Showing papers on "Noise pollution published in 2002"

Construction Noise: Exposure, Effects, and the Potential for Remediation; A Review and Analysis

Abstract: More than one-half million construction workers are exposed to potentially hazardous levels of noise, yet federal and state Occupational Safety and Health Administration (OSHA) programs provide little incentive to protect them against noise-induced hearing loss. Construction noise regulations lack the specificity of general industry noise regulations. In addition, problems that characterize the construction industry, such as worker mobility and the large proportion of small businesses, make implementing hearing conservation measures more difficult. The apparent severity of exposure depends greatly on the measurement method, with the 3-dB exchange rate almost always showing higher average exposure levels than the 5-dB (OSHA) rule. Construction workers demonstrate hearing threshold levels that generally conform to those expected in manufacturing. The prevalence of hearing protection device (HPD) use among U.S. construction workers is very poor, partly because of perceived difficulties in hearing and understanding speech communication and warning signals. In addition, masking by noise of necessary communication and warning signals is of particular concern in construction, where recent research demonstrated the association between fatalities and the failure to hear reverse alarms. Judicial use of HPDs is of the utmost importance, along with avoiding overattenuation, selecting HPDs with uniform attenuation, and using noise-attenuating communication systems when possible. A successful hearing conservation program in British Columbia can serve as a model for the United States, with a long-standing positive safety culture, a high percentage of HPD use, improvement in average hearing threshold levels over the last decade, and a centralized record-keeping procedure, which helps solve the problem of worker mobility. However, controlling construction noise at the source is the most reliable way to protect worker hearing. U.S. manufacturers and contractors should benefit from the activities of the European Community, where noise control and product labeling in construction has been carried out for more than 20 years.

Ambient neighbourhood noise and children's mental health

Abstract: Objectives: To investigate the relation between typical ambient noise levels (highway, rail, road) and multiple mental health indices of school children considering psychosocial and biological risk factors as potential moderators. Methods: With a two stage design strategy (representative sample and extreme sample) two cross sectional samples (n=1280; n=123) of primary school children (age 8‐11) were studied. Individual exposure to noise at home was linked with two indices of mental health (self reporting by the child on a standard scale and rating by the teacher of classroom adjustment on a standard scale). Noise exposure was modelled firstly according to Austrian guidelines with the aid of a geographical information system and then calibrated and corrected against measurements from 31 locations. Information on potential confounders and risk factors was collected by mothers and controlled in regression modelling through a hierarchical forward stepping procedure. Interaction terms were also analysed to examine subgroups of children at risk—for example, low birth weight and preterm birth. Results: Noise exposure was significantly associated in both samples with classroom adjustment ratings. Child self reported mental health was significantly linked to ambient noise only in children with a history of early biological risk (low birth weight and preterm birth). Conclusions: Exposure to ambient noise was associated with small decrements in children’s mental health and poorer classroom behaviour. The correlation between mental health and ambient noise is larger in children with early biological risk.

Chronic effects of workplace noise on blood pressure and heart rate

Abstract: Environmental noise levels in the United States are increasing, yet there are few studies in which the nonauditory effects of workplace noise are assessed. In the current study, the authors examined chronic effects of noise on blood pressure and heart rate in 374 workers at an automobile plant. Data were collected from subjects prior to the start of their workshift. Participants completed questionnaires about diet, alcohol use, lifestyle, noise annoyance, use of hearing protection, noise exposure outside of the work environment, personal and family health histories, and demographic information. Resting blood pressure, heart rate, and body mass index were obtained. Noise exposure levels were extracted retrospectively from company records for each participant for the past 5 yr. Summary statistics were generated for each variable, and the authors performed bivariate correlations to identify any unadjusted associations. The authors then completed statistical modeling to investigate the effects of noise on blood pressure and heart rate, after they controlled for other variables (e.g., gender, race, age). The authors controlled for confounding variables, after which use of hearing protection in high-noise areas was a significant predictor of a decrease in both systolic and diastolic blood pressures. The results suggested that the reduction of noise exposure by means of engineering controls or by consistent use of hearing protection by workers may positively affect health outcomes.

