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1.
Drug Chem Toxicol ; : 1-7, 2024 Aug 19.
Article in English | MEDLINE | ID: mdl-39155643

ABSTRACT

Mineral oils, untreated or mildly treated, have been classified in group 1 as a potential source of cancer by the International Agency for Research on Cancer (IARC). Although numerous studies have implicated metalworking fluids (MWFs) as human carcinogens, toxicology data regarding the mechanism of carcinogenicity are limited. This study is intended to examine the systemic effects of machining workers' exposure to MWFs. The potential toxicity of mineral oils was investigated in 65 lathe workers compared to controls (66 men). The occupational exposure was measured by the National Institute for Occupational Safety and Health (NIOSH) 5026. The DNA damage has been examined by the comet assay method. According to the field assessments, the time-weighted average (TWA) exposure to mineral oil mist was 7.67 ± 3.21 mg/m3. A comet assay of peripheral blood cells showed that tail length (TL) and olive moment (OM) were significantly higher in the exposed group (p < 0.05). A multiple logistic regression analysis revealed that, within subjects with over 10 years of exposure, the odds ratio of worker with high TL, percent of DNA in tail, OM, and tail moment (TM) were 1.68, 1.41, 1.71, and 2.71, respectively. DNA strand break in exposed workers was associated with higher exposure time in years. Mineral oil toxicity could be altered in the presence of by-products and impurities. For a better understanding of genotoxicity, further studies are required.

2.
Asian Pac J Cancer Prev ; 25(6): 1929-1934, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38918653

ABSTRACT

BACKGROUND AND OBJECTIVE: Exposure to noise by generation of free radicals causes oxidative stress in body. The aim of this study was the evaluation of oxidative stress in workers who have used hearing protection devices during working time. MATERIAL AND METHOD: Pressing workers (n=24) of a home appliance industry were studied using hearing protection devices to reduce noise exposure. Twenty two office staff (without exposure to noise) were considered as a control group. Two groups were matched for age, work experience and smoking. Exposure to noise was measured by dosimeter method at workstations. By obtaining 3 ml blood sample, Malondialdehyde levels, Thiol groups and total antioxidant capacity were evaluated in all subjects. RESULTS: Exposure to sound pressure level in pressing workers by considering the noise reduction factor of the earplug was observed in 77.65 dB with minimum 75.1 dB and Maximum 81.22 dB. Plasma thiol groups (0.076 (0.041-0.119) vs (0.110 (0.076-0.197), mmol/l P =0.0001) and total antioxidant capacity (361.33± 54.65 vs 414.14± 96.82, µmol/ml P = 0.026) in pressing workers significantly decreased than control group. Pearson correlation showed significant results between exposure to noise and oxidative stress parameters. CONCLUSION: Exposure to noise wave cause oxidative stress in different site of body. Oxidative stress is an intermediate way for different disease due to noise exposure. Reducing of noise exposure by earplug in pressing workers is not efficient protection for oxidative stress generation. Therefore, hearing protection devices are not a barrier to the harmful effects of noise in occupational exposure.


Subject(s)
Ear Protective Devices , Noise, Occupational , Occupational Exposure , Oxidative Stress , Humans , Occupational Exposure/adverse effects , Occupational Exposure/prevention & control , Adult , Male , Noise, Occupational/adverse effects , Case-Control Studies , Hearing Loss, Noise-Induced/prevention & control , Hearing Loss, Noise-Induced/etiology , Antioxidants/metabolism , Middle Aged , Follow-Up Studies , Malondialdehyde/blood , Female , Occupational Diseases/prevention & control , Occupational Diseases/etiology , Industry , Prognosis
3.
J Chromatogr A ; 1725: 464949, 2024 Jun 21.
Article in English | MEDLINE | ID: mdl-38688054

