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The impact of new regulations on the incidence and severity of ocular injury sustained in hurling.

AIM: To prospectively evaluate, and compare, the incidence of hurling-related eye injuries in the South East of Ireland before and after implementation of new rules rendering the use of protective head gear and face masks compulsory for players aged 18 years or under. METHODS: Details relating to patients attending the regional ophthalmic department with injuries sustained during hurling were prospectively recorded between 1 October 2003 and 31 March 2006. RESULTS: Sixty players attended with hurling-related ocular injuries during the study period. Of these, 43 (71.6%) and 17 (28.3%) sustained the ocular injuries during the 15-month period before, and after implementation of the new rules (1 January 2005), respectively. Restricting our analysis to players aged 18 years or under, and, for statistical validity, to the 12-month period immediately before and immediately after implementation of the new rules, a statistically significant reduction in the number of hurling-related injuries was seen (1 January 2004 to 31 December 2004: 11; 1 January 2005 to 31 December 2005: 2; chi(2) test P<0.05) in this age group. A permanent visual deficit was seen in 11 (18.3%) patients. Of these, one (9%) was aged 18 years or under, and this injury was sustained before the new regulations. CONCLUSION: New rules rendering the use of protective eye wear compulsory for players aged 18 years or under have resulted in a significant reduction in the incidence and severity of hurling-related eye injuries in this age group.

Adult↗

A case-control study of the effectiveness of bicycle safety helmets.

Bicycling accidents cause many serious injuries and, in the United States, about 1300 deaths per year, mainly from head injuries. Safety helmets are widely recommended for cyclists, but convincing evidence of their effectiveness is lacking. Over one year we conducted a case-control study in which the case patients were 235 persons with head injuries received while bicycling, who sought emergency care at one of five hospitals. One control group consisted of 433 persons who received emergency care at the same hospitals for bicycling injuries not involving the head. A second control group consisted of 558 members of a large health maintenance organization who had had bicycling accidents during the previous year. Seven percent of the case patients were wearing helmets at the time of their head injuries, as compared with 24 percent of the emergency room controls and 23 percent of the second control group. Of the 99 cyclists with serious brain injury only 4 percent wore helmets. In regression analyses to control for age, sex, income, education, cycling experience, and the severity of the accident, we found that riders with helmets had an 85 percent reduction in their risk of head injury (odds ratio, 0.15; 95 percent confidence interval, 0.07 to 0.29) and an 88 percent reduction in their risk of brain injury (odds ratio, 0.12; 95 percent confidence interval, 0.04 to 0.40). We conclude that bicycle safety helmets are highly effective in preventing head injury. Helmets are particularly important for children, since they suffer the majority of serious head injuries from bicycling accidents.

Accidents, Traffic↗

Snowhole blues: comments on Kinney and Corth.

Empirical observations are reported on illuminance and visibility in overcast snowscapes. Reasons for the improved visibility achieved with yellow goggles are discussed.

Color Perception↗

Quantitative fit testing of personnel utilizing a mouthpiece respirator.

A respirator test facility using Refrigerant 12 as a challenge gas has been developed. More than 6000 people have received training in the effective use of mouthpiece respirators. Leakage is determined by the use of a halide detection meter analyzing the exhaled breath. The facilities have been used to provide training and quantitative fit testing for practically all types of respiratory protective equipment. An actual use investigation was made to determine the suitability of the mouthpiece respirator for use in a chlorine producing plant work situation. The mouthpiece respirator was compared with a group of half-face respirators. A clear distinction was made: the half-face respirator offered less protection than the mouthpiece respirator.

Chemical Industry↗

Hearing protector performance--an update.

A single-number descriptor, the A-weighted sound pressure level, has been used widely during the last 10 years for the assessment of noise exposure levels. Prior to that time octave band levels were the common means for describing noise exposures. Hearing protector noise reduction data have been presented in various ways to facilitate the calculation of exposure levels while wearing hearing protectors. This paper describes both single-number and octave band procedures for presenting hearing protector noise attenuation data and discusses advantages and disadvantages of each.

Auditory Threshold↗

Effects of respirators under heat/work conditions.

Physiological responses and perceived strain of five unacclimatized male subjects were studied. The subjects were exposed to heat during an exercise task and were evaluated while wearing half and full facepiece, cartridge-type, air-purifying respirators, and without a respirator. The exercise consisted of walking on a treadmill for a period of 1 hour in a controlled environmental chamber at each of two different energy expenditure levels (200 and 400 Kcal/hr) (approximately equal to 58 and 116 Watts) and two different heat exposures (air temperatures of 25 degrees C and 43.3 degrees C). The results indicated that wearing a full facepiece respirator imposed significant physiological strain added to that caused by the heat and workloads used in the study. Five of the six physiological measures show this increased physiological strain: heart rate; minute ventilation; oxygen consumption; energy expenditure; and oral temperature. There was no detectable effect on sweat rate. Although subjective ratings indicated more discomfort with increasing physiological strain, the observed correlations between such measures were low (Tb less than .60). The net consequence of the significant effects indicates that workers' tolerance to moderate or higher levels of work under hot conditions while wearing a respirator is reduced. The reduction is more pronounced when wearing a full mask than when wearing a half mask. Changes in respirator design which minimize respiratory dead space are suggested to alleviate this problem. Otherwise, prevention of excessive physiological strain from respirator use when working at moderate or higher levels at hot job sites could necessitate more rest breaks or limiting work time under such conditions.