Annoyance Caused by Exposure to Road Traffic Noise: An Update.

Abstract: This paper addresses the negative effects resulting from the exposure to road traffic noise on people's well being with a focus on annoyance. Following the observations that noise exposures engender physiological reactions typical of stress, the non-auditory effects of noise on humans are generally viewed as being stress-related, and annoyance is one of the first and most direct reactions to environmental noise. In general terms, it is found that the continuous exposure of people to road traffic noise leads to suffering from various kinds of discomfort thus reducing appreciably the number of their well being elements. However drawing such a conclusion is hindered by difficulties when non-acoustical factors like sensitivity, socio-economic situation and age are also taken into account along with the usual acoustical factors of road traffic noise. The results of several decades of research on this topic have permitted lately to establish a quantitative relationship between the objective quantities characterizing road traffic noise, namely the day to night noise level, and the human subjective reaction to it as expressed by the percentage of highly annoyed people. These findings are important at both the society and the individual level in as much as they may help in regulating in a more efficient way the planning of road traffic activity in order to secure minimum comfort to the affected population.

Human response to environmental noise: the role of perceived control.

Abstract: Negative impacts of noise exposure on health and performance may result in part from “learned helplessness,” the syndrome of deficits typically produced by exposure to uncontrollable events. People may perceive environmental noise to be uncontrollable, and several effects of noise exposure appear to parallel “learned helplessness” deficits. In the present socioacoustic survey (N = 1,015), perceived control over aircraft noise correlated negatively with some effects of noise (though not others). Furthermore, these effects were better predicted by perceived control than by noise level. These observational data support the claim that “learned helplessness” contributes to the effects of noise exposure.

Cardiovascular and autonomic response to environmental noise during sleep in night shift workers.

Abstract: Polysomnograph, beat-by-beat heart rate and blood pressure were monitored in night shift workers exposed to environmental and laboratory noise events during day sleep. The study was carried out in a sleep laboratory. Subjects were nine young, healthy female night shift workers. Recorded noises from trucks, civilian aircraft, low altitude military aircraft and tones were presented at 55, 65, and 75 L Amax . Sleep stage, heart rate, and systolic and diastolic blood pressures before and immediately after onset of noise events were compared. Spectral analyses of heart rate and blood pressure variabilities were used to compare sympathetic and parasympathetic nervous tone in 10-min, intervals containing noise and quiet. Heart rate was responsive to noise level but not noise type. Blood pressure increased primarily to sounds of sudden onset. Noise-induced awakening and alpha EEG responses were related to BP increase. Increase in HR was greatest when subjects were awakened by noise or already awake. Spectral analysis of BP variabilities indicated increased sympathetic vascular tone due to noise. Similar analyses of HR data indicated no noise effect. No habituation to noise was apparent over three consecutive sleep sessions. It was concluded that over the range of noise levels used, heart rate responds to noise level during sleep; blood pressure to sounds of sudden onset. Spectral analysis of blood pressure variabilities is a sensitive measure of autonomic nervous response to environmental noise and should also be studied in subjects sleeping at home.

Social survey of community response to a step change in aircraft noise exposure.

Abstract: Community response to a step change in aircraft noise exposure associated with the opening of a new runway at Vancouver International Airport was documented in two rounds of telephone interviews. One round of interviews was conducted 15 months prior to the start of operations on the new runway, while a second round of interviews was undertaken 21 months after the start of operations. The proportion of respondents who described themselves as “very” or “extremely” annoyed by aircraft noise in a residential area with increased aircraft noise exposure after the runway opening was markedly greater than that predictable from well-known dosage–response relationships. Analysis suggests that a good part of the “excess” annoyance is attributable to the net influence of nonacoustic factors.

Press-in piling: Ground vibration and noise during pile installation

Abstract: Conventional dynamic piling methods are ill-suited to the urban environment. The press-in method offers an alternative technique of pile installation, which allows pre-formed piles to be installed with minimal noise and vibration. Field measurements of noise and ground vibrations during press-in piling are presented and compared to existing recommended limits. Based on this initial database, tentative prediction curves are presented. Equipped with these tools, designers can assess the relative environmental impact of each installation method when planning piling works.