ABSTRACT

This study introduces an innovative needle trap device (NTD) featuring a molecularly imprinted polymer (MIP) surface-modified Zeolite Y. The developed NTD was integrated with gas chromatography-flame ionization detector (GC-FID) and employed for analysis of fuel ether oxygenates (methyl tert­butyl ether, MTBE, ethyl tert­butyl ether, ETBE, and tert­butyl formate, TBF) in urine samples. To optimize the key experimental variables including extraction temperature, extraction time, salt concentration, and stirring speed, a central composite design-response surface methodology (CCD-RSM) was employed. The optimal values for extraction in the study were found to be 51.2 °C extraction temperature, 46.2 min extraction time, 27 % salt concentration, and 620 rpm stirring speed. Under the optimized conditions, the calibration curves demonstrated excellent linearity within the range of 0.1-100 µg L-1, with correlation coefficients (R2) exceeding 0.99. The limits of detection (LODs) for MTBE, ETBE, and TBF were obtained 0.06, 0.08, and 0.09 µg L-1, respectively. Moreover, the limits of quantification (LOQs) for MTBE, ETBE, and TBF were obtained 0.18, 0.24, and 0.27 µg L-1, respectively. The enrichment factor was also found to be in the range of 98-129.The NTD-GC-FID procedure demonstrated a high extraction efficiency, making it a promising tool for urinary biomonitoring of fuel ether oxygenates with improved sensitivity and selectivity compared to current methods.


Subject(s)
Limit of Detection , Methyl Ethers , Zeolites , Zeolites/chemistry , Humans , Methyl Ethers/urine , Methyl Ethers/chemistry , Molecularly Imprinted Polymers/chemistry , Biological Monitoring/methods , Chromatography, Gas/methods , Ethyl Ethers/urine , Ethyl Ethers/chemistry
5.
Food Chem ; 442: 138455, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38271905

ABSTRACT

The study was performed in two phases. First, the polymerization was carried out upon three magnetized surfaces of silica aerogel, zeolite Y, and MIL-101(Cr). Then, optimal molecularly imprinted polymer and optimal extraction conditions were determined by the central composite design-response surface method. Subsequently, the validation parameters of dispersive solid-phase extraction based optimal molecularly imprinted polymer were examined for the extraction of the fuel ether oxygenates. The optimal conditions include the type of adsorbent: Zeolite-magnetic molecularly imprinted polymer, the amount of adsorbent: 40 mg, pH: 7.7, and absorption time: 24.8 min which was selected with desirability equal to 0.996. The calibration graphs were linear between 1 and 100 µg L-1, with good correlation coefficients. The limits of detection were found to be 0.64, 0. 4, and 0.34 µg L-1 for methyl tert-butyl ether, ethyl tert-butyl ether, and tert butyl formate, respectively. The method proved reliable for analyzing fuel ether oxygenates in drinking water.


Subject(s)
Drinking Water , Metal-Organic Frameworks , Molecular Imprinting , Zeolites , Molecularly Imprinted Polymers , Silicon Dioxide , Ether , Polymers , Solid Phase Extraction , Ethers , Magnetic Phenomena , Molecular Imprinting/methods
6.
Int J Environ Health Res ; 34(2): 1044-1052, 2024 Feb.
Article in English | MEDLINE | ID: mdl-36970880

ABSTRACT

The incidence of DNA damage from exposure to specific types of metalworking fluids has been reported. In this research, size-selective permissible limits to prevent genotoxic damage in A549 cell lines exposed to two types of mineral oil were estimated for the first time using a benchmark dose approach and extrapolated to workers. The comet assay was performed based on Olive and Banath protocol to determine DNA damage. Then, the Benchmark Dose, the 95% lower bound confidence limit BMD, and the 95% upper-bound confidence limit BMD were determined using continuous response data. Finally, the four Benchmark Dose levels reported in the A549 cell line were extrapolated to the human population in occupational settings in two phases. This study showed when determining the permissible limits, the type used or unused, the type of injury, the organ affected in the body and the size of the particles should also be considered.


Subject(s)
Air Pollutants, Occupational , Occupational Exposure , Humans , Occupational Exposure/analysis , Mineral Oil/toxicity , Metallurgy , DNA Damage
7.
Int J Environ Health Res ; 34(9): 3126-3135, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38146704

ABSTRACT

Workers in the iron casting industries are exposed to various chemicals, especially graphite in furnace process. This study aims to investigate the toxic effects of graphite particles on human lung cells. Particle characteristics were confirmed by electron microscope and light scattering. Cell viability and oxidative stress markers were measured. The expression of oxidative repair genes, namely OGG1, MTH1, and ITPA, was evaluated. The average particle size was determined to be 172.1 ± 11.96 nm. The median inhibition concentration (IC50) of graphite particles was 46.75 µg/mL. Notably, 25 and 50 µg/mL concentrations resulted in significant GSH depletion and MDA production. The high concentration of graphite particles (200 µg/mL) led to OGG1 suppression and increased MTH1 expression. Based on these findings, graphite exposure may induce toxicity in human lung cells by increasing oxidative stress. Further research is necessary to fully understand the mechanisms underlying graphite toxicity.


