The effects of noise on hearing and oxidative stress in textile workers

Click evoked otoacoustic emissions in occupational exposure to lead, concentrations of selected essential elements and markers of oxidative stress

PURPOSE

This study focused on the selected markers of oxidative stress, impact of elevated lead levels on long-term hearing quality. We investigated whether the presence of certain essential minerals might provide protection to the auditory system against the effects of lead (and cadmium) compounds.

METHODS

The research group included 280 male employees of the zinc and lead smelter, which was divided into: L-Pb-low blood lead concentration (PbB) subgroup, H-Pb-high PbB subgroup. Hearing tests were performed using the click evoked otoacoustic emission (CEOAE).

RESULTS

Zinc protoporphyrin level was significantly higher in the H-Pb subgroup by 68%. Cd concentration was significantly higher in H-Pb by 33%. The Ca concentration was significantly lower in the H-Pb by - 2%. Selected oxidative stress markers concentration were significantly higher in the H-Pb group: malondialdehyde (MDA) by 4%, and lipofuscin (LPS) by 9%. In the CEOAE results showed statistically significant differences between the L-Pb and H-Pb subgroups. Larger negative changes in otoemission amplitude were observed in H-Pb subgroup. All otoemission results showed a statistically significant negative correlation with age, time of work, MDA concentration, and with PbB. Selected CEOAE parameters showed a significant negative correlation with cadmium blood concentration (CdB), and a positive correlation with Ca and Zn.

CONCLUSION

Elevated blood lead content in occupational exposure is associated with an increase in MDA and LPS concentration, which negatively correlates with CEOAE parameters. This suggests an important role of oxidative stress in the long-term deterioration of hearing.

Noise exposure and the risk of cancer: a comprehensive systematic review

The association between noise exposure and increased risk of cancer has received little attention in the field of research. Therefore, the goal of this study was to conduct a systematic review on the relationship between noise exposure and the incidence of cancer in humans. In this study, four electronic bibliographic databases including Scopus, PubMed, Web of Science, and Embase were systematically searched up to 21 April 2022. All types of noise exposure were considered, including environmental noise, occupational noise, and leisure or recreational noise. Furthermore, all types of cancers were studied, regardless of the organs involved. In total, 1836 articles were excluded on the basis of containing exclusion criteria or lacking inclusion criteria, leaving 19 articles retained for this study. Five of nine case-control studies showed a significant relationship between occupational or leisure noise exposure and acoustic neuroma. Moreover, four of five case-control and cohort studies indicated statistically significant relationships between environmental noise exposure and breast cancer. Of other cancer types, two case-control studies highlighted the risk of Hodgkin and non-Hodgkin lymphoma and two cohort studies identified an increased risk of colon cancer associated with environmental noise exposure. No relationship between road traffic and railway noise and the risk of prostate cancer was observed. In total, results showed that noise exposure, particularly prolonged and continuous exposure to loud noise, can lead to the incidence of some cancers. However, confirmation of this requires further epidemiological studies and exploration of the exact biological mechanism and pathway for these effects.

Bats experience age-related hearing loss (presbycusis)

Hearing loss is a hallmark of aging, typically initially affecting the higher frequencies. In echolocating bats, the ability to discern high frequencies is essential. However, nothing is known about age-related hearing loss in bats, and they are often assumed to be immune to it. We tested the hearing of 47 wild Egyptian fruit bats by recording their auditory brainstem response and cochlear microphonics, and we also assessed the cochlear histology in four of these bats. We used the bats' DNA methylation profile to evaluate their age and found that bats exhibit age-related hearing loss, with more prominent deterioration at the higher frequencies. The rate of the deterioration was ∼1 dB per year, comparable to the hearing loss observed in humans. Assessing the noise in the fruit bat roost revealed that these bats are exposed to continuous immense noise-mostly of social vocalizations-supporting the assumption that bats might be partially resistant to loud noise. Thus, in contrast to previous assumptions, our results suggest that bats constitute a model animal for the study of age-related hearing loss.

Long-term exposure to traffic noise and risk of incident colon cancer: A pooled study of eleven Nordic cohorts