A multiple regression model for urban traffic noise in Hong Kong.

Abstract: This article describes the roadside traffic noise surveys conducted in heavily built-up urban areas in Hong Kong. Noise measurements were carried out along 18 major roads in 1999. The measurement data included L10, L50, L90, Leq, Lmax, the number of light vehicles, the number of heavy vehicles, the total traffic flow, and the average speed of vehicles. Statistical analysis using the analysis of variance (ANOVA) and Tukey test (p<0.05) reveals that the total traffic flow and the number of heavy vehicles are the most significant factors of urban traffic noise. Multiple regression was used to derive a set of empirical formulas for predicting L10 noise level due to road traffic. The accuracy of these empirical formulas is quantified and compared to that of another widely used prediction model in Hong Kong—the Calculation of Road Traffic Noise. The applicability of the selected multiple regression model is validated by the noise measurements performed in the winter of 2000.

Changes over time in audiometric thresholds in a group of automobile stamping and assembly workers with a hearing conservation program.

Abstract: Noise induced hearing loss (NIHL) is among the 10 leading occupational diseases, afflicting between 7.4 and 10.2 million people who work in noise above 85 dBA. Although mandatory hearing conservation programs (HCPs) have been in effect since 1972, this problem persists, as hearing protectors are not consistently used by workers, or may not attenuate to manufacturer's estimates in real world conditions. In this study, information from noise and hearing protection use measurements taken at an automobile assembly plant were used to construct average lifetime noise exposure and hearing protection compliance estimates for use in modeling to predict both total hearing loss and onset of two accepted definitions of hearing loss. There were 301 males and females in this cohort; their mean age was 42.6 (7.2) years, and mean tenure was 14.3 (3.5) years. Average length of follow-up was 14.0 years. There were 16 members of this cohort who had hearing loss at the speech frequencies (defined as an average hearing level ...

A Tool for Low Noise Procedures Design and Community Noise Impact Assessment: The Rotorcraft Noise Model (RNM)

Abstract: To improve aircraft noise impact modeling capabilities and to provide a tool to aid in the development of low noise terminal area operations for rotorcraft and tiltrotors, the Rotorcraft Noise Model (RNM) was developed by the NASA Langley Research Center and Wyle Laboratories. RNM is a simulation program that predicts how sound will propagate through the atmosphere and accumulate at receiver locations located on flat ground or varying terrain, for single and multiple vehicle flight operations. At the core of RNM are the vehicle noise sources, input as sound hemispheres. As the vehicle "flies" along its prescribed flight trajectory, the source sound propagation is simulated and accumulated at the receiver locations (single points of interest or multiple grid points) in a systematic time-based manner. These sound signals at the receiver locations may then be analyzed to obtain single event footprints, integrated noise contours, time histories, or numerous other features. RNM may also be used to generate spectral time history data over a ground mesh for the creation of single event sound animation videos. Acoustic properties of the noise source(s) are defined in terms of sound hemispheres that may be obtained from theoretical predictions, wind tunnel experimental results, flight test measurements, or a combination of the three. The sound hemispheres may contain broadband data (source levels as a function of one-third octave band) and pure-tone data (in the form of specific frequency sound pressure levels and phase). A PC executable version of RNM is publicly available and has been adopted by a number of organizations for Environmental Impact Assessment studies of rotorcraft noise. This paper provides a review of the required input data, the theoretical framework of RNM's propagation model and the output results. Code validation results are provided from a NATO helicopter noise flight test as well as a tiltrotor flight test program that used the RNM as a tool to aid in the development of low noise approach profiles.

Assessment of the noise exposure of call centre operators.

