Noise Pollution Levels Research Articles

Monitoring and measuring noise pollution in urban environments (Case study: Khorramabad city)

Introduction: Environmental noise, caused by traffic, leads to increased risk of health problems. Nowadays, noise pollution is one of the most important problems in the communities which adversely affects the health. The aim of this study was to assess the noise pollution in Khorramabad city. Materials and methods: To measure the noise level in the city, 39 stations near to sensitive places such as hospitals, educational centers, and so on were selected. Measurements were performed, for 30 min, in the mornings (7-10 AM) and evenings (5-8 PM) using a standard sound level meter. The measurements were made on working days during the week and assuming the traffic load was the same. Results: The sound level in all 39 considered stations was higher than the standard of residential-commercial in more than 90% of the stations compared to the environmental standard. The mean of sound measured in the monitored stations was equal to 68.28±2.6 dB. The maximum measured sound level belonged to station S2. In station S2, the maximum measured sound was reported as 81.72±11.3 dB. The findings showed that sound level in the evenings were slightly higher than the mornings. Also, in the evening, the highest and lowest measured sound values belonged to stations S1 and S20. The amount of measured sound level at stations S1 and S20 was equal to 80.9 and 39.7 dB, respectively. Based on findings, the highest and lowest sound recorded belonged to stations S39 and S20 which area type of stations S20 and S39 was commercial and residential, respectively. Conclusion: This study showed that the average level of sound pressure was higher than the permissible limit, so the necessity of planning is suggested to reduce the level of noise pollution and consequently reduce the anxiety level of citizens and increase health.

ENVIRONMENTAL NOISE AND CARDIOVASCULAR DISEASES IN BULGARIA

Purpose: Noise has emerged as a leading environmental nuisance. Cardiovascular diseases rank first among the causes of death on a global scale and one of the possible effects of noise impact on the human organism. The study aims to analyze the level of noise pollution in Bulgaria and to measure its association with cardiovascular diseases. Methods: Data provided by the National Statistical Institute, Eurostat and other databases were used to analyze the noise pollution in Bulgaria. The 28 regions in Bulgaria were compared according to the proportion of surveyed points above permissible limits and the death rates due to cardiovascular diseases, /2022/. Data were statistically processed with SPSS v.26. Results: A positive fact is the absence of high values of noise levels in the range of 78-82 dB(A) and over 82 dB(A) and the decrease in the share of surveyed points with noise levels in this range during the analyzed period- from 27.3% in 2006 to 18.56% in 2022. The study found that almost all districts with the highest share of surveyed points above permissible limits have higher levels of death rate due to CVD. There is a positive moderate correlation between the share of surveyed points above permissible limits and the Death rate due to CVD - coefficient of Pearson is 0.423 (p=0.025). Conclusion: Cardiovascular diseases have a multifactorial genesis, but the reduction of noise in urban areas would help prevent these diseases.

Modelling of passengers behaviour under the influence of noise in public transport buses: a structural equation approach

This study aims to investigate the impact of noise pollution levels on passengers during travel. Specifically, the aim was to explore the interconnections between noise-induced annoyance, sensitivity to noise, sleep disturbances, and physical health problems using a structural equation modelling (SEM) approach. 14 routes were selected for detailed analysis across different time periods. The noise levels were observed, and the impact of these levels on passengers was assessed through a questionnaire survey to know their perception towards noise and its impacts. A total of 252 responses from passengers were collected through the personal interview. Findings reveal that noise pollution levels exceeded 70 dBA on most of the routes. A significance test (t-test) conducted on 15-minute frequency intervals showed no significant difference in noise pollution levels during morning, evening, and afternoon periods. Subjective analysis indicates 31% of passenger were found to be highly annoyed due to noise within public buses. Additionally, 32% and 9% of passengers reported moderate and minimal annoyance, respectively, attributed to traffic and engine noise inside buses. Structural equation approach showed that sensitivity to noise affects the annoyance level most with coefficient 0.76, followed by physical health factors and sleep disturbance with coefficient 0.48 and 0.44 respectively.

Does Urban Green Space Pattern Affect Green Space Noise Reduction?

