The Associations Between Workplace Noise, Ototoxic Chemicals, and Tinnitus

Sources of noise exposure across Australian workplaces: cross-sectional analysis and modelling the impact of a targeted noise-source reduction initiative

CONTEXT

Workplace noise regulations and guidance follow the hierarchy of control model that prioritizes eliminating or reducing noise at its source.

OBJECTIVES

To determine the main sources of workplace noise exposure in the Australian working population and estimate the reduction of workers exposed over the noise limit (LAeq,8h > 85 dB) if noise levels of specific tools or equipment were reduced by 10 dB.

METHODS

Information on the tools used and tasks performed during each participant's last working shift was collected from 4,977 workers via telephone survey. Using a predetermined database of task-based noise levels, partial noise exposures (Pa2h) were determined for each noisy activity performed by the workers and their daily noise exposure level (LAeq,8h) was estimated. Partial exposures were categorized into 15 tool/task groups and the tally, average, and sum (Pa2h) for each group were calculated. The impacts of 5 different scenarios that simulated a reduction of 10 dB in noise emissions for specific tool groups were modelled.

RESULTS

Powered tools and equipment were responsible for 59.3% of all noise exposure (Pa2h); vehicles for 10.6%; mining, refineries, and plant equipment for 5.1%; and manufacturing and food processing for 4.2%. Modelling demonstrated that a 10 dBA noise-level reduction of all powered tools and equipment would lead to a 26.4% (95% confidence interval: 22.7% to 30.3%) reduction of workers with an LAeq,8h > 85 dB. This could represent over 350,000 Australian workers no longer exposed above the workplace limit daily.

CONCLUSIONS

A universal reduction of 10 dB to power tools and equipment would substantially reduce the future burden of hearing loss, tinnitus, workplace injuries, and other health effects. Initiatives to reduce the noise emissions of specific powered tool groups are warranted.

Recent Advances in Preparation and Structure of Polyurethane Porous Materials for Sound Absorbing Application

Various acoustic materials are developed to resolve noise pollution problem in many industries. Especially, materials with porous structure are broadly used to absorb sound energy in civil construction and transportation area. Polyurethane (PU) porous materials possess excellent damping properties, good toughness, and well-developed pore structures, which have a broad application prospect in sound absorption field. This work aims to summarize the recent progress of fabrication and structure for PU porous materials in sound absorption application. The sound absorption mechanisms of porous materials are introduced. Different kinds of structure for typical PU porous materials in sound absorption application are covered and highlighted, which include PU foam, modified PU porous materials, aerogel, templated PU, and special PU porous materials. Finally, the development direction and existing problems of PU material in sound absorption application are briefly prospected. It can be expected that porous PU with high sound absorption coefficient can be obtained by using some facile methods. The design and accurate regulation of porous structures or construction of multilayer sound absorption structure is favorably recommended to fulfill the high demand of industrial and commercial applications in the future work.

Advances in acupuncture treatment for tinnitus

Tinnitus is the abnormal perception of sound in the absence of a corresponding external acoustic stimulus, which seriously affects the patients' quality of life, physical and mental health, and the safety of life. There is almost no effective cure for tinnitus, primarily due to its complicated etiopathogenesis and unclear mechanisms. As a major and ancient physical therapy in Traditional Chinese Medicine, acupuncture has been widely used in tinnitus because of its simple operation, rapid effect, and low cost. This paper reviews the relevant literature on the treatment of different kinds of tinnitus by acupuncture, and summarizes the therapeutic efficacy and mechanism of acupuncture on tinnitus, which is expected to provide new ideas and research directions for the study of tinnitus treatment by acupuncture. Tinnitus is the abnormal perception of sound in the absence of a corresponding external acoustic stimulus, which seriously affects the patients' quality of life, physical and mental health, and the safety of life. There is almost no effective cure for tinnitus, primarily due to its complicated etiopathogenesis and unclear mechanisms. As a major and ancient physical therapy in Traditional Chinese Medicine, acupuncture has been widely used in tinnitus because of its simple operation, rapid effect, and low cost. This paper reviews the relevant literature on the treatment of different kinds of tinnitus by acupuncture, and summarizes the therapeutic efficacy and mechanism of acupuncture on tinnitus, which is expected to provide new ideas and research directions for the study of tinnitus treatment by acupuncture.