Background Colon cancer incidence is rising globally, and factors pertaining to urbanization have been proposed involved in this development. Traffic noise may increase colon cancer risk by causing sleep disturbance and stress, thereby inducing known colon cancer risk-factors, e.g. obesity, diabetes, physical inactivity, and alcohol consumption, but few studies have examined this. Objectives The objective of this study was to investigate the association between traffic noise and colon cancer (all, proximal, distal) in a pooled population of 11 Nordic cohorts, totaling 155,203 persons. Methods We identified residential address history and estimated road, railway, and aircraft noise, as well as air pollution, for all addresses, using similar exposure models across cohorts. Colon cancer cases were identified through national registries. We analyzed data using Cox Proportional Hazards Models, adjusting main models for harmonized sociodemographic and lifestyle data. Results During follow-up (median 18.8 years), 2757 colon cancer cases developed. We found a hazard ratio (HR) of 1.05 (95% confidence interval (CI): 0.99-1.10) per 10-dB higher 5-year mean time-weighted road traffic noise. In sub-type analyses, the association seemed confined to distal colon cancer: HR 1.06 (95% CI: 0.98-1.14). Railway and aircraft noise was not associated with colon cancer, albeit there was some indication in sub-type analyses that railway noise may also be associated with distal colon cancer. In interaction-analyses, the association between road traffic noise and colon cancer was strongest among obese persons and those with high NO₂-exposure. Discussion A prominent study strength is the large population with harmonized data across eleven cohorts, and the complete address-history during follow-up. However, each cohort estimated noise independently, and only at the most exposed façade, which may introduce exposure misclassification. Despite this, the results of this pooled study suggest that traffic noise may be a risk factor for colon cancer, especially of distal origin.

Combined effects of the exposure to silver nanoparticles and noise on hearing function and cochlea structure of the male rats

AIMS

This study intended to investigate whether exposure to the combination of noise and Ag-NPs in rats induces cochlear damage and hearing dysfunction.

MAIN METHODS

A total of 24Wistar rats were divided into four treatment groups and received/exposed to saline (IP), Ag-NPs (100 mg/kg, 5d/w for 4 weeks), 8 kHz narrowband noise (104 dB SPL, 6 h/day, 5d/w for 4 weeks) and Ag-NPs plus noise. The DPOAE, serum levels of MDA and SOD and changes in body weight were assessed. The rat cochlea was further stained for investigating the mRNA expression (TL-6, NOX3, and TNF-), IHC (TUJ-1 and MHC7), and histological alterations. The Ag-NPs characteristics were also analysed by SEM and XRD.

KEY FINDINGS

DPOAE values were remarkably reduced (p < 0.05) among the exposed groups. Furthermore, exposure to noise and Ag-NPs significantly increased MDA levels and decreased the SOD activity in the serum. In comparison to the control group, the expression of IL-6, TNF-, and NOX3 was shown to be elevated in the Ag-NPs plus noise group. The body weight also increased significantly in all groups with the exception of the Ag-NPs plus noise group. IHC tests showed remarkable down-regulation of TUJ1 and MYO7A. Morphological changes confirmed our findings as well. SEM and XRD data validated the production of Ag-NPs.

SIGNIFICANCE

According to the findings of this study, sub-acute exposure to noise and Ag-NPs causes permanent damage to the hair cells that are in charge of high-frequency perception.

Evaluation of oxidative stress and biochemical biomarkers, and psychological parameters in cement plant workers

The cement industry is one of the main world industries with exposure to a wide range of hazardous chemical and physical occupational agents that may increase free radicals and lead to disease. The aim of this study was to evaluate oxidative stress, biochemical markers, and psychological parameters among cement plant workers. In this cross-sectional study, 40 workers exposed to cement and 40 office employees were selected as the exposed and non-exposed groups, respectively. Exposure to cement dust, silica, and noise were, respectively, assessed using the NIOSH 0600, NIOSH 7601, and noise dosimetry methods. Oxidative stress biomarkers including malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (TAC), and biochemical parameters were measured in the serum of all participants. Depression, anxiety, and stress were assessed by the Depression Anxiety Stress Scales (DASS-21) questionnaire. The results demonstrated that the level of MDA as a marker of oxidative stress was significantly higher in the exposed group. The level of antioxidant enzymes including SOD and CAT were also significantly higher in the exposed group. The level of TAC was lower in the exposed group, but the difference was not statistically significant. The levels of alkaline phosphatase (ALP), aspartate transaminase (AST), and the scores of depression and stress were also significantly higher in the exposed group. According to our results, noise, cement dust, and silica exposure were associated with oxidative stress, and this may be one of the mechanisms in which they adversely affect liver function and mental health.

The combined effects of noise and vibration stress on sex hormone levels, fertility capacity, and the protective role of cinnamon extract in rats: an experimental study

