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1.
Sci Rep ; 14(1): 12006, 2024 05 25.
Article in English | MEDLINE | ID: mdl-38796506

ABSTRACT

Formaldehyde, a known carcinogenic compound, is commonly used in various medical settings. The objective of this study was to assess the carcinogenic and non-carcinogenic risks associated with occupational exposure to formaldehyde. This study was conducted in the pathology labs of four hospitals in Tehran. Cancer and non-cancer risks were evaluated using the quantitative risk assessment method proposed by the United States environmental protection agency (USEPA), along with its provided database known as the integrated risk information system (IRIS). Respiratory symptoms were assessed using the American thoracic society (ATS) questionnaire. The results indicated that 91.23% of exposure levels in occupational groups exceed the NIOSH standard of 0.016 ppm. Regarding carcinogenic risk, 41.03% of all the studied subjects were in the definite carcinogenic risk range (LCR > 10-4), 23.08% were in the possible carcinogenic risk range (10-5 < LCR < 10-4), and 35.90% were in the negligible risk range (LCR < 10-6). The highest index of occupational carcinogenesis was observed in the group of lab technicians with a risk number of 3.7 × 10-4, followed by pathologists with a risk number of 1.7 × 10-4. Furthermore, 23.08% of the studied subjects were within the permitted health risk range (HQ < 1.0), while 76.92% were within the unhealthy risk range (HQ > 1.0). Overall, the findings revealed significantly higher carcinogenic and non-carcinogenic risks among lab technicians and pathologists. Therefore, it is imperative to implement control measures across various hospital departments to mitigate occupational formaldehyde exposure levels proactively. These findings can be valuable for policymakers in the health sector, aiding in the elimination or reduction of airborne formaldehyde exposure in work environments.


Subject(s)
Carcinogens , Formaldehyde , Occupational Exposure , Formaldehyde/adverse effects , Formaldehyde/toxicity , Formaldehyde/analysis , Humans , Occupational Exposure/adverse effects , Occupational Exposure/analysis , Iran/epidemiology , Risk Assessment , Carcinogens/toxicity , Carcinogens/analysis , Male , Female , Adult , Hospitals , Middle Aged , Surveys and Questionnaires , Laboratories, Hospital
2.
Int J Hyg Environ Health ; 256: 114319, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38171266

ABSTRACT

This study aimed to determine the short-term effects of ambient temperature variations exposures on the incidence of preterm birth (PTB) for each single lag day (lag0 to lag6) and cumulative lag days (lag0-1 to lag0-6) up to a week before birth. To find relevant publications, online databases, including Web of Science, PubMed, and Scopus were searched with appropriate keywords and Mesh terms from their inception to October 25, 2023. Overall, the number of 39 observational studies with 12.5 million pregnant women and 700.000 cases of PTB met our eligibility criteria. The associations of temperature variations with the incidence of PTB were investigated with two different meta-analyses, including the percentile meta-analysis (comparing different percentiles (P1 to P99) with a referent percentile (P50)), and the linear meta-analysis (per 5 °C increment of the temperature levels). For the percentile meta-analysis, we observed both extreme cold (P1, only lag 0) and heat (P95 and P99 with the highest risk at lag1 and lag0-6) exposures can be significantly associated with a higher risk of PTB. The pooled RR (95 % CI) per 5 °C increase in the temperature levels at lag0-6 was estimated as 1.038 (1.018, 1.058) for the overall analysis. Subgroup analysis based on the season shows a significant association in the warm season (RR = 1.082 and 95 % CI = 1.036, 1.128) at all lag days but not the cold season. For the single lag day, we observed the risk of PTB is the highest at lag1 and decreased with moving to lag6. In sum, we suppose there is a nearly V-shape non-linear association between air temperature levels and the incidence of PTB with the linear relationship for each unit increase (also decrease) in the temperature levels above (also below) moderate temperature limits. Future studies should investigate possible association of occupational heat and cold exposure during pregnancy on the incidence of adverse birth outcomes such as PTB.


