Noise - 2,325 entradas encontradas
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Barham T.D., Russell M.F., Gooding D.
Improving the protection afforded by earmuffs to employees who are exposed to noise
This study investigated causes of variations in the protection afforded by earmuffs among different wearers. Microphones were installed in five earmuff cups worn by workers in an electronics factory where the noise was due to a large lamination press. Real-time measurements of sound level pressure were made both before and after instruction on how to fit the earmuffs correctly. Results showed that simple instruction on how to fit the hearing protectors gave an overall improvement in protection of 4dB. The effect of wearing safety spectacles was found to be negligible. Subjects with short hair tended to achieve higher levels of protection than those with long or curly hair.
Noise Control Engineering Journal, Sep.-Oct. 1989, Vol.33, No.2, p.67-76. Illus. 13 ref.
Zhuang W.X., Zhou D., Jin R.D., Yun H.
Case history: Shuttle loom noise control at the source: Principle and practice
This paper introduces the principles and applications of reducing the general A-weighted sound level in shuttle loom shops. Identification of noise sources indicated that over 95% of the sound power comes from impact noise produced by picking and checking. Four measures were adopted to control the noise and ten components were improved. As a result, the A-weighted sound level of one loom was reduced from 95dB to 85dB and the electric power consumption decreased by 5%. These measures and improvements are now widely used in China.
Noise Control Engineering Journal, May-June 1989, Vol.32, No.3, p.111-117. Illus. 6 ref.
Prevention of occupational diseases caused by intermittent vibration, noise and physical overloading among mechanical assembly fitters - Methodological recommendations
Profilaktika professional'noj patologii, obuslovlennoj vozdejstviem preryvistoj vibracii, šuma i fizičeskih peregruzok, u slesarej mehanosboročnyh rabot: Metodičeskie rekomendacii [en ruso]
These recommendations are issued with the approval of and in consultation with the Health Ministry of the Russian Federation. They are intended for physicians, engineering plant safety and health officers and trade-union safety inspectors, and propose a set of organisational, technical and medical measures, aimed at preventing harmful effects of vibration, noise and physical overloads on mechanical assembly fitters, engaged in metal roughing, scraping and grinding with abrasive wheels. A brief description is given of work processes and common workplace hazards as well as occupational disease clinical picture, course, diagnosis and treatment characteristics. In appendices: recommendations for developing good work time schedules; physical excercises for workers, exposed to noise and vibration (8-10min. exercise break); self- and mutual massage of the hands, arms and shoulders.
Ministerstvo zdravoohranenija RSFSR, Leningrad, USSR, 1989. 34p. Gratis.
Chavalitsakulchai P., Kawakami T., Kongmuang U., Vivatjestsadawut P., Leongsrisook W.
Noise exposure and permanent hearing loss of textile workers in Thailand
Hearing loss induced by noise exposure in a large scale textile mill (number of workers = 1,611) in Thailand was investigated on the basis of interviews, noise measurements, and audiometric tests. The frequency of subjective symptoms relating to noise exposure was higher in the weavers than among other mill workers and office workers. The average noise levels in the weaving sections and other sections were 101.3±2.7dBA and 89.8±5.3dBA, respectively. The results of the audiometric tests revealed a significantly higher incidence of noise-induced hearing loss among workers in the weaving section than among other mill workers and office workers (P<0.01). Among weavers, hearing levels decreased with the longer years of work. It was found that 38.6% of the weavers never used personal hearing protection devices. It was concluded that there was a serious loss of hearing among workers in the mill. Improvements by means of integrated work organisation activities were recommended.
Industrial Health, 1989, Vol.27, No.4, p.165-173. 8 ref.
Work in a dangerous environment - the road as work environment
Arbeiten in gefährlicher Umwelt - die Strasse als Arbeitsumgebung [en alemán]
The fears of road repair workers of being run over by a car are illustrated by quoting accounts of near misses. Other hazards encountered by these workers are exposure to noise levels above 85dB(A) during most of their work and to air pollutants from exhaust gases. A study of 70 workers revealed hearing losses between 23 and 26dB(A) after an average of 15 years of noise exposure. A survey of information on the effects of exhaust gas components on the respiratory tract of workers showed that few specific studies exist.
Arbeit und Betrieb, 1989, No.22, p.74-93. Illus. 27 ref.
Leśnik H., Makowiec-Dąbrowska T.
Hemodynamic reactions to monotonous work performed in silence and in noise of 70dB(A)
Haemodynamic parameters (cardiac contraction rate, ejection volume, arterial blood pressure and total vascular peripheral resistance) were evaluated in women during monotonous work lasting 4h, accompanied by moderate exercise, and during monotonous visual work performed under laboratory conditions. Subsequently, the effect of noise levels of 70dB(A) on haemodynamic parameters was evaluated. It was found that noise did not affect work efficiency, but it did cause an increase in ejection volume and a rise in arterial (especially diastolic) blood pressure. Thus noise levels of 70dB(A) cause an increase of physiological effort of work.