Due to the high prevalence of noise and vibration exposure in most industries, this study aimed to investigate the effects of simultaneous exposure to noise and vibration on sex hormone levels and fertility capacity in rats, as well as the protective effects of the hydroalcoholic extract of cinnamon. In this experimental study, 64 adult male rats were randomly divided into 8 groups, control, noise (N), cinnamon (C), noise + cinnamon (NC), vibration (V), vibration + cinnamon (VC), noise + vibration (NV) and groups Noise + Vibration + Cinnamon (NVC). Groups C, NC, VC and NVC received a 75 mg/kg dose of cinnamon extract by gavage. The rats of groups N and NC, V and VC and NV and NVC were each exposed to noise at 100 dB (700-5700 Hz), vibration acceleration of 1 m/s² rms (frequency range of 4-8 Hz), and simultaneously exposed to vibration and noise for 8 hours continuously every night (23:00-7:00) for 50 consecutive nights. Next, a blood sample was taken from the lateral tail vein and the levels of LH, FSH and testosterone were measured with ELISA kits. Each male rat was caged with 3 female rats for one week. The pregnant rats were kept until all of the rat pups were born. Then the fertility capacity, the total number of births, the live births and the birth weight of the rat pups were analyzed with the software SPSS. In the N and NV groups, compared to the control group, a significant decrease in LH and testosterone levels, the number of births and the birth weight was observed (p < 0.05). A significant decrease in testosterone levels, number of births and birth weight was observed in Group V compared to the control group (p < 0.05). In addition, significant increases in LH, FSH and testosterone levels and in birth weight were observed in group C compared to the control group (p < 0.05). Significant increases in FSH and testosterone levels, birth weight, and the number of births were noted in the NVC group compared to the NV group (p < 0.05). Based on the results of this study, cinnamon extract could alleviate the destructive effects of noise and vibration (both individually and in combination) on levels of sex hormones (LH, FSH, and testosterone), the number of births, and birth weight.

Health Concerns of Textile Workers and Associated Community

Background: Workers in the textile industry risk developing various respiratory and pulmonary diseases due to exposure to cotton dust. The particles from the cotton lint are inhaled by the workers and results in the breathing problems including asthma, shortness of breath, cough and tightness in the chest. The poor health of labor contributes to the low productivity of the labor and in serious cases loss of jobs leading to the poverty. Objective: To assess the prevalence of respiratory symptoms among the textile workers and associated community. To contrast the health profiles of the textile workers, associated community and the control group to factor out any confounding factors. Methods: This study explores the health profiles of the textile workers and associated community and contrast them against the health profile of the control group to factor out any confounding factors. The study is conducted on cotton industry in Kasur, Pakistan. We interviewed 207 workers, 226 people from associated community (living in vicinities of weaving units) and 188 people for control group (from areas far away from weaving units and people are not associated with weaving industry) based on stratified random sampling technique. We employed descriptive methods and logistic regression to explore the association between respiratory diseases and weaving workers. Results: Overall, prevalence of postnasal drip, byssinosis, asthma, and chronic bronchitis were 47%, 35%, 20%, and 10%, respectively, among the workers. These percentages are significantly higher than the control group. An additional year of work increase the risk of postnasal drip, byssinosis, asthma, and chronic bronchitis by 5–6%. Among workers, 43% and 21% feel difficulty in hearing against noisy background and at low volume, respectively. Due to bad light arrangements at workstations, 21% and 31% workers are suffering from myopia and hyperopia, respectively. Proportions of the workers suffering from continuous headache, skin infection, depression, and low back pain are 28%, 29%, 27%, and 44%, respectively. Chi-square test results confirms that no confounding factor like air pollution is involved in this cause-and-effect study implying the association between the cotton dust and associated diseases is not spurious. Conclusion: Respiratory symptoms were statistically significantly more common in the weaving workers compared to control group. Better environment at workstations, use of protective gears and education are the factors which reduce the risk of associated diseases among workers.

The relationship among noise, total oxidative status and DNA damage

PURPOSE

Noise is one of the major environmental health problems and is defined as any unpleasant sound. It was shown that prolonged exposure to noise was associated with progress of diseases. There is no study evaluating the effect of noise on the oxidative parameters of Total Antioxidant Capacity (TAC), Total Oxidant Status (TOS) and DNA damage.

AIM

This study aimed to evaluate the effect of noise on TOS, TAC and DNA damage.

METHODS

In this study, we included 100 textile factory workers affected by noise as a noise group, and 56 healthy volunteers employed as office workers in our hospital who were not exposed to noise as the control group. Blood samples were obtained from both the groups. Oxidative Stress (OS) was measured by Oxidative stress index (OSI), TOS and TAC. The DNA damage level was measured by 8-Hydroxydeoxyguanosine (8-OHdG).

RESULTS

8-OHdG (21.8 ± 12.0 vs. 14.7 ± 5.6 pg/ml, p = 0.001),TOS (14.1 ± 2.5 vs. 10.9 ± 1.5 mol H2O2 equivalent/l, p < 0.001), TAC (0.96 ± 0.19 vs. 1.54 ± 0.28 Trolox equivalent/l, p < 0.001) and OSI (1.52 ± 0.37, etc. 0.76 ± 0.35 arbitrary units, p < 0.001) were significantly higher in noise group compared to control group. Linear regression analysis showed that noise was the independent predictor of DNA damage (β = 0.310, p < 0.001).