The effect of urban green spaces on traffic noise reduction has been extensively studied at the level of single vegetation, hedges, etc., but there is a lack of corresponding studies at the scale of spatial patterns of urban green spaces. Therefore, this study aims to analyze the relationship between the spatial pattern of urban green space and the change in green space’s noise reduction capacity. Through the morphology spatial pattern analysis method, this analysis divides the urban green space in the Fuzhou high-tech zone into seven types of elements with different ecological definitions and simulates the noise condition of the urban environment with the presence of green space as well as without the presence of green space by computer simulation, calculates the distribution map of the noise reduction produced by the urban green space, and analyzes the correlation between the seven types of green space elements and the noise reduction with the geographically weighted regression modeling analysis. The study finds that (1) Urban green space patterns can significantly affect the net noise reduction of green space. Areas with high green coverage can produce a stronger green space noise reduction effect. (2) More complex green space shapes and more fragmented urban green space can produce higher noise reduction. (3) The green space close to the source of noise can exert a stronger noise reduction effect. Therefore, in the process of planning and design, from the perspective of improving the urban acoustic environment, the configuration of high-quality green spaces in areas with higher levels of noise pollution should be given priority, which may have better noise reduction effects.

Commuter exposure to ultrafine particles (UFPs), lung deposited surface area (LDSA), and noise in Ho Chi Minh City, Vietnam

IntroductionTransport is a main contributor to air and noise pollution, particularly in urban areas with the high number of motorized vehicles. Promoting active transport (i.e., cycling and walking) and public transport is an instrumental factor in reducing traffic-related air and noise pollution. However, commuters of these transport modes are often exposed to high air and noise pollution than other commuter groups. MethodsThe levels of exposure to UFP, LDSA, and noise during commuting of different transport modes in Ho Chi Minh City (HCMC) were measured and compared. Then, the dose of inhaled pollutants during commuting was calculated for each commuter group by considering the travel time and minute ventilation. ResultsThe level of exposure to air and noise pollution varies across transport modes. Cyclists and motorcyclists were exposed to the highest level of air and noise pollution. Motorcyclists and cyclists were exposed to the highest UFP number concentrations during their trips, 3.6*105 and 3.1*105 particles/cm3, respectively. Car commuters were exposed to the lowest air and noise pollution level, followed by bus commuters. When considering the minute ventilation and travel time, cyclists inhaled significantly higher levels of air pollution than other commuters, followed by pedestrians, motorcyclists, bus commuters, and car users. As a result, the health impacts of exposure to traffic-related air and noise pollution for active commuters could be greater than other commuter groups. ConclusionsPromoting active and public transport is a promising approach to improving air quality and reducing congestion in HCMC. Using these transport modes also has potential positive health effects on commuters through physical activities. However, active commuters are faced with the highest risk of exposure to high air and noise pollution levels. To promote active transport and public transport in HCMC, measures to reduce the level of exposure to air and noise pollution for these commuter groups are needed.

Multidimensional analysis of road traffic noise and probable public health hazards in Barisal city corporation, Bangladesh

Noise pollution is a major challenge in urban contexts all around the world. The study was designed to assess road traffic noise pollution with possible health effects on those living in the study region. The IDW spatial interpolation approach and an ArcGIS-based evaluation were used to map the recorded noise levels in the research region. The noise descriptors including Noise Climate (NC), Traffic Noise Index (TNI), Equivalent Noise Level (Leq), and Noise Pollution Level (NPL) were computed. The required information has been collected through a questionnaire survey and previously published documents. The study reveals that the current noise level is higher than the recommended national threshold at every location. According to the study, the Nathullabad region had the highest level of noise pollution (86.5 dBA), while the Kaunia Abasik area had the lowest level (67.8 dBA). Study findings also show that in the area context, the highest levels of noise pollution are found in commercial areas (82 dBA), followed by industrial areas (80.4 dBA),mixed areas (81.3 dBA), and residential areas (72.7 dBA). The lowest level is found in sensitive areas (72.5 dBA). Statistical analyses, including one-way ANOVA, Tukey HSD post-hoc and LSD post-hoc test results, showed that there was no statistically significant difference (p > 0.05) between the noise pollution levels (NPL) in the morning, noon, and evening shifts. The results showed that 32 % of respondents stated they felt disturbed while working, and 27% of respondents said it was somewhat sensitive for them. As the last step in minimizing noise pollution in the research area, 37 % of respondents reported enforcing the regulations, 31% suggested making hydraulic horns illegally, and 21 % suggested raising public awareness. This study may contribute to academic knowledge and assist decision-makers of government officials in formulating appropriate local strategies to deal with this grave environmental problem.