Polish Journal of Occupational Medicine, Jan.1989, Vol.2, No.1, p.51-61. 28 ref.
Sound intensity as a method for sound power measurements and identification of noise sources
Ljudintensitet som metod för ljudeffektmätningar och för lokalisering av bullerkällor [en sueco]
Sound intensity as a measure of noise emission from machines has met increasing interest. This report describes the principles of sound intensity measurements, some theory and also the draft proposal for measuring sound power levels adopted in Oct. 1988 by the ISO. Some examples of measuring sound power using the intensity method are given, with measurements on a pistol blowing hot air. The results indicate that sound intensity can be used for determining sound power levels in diferent types of rooms. Pictures of the distribution of intensities can be made with the help of computers.
Arbetsmiljöinstitutet, Förlagstjänst, 171 84 Solna, Sweden, 1989. 25p. Illus. 19 ref.
Commission of the European Communities
Fourth ECSC research programme on technical control of nuisances and pollution at the place of work and in the environment of iron and steelworks: Status of research at 31 Dec. 1985
Quatrième programme de recherche CECA - Lutte technique contre les nuisances sur les lieux de travail et dans l'environnement des installations sidérurgiques: Etat des travaux de recherche au 31 déc. 1985 [en francés]
A general review of 83 research projects in the areas of: air and water pollution from coking plants; limiting NOx emissions from sintering plants and improvement of electrostatic precipitators; fume emission and noise from blast furnaces; fume emission, noise and dust in melting shops; effluent treatment and noise from rolling mills; methods and equipment for the measurement of atmospheric pollution, aqueous effluent analysis and harmonisation of sampling methods; general problems of pollution associated with all activities of an integrated iron and steelworks. The report includes a list of the projects covered by this research programme.
Office des publications des Communautés européennes, 2, rue Mercier, 2985 Luxembourg, Grand Duchy of Luxembourg, 1989. 87p. Price: ECU 8.75.
Vibration damping of circular saws
An idealised theoretical approach was used for calculating the viscous losses due to a thin layer of air between a vibrating plate and a rigid wall or a sound-absorptive wall. Damping is in both cases of the same order of magnitude. Loss factor measurements were performed on a model saw equipped with a rigid Plexiglas wall. Installation of a Plexiglas plate on a full-size circular saw so that a 0.6mm air layer was created between the rigid plate and the saw blade reduced the noise level by about 7dB.
Acustica, 1989, Vol.69, No.6, p.270-275. Illus. 10 ref.
Commission Directive of 2 Aug. 1989 adapting to technical progress Council Directive 86/662/EEC on the limitation of noise emitted by hydraulic excavators, rope-operated excavators, dozers, loaders and excavator-loaders [CEC]
Directive de la Commission du 2 août 1989, portant adaptation au progrès technique de la directive 86/662/CEE du Conseil relative à la limitation des émissions sonores des pelles hydrauliques et à câbles, des bouteurs, des chargeuses et des chargeuses-pelleteuses [CCE] [en francés]
Annex II to Directive 86/662/EEC (see CIS 90-382) is replaced by the Annex to this Directive, which lays down the dynamic test method of measurement of airborne noise emitted by earthmoving equipment.
Official Journal of the European Communities - Journal officiel des Communautés européennes, 30 Aug. 1989, Vol.32, No.L.253, p.35-43. Illus.
Velasco Abásolo J.
Actualización de la normativa de ruido - Real Decreto 1316/1989
This article provides information on the new Spanish legal standards (Royal Decree 1316/1989) on the protection of workers from noise. This decree adheres to Directive 86/188/EEC and it establishes a noise level limit based on the concept of an equivalent continuous level instead of a level of sound pressure as before. It covers: periodic evaluations in workplaces with a certain sound level; the classification of workplaces in 4 categories according to the prevailing noise level; preventive measures; personal protective equipment; specifications concerning sonometers and dosimeters; marking of equipment generating noise above 80dB(A) or 140dB at peak level; specifications concerning audiometry equipment; exposure and medical records; workers' participation; safety and health committees.
Mapfre seguridad, 4th Quarter 1989, No.36, p.3-10. Illus.
Chavalitsakulchai P., Kawakami T., Kongmuang U., Vivatjestsadawut P., Leongsrisook W.