CONCLUSION

In this study, we showed that TOS and DNA damage were significantly higher in subjects exposed to noise when compared with subjects of the control group. Noise was the only independent predictor of the DNA damage. Therefore, early detection of DNA damage and increased OS, early corrective measures may delay the development and progression of diseases such as hypertension, arrhythmias.

Correlation of SOD and MDA Expression in the Organ of Corti and Changes in the Function of Outer Hair Cells Measured by DPOAE Examination in Noise-Exposed Rat Cochlea

BACKGROUND

Hearing loss due to noise can cause the disturbances toward the quality of life and cause mechanical damage and metabolic decompensation. Distortion Product Otoacoustic Emission (DPOAE) is an examination to assess the sensory function of outer hair cells. Superoxide Dismutase (SOD) and Malondialdehyde (MDA) are markers of oxidative stress. The aim of this study was to identify the correlation between DPOAE examination and SOD and MDA expression in rats exposed to noise.

METHODS

This research was conducted on 27 rats which were divided into 3 groups, group 1 (control), group 2, and group 3 were groups with 100 dB and 110 dB noise exposure respectively.

RESULTS

Our findings show a decrease in SOD expression and DPOAE values as well as an increase in MDA expression in rats exposed to noise and there is a positive correlation between Signal to Noise Ratio (SNR) value with SOD expression (r= 0.733, p= 0.025) and a negative correlation between SNR value with MDA expression (r= -0.678, p= 0.045).

CONCLUSION

our study find the correlation of oxidant and antioxidant status values in the organ of corti and changes in the function of outer hair cells in noise-exposed rat models.

The effect of noise and dust exposure on oxidative stress among livestock and poultry feed industry workers

INTRODUCTION

Simultaneous exposure to noise and dust may have detrimental health effects. This study was conducted to determine the effect of exposure to noise and dust on oxidative stress.

METHODS

In this cross-sectional study, 82 employees of two livestock and poultry feed factories in Golestan Province, Iran, were selected as the exposed group and 82 office workers were selected as the control group. Occupational noise and dust exposure were measured using a dosimeter, sampling pump, and vinyl chloride filter. Oxidative stress was determined by measuring the levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in blood samples. T-tests, one-way analysis of variance, and multivariate linear regression were used to analyze the data.

RESULTS

The levels of MDA and SOD in the exposed group were significantly higher and lower than the control group (p < 0.001), respectively. The results showed the subgroup with both over the threshold dust and noise exposure had the highest MDA levels. The SOD level among those exposed to noise more than the recommended level, in the subgroup with more dust exposure, was significantly less than the subgroup with low noise exposure (p = 0.017).

CONCLUSION

Noise and dust exposure probably increase the level of oxidative stress by increasing the level of lipid peroxidation (MDA) and reducing the level of antioxidant enzymes (SOD).

Environmental cue affects the hearing-related behaviors of Drosophila melanogaster by targeting the redox pathways

Environmental cues like noise, pressure, and circadian rhythm can affect the hearing ability of human beings. Nevertheless, the complex physiology of the human being does not allow us to understand how these factors can affect hearing and hearing-related behaviors. Conversely, these effects can be easily checked using the hearing organ of Drosophila melanogaster, the Johnston organ. In the current study, the Drosophila was exposed to challenging environments like noise, low pressure, and altered circadian rhythm. The hearing organ of larvae, as well as adults, was analyzed for hearing-related defects. In the third instar larva, the cell deaths were detected in the antenna imaginal disc, the precursor of Johnston's organ. Elevated levels of reactive oxygen species and antioxidant enzymes were also detected in the adult antennae of environmentally challenged flies. The ultrastructure of the antennae suggests the presence of abundant mitochondria in the scolopidia of control. Fewer amounts of mitochondria are found in the environmentally challenged adult antennae. In adults, various hearing-related behaviors were analyzed as a readout of functionality of the hearing organ. Analysis of climbing, aggressive, and courtship behaviors suggests abnormal behavior in environmentally challenged flies than the control. The current study suggests that the environmental cues can alter hearing-related behaviors in Drosophila. The methods used in this study can be used to monitor the environmental pollution or to study the effect of alteration of noise, pressure, and circadian rhythm on hearing-related behaviors taking Drosophila melanogaster as a model organism. Graphical abstract.