Exploring multi-pollution variability in the urban environment: geospatial AI-driven modeling of air and noise

ABSTRACT This study addresses the critical need for comprehensive multi-pollution modeling in urban environments by employing Geospatial Artificial Intelligence (GeoAI) techniques. Specifically, it aims to elucidate the variability of air and noise pollution levels in Tehran, Iran, and develop precise multi-pollution susceptibility maps. A spatial database was compiled, encompassing annual average data (2019–2022) of the Air Quality Index (AQI) and Equivalent Continuous Sound Level (Leq), along with 19 influential factors related to both pollutants. The study utilized the CatBoost machine learning algorithm, enhanced with Grey Wolf Optimizer (GWO) and Harris Hawks Optimization (HHO) algorithms, to model and predict pollution patterns. Key quantitative achievements include a remarkable 15% reduction in Root Mean Square Error (RMSE) for air pollution and a 12% reduction in noise pollution when using the CatBoost-HHO configuration compared to the standalone CatBoost algorithm. Validation of the multi-pollution maps utilizing the Area Under the Curve (AUC) analysis showed high accuracy, with the CatBoost-HHO achieving AUC values of 0.943 for air pollution and 0.936 for noise pollution, outperforming CatBoost-GWO and standalone CatBoost models. These results underscore the efficacy of our approach in accurately identifying and mapping multi-pollution hotspots, contributing valuable insights for urban environmental management and public health preservation.

Evaluation of Noise Pollution Level in the Metro Construction Site in Mumbai, India

Evaluation of Noise Pollution Level in the Metro Construction Site in Mumbai, India

Measurement and prediction of road traffic noise at different floor levels of buildings in a mid-sized Indian city

It is widely accepted that residents of high-rise buildings located beside roads are inevitably exposed to significant levels of noise pollution due to traffic operation. This study aims to unveil crucial insights into the dynamic fluctuations of noise levels within the vertical dimensions of high-rise buildings nestled amidst the bustling streets of mid-sized Indian cities where heterogeneous traffic is under operation. Two cycles of data were collected on all floors for hourly duration on the façade line for two high-rise buildings. Traffic volume, speed, distance of the building from centre of the carriageway and honking were used to develop models for Leq and L10 using Artificial Neural Network (ANN). The R2 values obtained for Leq and L10 were 0.93 and 0.90, respectively indicating the efficacy of the models in predicting noise level at all floors. Results show that the sound level rises to a certain height of the building and then begins to decrease. Floor level 3, 4, 5 and 6 (height approx. 8.4–21 m) had the maximum noise level compared to the other floors, while the 1st and floor level above 10 were quieter floors. Frequency analysis reveals that buildings closer to roadways experience dominant honking noise, particularly at 3.15 kHz, whereas traffic noise prevails at frequencies up to 200 Hz. This work has the novelty of addressing the impact of heterogeneous traffic noise at various floor levels of Varanasi mid-sized city which has narrow carriageway. Such a traffic has prominence of honking which is modelled perhaps for the first time. The outcome of this research has importance in urban planning and formulating legislations.