Noise exposure and permanent hearing loss of textile workers in Thailand
Hearing loss induced by noise exposure in a large scale textile mill (number of workers = 1,611) in Thailand was investigated on the basis of interviews, noise measurements, and audiometric tests. The frequency of subjective symptoms relating to noise exposure was higher in the weavers than among other mill workers and office workers. The average noise levels in the weaving sections and other sections were 101.3±2.7 dB(A) and 89.8±5.3 dB(A), respectively. The results of the audiometric tests revealed the significantly higher noise-induced hearing loss among workers in the weaving section compared to other mill workers and office workers (P<0.01). Among weavers, hearing levels decreased with longer years of work. 38.6% of the weavers never used personal noise protective devices. It was concluded that hearing loss status in the workers of the mill was serious. Improvements by means of integrated work organisation activities were recommended.
Industrial Health, Mar. 1989, Vol.27, No.4, p.165-173. 8 ref.
Engineering for environmental noise control - Inter-Noise 89
Proceedings of an international conference on noise control engineering, held in Newport Beach, California, USA, 4-6 December 1989. Papers are grouped under the following headings: noise emission sources (sound generation mechanisms and noise levels for various types of machines and equipment); physical phenomena (noise tests, sound propagation measurement); noise control elements (acoustic barriers, absorptive materials, mufflers, silencers, active noise control); generation, transmission, isolation and reduction of vibration and shock; physical aspects of environmental noise (noise prediction and control in buildings, airports, road transport and concert halls); effects of noise (loudness evaluation, low frequency sound, noise nuisance from road traffic and aircraft); analysis (noise measurement equipment and techniques); requirements (legislation, standards, exposure levels).
Noise Control Foundation, Arlington Branch, P.O. Box 3469, Poughkeepsie, NY 12603, USA, 1989. Vol.I, p.1-700; Vol.II, p.701-1312. Illus. Bibl. Index. Price: USD 100.00.
Campo P., Cnockaert J.C.
Effect of noise during pregnancy on foetal hearing - Review
Risques auditifs encourus par le f¿tus chez la femme enceinte exposée au bruit - Etude bibliographique [en francés]
Literature review on the effects of noise on the inner ear (cochlea) of the foetus in pregnant women exposed to noise. The last 3 months of pregnancy are the 'critical period' during which the cochlea seems particularly susceptible to noise. Prolonged exposures to high noise levels, even below the 85dB(A) legal limit, can produce hearing loss in the foetus. Surrounding material tissue can attenuate noise exposure in the foetus by 20-30dB at frequencies above 500Hz. Low frequencies (<500Hz) are far less attenuated and therefore are more dangerous for the foetus. The A weighting is therefore not well adapted to estimate the harmfulness of a pre-natal noise exposure. In the absence of more data, it is recommended that the noise exposure of pregnant women be limited, especially during the last 3 months of pregnancy, and when there is much noise at frequencies <500Hz.
Cahiers de notes documentaires - Sécurité et hygiène du travail, 4th Quarter 1989, No.137, Note No.1756-137-89, p.633-637. 30 ref.
Noise control - Woodworking
Lärmbekämpfung- Holzbearbeitung [en alemán]
This information note provides guidelines on noise control measures for woodworking machines. Aspects covered: hearing loss, audiometric tests, regulatory threshold exposure limits, hearing protectors, sound pressure levels, reduction of sound levels, sound emission near the machines, examples of acoustic enclosures.
Allgemeine Unfallversicherungsanstalt, Abteilung für Unfallverhütung und Berufskrankheitenbekämpfung, Adalbert-Stifter-Strasse 65, 1200 Wien, Austria, 1989. 28p. Illus.
Eddington N., Eddington I.
Noise labelling and legislation
Noise labelling requires that manufacturers and retailers of certain categories of equipment must inform potential customers of the noise emitted by the equipment during a prescribed test. Labelling also serves health authorities, employers, industrial hygienists and others through a requirement that manufacturers must supply particular noise information prior to point of sale. Considerable work on international standardisation has already been carried out as well as independent work in Australia and some European countries. In order to ensure that noise labelling can function effectively, there must be a clearly defined noise descriptor linked to a clearly defined measuring method, and a methodology for the verification of labelled values. There must be continuing public education on labelling and consumer rights, and where possible, legislation should favour manufacturers of low-noise products.
Noise and Vibration Control, Apr. 1989, Vol.20, No.4, p.118-119.
Rentzsch M., Minks B.
Combined effects of sound, climate and air pollutants on noise induced hearing loss
In a laboratory experiment, 10 subjects were exposed to various sound loads at air temperatures of 24°C and 35°C. As expected, the greatest threshold shifts occurred at maximum sound and climate loads. A field study was also carried out to investigate permanent hearing loss in groups of welders and machinery and plant assembly workers exposed to a combination of noise and carbon monoxide. Welders suffered hearing damage when the noise limit for hearing impairment was scarcely exceeded, while the risk was relatively lower for the assembly workers with comparatively higher noise levels and lower carbon monoxide exposure. Results therefore indicate a relationship between combined noise and carbon monoxide exposure and risk of hearing damage.