Recurrent Indoor Environmental Pollution and Its Impact on Health and Oxidative Stress of the Textile Workers in Bangladesh

Perennial indoor environmental pollution in the textile industrial area is a potential health hazard for workers engaged in this line of work, resulting in mental aberration to severe health risks. This study was designed to investigate the indoor environmental quality of textile industries and correlate its effect on the occupational health and well-being of the textile workers by measuring plasma oxidative stress status in textile workers and healthy control subjects. Environmental samples were collected from 15 textile industries located in Dhaka division, and 30 volunteer textile workers and 30 volunteer office workers (control) aged 18 to 57 years participated in the study. The concentration of plasma ascorbic acid (P-ASC), plasma malondialdehyde (P-MDA), and plasma conjugated diene (P-CD) was measured in both groups. The noise level (78.0 ± 0.68 dB) and the formaldehyde level (141.80 ± 4.47 µg/m³) were found to be significantly higher in the indoor environmental area compared with those in the control area (70.17 ± 0.25 dB and 108.0 ± 0.76 µg/m³, respectively). Furthermore, the daily average concentration of suspended particulate matters (PMs), that is, PM_2.5 (322.2 ± 13.46 µg/m³) and PM₁₀ (411.0 ± 17.57 µg/m³), was also found to be significantly higher in the indoor environmental air compared with that in the control area (78.59 ± 1.66 and 174.0 ± 2.33 µg/m³, respectively). The levels of P-MDA (0.37 ± 0.03 nmol/L) and P-CD (14.74 ± 0.61 nmol/L) were significantly increased, whereas the level of P-ASC level (0.46 ± 0.04 mg/dL) was markedly decreased in the textile workers compared with the healthy control subjects (0.18 ± 0.01 nmol/L of P-MDA, 10.04 ± 0.44 nmol/L of P-CD, and 1.29 ± 0.06 mg/dL of P-ASC). The textile plants were found to have significantly elevated levels of indoor environmental pollutants compared with those in the control area, and the textile workers were significantly exposed to oxidative stresses compared with the control subjects. The use of noise pads and high-efficiency air filters is perhaps highly instrumental to put an end to this prevailing situation. Moreover, to overcome the oxidative stresses among workers, supplementation of antioxidant vitamins (ie, ascorbic acid and/or vitamin E) may be beneficial. In addition, to prevent serious health-related issues, proper precautions should be taken to protect the occupational health of the textile workers.

Effect of myricetin on the gene expressions of NOX3, TGF-β1, prestin, and HSP-70 and anti-oxidant activity in the cochlea of noise-exposed rats

Objective(s):

Noise-induced hearing loss is one of the most common occupational diseases in industrialized countries and can be affected by various environmental and genetic factors. This study was designed to examine the effect of myricetin in preventing this disorder.

Materials and Methods:

Twenty-one Wistar rats were randomly divided into five groups: Non-exposed, noise exposure only, noise exposure with vehicle, noise exposure with myricetin 5 mg/Kg, and noise exposure with myricetin 10 mg/kg. All animals were sacrificed after last noise exposure. The left cochlea was dissected from each rat. It was used for mRNA expression analysis (NOX3, TGF-β1, prestin, and HSP-70). Blood samples were collected to assess superoxide dismutase (SOD) activity, 1, 1 diphenyl picrylhydrazyl (DPPH), and malondialdehyde (MDA) measurements.

Results:

Real time-PCR assay revealed that noise decreased NOX3 and increased TGF-β1, prestin, and HSP-70 gene expressions. Administration of myricetin at the dose of 5 mg/kg, but not at 10 mg/kg, significantly reversed these changes. Noise also increased MDA levels and decreased SOD and DPPH scavenging activities. Myricetin at the doses of 5 and 10 mg/kg also reversed these changes.

Conclusion:

The findings of this study showed that myricetin at the dose of 5 mg/Kg was able to reverse noise-induced abnormalities in gene expression and oxidant/anti-oxidant balance. It is a possibility that myricetin via enhancement of anti-oxidant activity induced these effects.

Exposure to occupational noise and periodontitis in Korean workers

BACKGROUND

Chronic exposure to occupational noise is reported to cause a wide range of health problems. But, there are no reports on studies investigating the association between noise exposure and periodontitis. The purpose of this study was to examine the relationship between occupational noise exposure and periodontitis in a nationally representative sample of Korean workers.

METHODS

This cross-sectional study used data from the 4^th Korean National Health and Nutrition Examination Survey. The study sample included 8,927 workers aged 19 to 54 years. Noise exposure assessment was performed by using self-report questionnaires. The dependent variable was periodontitis. Age, sex, perceived stress level, place of residence, income, education, health behaviors (frequency of daily toothbrushing, binge drinking, smoking status, regular dental checkup), diabetes, obesity, and white blood cell count were included as covariates. Logistic regression analyses estimated the association between noise exposure and periodontitis after sequential adjustment.

RESULTS

Compared with never-exposed individuals, participants exposed to occupational noise had an increased prevalence of periodontitis. The association remained significant after full adjustment of covariates (odds ratio [OR] 1.34; 95% confidence interval [CI] 1.06 to 1.70). Association of noise exposure with periodontitis was particularly strong for individuals aged < 45 years (OR 1.65; 95% CI 1.22 to 2.23).