Subject(s)
Premature Birth , Humans , Infant, Newborn , Female , Pregnancy , Premature Birth/epidemiology , Temperature , Incidence , Seasons , Hot Temperature
3.
Sci Rep ; 14(1): 180, 2024 01 02.
Article in English | MEDLINE | ID: mdl-38168505

ABSTRACT

Nanomaterials (NMs) have the potential to be hazardous owing to their unique physico-chemical properties. Therefore, the need for Health Risk Assessment (HRA) of NMs is expanding. In this study, a novel HRA was developed by the Pythagorean Fuzzy Health Risk Assessment (PFHRA) approach. Risk is considered to be the outcome of parameters including Occurrence Likelihood (OL), Potential Exposure (PE) and Toxic Effects (TE). In our proposed method, priority weights of sub-factors in Pythagorean Fuzzy-Analytical Hierarchical Process (PF-AHP) were determined by pairwise comparison based on expert judgment. After determining parameter scores, both RM and risk class (i.e., negligible, minor, major and critical) were reported as Fuzzy Inference System (FIS) output. Ultimately, a risk management strategy is presented for NMs manufacturing workplaces. This proposed method provides experts with more flexibility to express their opinions. The PFHRA approach was applied for two scenarios. The production scenario for SiNPs can create minor (5%) and major (95%) occupational health risks; the production scenario for ZnONPs can create minor (100%) concerns. However, the production SiNPs and ZnONPs utilizing the CB Nanotool technique had a major and minor risk class, respectively. The results of the present study confirmed the reliability and applicability of this approach.


Subject(s)
Fuzzy Logic , Nanostructures , Reproducibility of Results , Risk Assessment/methods , Risk Management , Nanostructures/toxicity
5.
Int J Biometeorol ; 68(1): 163-177, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37962645

ABSTRACT

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.


Subject(s)
Heat Stress Disorders , Occupational Diseases , Humans , Male , Cross-Sectional Studies , Heat-Shock Response , Heat Stress Disorders/diagnosis , Heart Rate , Hot Temperature
6.
Iran J Public Health ; 52(8): 1613-1625, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37744536

ABSTRACT

Background: Asbestos is one of the most important environmental and occupational carcinogens. Nevertheless, the mechanisms by which asbestos fiber exposure causes chronic diseases are not fully understood. We performed the first systematic review on the epidemiological evidence to examine the association between occupational exposure to asbestos and oxidative stress and DNA damage. Methods: In this systematic review study, the PubMed and Scopus databases were searched for English-language publications. Eleven cross-sectional studies were included in the systematic review. A literature search was conducted by the main keywords including "Asbestos", "crocidolite", "chrysotile", "amphibole", "amosite", "Oxidative Stress", "DNA Damage", and "DNA injury". To evaluate the quality of studies, the "Newcastle-Ottawa Quality Assessment Scale" (NOS) was used. Results: Overall, 1235 articles were achieved by searching in databases. Finally, by considering the inclusion, and exclusion criteria, 11 articles were conducted for this study. These studies were published between 1986 and 2020. Oxidative stress and DNA damage can occur in exposure to asbestos. Among various biomarkers, 8-OHdG is the best. The analysis of 8-oxodG in asbestos workers can help identify subjects with a higher level of genotoxic damage. Conclusion: This systematic review suggests that oxidative stress and DNA damage are two main outputs of asbestos exposure. Therefore, oxidative stress and DNA damage biomarkers can be used for identifying subjects at higher risk of cancer. These findings support policy initiatives aimed at detecting and eliminating asbestos fiber exposure and preventing potential health hazards in occupational settings.