Archives of Complex Environmental Studies, Dec. 1989, Vol.1, No.1, p.41-44. Illus. Bibl.
Haider M., Groll-Knapp E., Kundi M.
Some theoretical viewpoints on combined effects of environmental factors
In order to combine measurements for multiple environmental influences, measured values of different environmental factors may be transformed into a universal scale. Combined reactions may then be categorised according to effect levels and types of interaction. Examples are given of combined effects of noise and carbon monoxide on the inner ear and on the central nervous system, and of nitric oxide and carbon monoxide on blood parameters, performance and CNS activity in experimental animals. Effect levels and types of interactions due to annoying environmental influences are discussed, and a theory on man-environment systems and their possible destabilisation due to combinations of environmental factors is described.
Archives of Complex Environmental Studies, Dec. 1989, Vol.1, No.1, p.7-13. Illus. Bibl.
van den Brulle P.
Bundesanstalt für Arbeitsschutz
Manual for surveys of factors of the working environment. Noise, lighting, climate and dangerous substances
Leitfaden für Kataster von Arbeitplatzumgebungsfaktoren. Lärm, Beleuchtung, Klima, Gefahrstoffe [en alemán]
This manual presents a method for compiling a register for each of the 4 most important factors of the workplace environment - noise, lighting, climate and dangerous substances. The registers are primarily designed for safety officers and institutions responsible for occupational safety and health. Each of the four manuals can be used separately. Their practical application is demonstrated by 3 studies - bottling, weaving mill and moulding.
Wirtschaftsverlag NW, PF 101110, 2850 Bremerhaven 1, Federal Republic of Germany, 1989. 186p. Illus. 37 ref.
Health and Safety Executive
Noise at work - Guidance on regulations [United Kingdom]
This guidance publication contains the text of The Noise at Work Regulations 1989 (see also CIS 90-21), together with extensive explicatory text and commentary. There are two parts to the publication: Noise Guide 1 (Legal duties of employers to prevent damage to hearing) and Noise Guide 2 (Legal duties of designers, manufacturers, importers and suppliers to prevent damage to hearing).
HMSO Books, P.O. Box 276, London SW8 5DT, United Kingdom, 1989. 27p. Illus. Price: GBP 3.00.
Confirmation of noise exposure levels by analysis of the audiometric data in long service underground train drivers
The results of 40 audiograms from otologically normal long-term underground train drivers were compared with the predicted values published by the National Physical Laboratory tables (Robinson and Shipton, 1977). The age-corrected hearing threshold levels were plotted as an arithmetic probability at varying frequencies and compared with the corresponding predicted distributions. The results indicate that London Transport Underground train drivers are subjected to a noise level of less than 85dB(A)LEQ(8h), which substantiates the surveyed noise levels.
Journal of the Society of Occupational Medicine, Autumn 1989, Vol. 39, No.3, p.107-110. 5 ref.
Estimation of occupational deafness in a pasta factory
Ektimēsē tōn epaggelmatikōn ōtopadeiōn se mia biomēhania zumarikōn [en griego]
The hearing of 264 workers was tested and the noise environment was measured in order to evaluate the relationship between noise exposure and occupational deafness in a pasta factory.
Iatrikē tēs Ergasias, Apr.-June 1989, Vol.1, No.2, p.103-108. Illus. 9 ref.
Hohmann B., Schmuckli F.
Noise hazards in the workplace
Gehörgefährdender Lärm am Arbeitsplatz [en alemán]
Rumore pericoloso per l'udito negli ambienti di lavoro [en italiano]
Dangers du bruit pour l'ouïe à l'emplacement de travail [en francés]
This booklet, usable for training purposes, collects and analyses the basic elements of hearing protection. Contents: basic legislation in Switzerland; basic notions of acoustics; hearing; techniques of noise measurement; noise in the workplace; noise control (with practical examples); role of the Swiss National Insurance Institution in the prevention of hearing damage. In annex: useful addresses and information concerning legislative texts, publications and audiovisual materials.
Caisse nationale suisse d'assurance en cas d'accidents, Case postale, 6002 Luzern, Switzerland, 1989. 143p. Illus.
Kahema H., Monyo R.A., Svedberg U.