CONCLUSIONS

Our study shows that there is an association between occupational noise exposure and periodontitis in a representative sample of Korean workers. Policy efforts to improve workplace noise environments might have an effect on improving periodontal health status among Korean workers.

The effects of industrial noise exposure on lipid peroxidation and antioxidant enzymes among workers

PURPOSE

The aim of this study was to measure individual exposure to noise and its effect on the levels of lipid peroxidation and enzymatic antioxidant defense.

METHODS

In this cross-sectional study, 94 male workers working in a food factory in Shahroud, Iran, were selected as the case group and 112 people were also included as the control group. The level of exposure to noise was measured using a dosimeter and the equivalent level was calculated. The levels of malondialdehyde (MDA), catalase (Cat), superoxide dismutase (SOD), and Total Antioxidant Capacity (TAC) were measured in the serum samples of all participants. Independent t test, one-way ANOVA, and multivariate linear regression were used to analyze the data.

RESULTS

The levels of MDA, Cat, and TAC were significantly higher in staff exposed to noise than in the controls. The starch and warehouse units' staff were exposed to the highest (99.3 ± 3.23 dB) and lowest (77.1 ± 9.68 dB) mean levels of sound pressure. Based on the linear regression model, noise exposure level was the most important predictor variable for levels of MDA (β = 0.48, CI 95% = 0.04-0.93), Cat (β = 0.43, CI 95% = 0.05-0.83), and TAC (β = 0.11, CI 95% = 0.06-0.16).

CONCLUSIONS

Noise exposure increases the production of free radicals. As exposure rate increases, the levels of MDA, Cat, and TAC enzymes increase as well.

Chronic occupational noise exposure: Effects on DNA damage, blood pressure, and serum biochemistry

Noise levels experienced by industrial workers may cause both auditory and non-auditory harmful effects. We have studied the effects of chronic industrial noise exposure on DNA damage, blood pressure, and serum biochemistry in factory workers. Male workers (109 individuals) in three parts of a food factory in Shahroud, Iran were enrolled as the exposed group and male office workers (123 individuals) were the unexposed control group. Noise exposure was measured (dosimetry) and the comet assay was used to evaluate DNA damage in peripheral blood mononuclear cells. Glutathione peroxidase (GPx) and ceruloplasmin (Cp) levels were measured in serum samples. GPx levels, systolic and diastolic blood pressure, and DNA damage were significantly higher in the exposed group than in the control group. However, ceruloplasmin levels were not significantly different. Based on multivariate linear regression analysis, noise exposure was the most important predictor of GPx levels, systolic and diastolic blood pressure, and DNA damage.

Effects of α lipoic acid on noise induced oxidative stress in rats

This study was conducted to identify how exposure to ambient noise that is over 75 dB affects the oxidant-antioxidant profile using hematological and biochemical indicators, and to investigate the effects of a strong and current antioxidant, α lipoic acid, on rats that were subjected to noise stress. For this purpose, five groups of eight rats were formed as follows: Control (K), Noise Exposure (GK), Lipoic Acid (LA), Noise Pollution + αLipoic Acid (GK + LA) and Oil (Y). The blood samples collected from rats were analyzed and MDA (malondialdehyde), GSH (glutathione), SOD (superoxide dismutase), CAT (catalase), NO (nitrit oxide), GPx (glutathione peroxidase), leukocytes, monocytes, lymphocytes, erythrocytes, hemoglobin, hematocrit, glucose, cholesterol, total protein, triglycerides, HDL (high density lipoprotein), LDL (low density lipoprotein), and urea-N levels were measured. The physical factory environment in a textile factory was preferred to simulate the noise exposure. Ambient noise was measured to be 75 dB. Exposure to physical ambient noise was sustained for 30 days. MDA level was measured at the lowest level in the LA and GKLA groups while it was statistically significantly higher in other groups than it was in the control group. It was observed that GSH reached its lowest level in the group that was exposed to noisy environment, the 100 mg/kg/day αlipoic acid administered on the experimental model increased this level to that of the control group and this change was statistically significant (p < 0.05). Considering the urea levels, the increases in GK and GKLA groups and the decreases in LA and Y groups were observed to be statistically significant. When glucose levels were compared to the control group, they were found to be statistically significantly lower in all groups. As a result, it was observed that exposure to noise for 30 days was likely to lead to leukocyte-based immune deficiency and using α lipoic acid as an antioxidant might provide a significant protection against the noise stress.

An evaluation of oxidative and nitrosative stress in children-who-stutter and its relationship to severity

OBJECTIVES

Although there has been much research into the cause of stuttering, it has not yet been fully clarified. There is known to be a close relationship between stress severity and stuttering. The aim of this study was to evaluate the levels of oxidative and nitrosative stress by comparing a stuttering group and a control group. It was also aimed to evaluate the relationship between the oxidative and nitrosative stress levels and the severity of the stutter.