Review of City-Wide 30 km/h Speed Limit Benefits in Europe

To date, more and more European cities are systematically working to expand the proportion of their street network with a speed limit of 30 km/h. This paper endeavored to assess the effectiveness of city-wide 30 km/h speed limits in Europe. In an effort to condense research outputs, a quantitative approach along with qualitative assessments were implemented. This study described the changes in safety, environment, energy, traffic, livability, and health before and after the phased implementation of city-wide 30 km/h speed limits. The systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Results from 40 different cities across Europe, including Brussels, Paris, and Zurich, indicated that reductions in speed limits improved road safety by decreasing the likelihood of crash risk and the severity of crashes that do occur. On average, the implementation of 30 km/h speed limits in European cities demonstrated a 23%, 37%, and 38% reduction in road crashes, fatalities, and injuries, respectively. Lower speed limits also yielded environmental benefits, with emissions decreasing on average by 18%, noise pollution levels by 2.5 dB, and fuel consumption by 7%, indicating enhanced fuel efficiency and reduced environmental impact. Encouraging citizens to embrace walking, cycling and utilizing public transit services can further contribute to a safer and environmentally sustainable urban environment.

Phytoncidal activity of the needles of Juniperus L. representatives in the technogenic conditions of the city of Dnipro

The territory of the Dnipro urban agglomeration is one of the most polluted in Ukraine. The high concentration of industrial enterprises, roads, density of residential buildings and urban population are factors of anthropogenic pressure on urban ecosystems that significantly affect the quality of the habitat of living organisms and human life. Therefore, an urgent problem of modern urban planning and urban amenities is compliance with sanitary requirements for landscaping residential and industrial areas. The creation of decorative compositions with a predominance of tree and shrub species ensures the landscape attractiveness of the city, reduces the level of noise and dust pollution, improves temperature and wind conditions, improves public health by normalizing the psychological state of people and purifying the city air with phytoncides of plants, especially conifers. Taking into account the high decorative qualities and resistance of junipers to adverse climatic conditions, the aim of the study was to analyze the annual dynamics of phytoncidal activity of Juniperus media V. D. Dmitriev «Blue gold» and J. sabina L. «Tamariscifolia» needles in conditionally clean and polluted by vehicle emissions areas of Dnipro city. The plant material was collected at 4 monitoring points in Dnipro, 1 was a conditional control, and the other 3 were experimental plots with different levels of vehicle traffic. Needles were sampled at all periods of shoot ontogeny. The phytoncidal activity was determined by the method of «steaming» microbial test cultures with volatile needle secretions on test cultures of Staphylococcus epidermidis, Staphylococcus aureus, Micrococcus sp., Bacillus subtilis, Esherechia coli, Pseudomonas fluorescens, Candida albicans. The results of the study show that the dynamics of phytoncidal activity of J. media and J. sabina needles during the year is the same in plants growing in a conditionally clean area and under the influence of motor vehicle traffic: the amount of released phytoncides increases in spring, during the period of intensive shoot growth, reaches a maximum at the stage of slowing down their growth (in summer), decreases in autumn, with the cessation of growth processes, and is minimal in winter, when there is no shoot growth. It has been shown that in a clean area, needle extracts of both representatives of the genus Juniperus have the greatest inhibitory effect on the growth of S. aureus colonies, and under the influence of vehicle emissions, the phytoncidal activity is highest against S. aureus and S. epidermidis strains. It was found that out of the two studied representatives of the genus Juniperus, J. media has the highest stability of the ability to secrete phytoncides under conditions of motor vehicle traffic load, which we recommend for use in urban landscaping.

Diurnal rail noise measurement, analysis, and evaluation of associated health impacts on residents living in the proximity of rail track area.

In India, railway is the major transportation mode for carrying goods and people. The tracks for the movement of the rail were initially constructed in the city for the pre-eminence and expediency of the vantage of the people. Rapid modernization and increasing population in the city crammed the area around the railway tracks. Moving rail on the tracks passing through the city is not compatible, which is creating problems for the nearby residents. In the urban and suburban regions, the railway noise has become a major problem. This study was conducted to examine the perception of the physiological and psychological effects of railway noise in the nearby areas of railway stations in Delhi, India. For this purpose, 10 sites near the railway station were selected for the study. To assess the impact of railway noise pollution on the health of humans, a questionnaire survey was conducted. The data of 344 individuals were collected through the questionnaire survey and analyzed to get the perception towards railway noise. Noise level was monitored by a Sound Level Meter (SLM) and the equivalent noise level (Leq) in dB(A) was used to compute the noise pollution in three shifts, i.e., morning, noon, and evening time. Results showed that 57.65% of female and 86.11% of male respondents in the survey reported the disturbance due to railway noise. The level of noise pollution was found higher in the evening time as compared to the noon and morningperiod, which exceeds the limit set by the Central Pollution Control Board (CPCB) at all the monitored locations. Findings of the study show that the primary cause of the health problems is railroad noise, which is negatively impacting the health of the residents, who are living in the proximity of the rail track region. The perception survey reported that headache, sleep disturbance, irritation, and stress are common health issues among the locals residing around the railway track proximity in Delhi.