Occupational noise measurement and control in Tanzanian textile mills
Surveys were conducted in the weaving and spinning sections of Tanzanian textile mills (4 shuttle loomsheds, 1 air-jet loomshed, 3 spinning sections). Equivalent sound pressure levels were 92.0 - 103.8dB(A) in the loomsheds and 91.0-93.7dB(A) in the spinning sections. Frequency analyses and noise rating curves were plotted. Noise emission from the shuttle looms was reduced by 3.2dB(A) by padding and enclosing the points of contact between the shuttle and the mechanism that catches and throws it. However, the solution was of limited practicality, because the padding wore quickly, which necessitated continual adjustment of the loom, and the noise level remained so high that workers had to wear hearing protectors. Replacement of the shuttle with air-jet looms is the only effective long-term solution of the noise problem.
East African Newsletter on Occupational Health and Safety, 20 Sep. 1989, No.1, p.12-15. Illus.
Ministerio de Relaciones con las Cortes y de la Secretaria del Gobierno
Real Decreto 1316/1989, de 27 de octubre, sobre protección de los trabajadores frente a los riesgos derivados de la exposición al ruido durante el trabajo
Decree issued in accordance with European Communities Directive 86/188 (see CIS 87-45). It covers: obligations of the employer to reduce noise to the lowest practicable level and to measure noise levels; rights of workers' representatives to be present during the measurement of noise levels and to be informed of the results of measurements; use of ear protectors (starting at equivalent daily noise levels of 85dB(A)); periodic audiological examinations (starting at daily average noise levels of 80dB(A)); maintenance of registers of data resulting from audiological examinations. In the annexes: definitions and general concepts; noise measurement; instruments of noise measurement and calculation methods; hearing tests of workers.
Boletín Oficial del Estado, 2 Nov. 1989, No.263, p.34428-34431.
Medical examinations for noise-exposed workers
Arbeitsmedizinische Vorsorgeuntersuchungen bei Arbeiten im Lärmbereich [en alemán]
Revision 4.1988 of the Federal German directive on medical examinations of noise-exposed workers is presented and commented upon. The revised version requires, inter alia, more detailed audiometric examinations prior to work in a noisy environment.
Arbeitsmedizin - Sozialmedizin - Präventivmedizin, 1989, Vol.24, No.6, p.125-133. Illus. 18 ref.
Selection of silent machines - Hobbing machines
Lärmminderung durch Auswahl leiser Maschinen - Wälzfräsmaschinen [en alemán]
A diagram relating maximum acceptable noise emission levels to motor power and tool speed of hobbing machines is given. New hobbing machines of a given class should have a noise-emission level lower than that of 75% of existing machines in that class.
Amtliche Mitteilungen der Bundesanstalt für Arbeitsschutz, Jan. 1989, No.1, p.6-8. Illus.
Noise legislation and the petrochemical industry
Description of major oil company programmes aimed at meeting the requirements of EC Directive 86/188/EEC on noise exposure limits.
Noise and Vibration Control, Sep. 1989, Vol.20, No.8, p.211-214. Illus.
Interpreting the Euro noise regulations
Interpretation of the EC Directive 86/188/EEC (see CIS 87-45) on noise control and its impact on UK regulations.
Noise and Vibration Control, Sep. 1989, Vol.20, No.8, p.209-210. Illus.
Soleo L., Cassano F., Mazzilli G., Martemucci A., Castrignanò G., Catamo E., Lasorsa G., Candilio G., Ambrosi L.
Evaluation of noise-induced hearing loss in a group of cement workers
La valutazione del danno da rumore: Considerazioni su una casistica di esposti addetti alla produzione del cemento [en italiano]
The study covered 1,334 workers employed in 12 cement factories located in southern Italy. They were submitted to audiometric screening consisting of a questionnaire containing questions on past otologic complaints, dysmetabolic diseases, use of ototoxic drugs and past occupational or non-occupational exposure to noise, plus otoscopic examination and full audiometric examination. The results revealed a statistically significant relationship between duration of exposure to noise and elevation in the hearing threshold. On the question of assessment of the audiometric tracings for preventive and insurance purposes, attention is drawn to the fact that there is a need for a method that will enable an evaluation for prevention to be transformed into an evaluation for insurance. This method should in any case allow for deduction of the portion of hearing loss regarding presbycusis and socioacusis and take due account of the 3KHz frequency. The attention of industry and public administration is drawn to the urgent need for prevention programmes to protect against noise-induced hearing loss in both occupational and non-occupational settings.
Medicina del lavoro, May-June 1989, Vol.80, No.3, p.229-243. Illus. 39 ref.
Grand Ducal Regulations of 1 June 1989 concerning sound emissions from construction equipment [Luxembourg]
Règlements grands-ducaux du 1er juin 1989 relatifs à l'émission sonore des engins et matériels de chantier [Luxembourg] [en francés]
Six regulations relating to the determination and limitation of sound emission levels from construction equipment.