7.
Environ Sci Pollut Res Int ; 30(33): 80791-80806, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37306882

ABSTRACT

The adsorbent MIL-101, a metal-organic framework material, was synthesized, characterized, and tested for removal of relatively low concentrations of benzene and toluene adsorbates (200 ppm) from a gas phase in a continuous flow system. Breakthrough studies were modeled based on Thomas, Yoon-Nelson, Yan, Clark, Bohart-Adams, bed-depth service time, modified dose response, Wolborska, and Gompertz in the continuous fixed-bed operation. Through statistical analysis, it was determined which type of regression is most suitable for the studied models, linear or nonlinear. By comparing the values of error functions, it was possible to infer that the Thomas model is the best match for the experimental breakthrough curves for benzene (with maximum solid-phase concentration qT=126,750 mg/g) and the Gompertz model for toluene (parameter ß=0.01 min-1). Overall, when compared to the model parameters of the linear regression, those obtained through nonlinear regression show a stronger correlation with the results found experimentally. Thus, this type of regression is more suitable for the adsorption model analysis. The liquid film and intraparticle diffusion analysis was described, and it was suggested that both types of diffusion contribute to the adsorption mechanism of benzene and toluene on MIL-101. As for the isotherms, the adsorption process was better fitted by the Freundlich isotherm. The reusability of MIL-101 after six cycles was 76.5% for benzene and 62.4% for toluene, indicating that MIL-101 was a better adsorbent for the removal of benzene in comparison with toluene.


Subject(s)
Metal-Organic Frameworks , Water Pollutants, Chemical , Water Purification , Benzene , Adsorption , Toluene , Water Purification/methods
8.
Nanoscale ; 15(6): 2674-2689, 2023 Feb 09.
Article in English | MEDLINE | ID: mdl-36655491

ABSTRACT

The increasing use of nanomaterials is a threat to human health and environment that has led to the expansion of risk assessment methods. Thus, the aim of this study was to assess the occupational risks of activities involving nanomaterials in nanomedicine research laboratories by Control Banding (CB) NanoTool and Guidance methods. Further, the symptoms of researchers working in these laboratories were investigated. This cross-sectional study was managed in nanomedicine research laboratories. Risk assessment was performed by the CB NanoTool and Guidance methods. Moreover, a questionnaire was used to assess the prevalence of non-specific symptoms. Finally, data were analyzed using the IBM SPSS software. Descriptive statistics were used for data analysis. Many activities are located on the risk level RL2 and category A based on the CB NanoTool and Guidance methods, respectively. Further, the highest severity of exposure to nanomaterials belonged to the preparation of suspension and emulsion and manufacture of metal nanopolymers, but the highest probability of exposure was in the manufacturing of carbon nanocomposites. In addition, there was a significant relationship between the level of risk in the two methods (P = 0.003). Although, cutaneous symptoms were the most common symptoms among laboratory researchers, chi-square test did not confirm any significant relationship between symptoms and risk levels (p-value >0.05) in these two methods. Since the NanoTool method uses more diverse parameters for risk assessment and is more acceptable, choosing control measures based on its results seems more reasonable. Moreover, Guidance can be used as a method for initial assessments and determine the need for further assessments.


Subject(s)
Nanocomposites , Occupational Exposure , Humans , Occupational Exposure/analysis , Laboratories , Cross-Sectional Studies , Risk Assessment/methods
9.
Int J Occup Saf Ergon ; 29(2): 627-641, 2023 Jun.
Article in English | MEDLINE | ID: mdl-35400307

ABSTRACT

Objectives. Occupational activities in open spaces can experience excessive heat exposure caused by sunlight and other artificial sources in these professional environments can be one of the current and future challenges of occupational safety and health due to increasing global warming. Use of lightweight portable parasols is the first available control measure to reduce the radiation emitted by the sun in outdoor workplaces, which has been used for a long time. Methods. Due to the lack of study and results on the effect of using parasols in scientific literature, this modeling study was conducted to investigate the effect of sunshade installation on radiant temperature reduction of the sun in outdoor work using COMSOL Multiphysics version 5.5. Results. In general, six different shapes of portable parasols in different positions were modeled and the average radiant temperature reduction effectiveness (TRE) was about 30% in the presence of different parasols. The designed conical, simple and pyramidal sunshades showed the most effectiveness, respectively. Conclusions. The results show that changing variables such as the axis, installation height and shape is more effective for improving parasol efficiency to reduce the radiant temperature below it.


