Industrial gassing poisonings due to trichlorethylene, perchlorethylene, and 1-1-1 trichloroethane, 1961-80

Developmental toxicity of prenatal exposure to toluene

Organic solvents have become ubiquitous in our environment and are essential for industry. Many women of reproductive age are increasingly exposed to solvents such as toluene in occupational settings (ie, long-term, low-concentration exposures) or through inhalant abuse (eg, episodic, binge exposures to high concentrations). The risk for teratogenic outcome is much less with low to moderate occupational solvent exposure compared with the greater potential for adverse pregnancy outcomes, developmental delays, and neurobehavioral problems in children born to women exposed to high concentrations of abused organic solvents such as toluene, 1,1,1-trichloroethane, xylenes, and nitrous oxide. Yet the teratogenic effects of abuse patterns of exposure to toluene and other inhalants remain understudied. We briefly review how animal models can aid substantially in clarifying the developmental risk of exposure to solvents for adverse biobehavioral outcomes following abuse patterns of use and in the absence of associated health problems and co-drug abuse (eg, alcohol). Our studies also begin to establish the importance of dose (concentration) and critical perinatal periods of exposure to specific outcomes. The present results with our clinically relevant animal model of repeated, brief, high-concentration binge prenatal toluene exposure demonstrate the dose-dependent effect of toluene on prenatal development, early postnatal maturation, spontaneous exploration, and amphetamine-induced locomotor activity. The results imply that abuse patterns of toluene exposure may be more deleterious than typical occupational exposure on fetal development and suggest that animal models are effective in studying the mechanisms and risk factors of organic solvent teratogenicity.

Acute effects of 1,1,1-trichloroethane inhalation on the human central nervous system

The object of this study was to examine the immediate nervous effects of variable 1,1,1-trichloroethane (TCE) exposure combined with physical exercise. The effects on the quantitative electroencephalography (EEG), visual evoked potentials (VEP) and body sway were analyzed. Nine male volunteers were exposed to either a stable or a fluctuating exposure pattern with the same time-weighted average concentration of 200 ppm (8.1 mumol/l). In both cases, the subjects engaged in physical exercise during the exposures. Exercise alone induced an increase in the dominant alpha frequency in the EEG and, after an initial drop, an increase in the alpha percentage with a concomitant decrease in theta, whereas delta and beta bands remained unaffected. By contrast, exposure to TCI and exercise did not affect the alpha, theta or delta activities but induced changes in beta during the morning recordings at peak exposure to TCE. The body sway tended to decrease slightly during the fluctuating TCE exposure, and the later peaks in VEPs showed slight prolongations. Overall, no deleterious effects of exposure were noted.

Increased incidence of renal cell tumors in a cohort of cardboard workers exposed to trichloroethene

A retrospective cohort study was carried out in a cardboard factory in Germany to investigate the association between exposure to trichloroethene (TRI) and renal cell cancer. The study group consisted of 169 men who had been exposed to TRI for at least 1 year between 1956 and 1975. The average observation period was 34 years. By the closing day of the study (December 31, 1992) 50 members of the cohort had died, 16 from malignant neoplasms. In 2 out of these 16 cases, kidney cancer was the cause of death, which leads to a standard mortality ratio of 3.28 compared with the local population. Five workers had been diagnosed with kidney cancer: four with renal cell cancers and one with a urothelial cancer of the renal pelvis. The standardized incidence ratio compared with the data of the Danish cancer registry was 7.97 (95% CI: 2.59-18.59). After the end of the observation period, two additional kidney tumors (one renal cell and one urothelial cancer) were diagnosed in the study group. The control group consisted of 190 unexposed workers in the same plant. By the closing day of the study 52 members of this cohort had died, 16 from malignant neoplasms, but none from kidney cancer. No case of kidney cancer was diagnosed in the control group. The direct comparison of the incidence on renal cell cancer shows a statistically significant increased risk in the cohort of exposed workers. Hence, in all types of analysis the incidence of kidney cancer is statistically elevated among workers exposed to TRI.(ABSTRACT TRUNCATED AT 250 WORDS)

An introduction to the clinical toxicology of volatile substances

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)

Diverse manifestations of trichloroethylene

Trichloroethylene, a solvent used in a variety of industrial settings for more than 60 years, has caused adverse health effects on the central and peripheral nervous system, the skin, liver, kidney, and heart. Three men have shown relatively unusual manifestations secondary to exposure to trichloroethylene in degreasing operations in the jewelry industry. Toxic encephalopathy, hepatitis, and carpal spasm occurred among young, healthy workers. Clinical and laboratory data, including measurement of urinary trichloroacetic acid concentrations, are presented.

Gassings due to methylene chloride, xylene, toluene, and styrene reported to Her Majesty's Factory Inspectorate 1961-80

For the period 1961-80, 118 cases of industrial gassings caused by the solvents methylene chloride, xylene, toluene, and styrene were reported to Her Majesty's Factory Inspectorate. The data have been collated and analysed according to the predetermined criteria of age, sex, mode and circumstances of use, clinical effect, and outcome. The means of collection of the data and their objectivity is discussed. The study shows the narcotic effect of these solvents and underlines the dangers of their use in confined spaces. Symptoms were most commonly attributable to the nervous and respiratory systems. The problem of addiction and the vulnerability of the younger worker is also discussed.