METHODS

The study included a total of 80 individuals, comprising a study group of 40 and a control group of 40. The severity of the stutter in the patient group was evaluated with the Stuttering Severity Instrument 3 (SSI). Blood samples were taken from both the patient and control groups and malondialdehyde (MDA), 3 nitrotyrosine (3-NT), nitric oxide (NO), catalase (CAT), and superoxide dismutase (SOD) concentrations were examined.

RESULTS

In the stuttering patients, MDA, 3-NT, NO, CAT, and SOD activity were determined to be statistically significantly higher than those of the control group (all p:0.001). In the ROC analysis, there was good diagnostic value for NO, with the area under the curve as 1.0. A direct, positive, statistically significant correlation was determined between SSI points and MDA values (r = 0.317, p = 0.046).

CONCLUSION

The results of the study showed that the oxidative and nitrosative stress levels of the stuttering patients were higher than those of the control group. With 100% sensitivity and specificity, it is thought that NO in particular could be important for the diagnosis and treatment of these patients. As the severity of the stutter increased, so there was an increase in MDA, suggesting that MDA is important in stuttering.

Effects of long-term construction noise on health of adult female Wistar rats

The aim of this study was to investigate the influence of long-term building construction noise from refurbishment, which including vibration, on some physiological parameters and histopathological changes of organs of Wistar rats. Twenty 12 month old female rats were divided into two groups: rats group I (n = 10) were exposed to long-term construction noise and rats group II (n = 10) were kept under normal noise level. Study results revealed that long-term construction noise from building refurbishment has an influence on body weight, haematological and some serum biochemical parameters affects caecal microbiota, and causes histopathological changes in the organs of adult female Wistar rats. It was noticed that rats in group I exihibited significantly higher mean values for total protein, albumin and lower values for glucose, AST, ALT, blood urea nitrogen, haematological and caecal microbiota parameters than rats in group II. The most common pathologies were determined in the kidney, liver and lungs. Other observed pathologies were lymphadenopathy, catarrhal inflammation of the intestines, spleen hyperplasia and mammary gland adenofibroma. Single cases were subcutaneous fibroma in the thoracic region, abortus with uterine inflammation and thymus hyperplasia with formation of cysts were found.

Modeled traffic noise at the residence and colorectal cancer incidence: a cohort study

PURPOSE

Traffic noise has become an increasing public health concern, associated with pervasive negative health effects, most likely through pathways of sleep disruption and stress. Both sleep disruption and stress have been associated with colorectal cancer. The purpose of this study was to investigate the association between residential traffic noise and colorectal cancer incidence.

METHODS

Traffic noise was calculated for all residential addresses from 1987 to 2012 for 51,283 Danes in the Diet, Cancer and Health Cohort. We used Cox proportional hazard models to investigate the association between residential traffic noise 5 and 10 years before diagnosis, and overall colorectal cancer incidence, as well as subtypes (rectal, proximal, and distal colon). Hazard ratios (HRs) were calculated as crude and adjusted for potential confounders.

RESULTS

During follow-up, 1,134 colorectal cancers developed (737 colon, 397 rectal). We found no association between residential road traffic noise and rectal cancer. We observed an association with distal colon cancer: HR 1.18, 95% CI 1.00-1.40, but not for proximal colon cancer: 0.99 (0.83-1.18), per 10 dB, 10 years preceding diagnosis. There was no association between railway noise and colorectal cancer, or any subtype.

CONCLUSION

The present study suggested that long-term exposure to residential road traffic noise might increase the risk for colon cancer, especially distal colon cancer.

Health impact and noise exposure assessment in the cricket bat industry of Kashmir, India

AIM

The aim of the present study was to identify and evaluate predominant noise sources in the cricket bat industry of Kashmir, India.

METHODS

Sound levels were measured at operator's ear level in the working zone of the workers of seven cricket bat factories. The impact assessment was made through personal interviews with each worker separately during their period of rest.

RESULTS

On average, 62.5% of the workers reported difficulty in hearing and 24.1% of the workers have become patients for hypertension. Only 58.1% of the workers complained of headache due to high noise level.

CONCLUSIONS

The workers engaged in the cricket bat industry of Kashmir are exposed to high noise levels. It is suggested that personal protective equipment like ear plugs and ear muffs be used by these workers as a protection against this hazard.

Road traffic noise effects on cardiovascular, respiratory, and metabolic health: An integrative model of biological mechanisms

BACKGROUND

Road traffic noise is a major public health issue, given the documented association with several diseases and the growing number of exposed persons all over the world. The effects widely investigated pertain to cardiovascular health, and to a lesser extent to respiratory and metabolic health. The epidemiological design of most studies has made it possible to ascertain long-term associations of urban noise with a number of cardiovascular, respiratory, and metabolic disorders and diseases; additionally, time series studies have reported short-term associations.

