Protection efficiency of hearing protectors against military noise from handheld weapons and vehicles.
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Noise attenuation against military noises has been measured in several cases under practical field conditions. Commercial and military versions of earmuff noise attenuation were measured against rifle noise. All the tested earmuffs attenuated the C-weighted peak level to less than 135 dB, which is less than the proposed recommendation value. Combat and shooting exercises create a risk of hearing damage, reaching a peak level of 180 dB. Measurements were done during attack exercises with blank and normal cartridges and during a defence exercise with normal cartridges. The noise exposure levels were relatively moderate (outside the ear 95-97 dB, in ear canal 82-85 dB) for military exercises. Peak levels of 110-120 dB for military trainers were measured in the ear canal during the conscript use of small-bore weapons. Combat vehicles and tanks are noisy, and for noise control during their use headgear with communication properties is worn. Noise inside such headgear was found to reach up to 120 dB, and the noise doses varied between 90 and 105 dB. Noise was also measured for aviation pilots in Finnish jet fighters. The cockpit values averaged 96 dB - 100 dB over the flight, whereas noise in the ear canal averaged 88 dB - 95 dB. The analyses indicated that radio noise is 4-10 dB higher inside the helmet than the background noise is, when measured as equivalent noise. The technicians on the ground were exposed to noise levels varying from 93 to 97 dB over the day. In practice, hearing protectors attenuate noise by 10-30 dB, depending on the frequency content of the noise sources. However, the difference when measured outside and inside hearing protectors varies by 5-10 dB because communication increases the noise level at the entrance of ear the canal. Currently the best protection for soldiers seems to be active noise cancellation ear muffs that are equipped for communication purposes and worn during the entire military exercise. (+info)
United States pedestrian fatality rates by vehicle type.
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OBJECTIVE: To describe the relation between motor vehicle type and the risk of fatally injuring a pedestrian. DESIGN: The risk of killing a pedestrian was measured as the number of pedestrian fatalities per billion miles of vehicle travel by each vehicle type in the US in 2002 as reported by the National Highway Traffic Safety Administration's Fatality Analysis Reporting System. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Rates for each vehicle type by sex, age, and rural/urban roadway type and rate comparisons using relative risks (RR) and 95% confidence intervals (CIs). RESULTS: Passenger cars and light trucks (vans, pickups, and sport utility vehicles) accounted for 46.1% and 39.1%, respectively, of the 4875 deaths, with the remainder split among motorcycles, buses, and heavy trucks. Compared with cars, the RR of killing a pedestrian per vehicle mile was 7.97 (95% CI 6.33 to 10.04) for buses; 1.93 (95% CI 1.30 to 2.86) for motorcycles; 1.45 (95% CI 1.37 to 1.55) for light trucks, and 0.96 (95% CI 0.79 to 1.18) for heavy trucks. Compared with cars, buses were 11.85 times (95% CI 6.07 to 23.12) and motorcycles were 3.77 times (95% CI 1.40 to 10.20) more likely per mile to kill children 0-14 years old. Buses were 16.70 times (95% CI 7.30 to 38.19) more likely to kill adults age 85 or older than were cars. The risk of killing a pedestrian per vehicle mile traveled in an urban area was 1.57 times (95% CI 1.47 to 1.67) the risk in a rural area. CONCLUSIONS: Outcomes reflect the ways in which a vehicle's characteristics (mass, front end design, and visibility) and its degree of interaction with pedestrians affect its risk per mile. Modifications in vehicle design might reduce pedestrian injury. The greatest impact on overall US pedestrian mortality will result from reducing the risk from the light truck category. (+info)
Application of the new ISO 2631-5 to health hazard assessment of repeated shocks in U.S. Army vehicles.
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The U.S. Army Aeromedical Research Laboratory conducted a research program to develop a new methodology for health hazard assessment of tactical ground vehicle rides. This paper describes the new method and compares the health risk prediction using the new multiple shocks standard International Standards Organization (ISO 2631-5) to predictions by the current whole-body vibration (WBV) standard (ISO 2631-1). This article also describes the software tool developed to implement both parts of ISO 2631, as well as Army Regulation 40-10. The comparison shows the new standard to be more sensitive to cross-country terrain than other standards. Data analysis demonstrates the applicability of the new ISO 2631-5 standard to tactical ground vehicles, especially in the vertical axis. (+info)
Noise annoyance in Canada.
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The present paper provides the results from two nation-wide telephone surveys conducted in Canada on a representative sample of 5,232 individuals, 15 years of age and older. The goals of this study were to gauge Canadians' annoyance towards environmental noise, identify the source of noise that is viewed as most annoying and quantify annoyance toward this principal noise source according to internationally accepted specifications. The first survey revealed that nearly 8% of Canadians in this age group were either very or extremely bothered, disturbed or annoyed by noise in general and traffic noise was identified as being the most annoying source. A follow-up survey was conducted to further assess Canadians' annoyance towards traffic noise using both a five-item verbal scale and a ten-point numerical scale. It was shown that 6.7% of respondents indicated they were either very or extremely annoyed by traffic noise on the verbal scale. On the numerical scale, where 10 was equivalent to "extremely annoyed" and 0 was equivalent to "not at all annoyed", 5.0% and 9.1% of respondents rated traffic noise as 8 and above and 7 and above, respectively. The national margin of error for these findings is plus or minus 1.9 percentage points, 19 times out of 20. The results are consistent with an approximate value of 7% for the percentage of Canadians, in the age group studied, highly annoyed by road traffic noise (i.e. about 1.8 million people). We found that age, education level and community size had a statistically significant association with noise annoyance ratings in general and annoyance specifically attributed to traffic noise. The use of the International Organization for Standardization/Technical Specification (ISO/TS)-15666 questions for assessing noise annoyance makes it possible to compare our results to other national surveys that have used the same questions. (+info)
Mice acquire flavor preferences during shipping.
