Human toxicology最新文献

1. Since the early 1960s the USA has attempted to combat the problem of volatile substance abuse through legislation including restricting sales, banning 'sniffing', labelling and adding unpleasant smells to abused products. None of this legislation appears to have had the desired effect. 2. VSA has been a growing problem in Britain since the 1970s and presently kills two people per week. The British Government initially adopted a low profile approach, although legislation restricting the sale of abused products was introduced in 1985. 3. In 1984 the British Adhesives Manufacturers Association founded Re-Solv, the society for the prevention of solvent and volatile substance abuse; it is now an independent national charity. Re-solv believe that a broad education programme is needed to combat VSA and are involved in many such projects.

1. Volatile substance abusers are a heterogeneous population despite some demographic and social characteristics which appear similar. 2. Though predominantly an adolescent group activity, adult cases have been reported. Family disruption, alcohol misuse and antisocial behaviour feature prominently. 3. Evidence currently available suggests that only a minority of cases progress to illicit drug use; however a review of literature reveals serious discrepancies. 4. Further research of a longitudinal nature using standardized criteria of psychiatric morbidity and social adjustment and long-term follow-up is indicated to examine the extent of progression to heavy alcohol or illicit drug use.

1. Most of the evidence for chronic non-neurological toxicity from volatile substance abuse is derived from case reports. 2. Factors important in assessing these reports are the marked variations in exposure conditions and in the composition of the products abused. 3. In a young and otherwise healthy population, any chronic organ toxicity arising from VSA has to be gross in order to become clinically apparent. This may partially explain the relatively low incidence of reporting. 4. Toluene and the chlorinated hydrocarbons 1,1,1-trichloroethane and trichloroethylene can cause permanent damage to the kidney, liver, heart and lung, in certain volatile substance abusers.

1. Drug education has to involve exposure not only to knowledge about drug and volatile substance abuse, but also to the effect that attitudes, values, external influences and personal and social skills have on drug behaviour. 2. Such education has also to consider the methods used, the learning process itself, and the need for self-esteem to be enhanced during this process. 3. There is a need to develop personal and social skills which will form the foundation for considering areas such as volatile substance abuse. The school must be supported by the home and by the community. 4. A range of practical resources produced by TACADE (The Advisory Council on Alcohol and Drug Education) allow the translation of this theory of drug education into a practical approach within education.

1. The acute toxicity of many volatile compounds is similar, being more related to physical properties than to chemical structure. 2. Volatile substance abusers experiences euphoria and disinhibition but this may be followed by nausea and vomiting, dizziness, coughing and increased salivation; cardiac arrhythmias, convulsions, coma and death occur in severe cases. 3. Laboratory analysis of blood and urine samples collected up to 24 h post-exposure may be helpful if the diagnosis of volatile substance abuse is in doubt. 4. There is only a weak correlation between blood toluene and 1,1,1-trichloroethane concentrations and the clinical features of toxicity, possibly because of rapid initial tissue distribution and elimination. 5. Recovery normally occurs quickly once exposure has ceased but support for respiratory, renal or hepatic failure may be needed as well as treatment for cardiac arrhythmias. Therapy with intravenous acetylcysteine should be considered in cases of acute carbon tetrachloride poisoning.

1. Volatile substance abuse is largely a teenage practice; it is estimated that in the UK 3.5-10% of young people have at least experimented and that 0.5-1% are current users. 2. The products abused are many and varied but only about 20 chemical compounds, notably toluene, chlorinated solvents such as 1,1,1-trichloroethane, fuel gases such as butane and aerosol propellants, are commonly encountered. 3. The acute hazard varies with the compound, product and mode of abuse. Mortality in the UK is now about 100 per year, from all social classes, 90% of whom are male. 4. Chronic toxicity is difficult to assess, partly because of the diversity of products abused. However it is clear that some long-term abusers suffer permanent damage to the central nervous system, heart, liver and kidney. 5. Toxicological analysis may be relied upon for confirmation of diagnosis, providing attention is paid to the kinetics of excretion and stability in the sample. 6. Responses include codes of practice for the sale of products and educational strategies; legislation has also been enacted. There is little evidence that any of these measures have made a significant impact on the problem.

1. The evidence from studies of the neuropsychological consequences of chronic volatile substance abuse is reviewed. 2. Studies of occupational exposure to solvent vapour are of limited relevance when considering the effects of volatile substance abuse because occupational exposure is normally to small quantities of many different compounds over prolonged periods of time. 3. Many studies of chronic volatile substance abusers suffer from serious shortcomings such as the use of small sample sizes, inadequate controls, failure to exclude the possibility of acute toxic effects and a disregard of other factors which could account for the findings. 4. There is reasonably good evidence that neuropsychological impairment is often present amongst volatile substance abusers with definite neurological abnormalities. 5. Although most studies have found that volatile substance abusers without reported neurological abnormalities obtain lower psychometric test scores than non-abusers, it remains uncertain whether these deficits are best explained in terms of a causal effect of volatile substance abuse, rather than a reflection of other factors associated with volatile substance abuse, such as background, social disadvantages or history of delinquency.

1. Although there are trends towards the use of 'safer' or non-solvent materials, the overall consumption of solvents will probably not change very much over the next few years. Substitution of solvents by 'safer' materials is a complex and difficult process and the rate of change is correspondingly slow. 2. HSE exposure data show that generally industry controls most solvent use quite well. High personal exposures are not widespread and tend to occur in a fairly small number of premises involving 'end user' processes (mixing, spraying, etc). 3. Exposure in industry is generally to mixtures of solvents rather than single substances. The degree to which abuse is a contributory factor in exposure is uncertain, but there is probably greater opportunity for abuse to occur in 'end user' processes. 4. The experience of the author and colleagues in the HSE supports the evidence for the occurrence of volatile substance abuse (particularly of organic solvents) in industry but the extent of the practice is not known. 5. The proposed Control of Substances Hazardous to Health Regulations (COSHH) will bring greater emphasis on the assessment of risks to health in industry, which must include the potential for abuse, together with appropriate training and supervision.

1. The LC50 values for acrolein (AC) vapour to Sprague-Dawley rats (combined sexes) were determined to be 26 ppm (1 h) and 8.3 ppm (4 h). Signs of severe irritancy were present, and death was due to lung injury. 2. Exposure of rats to a 2-methoxy-3,4-dihydro-2H-pyran (MDP) saturated vapour atmosphere statistically generated from liquid MDP containing 0.037% AC, caused severe irritancy and death from accumulation of AC vapour. Sparging the impure material with nitrogen gas before atmosphere generation significantly reduced or abolished lethal toxicity. 3. Dynamically generated MDP vapour atmosphere produced transient respiratory and ocular irritancy, but no mortalities. The intrinsic acute vapour inhalation toxicity of MDP is low. 4. The presence of highly volatile toxic impurities in a material may confer a significant acute inhalation toxicity and hazard under conditions of low air movement. Assessment of potential inhalation hazards from liquid mixtures may require investigation by static and dynamic methods for vapour generation.