Subject(s)
Sunlight , Workplace , Humans , Temperature , Hot Temperature
10.
Med Gas Res ; 13(3): 142-148, 2023.
Article in English | MEDLINE | ID: mdl-36571380

ABSTRACT

Acrylonitrile is a potential carcinogen for humans, and exposure to this substance can cause adverse effects for workers. This study aimed to carcinogenic and health risk assessment of acrylonitrile vapor exposure in exposed personnel of a petrochemical complex. This crosssectional study was performed in 2019 in a petrochemical complex. In this study, to sample and determine acrylonitrile's respiratory exposure, the method provided by the National Institute of Occupational Safety and Health (NIOSH 1601) was used, and a total of 45 inhaled air samples were sampled from men workers, aged 39.43 ± 9.37 years. All subjects' mean exposure to acrylonitrile vapors was 71.1 ± 122.8 µg/m3. Also, the mean exposure index among all subjects was 0.02 ± 0.034. The non-carcinogenic risk assessment results showed that the mean Hazard quotient index was 4.04 ± 6.93. The mean lifetime cancer risk index was also 2.1 × 10-3 ± 3.5 × 10-3 and was in the definite risk range. Considering that both carcinogenicity and health indicators of exposure to acrylonitrile in the studied petrochemical complex are more than the recommended limits, the necessary engineering and management measures to control and manage the risk to an acceptable level are essential to improving the worker's health.


Subject(s)
Acrylonitrile , Occupational Exposure , Male , United States , Humans , Acrylonitrile/toxicity , Cross-Sectional Studies , Occupational Exposure/adverse effects , United States Environmental Protection Agency , Carcinogens , Risk Assessment
11.
J Therm Biol ; 110: 103335, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36462874

ABSTRACT

Working in cold environments can have a variety of negative consequences on health, efficiency, quality, safety, and performance. The present study investigates the risk of cold stress in petroleum transfer centers in Iran's northwestern cold regions. The proposed method by ISO-15743 (E) was used to assess the risk of cold stress. The activity level (M) was calculated using the ISO 8996:2021 standard. The evaluation of local cooling, contact of cold surfaces, and hand and face temperature was performed using ISO 11079, ISO 13732-3, and ISO 9886, respectively. During their work, 28 outdoor site men and mechanics as a case group and 8 operators as a control group put through subjective analysis. According to the findings, the mean Icl,r, IREQmin, and IREQneutral were 1.59 ± 0.33, 2.1 ± 0.44, and 2.43 ± 0.45, respectively. The mean equivalent chill temperature was -13.83 ± 5.45, and workers were at risk of local cooling stress at levels 1 and 2. The case group showed greater losses in finger skin temperatures after short term exposure to extremely cold environments than the control group (P < 0.001). Based on the questionnaire results a significant percentage of workers performing the activity during the winter have more difficulty. Prolonged general and local cold exposure can cause pain, numbness, and frostbite in site men and mechanics. Careful planning, training, extensive distribution of cold protective clothing, rest periods, a relatively short stay in the cold environment, and proper equipment can greatly reduce these hazards.