Subject(s)
Cell Survival , Epithelial Cells , Graphite , Oxidative Stress , Particle Size , Humans , Graphite/toxicity , Oxidative Stress/drug effects , Cell Survival/drug effects , Epithelial Cells/drug effects , Iron/toxicity , Lung/drug effects , Lung/cytology , A549 Cells , DNA Glycosylases/genetics , Air Pollutants, Occupational/toxicity , Air Pollutants, Occupational/analysis , Metallurgy
8.
Int J Environ Health Res ; : 1-10, 2023 Nov 12.
Article in English | MEDLINE | ID: mdl-37952631

ABSTRACT

This study was designed to study dual risk of MWFs and vibration according to exposure simulation of selected industry. Air samples of two types MWFs were evaluated according to NIOSH 5026. Vibration acceleration exposure was assessed based on the ISO 8041:2005 standard. Cell treatment of both MWF air samples and vibration as the same as dual exposure to MWF airborne and vibration was assessed. There is a potency of nitrosamine formation in airborne samples of ethylamine containing MWF, while heterocyclic including bore is found in airborne bore containing MWF. DNA breaks caused by boron-containing MWF were higher than nitrosamine air samples. Oxidative stress production and chronic inflammation were highlighted in the response to cell treatments. The risk of cell toxicity in machining workers was evaluated at a level lower than the occupational exposure limit for MWFs and vibration.

9.
Asian Pac J Cancer Prev ; 24(7): 2245-2252, 2023 Jul 01.
Article in English | MEDLINE | ID: mdl-37505753

ABSTRACT

OBJECTIVE: This study was performed to assessment the health and carcinogenic risk of exposure to by-products of photocatalytic degradation of toluene in a spouted bed reactor Equipped with porous and non-porous draft tube. METHODS: For this purpose, titanium dioxide nanoparticles were used as photocatalysts and UV lamps as radiation sources. Degradation efficiency and CO2 selectivity were compared. By-products were also detected in three spouted bed reactors with and without a porous and non-porous draft tube. RESULT: The results revealed that the degradation efficiency of toluene in the spouted bed reactor without a draft tube was 30.75%. The insertion of porous and non-porous draft tubes in the spouted bed reactor increased the degradation efficiency up to 54.88% and 47.63%, respectively. Meantime, CO2 selectivity decreased from 100% to 50.8% within 180 min irradiation time in the spouted bed reactor without draft tube, while in the spouted bed reactors with porous and non-porous draft tube maintained at 89.85% and 84.35%, respectively. Toluene and four by-products with carcinogenic and non-carcinogenic risk of 0.002176 and 182.2, respectively, were detected in the spouted bed reactors without draft tube. However, no by-products with carcinogenic risk were found in the spouted bed reactor with porous and non-porous draft tube. CONCLUSION: photocatalytic degradation of toluene in a spouted bed reactor without a draft tube produces by-products with health and carcinogenic risks. The insertion of a porous and non-porous draft tube in spouted bed reactors provided mineralization more complete than spouted bed reactor without a draft tube by reducing the dead zone and providing appropriate contact between the toluene, photocatalyst, and UV. Therefore, prevent the formation of dangerous and carcinogenic by-products.


Subject(s)
Carcinogens , Toluene , Humans , Carbon Dioxide , Catalysis , Titanium
10.
Int J Environ Health Res ; 33(12): 1269-1277, 2023 Dec.
Article in English | MEDLINE | ID: mdl-35674128

ABSTRACT

This study has suggested an occupational exposure limit (OEL) based on the co-exposure approach in an iron-foundry industry. Respirable dust was collected in an iron casting industry using the NIOSH 0600 method. The DNA damage was obtained by comet assay. The lower confidence interval of the benchmark dose (BMDL) was employed for exposure limit evaluation. The estimated BMDL of the cell line was extrapolated to human subjects. Based on the Hill model, a BMDL 1.65 µg for chemical mixture has been estimated for the A549 cell line. According to uncertainty factors, permitted daily exposure (PDE) was predicted in humans. However, PDE of 3.9 µg/m3 was specified as the time-weighted average limit for toxic respirable dust in the casting industry. In this study, OEL for active respirable dust in the casting industry has been proposed. The industry-based standard for active respirable dust has been proposed for better management of co-exposure.