Prediction of Noise Level in Ota Metropolis Using Artificial Neural Network

Capturing noise data is laborious, time-consuming, expensive and dangerous due to the exposure of the investigator to the menace. Also, appropriate software, computational skill and computational time are also required before the captured data could be of any use. In this work, an artificial neural network (ANN) was deployed to learn and train noise data in Ota Metropolis. Data were captured from forty-one (41) locations for the morning, afternoon and evening in Ota Metropolis. ANN with Levenberg Marquardt algorithm and architectural configuration of 2-21-9 (input-hidden neuron-output) was used to predict noise descriptors for Ota Metropolis with 73% accuracy. The two input variables were the latitude and longitude of the location measured in degrees while the nine output variables are the noise descriptors such traffic noise index (TNI), noise pollution level (LNP), and average equivalent noise levels (LAeq) computed for each selected location for morning, afternoon and evening periods. The results could be used in mobile applications, Google Earth and other platforms to guide residence dwellers, travellers, industrialists and technocrats in selecting travelling routes, choice of apartment location and use of appropriate personal protective equipment (PPE) in unavoidable noisy locations.

Assessment and mapping of noise pollution in recreation spaces using geostatistic method after COVID-19 lockdown in Turkey

Increased use of recreational areas after the lifting of COVID-19 pandemic restrictions has led to increased noise levels. This study aims to determine the level of noise pollution experienced in recreational areas with the increasing domestic and international tourism activities after the lifting of pandemic lockdowns, to produce spatial distribution maps of noise pollution, and to develop strategic planning suggestions for reducing noise pollution in line with the results obtained. Antalya-Konyaaltı Beach Recreation Area, the most important international tourism destination of Turkey, is determined as the study area. To determine the existing noise pollution, 31 measurement points were marked at 100 m intervals within the study area. Noise measurements were taken during the daytime (07:00–19:00), evening (19:00–23:00), and nighttime (23:00–07:00) on weekdays (Monday, Wednesday, Friday) and weekends (Sunday) over 2 months in the summer when the lockdown was lifted. In addition, the sound level at each measurement point was recorded for 15 min, while the number of vehicles passing through the area during the same period was determined. The database created as a result of measurements and observations was analyzed using statistical and geostatistical methods. After the analysis of the data, it was found that the co-kriging-stable model showed superior performance in noise mapping. Additionally, it was revealed that there is a high correlation between traffic density and noise intensity, with the highest equivalent noise level (Leq) on weekdays and weekend evenings due to traffic and user density. In conclusion, regions exposed to intense noise pollution were identified and strategic planning recommendations were developed to prevent/reduce noise sources in these identified regions.

Sex-specific associations between the environmental exposures and low-grade inflammation and increased blood pressure in young, healthy subjects