Subject(s)
Cold-Shock Response , Petroleum , Male , Humans , Iran , Risk Assessment , Cold Temperature
12.
Int J Biometeorol ; 66(11): 2147-2158, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36178536

ABSTRACT

Thermal stress has a direct effect on various types of DNA damage, which depends on the stage of the cell cycle when the cell is exposed to different climate conditions. A literature review was conducted to systematically investigate and assess the overall effect of heat stress and DNA damage following heat exposure. In this study, electronic databases including PubMed, Scopus, and Web of Science were searched to find relevant literature on DNA damage in different ambient temperatures. Outcomes included (1) measurement of DNA damage in heat exposure, (2) three different quantification methods (comet assay, 8-hydroxy-2-deoxyguanosine (8-OHdG), and γ-H2AX), and (3) protocols used for moderate (31) and high temperatures (42). The evidence shows that long exposure and very high temperature can induce an increase in DNA damage through aggregate in natural proteins, ROS generation, cell death, and reproductive damage in hot-humid and hot-dry climate conditions. A substantial increase in DNA damage occurs following acute heat stress exposure, especially in tropical and subtropical climate conditions. The results of this systematic literature review showed a positive association between thermal stress exposure and inhibition of repair of DNA damage.


Subject(s)
DNA Damage , Heat Stress Disorders , Humans , 8-Hydroxy-2'-Deoxyguanosine , Heat-Shock Response , Hot Temperature
13.
Iran J Public Health ; 51(4): 871-879, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35936530

ABSTRACT

Background: We aimed to investigate the efficiency of neat polyacrylonitrile (PAN) nanofibers and photocatalytic PAN/TiO2 nanofibers for removal of airborne microorganisms. Methods: Nanofibers were fabricated from 16 wt% of PAN dissolved in dimethyl formamide through the electrospinning technique. The efficiency of media for removal of Staphylococcus epidermidis and Bacillus subtilis was investigated at different conditions such as face velocity, relative humidity, air temperature and UVC radiation intensity. as face velocity (0.1 and 0.3 m/s), relative humidity (35±5% and 60±5%), air temperature (22±3 °C and 30±3 °C) and the UVC radiation intensity (dark, 1±0.09 mW/cm2 and 1.8±0.07 mW/cm2) using air sampling from upstream and downstream of media by cascade impactor containing blood agar culture medium. Results: The mean diameter of electrospun fibers and coefficient of variation were 194 nm and 15%, respectively. The amount of immobilized TiO2 on the filter was 620±6.56 mg/m2. Photocatalytic nanofiber filter media presented the best performance for removal of airborne B. subtilis at 60±5% relative humidity, 0.1 m/s face velocity, air temperature 22 °C, and 1.8 ± 0.07 mW/cm2 UVC radiation. Conclusion: The filtration efficiency of photocatalytic media was significantly higher than neat ones. Lower efficiency of media was found in the higher air velocity for all bioaerosols. High UVC radiation intensity increased filtration efficiency. Moreover, the increase in air temperature and relative humidity (except for TiO2-coated media under UVC radiation) did not significantly affect the filtration efficiency of all media.

14.
Environ Sci Pollut Res Int ; 29(60): 90128-90139, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35864393

ABSTRACT

Titanium dioxide (nano-TiO2) is used abundantly in various industrial products and novel medical therapies. In addition, the impact of climate change on the health and safety will undoubtedly increase in the future. However, the effects of exposure to these nanoparticles and heat stress on hippocampal DNA damage and apoptosis remain unclear. This study was conducted to evaluate the DNA damage and apoptosis in the hippocampal tissue and the physiological responses in mice induced by intraperitoneal (i.p.) administration of TiO2 nanoparticles (NPs) and heat stress for 14 consecutive days. The results showed that heat stress and TiO2-NPs were induced in the mouse hippocampus that led to hippocampal reactive oxygen species generation, oxidative damage of DNA, and apoptosis in a partly dose-dependent manner, especially at very hot temperature. High doses of nanosized TiO2 and severe heat stress significantly damaged the function of the hippocampus, as shown in the comet assay and apoptosis tests. The results of this study may provide data for appropriate measures to control and assess the risk of nano-TiO2 and thermal stress hazards to human health, especially workers. Safety guidelines and policies should be considered when handling nanomaterials in a hot environment.