Mémorial - Journal officiel du Grand-Duché de Luxembourg, 17 June 1989, A - No.39, p.746-756.
Order of 31 Jan. 1989 concerning the medical supervision of workers exposed to noise. Technical instructions for occupational physicians [France]
Arrêté du 31 janv. 1989 concernant la surveillance des travailleurs exposés au bruit - Instructions techniques aux médecins du travail [France] [en francés]
Government order of 31 January 1989, issued pursuant to article R. 232-8-4 of the French Labour Code (published in the Journal officiel on 8 February 1989). Medical supervision includes: training and information of exposed workers with regard to the risks involved and the personal and collective means of protection available; the clinical and audiometric examination of workers before assignment to a noise-exposed workplace; periodic medical examinations and audiometric checkups. The results of these examinations and checkups, presented collectively, may be communicated to the committee responsible for safety, health and working conditions, to the Labour Directorate, to the occupational risk prevention departments of the Regional Health Insurance Funds and to professional organisations concerned with occupational safety and health and working conditions.
Cahiers de notes documentaires - Sécurité et hygiène du travail, 2d Quarter 1989, No.135, Note No.1740-135-89, p.369-371.
Health and Safety - The Noise at Work Regulations 1989 [United Kingdom]
These Regulations give effect in Great Britain to provisions of CEC Directive 86/188/EEC (see CIS 87-45). They impose requirements on employers, and to a lesser extent on employees, with respect to the assessment and prevention of noise exposure in the workplace, and with respect to the protection of workers exposed to noise. The first action level (the level at which assessment of exposure becomes mandatory) means a daily personal noise exposure (DPNE) of 85db(A). The peak action level (200 pascals) is a level of sound pressure the occurrence of which for any length of time requires the wearing of personal ear protectors.
HMSO Books, P.O. Box 276, London SW8 5DT, United Kingdom, 1989. 7p. Price: GBP 1.65.
Occupational noise exposure - French regulations
La protection contre le bruit [en francés]
This paper deals first with the presentation of the overall legislation written to enact the CEC directive (see CIS 87-45) in France. It then analyses the legislation designed to protect workers. Contents include: a basic principle, how to build silent; protecting workers against noise; monitoring of noise exposure and threshold limit values for industrial noise exposure; safety and health engineering; hearing protectors. An appendix contains the text of the decree (21 April 1988; see also CIS 89-724) together with its application circular (6 May 1988).
Cahiers de notes documentaires - Sécurité et hygiène du travail, 1st Quarter 1989, No.134, Note No.1715-134-89, p.17-28. 7 ref.
Noise at workplaces with personal computers
Lärm am PC-Arbeitsplatz [en alemán]
Noise levels emitted by microcomputers from different manufacturers have been measured to be 50-60dB(A). Printers may have noise levels as high as 73dB(A). Recent research has shown that noise levels of 50-60dB(A) could lead to performance impairment, in particular in complex intellectual activities where memorisation and concentration play an important role. It is therefore suggested to take into consideration the noise environment of PC workstations.
c't - Magazin für Computer-Technik, 1989, No.10, p.90, 92, 94-95. Illus. 4 ref.
Noise of medium intensity - effects on office and administrative tasks
Geräusche mittlerer Intensität - Auswirkungen auf Büro- und Verwaltungstätigkeiten [en alemán]
Conclusions to be drawn from the results of field and laboratory studies on the effects of noise levels between 30 and 80dB(A) on mental tasks are: tasks requiring intensive concentration, numerical ability and logical thinking are impaired at noise levels of 50dB(A) and higher; decision time is prolonged; work progress is slowed down; error rate increases; performance of short-time memory decreases.
Zeitschrift für Lärmbekämpfung, 1989, Vol.36, No.1, p.2-7. Illus. 23 ref.
Pathak B., Marha K., Louch W.J.
An industrial noise levels database
A data base of industrial noise levels has been developed and made available through an online system and on compact disc. The contents are compiled from the data reported in journals, health and safety reports, and industrial hygiene surveys made by industries, government agencies and independent institutions. Along with measured noise level data, information on engineering controls and use of ear protection is included whenever such data are available. The objective of the data base is to facilitate sharing of information on noise levels among those concerned with workplace health and safety.
Annals of Occupational Hygiene, 1989, Vol.33, No.2, p.269-274. 7 ref.
Trayer D.M., Thornton C.C., Lehman C.B.