Abstract: Call centres now play a major role in the daily operations of financial, technology and utility companies, as well as public bodies. It is predicted that 2002 will see 2.3% of the total British workforce employed in call centres. However, local authority enforcement officers, unions, voluntary organizations, employers and employees have all expressed concern that there are hazards to health and safety unique to this new and developing industry. One of the potential hazards reported in the press is hearing damage from using headsets. In a Health & Safety Executive funded project, the noise exposure of 150 call centre operators was evaluated, in call centres which included financial services, home shopping and telecommunications services. The results show that the daily personal noise exposure of these call centre operators is unlikely to exceed the 85 dB(A) action level defined in the Noise at Work Regulations 1989. The risk of hearing damage is therefore extremely low. Exposure to higher noise levels is possible, for example from fax tones, holding tones and high pitched tones from mobile phones. However, the duration of these events is likely to be short and they are therefore unlikely to have a significant effect on the operators’ overall noise exposure. A practical method of limiting exposure to unexpected high noises from headsets is to ensure that the headsets incorporate acoustic shock protection that meets the requirements of the Department of Trade and Industry specification 85/013. In the UK, this limiter ensures any noise above 118 dB is not transmitted through the headset. Operators should receive regular training on the headset and telephone equipment they are using. This training should include correct use of the headset and the volume control facilities, and advice on how and when to clean and maintain the headsets.

Noise levels of selected construction tasks.

Abstract: Current data regarding construction noise exposure are confusing, and their implications are not well understood. This is due in part to measurement challenges. Using standard dosimetry for measuring noise levels in the construction industry is inadequate due to the multitask, variable environment of the construction worker. This study used a task-based approach to collect noise exposure data on selected construction tasks. Results of this effort include the identification of additional tasks or tools producing high levels of noise that had not been previously identified by trade representatives. Noise levels for a variety of tasks were used in the development of a computer-based training program designed for three construction trade groups: roofers, laborers, and carpenters. Providing construction workers with information on noise levels specific to their trades can improve the effectiveness of hearing conservation education by making the information relevant to workers' day-to-day experience.

Relationship between low-frequency aircraft noise and annoyance due to rattle and vibration.

Abstract: A near-replication of a study of the annoyance of rattle and vibration attributable to aircraft noise [Fidell et al., J. Acoust. Soc. Am. 106, 1408–1415 (1999)] was conducted in the vicinity of Minneapolis-St. Paul International Airport (MSP). The findings of the current study were similar to those reported earlier with respect to the types of objects cited as sources of rattle in homes, frequencies of notice of rattle, and the prevalence of annoyance due to aircraft noise-induced rattle. A reliably lower prevalence rate of annoyance (but not of complaints) with rattle and vibration was noted among respondents living in homes that had been treated to achieve a 5-dB improvement in A-weighted noise reduction than among respondents living in untreated homes. This difference is not due to any substantive increase in low-frequency noise reduction of acoustically treated homes, but may be associated with installation of nonrattling windows. Common interpretations of the prevalence of a consequential degree of annoyance attributable to low-frequency aircraft noise may be developed from the combined results of the present and prior studies.

The Need for a Specific Noise Measurement for Population Exposed to Aircraft Noise during Night-time.

Abstract: Most of subjective complaints about aircraft noise during night-time refers to sleep disruption. In order to protect populations who live around airports, it is of major importance to define levels of noise considered to be unacceptable during that particular time of the 24-hour period. In addition to an integrated indicator which describes the global noise exposure (Lden), the French authority on airport noise control (Autorite de Controle des Nuisances Sonores Aeroportuaires: ACNUSA) is considering the possibility of defining a maximum noise level [LAmax (1s)] that should not be exceeded at night (from 22.00 to 06.00) by any flying aircraft over residential areas. The main benefit of this single event indicator would be the identification of contravening vessels and application of possible penalty. It is believed that this type of sanction would help protecting sleep in highly noise-exposed areas.

Night-time Noise Annoyance: State of the Art.

Abstract: The annoyance-reaction is one of the central variables in noise research After an introduction to different concepts and definitions of noise annoyance different scales of how noise annoyance can be measured are shown The question is discussed whether disturbance effects of noise at different times of day are given To clarify this problem, the results of a series of actual German noise studies are reported In these studies differences between day- and night­time annoyance are found depending on the sound sources For the case of road traffic noise no differences between day and night-time annoyance were found In contrast, annoyance reactions are related to the time of day for railway and air traffic noise Especially for aircraft noise, above a Leq of 50 dB(A) night-time annoyance rises faster than day-time annoyance The effects are discussed in the frame of a cognitive model of noise annoyance It is argued that annoyance judgments are based on an internal representation of the noise situation Part of this representation are the event characteristics of the sound sources and their estimated impacts for disturbances at different times of day

A comprehensive investigation of noise exposure in and around an integrated iron and steel works.