Subject(s)
Oxidative Stress , Policy , Humans , Animals , Mice , Apoptosis
15.
Am J Mens Health ; 16(1): 15579883221074821, 2022.
Article in English | MEDLINE | ID: mdl-35172663

ABSTRACT

The present study aims to investigate the effects of using the supplementation of vitamin E and Omega 3 fatty acids on reproductive indices among workers in an automobile parts manufacturing plant. The effect of exposure to electromagnetic fields on certain sex hormones and sperm parameters will also be assessed. The participants were deployed into four groups as per the double-blind block randomization method. Semen parameters and sex hormones of the participants were analyzed before and after 3-month consumption of supplements. The level of workers' exposure to low-frequency magnetic and electrical fields was measured through the recommendation of National Institute for Occupational Safety and Health. Univariate analysis of variance indicated that exposure to electric fields had a statistically significant effect on sperm count, morphology, and motility. The simultaneous consumption of vitamin E + Omega 3 had a statistically significant effect on sperm morphology and motility.


Subject(s)
Fatty Acids, Omega-3 , Vitamin E , Electromagnetic Fields/adverse effects , Fatty Acids, Omega-3/pharmacology , Humans , Male , Reproductive Health , Semen , United States , Vitamin E/pharmacology
16.
Int J Occup Saf Ergon ; 28(1): 223-255, 2022 Mar.
Article in English | MEDLINE | ID: mdl-32164499

ABSTRACT

Humans in hot environments are exposed to health risks and thermal discomfort which seriously affect their physical, physiological and mental workload. This study aimed to assess the effects of using cooling vests (CVs) on physiological and perceptual responses in the workplace. Three main databases were searched using subject headings and appropriate Mesh terms. The article has been written according to the preferred reporting items for systematic reviews checklist. A total of 23,837 studies were identified for screening and 63 studies were eligible for data extraction. A statistically significant difference was observed in body temperature among hybrid cooling garments (HBCGs), phase-change materials (PCMs) and air-cooled garments (ACGs) at 31.56-37 °C (60% relative humidity), evaporative cooling garments at 25.8-28.1 °C and liquid cooling garments at 35 °C (49% relative humidity) compared to without CVs (p < 0.001). HBCGs (PCMs and ACGs) are effective means in hot, moderate, humid or dry environments.


Subject(s)
Body Temperature Regulation , Protective Clothing , Body Temperature , Body Temperature Regulation/physiology , Cold Temperature , Hot Temperature , Humans
17.
BMC Public Health ; 21(1): 2323, 2021 12 30.
Article in English | MEDLINE | ID: mdl-34969389

ABSTRACT

BACKGROUND: The thermal strain can be measured using subjective methods without the use of sensitive equipment. The purpose of the present study was the development and validation of an observational - perceptual heat strain risk assessment (OPHSRA) method. METHODS: This cross-sectional study, in 2019, was performed. At first, an observational-perceptual questionnaire was designed using effective items in producing heat strain. Then, the reliability and validity of the questionnaire were examined. Later, 201 male workers were asked to perform the routine tasks for 90 min under various climatic conditions after resting in a cool room. At the end of the activity, the tympanic temperature of the subjects was accurately measured. Also, the designed questionnaire was completed by researchers and participants. Then, the effect coefficients of the items were calculated and used for developing the novel index. At final, the index validity was investigated. RESULTS: The values of the content validity ratio (CVR), content validity index (CVI), and Cronbach's coefficient alpha (α) of the designed questionnaire with 16 questions were equal to 0.793, 0.913, and 0.910, respectively. The results indicated that environmental, job, administrative, and clothing items assessed by the questionnaire with the coefficients of 0.860, 0.658, 0.783, and 0.566 had significant effects on the thermal strain, respectively. These coefficients were exploited to develop the index. The result revealed that the OPHSRA index justified 69% of the variations of the tympanic temperature (R2 = 0.69). CONCLUSION: The novel index developed by the questionnaire had an acceptable validity. Therefore, this index can be used for estimating the risk of thermal strain in a variety of thermal conditions.