Subject(s)
Air Pollutants, Occupational , Occupational Exposure , Humans , Occupational Exposure/analysis , Dust/analysis , Industry , Iron , Inhalation Exposure/analysis , Environmental Monitoring/methods
11.
Xenobiotica ; 52(4): 370-379, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35608272

ABSTRACT

Although the toxic effects of urban airborne particulate matter (PM) have been known on lung cells, there is less attention to co-exposure to PM and extremely low frequency magnetic (ELF-MF) in occupational settings. The present study investigated the influences of PM and ELF-MF co-exposure on toxicity in human lung cells (A549).In this case, total PM (TPM) was evaluated according to NIOSH-0500. The TPM SiO2 and metal contents were determined based on NIOSH-7602 and 7302, respectively. Besides, 900 mG ELF-MF exposure was simulated based on field measurements. The toxicity mechanisms were assessed by examining malondialdehyde, glutathione ratio, gene expression, and DNA strand breaks. Also, the toxicity indicators of the TPM samples were MDA generation, glutathione depletion, and DNA damage, and their impacts were analysed at doses below the LD50 (4 µg).In addition, gene expression of OGG1 and MTH1 was upregulated after TPM exposure at the lowest dose (2 µg). But ITPA was upregulated in the presence of ELF-MF. The co-exposure to TPM and ELF-MF decreased oxidative stress and DNA damage levels compared to a single exposure to TPM.Although the ELF-MF reduced toxicity in response to TPM, this reduction was not lower than the unexposed cells.


Subject(s)
Particulate Matter , Silicon Dioxide , Glutathione/metabolism , Humans , Lung/metabolism , Magnetic Fields , Particulate Matter/toxicity
12.
Toxicol Ind Health ; 38(5): 270-276, 2022 May.
Article in English | MEDLINE | ID: mdl-35465785

ABSTRACT

Exposure to aerosols has been found to be linked to respiratory impairment. Although the effects of both indoor and outdoor exposures to particulates have been extensively reported, exposures to mists are less studied. Herein, we reported a survey of mineral oil mist toxicity in an occupational exposure scenario. For the purpose of this study, 65 lathe workers of the metal processing industry, as mineral oil mist-exposed population, were studied. Thereafter, the participants' age, smoking habits and work experience were matched with those of the control workers (n = 65) who were not occupationally exposed to mist. Thereafter, air samples were evaluated from the breathing zone of the workers using NIOSH method 5026. Plasma Interleukin-1ß as a pro-inflammatory indicator was assessed in all the studied subjects. Mean ± standard deviation of mineral oil mist time-weighted average exposure in lathe workers was 7.10± 3.49 mg/m3. IL-1ß cytokine levels were significantly higher in the lathe groups compared to the control group. The mean level of Interleukin-1ß in the control subjects (2922 pg/L) was selected as the cut-off point of the inflammation effect. Based on this pro-inflammatory point, the results of monitoring showed that 60% of the exposed were affected. A Spearman correlation was also found between mineral oil mist exposure and inflammation in the affected subjects. Our findings highlighted the immunological potential of mineral oil mist in occupational exposure. Overall, the results of this study suggested that Interleukin-1ß evaluation in mineral oil mist exposure could be considered as both an acute and chronic inflammation marker.


Subject(s)
Air Pollutants, Occupational , Occupational Exposure , Air Pollutants, Occupational/toxicity , Humans , Inflammation/chemically induced , Interleukin-1beta , Mineral Oil/analysis , Mineral Oil/toxicity , Occupational Exposure/adverse effects , Occupational Exposure/analysis
13.
Toxicol Rep ; 8: 1948-1954, 2021.
Article in English | MEDLINE | ID: mdl-34917486