Abstract: A comprehensive environmental noise exposure study was carried out in and around a major iron and steel works. The works was located in the central part of the city and was surrounded by residential, commercial, and sensitive receptors. Traffic activity near the plant was significant and added to the background noise level. Considering the variety of noise sources in the plant area and in the neighborhood, a practical approach to measure noise equivalent level in the plant and in the residential, commercial, industrial, and silence zone was adopted. A modular precision integrating sound level meter with statistical analyzer module, octave filter set, and calibrator were used during the measurements. The day and night level, Ldn, was determined. Worker exposure was assessed by determining the speech interference level (SIL), loudness level, and noise rating level at one of the major sources located in the power plant of the steel works. The results indicate that SIL was 94 dBA, loudness level was 112 phons...

High-frequency noise in dentistry.

Abstract: Earlier studies have revealed that dentists have higher hearing thresholds than expected. The aim of this study was to evaluate the noise levels of current dentistry equipment under very controlled conditions. This noise study was carried out in the Acoustics Laboratory of Kuopio Regional Institute of Occupational Health, the background noise of which is about 0 dB(A). Working noise was simulated by drilling a polyacetal plate. During drilling and idling, the noise of the hand pieces was measured over a reflecting plane on the hemisphere surface, the radius of which was 0.3 m, and 10 noise samples were picked for each hand piece. The average sound pressure level and the sound power level of the devices were calculated applying the standard ISO 3744. The measurement and analysis were done in the one-third octave bands of 25–80,000 Hz. The measuring instruments used were the B&K 4135 microphones, the B&K 2633 preamplifiers, the B&K 2811 multiplexer, and the B&K 2133 real-time analyzer with the ZT 0318 high-...

Principles of Environmental Law

Abstract: Elements of environmental law European Community environmental law the development of a community environmental policy the common law and civil liability the Environment Agency and other regulatory authorities pressure groups, individuals and the environment and access to information atmospheric pollution water pollution integrated pollution and air pollution control the legal regulation of waste on land waste - the duty of care contaminated land planning and pollution control statutory nuisance noise and noise law.

Hearing Protector Use in Noise-Exposed Workers: A Retrospective Look at 1983

Abstract: Although hearing protectors have been available for more than 60 years, little field surveillance has been done to assess their appropriate wear in noisy occupational environments. This study examined historical field survey data to determine whether workers use hearing protection when exposed to loud noise. Data from the 1981–83 NIOSH National Occupational Exposure Survey were analyzed to determine whether workers in noise greater than or equal to 85 dBA were using hearing protection. The study also looked at the effect of company personal protective equipment (PPE) policies on hearing protector compliance. This study found that, in 1981–83, an estimated 4.1 million industrial workers were exposed to noise greater than or equal to 85 dBA. Of these, 41% were wearing some form of hearing protection. This percentage varied from 79% of workers exposed in SIC 76 (Miscellaneous Repair Service) to less than 1% in Communications (SIC 48), Wholesale Trade Nondurable Goods (SIC 51), and Automotive Dealers & Servic...

Aircraft noise exposure from schiphol airport: a relation with complainants.

Abstract: The possible relation between aircraft noise exposure and the prevalence of complainants around Schiphol airport was studied. The home address of people who complain about aircraft noise at the Environment Advisory Committee Schiphol was combined with annual average noise levels, using a Geographic Information System. The prevalence of complainants in areas with different noise exposure was calculated. In addition, data from a questionnaire survey was used to gain insight into the influence of sound insulation, personal characteristics, and aspects of health on complaint behaviour. The prevalence of complainants increases from < 1% at 50 dB(A) (Lden) to about 7% at 62 dB(A). Above this level the prevalence drops back to < 3%. An increase in the percentage of sound insulated houses with increasing noise levels is observed, rising markedly above 60 dB(A) (from 24% to almost 90%). When comparing people who complain with those who do not complain about aircraft noise, complainants report more noise annoyance (OR=10.2, 95% CI=8.54-12.3), sleep disturbance (OR=9.87, 95% CI=8.19-11.9), concern about health (OR=8.02, 95% CI=6.75-9.53), and fear for an aircraft crash (OR=3.64, 95% CI=3.07-4.31). Results indicate a relation between aircraft noise exposure and the prevalence of complainants, possibly influenced by sound insulation. Important determinants of complaint behaviour apart from noise level are noise annoyance, sleep disturbance, concern about health, and fear for an aircraft crash. Although complainants do not seem to be representative for the total population, and do not reflect the full extent of noise annoyance, their prevalence does reflect the regional distribution of aircraft noise annoyance in a noise polluted area.