Subject(s)
Hot Temperature , Cross-Sectional Studies , Humans , Male , Reproducibility of Results , Risk Assessment/methods , Surveys and Questionnaires
18.
Saf Health Work ; 12(3): 396-402, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34527402

ABSTRACT

BACKGROUND: Styrene is one of the aromatic compounds used in acetonitrile-butadiene-styrene (ABS) producing petrochemicals, which has an impact on health of workers. Therefore, this study aimed to investigate the health risks of styrene emitted from the petrochemical industry in Iran. METHODS: Air samples were collected based on NIOSH 1501 method. The samples were analyzed by the Varian-cp3800 gas chromatograph. Finally, risk levels of styrene's health effects on employees were assessed by the quantitative method of the U.S. Environmental Protection Agency (U.S. EPA) and the semiquantitative way by the Singapore Occupational Safety and Health Association. RESULTS: Based on the results, the employees had the highest average exposure to styrene vapors (4.06 × 10 - 1 m g . ( k g - d a y ) - 1 ) in the polybutadiene latex (PBL) unit. Therefore, the most top predictors of cancer and non-cancer risk were 2.3 × 10 - 4 and 7.26 × 10 - 1 , respectively. Given that the lowest average exposure (1.5 × 10 - 2 m g . ( k g - d a y ) - 1 ) was in the dryer unit, the prediction showed a moderate risk of cancer (0.8 × 10 - 6 ) and non-cancer (2.3 × 10 - 3 ) for the employees. The EPA method also predicted that there would be a definite cancer risk in 16% and a probable risk in 76% of exposures. However, according to the semiquantitative approach, the rate of risk was at the "low" level for all staff. The results showed that there was a significant difference (p < 0.05) between the units in exposure and health risk of styrene (p < 0.05). CONCLUSION: Given the high risk of styrene's health effects, appropriate control measures are required to reduce the exposure level.

19.
MethodsX ; 8: 101354, 2021.
Article in English | MEDLINE | ID: mdl-34430255

ABSTRACT

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.

20.
Toxicol Ind Health ; 37(7): 377-390, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34018890

ABSTRACT

The present study investigated the relationship between occupational exposure to noise and whole-body vibration (WBV) with the levels of sex hormones in an automobile parts manufacturing plant. The level of workers' exposure (n = 162) to each of the mentioned stressors was measured through standard methods, and the time-weighted average of exposure was calculated for each person. In order to determine serum sex hormones (free testosterone, luteinizing hormone, and follicle-stimulating hormone), blood samples were taken from all participants after 8-10 h of fasting between 7 and 9 am and then the blood samples were analyzed by an enzyme-linked immunosorbent assay method. In general, regarding testosterone as the main male sex hormone, only 49% of the participants were in the normal range. In a total of three sections, the lowest mean testosterone levels were observed in the third exposure group (WBV > 1.93 m/s2; noise >92.69 dB) of the studied stressor; however, only the difference in testosterone levels between the three different groups of exposure to noise was statistically significant (p = 0.001). The relationship between demographic variables and levels of noise and WBV exposure with sex hormones was not linear and only the relationship between noise exposure and testosterone levels was statistically significant (R = -0.201, p = 0.013). According to the results of logistic regression, the WBV had the greatest effect on testosterone levels. However, according to the results of the correlation test, only the relationship between noise exposure and testosterone levels was statistically significant.


Subject(s)
Automobiles , Gonadal Steroid Hormones/blood , Gonadal Steroid Hormones/physiology , Manufacturing and Industrial Facilities , Noise, Occupational/adverse effects , Occupational Exposure/adverse effects , Vibration/adverse effects , Adult , Humans , Male , Middle Aged
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