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Acute poisoning with organic solvents and other volatile compounds now usually follows deliberate inhalation (volatile substance abuse) or ingestion of these compounds. Solvents from adhesives, typewriter correction and dry cleaning fluids, cigarette lighter refills (butane) and aerosol propellants are commonly abused. The major risk is that of sudden death. Arrhythmias leading to cardiac arrest are thought to cause most deaths, but anoxia, respiratory depression and vagal stimulation leading to cardiac arrest may also contribute, as may indirect causes such as aspiration of vomit or trauma. In the United Kingdom (UK), 3.5 to 10% of young people have at least experimented with volatile substance abuse and mortality is more than 100 per annum. The products abused are cheap and readily available despite legislation designed to limit supply. Volatile substance abuse is not illegal and only a minority of abusers are known to progress to heavy alcohol or illicit drug use. Prevention of abuse by education, not only of children but also of parents, teachers, retailers and health care workers, is important in limiting the problem. However, volatile substance abuse-related deaths are still increasing in the UK despite many measures aimed at prevention. Clinically, volatile substance abuse is characterised by a rapid onset of intoxication and rapid recovery. Euphoria and disinhibition may be followed by hallucinations, tinnitus, ataxia, confusion, nausea and vomiting. It is important not to further alarm the patient if signs of serious toxicity are present, since a cardiac arrest may be precipitated. Further exposure should be prevented and the patient resuscitated and given supplemental oxygen if necessary. Cardiac arrhythmias should be treated conventionally and respiratory failure managed supportively. Long term exposure to n-hexane is associated with the development of peripheral neuropathy, while prolonged abuse (notably of toluene or chlorinated solvents) can cause permanent damage to the central nervous system, heart, liver, kidney and lungs. Knowledge of the routes of absorption, distribution and excretion of volatile compounds, and of the rates governing these processes, is important in understanding the rate of onset, intensity and duration of intoxication, and rate of recovery after volatile substance abuse. In addition, such knowledge is helpful when the clinician is attempting to interpret the results of toxicological analyses performed on samples (blood, other tissues, urine) from such patients. Many volatile substances are partly metabolised, the metabolites being eliminated in exhaled air or in urine. Although metabolism normally results in detoxification, enhanced toxicity may also result as with carbon tetrachloride, chloroform, dichloromethane, n-hexane, trichloroethylene and possibly halothane.(ABSTRACT TRUNCATED AT 400 WORDS)

Current requirements for the registration of agrochemicals, particularly in the U.S.A., often require the provision of dermal absorption data. In this process the rat is often used and complex in vivo studies, using large numbers of animals, are performed. We have compared the data obtained from in vivo and in vitro dermal absorption studies using eight pesticides with a range of physicochemical properties. Measurements were made of the 14C-labeled pesticides which could be washed from the skin, were associated with (on/in) skin, or absorbed through the skin following dermal applications in vivo and in vitro at various time points over a 24-hr exposure period. Good agreement was found between the amounts washed from and associated with the skin in vivo and in vitro. Over the time period 4-24 hr after application the in vitro experiments predicted the in vivo absorption within a factor of 2-3. These results show that, with a range of pesticide molecules, the in vitro method accurately predicted in vivo absorption supporting the utilization of the in vitro method for risk assessment from exposure to pesticides and other chemicals.

This study was performed to evaluate the changes in physiological responses to task performance in trained male and female subjects while stoopwalking in increasingly bent postures. Following a 10-day training program, 5 male and 5 female subjects stoopwalked at heights corresponding to 100, 90, 80, and 70 percent of each subjects normal upright stature at speeds of 1.5, 2.0, 2.5, 3.0, and 3.5 miles per hour. Physiological variables were equilibrium heart rate, ventilation volume, weight adjusted oxygen uptake, and the percentage of work capacity required for task performance. A MANOVA analysis of the dependent variables showed there to be a significant sex difference in the composite response to task performance. Univariate ANOVA and discrimate analyses performed on the dependent variables showed that this difference was due to females experiencing significantly greater heart rates than the males, and greater, but not significantly so, percentages of work capacity to perform the same task loadings as the males.

This article discusses an experimental approach to the correlation of some mechanical measures of work with some physiological measures of work for a task performed by the upper limb. The seven mechanical measures of work considered were velocity and acceleration of movement, total mechanical energy, force, torque, linear impulse, and angular impulse. The three physiological measures were pulmonary ventilation rate, pulse rate, and oxygen consumption. Pulmonary ventilation rate was found to correlate best with all the mechanical measures, with shoulder angular impulse and average shoulder torque having the highest correlation of the mechanical measures (r = 0.53).

Although several photogrammetric systems are commercially available, their cost limits the application of photogrammetric human factors studies. This paper describes a relatively low cost system developed at Texas Tech University to be used in connection with biomechanics and human performance studies. A detailed description of the basic theoretical and laboratory investigations of the various parameters which influence the design, construction, and use of the system is presented. The adequacy and accuracy of the system were measured by conducting two verification tests under static and dynamic orientations. Typical acceleration and velocity curves for human hand motion, obtained by the system, are presented.

SUMMARY The primary purpose of this investigation was to evaluate various quantitative measures of the human effort involved in three dimensional planar movement of the upper limbs. The instrumentation, procedures and techniques for obtaining such mechanical data were also developed. The quantitative measures, as calculated from an experimental task, were analyzed at various levels of weight, distance, work duration and angle of abduction in order to determine significant variable effects. The specific work and motion characteristics of interest were the instantaneous velocity and acceleration of each arm segment, the changes in mechanical energy of the entire arm system during the work task, the instantaneous forces and moments at each arm joint, and the linear and angular impulse during the task. These characteristics which define human work activity in a mechanical sense were compared and evaluated for adequacy in describing human effort, and were used to develop appropriate predictive equations.

This paper reports the use of two techniques which were used to evaluate the important design parameters in a cranking type task. Namely, electromyography served as an indicator of physiological costs for the task, and biomechanical analysis provided quantitative data concerning the mechanical costs for the task. Both these measures were shown to support the importance of handle radius, torque, and working height as critical criteria in design of a cranking task.

Performance by females on sedentary work tasks did not show meaningful decrement as a function of work place temperatures. In general, females showed less effect on performance in hot environments than did male subjects engaged in the same work activities.

Incidence de l'inhalation volontaire de substances volatiles (colles, solvants, aerosol, gaz combustibles, derives de l'essence, hydrocarbures chlores, anesthesiques volatils) au Royaume-Uni. Toxicite aigue et chronique, neurologique ou non. Mecanisme de mort subite. Diagnostic, traitement et prevention

The removal of salicylate by extracorporeal circulation of blood through a column of encapsulated activated charcoal (haemoperfusion) has been studied experimentally in intoxicated dogs (greyhounds). The average time taken to reduce the whole blood salicylate level to one-half of the initial equilibrium level in 30 kg dogs was 2 hrs. A half-life of 3 hrs is predicted for salicylate removal by haemoperfusion in a 70 kg man and this rate of removal is shown to be comparable to that reported for haemodialysis. No unacceptable adverse physiological, biochemical, or haematological effects were found to result from haemoperfusion. The possible use of this technique in the management of severe salicylate poisoning in man is discussed. Haemoperfusion is foreseen as providing a method of rapid removal of salicylate in circumstances where forced diuresis is contra-indicated or inadequate and haemodialysis is not readily available.