Development and testing of a new thermal-acoustic industrial insulation
Following laboratory tests of several candidate materials, one was selected for full-scale tests on high-speed boiler-feed water pumps in an electric power plant. The field tests showed a noise reduction of 10 to 30 decibels in the frequency range of 250 to 4000Hz. It is thought that at least 10 decibels of mid-frequency noise attenuation can be achieved on noisy process equipment such as high-speed pumps, turbines, and control valves. Heat stress conditions in the area of pumps were also alleviated as the result of a temperature reduction of 6°K (10°F) dry-bulb. An investigation is being conducted to determine if this represents a significant thermal energy gain in the process feedwater - a factor which could offset the cost of the insulation. The insulation is asbestos-free, and the removal and replacement of individual components are achieved without generation of excessive airborne dust.
Applied Industrial Hygiene, Feb. 1989, Vol.4, No.2, p.45-49. Illus. 5 ref.
Noise reduction by selection of quiet machines - Pneumatic hammers
Lärmminderung durch Auswahl leiser Maschinen - Drucklufthämmer [en alemán]
On the basis of existing directives (VDI 3749 Part 2 and EC-guidelines), sound pressure levels of 108, 111 and 114dB (for weights of up to 20kg, 20-35kg and over 35kg) were determined to characterise pneumatic hammers with the lowest noise emission. For selecting quiet pneumatic hammers, A-weighted sound pressure levels according to DIN 45649 Part 1 or 2 and sound levels determined under operating conditions according to DIN 45635 Part 20 should be compared with the above values.
Amtliche Mitteilungen der Bundesanstalt für Arbeitsschutz, Apr. 1989, No.2, p.8-10. Illus.
Nurminen T., Kurppa K.
Occupational noise exposure and course of pregnancy
The experience of 1,190 reference mothers from a case-referent study based on the Finnish Register of Congenital Malformations was scrutinised. Exposure to noise was blindly assessed from a description of the mother's workday by two industrial hygienists. Women exposed to an estimated noise level of 80dB or higher were considered exposed. Threatened miscarriage was not associated with noise exposure alone, but, when it was combined with shift work, the adjusted risk was over twofold. The adjusted risk of pregnancy-induced hypertension was twice as high among the mothers exposed to noise in shift work, and the duration of their pregnancy was shorter. The analyses produced indications of a relation between noise and growth retardation which was not connected with shift work. There were significantly increasing trends in the incidence of these outcomes according to exposure intensity.
Scandinavian Journal of Work, Environment and Health, Apr. 1989, Vol.15, No.2, p.117-124. 31 ref.
Kurppa K., Rantala K., Nurminen T., Holmberg P.C., Starck J.
Noise exposure during pregnancy and selected structural malformations in infants
The study tested the hypothesis of exposure to noise during pregnancy being teratogenic. It included 1,475 Finnish mothers who had given birth to a malformed child (orofacial cleft or structural defect of the central nervous system, skeleton, or heart and great vessels) and 1,475 reference mothers. A special interview soon after delivery yielded the primary information on exposure. Of the 783 mothers who reported noise exposure in the first trimester, 370 were case mothers and 413 were referents. Hygienic assessment indicated that 102 case mothers and 103 referents had been exposed in the first trimester to a sound level of around 80dB or higher. Adjustment for potential confounders by logistic regression methods gave similar results. There was no obvious trend suggesting a hazard when different exposure categories were considered.
Scandinavian Journal of Work, Environment and Health, Apr. 1989, Vol.15, No.2, p.111-116. 26 ref.
Weck M., Jansen U.
Identification of noise sources in toothed belt drives
Ermittlung der Geräuschursachen von Zahnriementrieben [en alemán]
Evaluation of a large number of noise measurements on toothed belt drives led to identification of the major noise source: the impact of the belt on the teeth. At extremely high velocities, air circulation noise adds to the noise level. Coating of the teeth or the belt brought about noise reductions of approximately 10dB.
Industrie-Anzeiger, 1989, Vol.111, No.3/4, p.22-26. Illus. 7 ref.
Noise exposure of motorcyclists
This study was designed to evaluate noise exposure of motorcyclists at work. Open and full face safety helmets were compared and the effects of helmet design and the contribution of radio intercoms investigated. Special measuring equipment is described and hearing protection discussed. Previous studies concentrated mainly on the attenuation of noise by safety helmets, and were made under conditions untypical of day-to-day motorcycling. During town driving the sample equivalent continuous noise level (s.leq) ranged from 63 to 90dB(A), the intercom giving the highest peak levels. On the open road s.leq was up to 105dB(A); exposure to this level for only 15min would exceed the present recommended maximum 90db(A) for an 8h working day.
Annals of Occupational Hygiene, 1989, Vol.33, No.1, p.123-127. Illus.
Personal hearing protection equipment
Der persönliche Gehörschutz [en alemán]
La protezione individuale dell'udito [en italiano]
La protection individuelle de l'ouïe [en francés]
Users' guide intended for workers and employers. Aspects covered: definition of noise hazardous to hearing; effects of acoustic load on the hearing organ; evaluation of different types of hearing protection equipment, their acoustic isolation, the length of time they can be used, the upper acoustic level the worker is protected against; requirements for the understanding of communication and signs; legal aspects of the use of hearing protection in Switzerland.