ABSTRACT

The present study aims to investigate the effects of co-exposure to heat and psychological stress on sperm DNA and semen parameters among male rats. The study was conducted on 40 healthy adult male Wistar rats. The rats were randomly categorized into four groups of same size consisting of a control group, a heat stress, psychological and co-exposure groups. The heat stress group was exposed to a temperature of 36 °C at 20% relative humidity. The psychological stress exposure group was subjected to three stressors including exposure to strobe light, noise and tilting cage. According the results,the co-exposure group had lower mean sperm parameters including sperm count (17.22 ± 4.22 106/ml), motility (42.63 ± 12.95 %), viability (48.50 ± 23.25 %), normal morphology (56 ± 7.5%), progressive motility (11.61 ± 7.81%), non-progressive motility (31.18 ± 7.77%), curvilinear velocity (24.11 ± 3.81 µm/s) and straight-line velocity (3.2 ± 1.4 µm/s) when compared with those of the other groups (P = 0.001). Mean sperm immobility (57.36 ± 12.95%) and non-progressive motility (37.93 ± 11.15%) in the co-exposure group was higher compared to the other groups (P = 0.001 and P = 0.333, respectively). Assessment of damage to sperm DNA revealed that the heat exposure group had a higher percentage of sperm DNA damage (9.44 ± 6.80 %) compared to others (P = 0.185). In case of all of exposure scenario, the chance that the semen quality decreased compared to the control group has been increased. In general the combined stress had a greater significant effect on sperm parameters compared to other exposure groups, except for DNA damage.

14.
Int J Prev Med ; 12: 96, 2021.
Article in English | MEDLINE | ID: mdl-34584661

ABSTRACT

BACKGROUND: There is a wide range of challenges through the use of nano-material in buildings. By developing construction industries the use of flame retardant nano-materials is a hurdle for human health. However occupational exposure measurement is not applicable for nano-particles monitoring. Risk assessment is an alternative method for industrial hygiene strategies. In this study, we use the control banding approach for risk assessment of 3 nano-fire retardant (NFR) in the building industry. METHODS: We used control banding as a risk assessment approach for decision making about nano-materials in the building industry. The risk of nano-fire retardants such as monokote accelerator, monokote Z-106 G and monokote Z-106 HY in the construction industry was studied. The level of risk was evaluated by the matrix of hazard severity and probability score. Hazard severity was scored by toxicological information. The probability score was estimated by the state work operation. RESULTS: A score of hazard severity in monokot Z-106 HY was higher than other nano-materials. The probability score of spraying tasks was lower than mixing and transportation tasks. The results show the application of all nano-materials had the higher risk level in transportation and mixing tasks. The risk level of monokote accelerator and monokote Z-106 G in spraying task is lower than monokot Z-106 HY. CONCLUSIONS: There is a high risk level for studied nano-materials in the coating tasks of the construction industry. In conclusion, powerful controlling strategies such as the substitution of nano-materials was suggested to decrease the risk of nano-fire retardants.

15.
Indian J Occup Environ Med ; 25(2): 78-83, 2021.
Article in English | MEDLINE | ID: mdl-34421242

ABSTRACT

CONTEXT: Exposure to bio-aerosols in a variety of environments has been of great interest due to the health effects on humans. Hospitals can be the reservoir of these biological agents because of the presence of infectious patients; which can lead to hospital infections and various occupational hazards. In this way, we assessed bacterial contamination in two teaching hospitals in Tehran. AIMS: Our purpose in this study assessment of bacterial pathogens and their antibiotic resistance in the air of different wards of selected teaching hospitals in Tehran. SETTINGS AND DESIGN: In this study, sampling was done according to NIOSH 0800. METHODS AND MATERIAL: This descriptive study was carried out in the different sections of two hospitals in Tehran. A total of 180 air samples were evaluated according to NIOSH 0800. In each section sampling was performed on the culture media in three stations including primary room, end room, and nursing position then the number of colonies counted. The zone of inhibition was measured in antibiotic disks to determine antibiotic resistance of samples. STATISTICAL ANALYSIS USED: Data analysis was performed using SPSS version 21. Initially, the data were normalized using the Kolmogorov-Smirnov test. The difference between the two hospitals was achieved with Mann-Whitney U test for un-normal distribution data. RESULTS: Bacterial contamination in hospital 2 was significantly higher than the hospital 1(P < 0.001). The median number of colonies in hospital 1 was 129.87 (87.46-268.97) CFU/m3 and 297.97 (217.66-431.85) CFU/m3 for hospital 2. Bacterial contamination in the all of stations in hospital 2 and 87% of samples in hospital 1 was higher than the acceptable range of ACGIH (75 CFU/m3). CONCLUSIONS: High bacterial contamination may be related to a lack of hygiene management and poor ventilation system. It seems effective infection control processes, appropriate ventilation systems and supervision systems should be improved.