Long-term exposures to environmental factors including airborne as well as noise pollutants, are associated with cardiovascular risk. However, the influence of environmental pollution on the young population is controversial. Accordingly, we aimed to investigate the relationships between long-term exposures to different environmental factors and major cardiovascular and inflammatory parameters and biomarkers in young, healthy subjects. Representative sample of permanent residents of two cities differing in air and noise pollution levels, aged 15–21 years, were recruited. Krakow and Lublin, both located in southern Poland, were chosen in relation to their similarities in demographic and geopolitical characteristics, but differences in air pollution (higher in Krakow) and noise parameters (higher in Lublin). A total of 576 subjects were studied: 292 in Krakow and 284 in Lublin. All subjects underwent health questionnaire, blood pressure measurements and biomarker determinations. Inflammatory biomarkers, such as CRP, hs-CRP, fibrinogen as well as homocysteine were all significantly higher in subjects living in Krakow as opposed to subjects living in Lublin (for hsCRP: 0.52 (0.32–0.98) mg/l vs. 0.35 (0.22–0.67) mg/l; p < 0.001). Increased inflammatory biomarker levels were observed in Krakow in both male and female young adults. Interestingly, significant differences were observed in blood pressure between male and female subjects. Males from Krakow had significantly higher mean systolic blood pressure (127.7 ± 10.4 mm/Hg vs. 122.4 ± 13.0 mm/Hg; p = 0.001), pulse pressure (58.7 ± 8.9 mm/Hg vs. 51.4 ± 12.3 mm/Hg; p < 0.001) and lower heart rate (p < 0.001) as compared to males living in Lublin. This was not observed in young adult females. Long-term exposure to environmental factors related to the place of residence can significantly influence inflammatory and cardiovascular parameters, even in young individuals. Interestingly, among otherwise healthy young adults, blood pressure differences exhibited significant variations based on biological sex.

Investigation of indoor noise pollution level and air quality of furniture manufacturers

Indoor air quality has become a more prominent concern since the arrival of the COVID-19 pandemic. Manufacturing industries have always been prone to occupational health risks, which depend on the dynamics of the production shop floors. The furniture industry is one of these sectors with a unique work environment. Although a typical furniture manufacturing facility involves physical, chemical, and noise pollution-producing elements, this industry has been studied relatively less for indoor air quality and noise-related risks. This study investigated nine furniture manufacturing organizations’ indoor air quality and noise pollution levels through comprehensive quantitative techniques. The results of the measurements were compared against reference values set by specific guidelines to explore the degree of occupational health risk associated with the World Health Organization’s (WHO) suggested levels. Repetitive measurements from five pre-designated workstations were taken at each facility. The study’s results indicated that organization size and department were significant factors for PM 2.5 and HCHO parameters, while only department type was substantial for noise exposure levels. However, across all departments and organization sizes, LAeq noise levels were below the safety threshold of 85 dB(A). Most organizations presented a lack of proper use of personal protective equipment and poor ventilation across shop floors.

Analysis of Noise pollution level in Enugu campus, of the University of Nigeria

Noise is sound of any kind that is undesirable and unwanted as part of the environment under consideration. It is one of the types of pollution that have great impact on our health and wellbeing. The occurrence of noise in our environment is increasing daily because of growing population and industrialization. Noise pollution have great consequences on our social and economic lives especially in teaching and learning environment, which is presumed to be in silent zone. It is worth investigating whether environment in which teaching and learning take place is in quiet condition? The aim of the study was to analyze the level of noise pollution at different locations in the University of Nigeria, Enugu Campus. The Nigeria Standard noise level for higher education institutions and hospitals should be 60 dB for day and 50 dBA for night. The Noise levels dBA was measured with the help of noise meter at 14 points and at a height of 1 m above the ground level within the campus at three different times (6–8 am, 12–2 pm and 4–6 pm). The total Leq noise level in the University of Nigeria, Enugu Campus is 70.94 dBA which is above the level recommended for educational institutions. The period of intensity of noise was recorded during afternoon, morning and evening respectively. This rate of noise level during the day is high and unsuitable for teaching-learning process. Therefore, university management should take proactive measures to regulate noise pollution within the campus and indeed, other university campuses in Nigeria.

Investigating the Relationship between Noise Exposure and Human Cognitive Performance: Attention, Stress, and Mental Workload Based on EEG Signals Using Power Spectrum Density

