Biomedical subjects

E R Hermann

Publications and source records attributed to E R Hermann.

16 recordsLinked to original sources

PubMed1982

Efficacy of enforcement in an industrial hearing conservation program.

Relative efficacy of various levels of enforcement in the use of personal hearing protective devices was investigated among employees of a large industrial plant. The main variable was that each of four groups of employees worked during a different period of enforcement policy on the use of personal hearing protection. Analysis of variance of mean hearing levels using three different audiometric grading schemes with different levels of sensitivity, namely, the 0.5, 1, 2 kHz Hearing Level Index, the 1, 2, 3 kHz Hearing Level Index, and the 4000 Hz single puretone test indicate that the enforcement policy did have a dramatic effect on the efficacy of the hearing conservation program and should give similar results in other industrial settings. When and where the use of personal hearing protection was left to the employee it was found that hearing loss among the noise-exposed was very much in excess of that among a non-noise-exposed group. Mandatory use of personal protective devices was found to be much more effective in conserving hearing that the voluntary approach. Mandatory use of earmuffs exclusively proved to be less effective than mandatory use of personal hearing protection when the employee was given a choice of earmuffs or earplugs. Enactment of the Occupational Safety and Health Act did not result in greater hearing conservation over the existing company mandatory hearing conservation program which is quite effective.

Adult↗

PubMed1981

Inhibition of oxygen utilization by substances in combination.

Measurement of concentrations at which substances in combination become toxic is complex, especially if quantitative definition of additive, antagonistic or synergistic toxicity is desired. Using inhibition of oxygen utilized by aerobic micro-organisms in their metabolism of a standard substrate, seven chemicals were tested singly and in eight combinations for their graded toxic effects. In two of the experimental investigations the combined effects of three chemicals were determined. By comparing summations of the measured effects of the chemicals tested singly with similar results from testing the toxicity of actual combinations of the chemicals in solution it was found that the actual inhibitions of the oxygen utilization were essentially the same as predicted inhibitions over a range of aqueous concentrations. Statistical analysis of all combinations tested indicated the effects to be additive. Neither synergism nor antagonism was shown. The pure compounds tested were: mercuric chloride, potassium cyanide, nickel chloride, potassium chromate, copper sulfate, phenol and nitrobenzene. Although the toxicity of each chemical has been quite extensively studied, results regarding combined effects are relatively few. The methods presented here are applicable to many compounds in combination.

Drug Interactions↗

PubMed1979

Influence of sonic noise on human stereoscopic depth perception.

Scientific establishment of the no-effect response to finite levels of exposure to a physical or chemical agent is indeed a rigorous exercise and is frequently controversial. In earlier research by Slutsky under direction of the senior author, a statistically significant increase in stereoscopic depth perception error was noted among 24 test subjects exposed to high intensity noise. Additional extensive research reported in this paper indicates that error in stereoscopic depth perception is not significantly altered by exposure to continuous white noise of short duration at levels ranging from 70 to 115 dBA. Furthernore, exposure of humans for periods of a few minutes to white noise in octave bands centered on 250 Hz, 1000 Hz, 4 kHz and 16 kHz at 115 dB does not affect their depth perception measured by the Howard-Dolman test. A comprehensive analysis of depth perception errors measured under noise exposure conditions (n = 4040) in comparison with those obtained under control conditions (n = 1430) produced a mean change in error of -0.38 mm, a statistically insignificant difference (p = 0.17). Even if such an error were attributable to high level noise, it should be noted that minus sign designates an improvement of depth perception in noise and that it is difficult to imagine visual tasks in which change in error of +/-0.38 mm at a distance of 6.0 meters is meaningful.

Depth Perception↗

PubMed1978