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Vigorous motion can cause rodents to develop flavor aversions and show other signs of malaise. We tested whether a flavor aversion could be induced by shipping mice from an animal breeder to a test site. Boxes of 12 male C57BL/6J mice were shipped approximately 950 km from Bar Harbor, ME to Philadelphia, PA by truck. For some boxes, the gel provided for hydration was flavored with almond and for others it was flavored with banana. After the journey, the mice were individually housed and allowed to recover for 5 days. They then received a choice between the two flavors of gel. Contrary to expectations, mice preferred the flavor they had previously ingested during shipping. Controls given flavored gel under similar conditions but while stationary did not show a preference. These results suggest that mice find shipping or its sequelae pleasurable. If mice are travel sick this must be inconsequential relative to other components of the shipping experience. (+info)
Hypertension and Exposure to Noise near Airports (HYENA): study design and noise exposure assessment.
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An increasing number of people live near airports with considerable noise and air pollution. The Hypertension and Exposure to Noise near Airports (HYENA) project aims to assess the impact of airport-related noise exposure on blood pressure (BP) and cardiovascular disease using a cross-sectional study design. We selected 6,000 persons (45-70 years of age) who had lived at least 5 years near one of six major European airports. We used modeled aircraft noise contours, aiming to maximize exposure contrast. Automated BP instruments are used to reduce observer error. We designed a standardized questionnaire to collect data on annoyance, noise disturbance, and major confounders. Cortisol in saliva was collected in a subsample of the study population (n = 500) stratified by noise exposure level. To investigate short-term noise effects on BP and possible effects on nighttime BP dipping, we measured 24-hr BP and assessed continuous night noise in another subsample (n = 200). To ensure comparability between countries, we used common noise models to assess individual noise exposure, with a resolution of 1 dB(A). Modifiers of individual exposure, such as the orientation of living and bedroom toward roads, window-opening habits, and sound insulation, were assessed by the questionnaire. For four airports, we estimated exposure to air pollution to explore modifying effects of air pollution on cardiovascular disease. The project assesses exposure to traffic-related air pollutants, primarily using data from another project funded by the European Union (APMoSPHERE, Air Pollution Modelling for Support to Policy on Health and Environmental Risks in Europe). (+info)
Motor vehicle trauma: analysis of injury profiles by road-user category.
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BACKGROUND: Vehicle accidents in Greece are among the leading causes of death and the primary one in young people. The mechanism of injury influences the patterns of injury in victims of vehicle accidents. OBJECTIVE: Identification and analysis of injury profiles of motor-vehicle trauma patients in a Greek level I trauma centre, by road-user category. PATIENTS AND METHODS: The trauma registry data of Herakleion University Hospital of adult trauma patients admitted to the hospital after a vehicle accident between 1997 and 2000 were retrospectively examined. Patients were grouped based on the mechanism of injury into three road-user categories: car occupants, motorcyclists, and pedestrians. RESULTS: Of 730 consecutive patients, 444 were motorcyclists (60.8%), 209 were car occupants (28.7%), and 77 were pedestrians (10.5%). Young men constituted the majority of injured motorcyclists whereas older patients (p = 0.0001) and women (p = 0.0001) represented a substantial proportion of the injured pedestrians. With regard to the spectrum of injuries in the groups, craniocerebral injuries were significantly more frequent in motorcyclists and pedestrians (p = 0.0001); abdominal (p = 0.009) and spinal cord trauma (p = 0.007) in car occupants; and pelvic injuries (p = 0.0001) in pedestrians. Although the car occupants had the highest Injury Severity Score (ISS) (p = 0.04), the pedestrians had the poorest outcome with substantially higher mortality (p = 0.007) than the other two groups. CONCLUSIONS: The results reveal a clear association between different road-user categories and age and sex incidence patterns, as well as outcomes and injury profiles. Recognition of these features would be useful in designing effective prevention strategies and in comprehensive prehospital and inhospital treatment of motor-vehicle trauma patients. (+info)
Motor vehicle mismatch-related spinal injury.
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BACKGROUND/OBJECTIVE: Motor vehicle collision (MVC)-related spinal cord injury (SCI) is the most prevalent etiology of SCI. Few studies have defined SCI risk factors. Vehicle mismatch occurs in 2-vehicle MVCs in which there are significant differences in vehicle weight, stiffness, and height. This study examined SCI risk and vehicle mismatch. METHODS: A matched case-control study using the 1995 to 2003 National Automotive Sampling System (NASS). Study subjects were identified from 2-vehicle MVCs. Cases were occupants who had suffered a cervical, thoracic, or lumbar SCI. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. RESULTS: There were 101,682 cases of SCI matched to 805,091 controls. Occupants of passenger vehicles involved in MVCs with a light truck or van (LTV) were at increased risk for SCI (OR = 1.87, 95% CI = 1.07-3.24) and this risk was greatest for thoracic SCI (OR = 5.09, 95% CI = 2.33-11.13). In addition, occupants of LTVs involved in MVCs with passenger vehicles were at significant increased risk for cervical (OR = 1.39) and lumbar (OR = 2.65) SCI; and occupants of LTVs involved in MVCs with other LTVs were at increased risk of any SCI (OR = 2.02, 95% CI = 1.52-2.69). For these subjects, significant increased risks were seen for all spine regions: cervical (OR = 1.41), thoracic (OR = 2.86), and lumbar (OR = 2.38). CONCLUSIONS: The results of this study suggest that occupants of passenger vehicles are at increased SCI risk when involved in 2-vehicle MVCs with LTVs; and that occupants of LTVs are at increased SCI risk, regardless. (+info)