16.
Toxicol Ind Health ; 37(8): 504-512, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34247554

ABSTRACT

Foundry workers are exposed to numerous occupational health hazards, which may result in increased risk of cancer, respiratory disease, and other diseases. Oxidative stress is known to be involved in the pathogenesis of such diseases. The present study aimed to investigate the association between multiple occupational exposures in foundry workers and expression of deoxyribonucleic acid (DNA) repair genes as a biomarker of oxidative DNA damage. The study sample comprised 17 foundry workers and 27 matched control subjects. Expression of 8-oxoguanine DNA glycosylase-1 (OGG1), inosine triphosphate pyrophosphate (ITPA), and MutT homolog 1 (MTH1) in peripheral blood was examined using the real-time polymerase chain reaction method. Air sampling to determine exposure to metal-rich particulate matter and measurement of extremely low-frequency electromagnetic fields (ELF-EMFs) were conducted according to the National Institute for Occupational Safety and Health standard methods. Personal air sampling revealed that occupational exposure to particulate matter exceeded the threshold limit values (TLVs) in 76% of the workstations, whereas ELF-EMF exposure appeared to be lower than the TLV. ITPA was significantly upregulated in foundry workers compared with control subjects, whereas no significant difference was observed for OGG1 and MTH1. Moreover, ITPA was strongly and positively correlated with the concentration of metal-rich particulate matter in foundry workers. No significant correlation was found between ELF-EMF exposure and expression of DNA repair genes. DNA repair gene expression may be a sensitive biomarker for occupational exposures, which suggests an involvement of oxidative stress in metal-induced toxicity. Further studies are needed to determine the role of DNA repair gene expression in response to occupational/environmental hazards.


Subject(s)
DNA Damage , Electromagnetic Fields/adverse effects , Metals, Heavy/adverse effects , Occupational Exposure/adverse effects , Particulate Matter/adverse effects , Adult , Biomarkers/blood , Case-Control Studies , DNA Glycosylases/blood , DNA Repair Enzymes/blood , Humans , Iran , Male , Metallurgy , Middle Aged , Occupational Exposure/analysis , Oxidative Stress , Particulate Matter/analysis , Phosphoric Monoester Hydrolases/blood , Pyrophosphatases/blood
17.
Environ Sci Pollut Res Int ; 28(41): 58781-58786, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34120293

ABSTRACT

Mixtures of organic solvents are widely used in industrial processes. Risk assessment for chemical co-exposure has always been a challenge in past years. The present study aims to employ principle component analysis (PCA) to produce an entry for benchmark dose approximation in shoemakers based on the color vision effect. A total of 134 subjects consisting of 67 shoemakers and 67 staff workers were employed for Benchmark Dose (BMD) evaluation. Occupational exposure to benzene, toluene, xylene, and n-hexane was evaluated using NIOSH 1501 and OSHA ID-07 methods. The color vision effect was quantified using Lanthony D-15 desaturated test (D-15d). PCA was run for cumulative exposure dose (CED) of the solvents by MATLAB 2018. Finally, the lowest 95% confidence limit of the benchmark dose (BMDL) was determined using US EPA benchmark dose software (BMDS) version 3.2.1. The color confusion index (CCI) level in shoemakers increased from 1 to 1.15 by a median of 1.07. There was a significant difference in the CCI level (p value<0.0001) between exposed and control subjects. The first score of PCA was used as intake dose level (IDL) in solvents co-exposure. Using BMD analysis, the log-logistics model was fitted with a p-value> 0.1 and the lowest BMDL level. BMDL level was evaluated at 1.63, 10.25, 2.21, and 3.35 ppm for benzene, toluene, xylene, and n-hexane, respectively. The results showed a risk of color vision effect with co-exposure to solvents at different levels in the occupational exposure standards. In conclusion BMDL-PCA approach has been suggested for the risk assessment of chemical co-exposure.