SUVA, Postfach, 6002 Luzern, Switzerland, Mar. 1989. 51p. Illus. 17 ref.
Reduction of noise from multi-head woodworking planers - A technical guide
This guide outlines noise criteria associated with the operation of multi-head planing machines, relevant New Zealand legislation and the limitations of noise reduction techniques at the design stage. Details are given of the design of acoustic enclosures for the reduction of noise exposure (isolation, construction materials, doors, windows, feed and discharge apertures, ventilation). Additional benefits of such enclosures include dust and chip control.
Occupational Safety and Health Service, Department of Labour, P.O. Box 3705, Wellington, New Zealand, 1988. 15p. Illus.
Noise solutions: Controlling noise in industry. No. 1, Compressed air
Sources of air noise in industry are described and methods of reducing compressed air noise are presented. Pneumatic valve exhaust silencing and reducing noise with compressed air jets are discussed.
Workers' Compensation Board of British Columbia, 6951 Westminster Highway, Richmond, British Columbia V7C 1C6, Canada, 1988. 12p. Illus.
Acoustics - Declared noise emission values of computer and business equipment
Acoustique - Valeurs déclarées d'émission acoustique des matériels informatiques et de bureau [en francés]
This international standard specifies: the method for determining the declared noise emission values of computer and business equipment; acoustical and product information to be given in technical documents supplied by the manufacturer; the method for verifying the declared noise emission values given by the manufacturers.
International Organization for Standardization, Case postale 56, 1211 Genève 20, Switzerland, 15 Apr. 1988. 7p. 5 ref.
Acoustics - Measurement of exterior noise emitted by earth-moving machinery - Dynamic test conditions
Acoustique - Mesurage du bruit émis à l'extérieur par les engins de terrassement - Conditions d'essai dynamiques [en francés]
This international standard describes a method for determining the noise emitted by earth-moving machinery in terms of the A-weighted sound power level while the machine is working under dynamic test conditions. Contents: definitions; instrumentation; requirements for the test environment; technique for the measurement of equivalent continuous A-weighted sound power level. Annexes describe procedures for specific types of equipment.
International Organization for Standardization, Case postale 56, 1211 Genève 20, Switzerland, 1 June 1988. 13p. Illus. 3 ref.
Acoustics - Determination of sound power levels of noise sources - Precision methods for broad-band sources in reverberation rooms
Acoustique - Détermination des niveaux de puissance acoustique émis par les sources de bruit - Méthodes de laboratoire en salles réverbérantes pour les sources à large bande [en francés]
This international standard specifies in detail 2 laboratory methods for determining the sound power radiated by a source. It applies primarily to sources which produce steady broad-band noise. Contents: definitions; test room requirements; instrumentation; installation and operation of sources; measurement of mean-square sound pressure; calculation of sound power level. Annexes include a test room qualification procedure for the measurement of broad-band sound, and characteristics and calibration of a reference sound source.
International Organization for Standardization, Case postale 56, 1211 Genève 20, Switzerland, 21 Jan. 1988. 16p. 14 ref.
A small-scale survey into the use of audiometry in practice
The aim of this survey was to find out why and how audiometry was practiced by various enterprises, and what use was made of audiometric results. Eleven employers and one independent training, safety and medical organisation were visited. The report concludes that among employers who practice audiometry, hearing levels of employees are not deteriorating to a significant extent, thanks to the use of hearing protection; that if hearing threshold levels rise significantly, for whatever reason, they will be detected; that audiometry is an educational tool which brings about more assiduous use of hearing protection.
Health and Safety Executive, St. Hugh's House, Stanley Precinct, Trinity Road, Bootle, Merseyside L20 3QY, United Kingdom, 1988. 50p. Price: GBP 20.00.
Acoustics - Determination of sound power levels of noise sources - Engineering methods for special reverberation test rooms
Acoustique - Détermination des niveaux de puissance acoustique émis par les sources de bruit - Méthodes d'expertise en salles réverbérantes spéciales [en francés]
This international standard specifies relatively simple engineering methods for determining the weighted and octave-band sound power levels of small noise sources. The methods are not suitable for noise sources which emit impulsive noise consisting of single noise bursts. Contents: definitions; test room requirements; instrumentation; installation and operation of source; measurement of noise emitted by source; calculation of sound power levels. Annexes include characteristics and calibration of a reference sound source.
International Organization for Standardization, Case postale 56, 1211 Genève 20, Switzerland, 12 Jan. 1988. iii, 19p. Illus. 14 ref.
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