samples. RESULTS: The highest and lowest values of exposures during summer and autumn in all sampling stations were recorded for benzo[a]anthracene and benzo[ghi]perylene, respectively. Mann-Whitney test results showed that seasonal variation had significant influence on concentrations of all studied PAHs (P= 0.001) except benzo[ghi]perylene (P= 0.089). An increase in concentrations of PAHs was observed in autumn. CONCLUSION: The workers of the newsstands in the south area of Tehran City were experiencing higher levels of exposures to PAHs. Newsagents' breathing zone exposures to PAHs during the cold period were two to three folds higher than those during the warm period were. The levels of exposures in all sampling stations were below the OSHA and NIOSH's recommended exposure limits.

Assessment of airborne asbestos exposure at an asbestos cement sheet and pipe factory in Iran.

Iran imports nearly 55,000 metric tons of asbestos per year, and asbestos cement (AC) plants contribute nearly 94% of the total national usage. In the present study, asbestos fiber concentrations during AC sheet and pipe manufacturing were measured by phase-contrast microscopy (PCM) and polarized light microscopy (PLM) in 98 personal air samples. The fiber type and its chemical composition were also evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). Personal monitoring of fiber levels indicated a range from 0.02 to 0.55PCM f/ml (0.02-0.69PLM f/ml). The AC workers' geometric mean asbestos exposure was 0.09 PCM f/ml (0.11 PLM f/ml), with arithmetic mean of 0.13 PCM f/ml (0.16 PLM f/ml). The observed fiber concentrations in many processes were higher than the threshold limit value (TLV) proposed by the American Conference of Governmental Industrial Hygienists (ACGIH), which is 0.1 f/ml. Based on these findings, the PLM values were approximately 25% higher than PCM values. The SEM data demonstrate that fibrous particles contained chrysotile. The thinnest fiber recognized by SEM had a diameter of 0.2µm. Mean exposure exceeded the TLV for asbestos in pipe molding and finishing (100%) as well as sheet molding and finishing (45.5-83.3%). In conclusion exposure control may be needed to be in compliance with the ACGIH TLV and other guidance levels. Also, with regard to PCM limitations for airborne fiber analysis, the use of microscopic methods other than PCM can be used to improve the techniques used presently.

Formaldehyde exposure in some educational hospitals of Tehran.

This research was conducted to determine formaldehyde exposure of staffs in pathology laboratories, surgery rooms and endoscopy wards in eight large hospitals of Tehran University of Medical Sciences located at Tehran, Iran. Air sampling have been made by both long and short-term methods. Total numbers of samples were 160 for both methods. Nineteen samples of 160 samples were collected as blank in other non-exposed environments such as administrative sections. The mean (SD) levels of formaldehyde in long-term methods were 0.96 (0.74), 0.25 (0.21) and 0.13 (0.18) ppm, at pathology laboratories, surgery rooms and endoscopy wards, respectively. The results of measurements showed that mean (SD) concentration of formaldehyde in one hour sampling at short intervals were 0.83 (0.29), 0.23 (0.16) and 0.75 (0.25) ppm at pathology labs, surgery rooms and endoscopy wards, respectively. There were significant differences in the mean levels of formaldehyde (long-term) at surgery rooms (p < 0.02) and endoscopy wards (p < 0.005) in eight hospitals of this study. It is concluded that the concentration levels of formaldehyde at pathology laboratories exceeded recommended limit which established by the American Conference of Governmental and Industrial Hygienists ACGIH (TLV-C = 0.3 ppm). It is recommended that local exhaust ventilation should be installed to minimize the contact to formaldehyde in the staffs.