Environmental Noise and Community in Hong Kong.

Abstract: In order to find out the attitude of the community towards environmental noise, community surveys were conducted over the territory of Hong Kong through telephone sampling. Specific surveys were also carried out for areas previously affected by severe aircraft noise. Main observations on the community's response towards noise are that noise pollution was ranked the third among five selected social concerns (after "air pollution" and "security", and higher than "traffic jam" and "cleanliness"); about 60% of the respondents found the territory "noisy"; the most annoying noise source was "traffic noise"; 40% of people found the most annoying noise not tolerable and that most people affected by noise suffered from "distraction". Nonetheless, many did nothing (e.g. did not complain) against the noise and still preferred an open-window life style.

Environmental impact of noise levels in and around opencast bauxite mine.

Abstract: Until recently, noise pollution has not been paid adequate attention as air, water and land pollution. In order to assess (predict) the impact of bauxite mine noise on employees health and in and around bauxite mine environment, general noise sources and equipment noise were monitored. All these noise sources were compared with prescribed standard noise levels laid down by Central Pollution Control Board (CPCB). Data has also been compared with reference site, north block hill top which is barren and virgin plateau/top covered with grass only and free from human interference. Equipment noise levels were much higher than the other zone of the mine which does not have the corresponding standards. Rock breaker recorded the highest noise level with 73.1 +/- 14.2 to 89.5 +/- 10.1 dB (A) while from ripper dozer it was least with 61.0 +/- 17.3 to 76.2 +/- 6.2 dB (A). Meteorological parameters did not have much influence upon equipment noise up to 100 feet from the source.

Noise emissions in thermal spray operations

Abstract: Acoustic noise generation is an accompanying effect produced during thermal spraying. This type of noise is found both during the preparatory stages, such as grit blasting and compressed air cleaning, and during thermal spraying. A real-time noise meter was used to measure the noise level at frequencies between 63 and 8000 Hz during the operation of powder flame, wire flame, wire arc, air plasma, and high velocity oxygen fuel (HVOF) spraying processes. Noise was reported as either an A-weighted noise spectrum or an equivalent sound pressure level. The effect of different parameters, such as secondary plasma gas type, modes of wire flame torch operation, and use of compressed air cooling were investigated. The results indicated that the turbulence of the gas departing from the torch gives rise to jet noise. High gas flows mainly contributed to the lower frequencies, whereas combustion and plasma generation contributed to the higher frequencies. Noise level was the highest (123 dB(A)) with HVOF spraying and air plasma spraying with the use of a small-diameter nozzle and hydrogen as a secondary plasma gas. All manual operators of thermal spray equipment require hearing protection. The use of different hearing protection devices is discussed and the attenuation provided by each device is reported.

Barrier designs to reduce road traffic noise

Abstract: Traffic noise reduction is an important area of public concern since nearly ten per cent of the population are seriously bothered by this type of noise. The reduction of noise annoyance can be tackled at any stage from generation at the source to the perception by the listener. Three stages can be identified: generation, propagation and reception. Mitigation measures fall into all three categories and an overview of relevant research into reducing sound propagation using roadside barriers is described in this paper. It should be borne in mind that to obtain a significant reduction in noise it may sometimes be necessary to effect a reduction at two or more stages. This is a ‘combined mitigation’ approach; for example, the use of low noise surfaces with noise barriers. Cost-effectiveness is also very important especially when public funds are involved. Additionally, public acceptability needs to be considered since a mitigation may be highly effective in reducing noise but not appropriate; for example, a vi...