Adult↗

A comparison of iron oxide fume inside and outside of welding helmets.

A study was conducted to compare the iron oxide fume concentrations inside and outside the helmets of welders. Airborne iron oxide fume concentrations were determined simultaneously at four body locations--the left front shoulder, right front shoulder, front chest, and inside the helmet--during welders' normal activity. Results indicate that the fume concentrations at the actual breathing zone inside helmets are reduced to 36%-71% of concentrations outside the helmets, depending on the type of welding and employees' postures.

Ferric Compounds↗

The effects of protector-noise interaction on the accuracy of the NRR estimate of hearing protector attenuation.

A total of 262 noise spectra were divided empirically into three groups and the accuracy of the NRR estimate of hearing protector attenuation was evaluated for each group using 15 hearing protectors. The mean and the standard deviation of the error in the NRR estimate was most stable across the 15 protectors, when noise spectra were characterized by a simple monotonic band-level function yielding a dBC-dBA difference of 3.5 dB or less. Both the octave band attenuation function of the hearing protector and the octave band spectrum of the noise appeared to contribute to the error in the NRR estimate.

Ear Protective Devices↗

Particle concentration in exhaled breath.

Measurements were made of the number concentrations of particles in exhaled breath under various conditions of exercise. A laser light scattering particle spectrometer was used to count particles exhaled by test subjects wearing respirators in a challenge environment of clean, dry air. Precautions were taken to ensure that particles were not generated by the the respirators and that no extraneous water or other particles were produced in the humid exhaled air. The number of particles detected in exhaled air varied over a range from less than 0.1 to about 4 particles per cm3 depending upon the test subject and his activity. Subjects at rest exhaled the lowest concentration of particles, whereas exercises producing a faster respiration rate caused increased exhalation of particles. Exhaled particle concentrations can limit the usefulness of nondiscriminating, ambient challenge aerosols for the fit testing of highly protective respirators.

Aerosols↗

Subjective tolerance of respirator loads and its relationship to physiological effects.

Subjective and physiological responses to a variety of respiratory loads were measured in a group of 52 normal volunteers during steady, moderate treadmill exercise. Subjective response (SR) was determined with two visual analogue scales developed for this study: EXERT (perceived limitation of exercise duration) and DISC (perceived discomfort). There was a linear relationship between inspiratory resistance and SR. Expiratory and inspiratory resistance loading produced similar subjective effects. Dead space loading, however, produced very little subjective effect on either scale. The study suggests that subjective response can be measured quantitatively and should be considered in respirator design.

Adult↗

Quantitative respirator fit testing: dynamic pressure versus aerosol measurement.

A noninvasive, fast, inexpensive new fit testing method has been invented which relates the slope of the pressure decay inside a respirator during breath-holding to the fit of the respirator on the wearer's face. The dynamic pressure test has been compared with the conventional aerosol test at different leakage levels. The results of this comparison show that the sensitivity of the dynamic pressure test is similar to that of the aerosol test. The pressure test, however, is independent of leak site and probe location and can be performed on respirators before and after their use.

Aerosols↗

A study of burn-through times for laser protective eyewear.

The authors studied the performance of laser protective eyewear currently in use at the Lawrence Livermore National Laboratory: a goggle with a cellulose propionate filter from Glendale Protective Technologies and a goggle with a glass optical filter from Spectra Optics. A new polycarbonate optical filter material from Glendale was studied also, and its performance was compared with that of the cellulose propionate material. The authors used three lasers in the study: a single-pulse (variable pulse length) Nd:YAG laser with a wavelength of 1064 nm; a pulsed copper-vapor laser with a pulse-repetition frequency of 6.08 kHz and a wavelength of 510.6 nm; and a pulsed xenon-fluoride laser with a repetition rate variable up to 100 Hz and a wavelength of 351 nm. Where possible, the output power of each laser was increased systematically to the damage threshold of the material and beyond. The results showed that the new polycarbonate optical filter suffered less damage at equivalent laser beam challenges than the cellulose propionate optical filter. The glass goggle, which was designed specifically for use at the 510.5-nm wavelength, sustained no visible damage from the specified laser light at the highest power levels the authors could achieve.

Eye Protective Devices↗

Noninvasive measurement of respirator effect at rest and during exercise.

Ventilation and respiratory timing during rest and exercise were measured in normal volunteers by pneumotachograph and by respiratory inductive plethysmography (RIP) to determine if RIP is accurate and to determine if the usual methods of ventilation measurement during respirator research lead to artifacts. Data were collected with a mouthpiece, a sham mouthpiece, and no mouthpiece. A dead space and inspiratory resistance load similar to respirators were employed also. The study showed that no significant artifact is produced, particularly during exercise, by measurements using a mouthpiece. RIP is sufficiently accurate and precise for use in unobtrusively measuring ventilation during respirator studies when traditional methods cannot be used.

Humans↗