A pervasive environmental stressor is one that damages mental and physical health as well as cognitive abilities by producing noise at a specific frequency and level. Current noise pollution levels pose a significant threat to public health, potentially leading to impaired cognitive function, increased stress, and other negative health consequences. This study aims to investigate the relationship between noise exposure and human cognitive abilities using a comprehensive analysis of power spectrum density (PSD) derived from EEG signals. Twenty-four participants completed the experiment to identify the effect of exposure to different noise levels (55 dB, 65 dB, 70 dB, 75 dB, 80 dB, and 85 dB) and two types of continuous and intermittent noise. The Stroop Color–Word Test and the Emotive Epoch EEG are cognitive task instruments used during experiments. Behavioral performance (accuracy and response time) and power spectrum electroencephalographic density were collected and analyzed. The methodology involved collecting EEG data from participants exposed to controlled noise stimuli and a subsequent PSD analysis to uncover frequency-specific patterns associated with cognitive processes. Attention levels were measured by examining beta wave activity, while stress responses were evaluated through an alpha wave analysis. Additionally, mental workload was assessed by considering the overall distribution of PSD through the theta-to-alpha ratio. The results revealed a significant relationship between the exposure to noise types and levels and human cognitive ability. The analysis of the power spectrum density on the cognitive aspects of attention and stress yielded results indicating that participants were in the best attention condition and in a relaxed or unstressed state when exposed to noise levels of 65 dB in both continuous and intermittent noise types. For the mental workload aspect, participants exposed to both continuous and intermittent noise types at a noise level of 70 dB began to indicate the presence of mental workload. These findings supported the importance of considering the impact of environmental noise on human cognitive well-being and demonstrated the potential of EEG monitoring as an objective tool for assessing the impact of noise on cognitive performance.

Urban noise slows down the antipredator reaction of Eurasian Magpies

Urban areas are known to have high levels of noise pollution, which can impact an animal’s antipredator behavior. Noise can either distract the animal or mask the sounds of a predator, increasing the animal’s vulnerability to predation. However, the prey may increase vigilance in noisier environments, thus reducing energy and time spent on other activities. Alert Distance (AD) refers to the distance at which an animal becomes alert to a potential predator approaching. Flight Initiation Distance (FID) is the distance from the potential predator at which the animal flees. We studied the impact of ambient noise pollution on the AD and a corrected FID (FID/AD) of Eurasian Magpies (Pica pica) using a field investigator as a potential predator walking towards birds at a constant speed. We found that the noise level did not affect the AD. Still, noise had a negative effect on the Eurasian Magpies’ FID/ADs, suggesting that noise may slow their reaction to a potential threat but not their ability to detect it. Thus, our research highlights that urban noise pollution can increase an individual's vulnerability to predation, even when predators are still detectable. Ambient noise may distract the bird by diverting some of its limited attention and causing a delayed response to the predators. Alternatively, noise could be masking auditory cues that would have otherwise been added together with visual cues to cause an enhanced response. More research is necessary to understand the effects of noise pollution on the antipredator behavior of birds in urban areas, taking into account the specific strategies and adaptations of each species.

Evaluation of Noise Pollution Level in Selected Sawmill Factories in Port Harcourt and Environs, Rivers State, Nigeria

Evaluation of noise pollution level has been carried out in in some selected Sawmill factories in Port Harcourt and environs using noise level and frequency meters in seven locations. The mean values of maximum and minimum sound levels in Mile2, Mile3, Marine base, Oluwood were 81.98±0.43 and 79.28±2.00, 82.450±0.66 and 80.28±0.80, 81.50±4.73 and 74.75±1.10, 81.40±0.40 and 78.03±2.02 respectively. Also the mean values of maximum and minimum sound levels at Igwuruta, Rumosi, Rumuji were found to be 82.00±0.64 and 79.40±2.00, 81.53±0.60 and 78.66±1.63, 81.78±0.40 and 77.95±1.86 respectively. The average noise equivalent (Leq) ranged from 77.20 to 82.25 dB whereas the average noise pollution level (Lnp) ranged from 96.13 to 101.23 dB. Therefore, the indication is that the Sawmill at Igwuruta has the highest average Lnp whereas Rumuosi has the least average when compared with the recommend permissible value by the Nigerian Federal Ministry of Environment (FMEnv). This study has determined the noise level generated in study area through set objectives which included but not limited to measuring the sound level, investigating noise some meters away from the source and of course comparing results with best known standards. The results therefore suggested that the noise level is high at the saw mills and the day exposure to this unwanted sound could threaten the health of the factory workers and the residents at proximity to the noise sources.