Subject(s)
Color Vision Defects , Occupational Exposure , Benchmarking , Humans , Occupational Exposure/analysis , Risk Assessment , Toluene
18.
Toxicol Res (Camb) ; 10(1): 134-140, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33613980

ABSTRACT

Several studies have shown that tea consumption is associated with beneficial effects on human health, which is mainly explained by the antioxidant properties of tea. However, evidence on the effect of nutrition interventions on oxidative stress in an occupational setting is limited. Therefore, the present study aimed to investigate the effect of tea consumption on oxidative stress in noise-exposed metal press workers. The study sample comprised 24 metal press workers and 24 age-matched control subjects. Metal press workers were assigned to the intervention group consisting of a glass of jujube tea and a portion of raisins per day for 4 weeks. Full-shift noise dosimetry was performed to measure noise exposure with average noise levels of 89.91 ± 2.92 dB for metal press workers and 61.54 ± 1.03 dB for control subjects. Elevated levels of baseline oxidative stress were observed in metal press workers compared with control subjects as indicated by significantly decreased levels of total antioxidant capacity (TAC) (P = 0.026) and total thiol groups (TTG) (P = 0.0001), whereas no significant difference was observed in case of malondialdehyde (MDA). Intervention with jujube tea and raisins in metal press workers led to a decrease of oxidative stress as displayed by increased levels of TAC and TTG (P = 0.0001) as well as decreased levels of MDA (P = 0.012). Moreover, the intervention significantly altered expression of repair genes in metal press workers as demonstrated by decreased levels of OGG1 (P = 0.0002) and ITPA (P = 0.009), whereas no significant difference was observed in case of MTH1. These data suggest that regular tea consumption may protect occupational noise-exposed subjects from oxidative damages.

19.
Tanaffos ; 20(3): 240-245, 2021 Mar.
Article in English | MEDLINE | ID: mdl-35382077

ABSTRACT

Background: Ventilation system besides other prevention strategies such as surface disinfecting and personal protective equipment (PPE) decrease the risk of coronavirus disease 2019 (COVID-19) infection. This study aimed to examine the ventilation system of an intensive care unit (ICU) in a hospital in Tehran, Iran to evaluate the potency of heating, ventilation, and air conditioning system (HVAC) for COVID-19 spread. Materials and Methods: Contamination of air turnover caves was evaluated in supplier diffuser and extractor grills of negative pressure HVAC by ten samples. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the samples was evaluated by the real time reverse transcription-polymerase chain reaction (PCR). Moreover, air conditioning and sick building syndrome (SBS) was assessed according to MM040EA questioning from health care workers. Results: In the health care workers, respiratory effects were more prevalent compared to other signs. Despite suitable air conditioning, this study highlighted carrier potency of ICU workers for SARS-COV-2. Conclusion: According to our results, although the HVAC of ICU ward had an appropriate air movement, it was not safe enough for health care workers.

20.
Environ Sci Pollut Res Int ; 27(36): 45374-45380, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32789635

ABSTRACT

Previous studies have shown the effect of extremely low-frequency (ELF) magnetic fields on the hematopoietic system. However, molecular modification and biological toxicity are not known yet. The aim of this study was to investigate the effect of occupational exposure to ELF magnetic field on the hemoglobin and DNA alteration using Fourier transform infrared (FTIR) spectroscopy. Twenty nine individuals were selected among those working as the controller in a powerhouse in order to be studied as the population exposed to ELF magnetic field. Control group comprised of 29 administrative employees voluntarily participated who were matched with the exposed subjects in terms of sex, age, work experiences, smoking habit, and socioeconomic status. DNA and hemoglobin were extracted from blood samples and then were studied by FTIR spectroscopy. The results showed the level of magnetic field exposure was between 0.38 to 50 µT in the exposed subjects while the level of magnetic field exposure was between 0.19 and 20 µT for the unexposed people. Hemoglobin level was equal to 15.67 ± 1.42 g/dL for exposed subjects which is significantly lower than that of the unexposed people (p = 0.0001). There was a significant alteration in CH content and COO structure of the hemoglobin structure. Moreover, DNA showed significant changes by functional group of organic base. This change in the structure of DNA and hemoglobin can lead to the creation of risks in human health. In conclusion, FTIR method could reveal the quality of DNA and hemoglobin structure in subjects after exposure to ELF magnetic field.


Subject(s)
Magnetic Fields , Occupational Exposure , DNA , Electromagnetic Fields , Hemoglobins , Humans , Occupational Exposure/analysis , Spectroscopy, Fourier Transform Infrared
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