OBJECTIVES

To review the various biological mechanisms that may account for all long-term as well as short-term associations between road traffic noise and cardiovascular, respiratory, and metabolic health. We also aimed to review the neuroendocrine processes triggered by noise as a stressor and the role of the central nervous system in noise-induced autonomic responses.

METHODS

Review of the literature on road traffic noise, environmental noise in general, psychosomatics, and diseases of the cardiovascular, respiratory, and metabolic systems. The search was done using PubMed databases.

DISCUSSION

We present a comprehensive, integrative stress model with all known connections between the body systems, states, and processes at both the physiological and psychological levels, which allows to establish a variety of biological pathways linking environmental noise exposure with health outcomes.

CONCLUSIONS

The long- and short-term associations between road traffic noise and health outcomes found in latest noise research may be understood in the light of the integrative model proposed here.

Urinary concentrations of metabolites of pyrethroid insecticides in textile workers, Eastern China

Pyrethroid insecticides have been applied in the production of cotton, wool and textile. In order to examine whether textile workers are exposed to pyrethroid insecticides, we recruited 50 textile workers in two textile plants in Eastern China. Their urine samples were collected for the measurement of pyrethroid metabolites: cis- and trans-isomers of 2,2-dichlorovinyl-2,2-dimethylcyclopropane-1-carboxylic acid (cis-Cl2CA and trans-Cl2CA) and 3-phenoxybenzoic acid (3-PBA). Our results showed that textile workers were exposed to high levels of pyrethroid insecticides. cis-Cl2CA and 3-PBA were dominant metabolites with concentrations of 0.17-261μg/L, while concentrations of trans-Cl2CA were in the range of 0.26-11μg/L. Levels of three metabolites were in a descending order: cis-Cl2CA, 3-PBA, and trans-Cl2CA. Levels of the metabolites were associated with ages and job responsibilities of textile workers. Sewing workers, cutting workers, machine operators, reorganizers, and older workers were more likely in contact with pyrethroid insecticides in the textile production. trans- to cis-Cl2CA ratios might indicate that exposure of textile workers was via dermal absorption and inhalation.

Effects of noise exposure on catalase activity of growing lymphocytes

Oxidative stress due to noise was estimated at cell level using model of growing lymphocytes. Lymphocytes were isolated and cultured using conventional methodology. Cell culture of each group was exposed to sound of frequency 1 KHz during incubation. Three groups were defined on the basis of exposure of sound with specific range of intensity and duration of exposure. Group A and Group B were exposed to sound with intensity 110 dBA for four hours per day and for eight hours per day respectively. Control group was exposed to sound less than 85 dBA. Viable cell count was performed using trypan blue. Catalase activity of each group was estimated using ELISA kit.Viable cell count of Group A and Group B was almost same but significantly less than that of control group. Catalase activity of lymphocytes in Group B was significantly low as compared to Group A and controls (p=0.003, p< 0.05). There was no significant difference between catalase activity of Group A and control group.Exposure of sound with frequency 1 KHz and intensity 110 dBA for 4 hours and eight hours per day may induce oxidative stress in growing lymphocytes causing the difference in viable cell count. However the catalase activity depends on duration of exposure. In case of noise exposure of 8 hours per day, it declines significantly as compared to noise exposure of 4 hours per day.

Association between polymorphisms in SOD1 and noise-induced hearing loss in Chinese workers

CONCLUSION

SOD1 is an important gene related to noise-induced hearing loss (NIHL), and its effect is dependent on noise exposure levels.

OBJECTIVES

To test whether the polymorphisms in the CuZn-superoxide dismutase gene (SOD1) are associated with susceptibility to NIHL in the Chinese population.

METHODS

Audiometric data from 2400 Chinese Han people exposed to occupational noise were analyzed. DNA samples were collected from the 10% most susceptible and the 10% most resistant individuals. Four SNPs in the introns of SOD1 were genotyped and their effects and interactions with noise exposure were analyzed.

RESULTS

Genotype AA of rs2070424 conferred protection against NIHL (adjusted OR = 0.45, p = 0.005), while GG of rs10432782 was a risk genotype (adjusted OR = 1.88, p = 0.026). One protective haplotype TATG (OR = 0.56, p = 0.003) and two risk haplotypes, CATG and TGGA (OR = 1.58, 28.75 and p = 0.017, <0.001, respectively) were identified. Significant interactions between SOD1 SNPs and noise levels were found. Further analysis of effects of SOD1 SNPs found that those carrying GG genotype of rs10432782 had significantly higher SOD1 activity (p = 0.022), but a significantly lower level of malondialdehyde in plasma, compared with TT carriers (p = 0.007).