Chris B. Burns

The neurobehavioural consequences of petrol (gasoline) sniffing.

This review will introduce petrol (gasoline) sniffing as a specific form of substance abuse. Petrol sniffing is associated with dysfunctions that range in severity from subtle cognitive impairment to encephalopathy and death, and these are discussed with respect to their specific neurological and cognitive bases. Morbidity and mortality rates will also be presented that suggest severe central nervous system damage occurs as a result of petrol sniffing. The neuropharmacological actions of tetraethyl lead and volatile hydrocarbons, the components within petrol, and their contributions to the effects of sniffing petrol are investigated. Reports of human occupational or recreational exposure to either lead additives or volatile hydrocarbons (i.e. inhalants) have provided evidence of the neurological and cognitive effects that may also occur with petrol sniffing. Petrol sniffing causes a progressive decline of cognitive function that eventually leads to permanent neurological changes.

Neurological and Cognitive Recovery Following Abstinence from Petrol Sniffing

Anecdotal observations suggest that neurological impairments associated with petrol (gasoline) sniffing resolve with abstinence, although these effects have not been proven empirically. Severe exposure to leaded petrol may induce a lead encephalopathy that extends beyond any acute intoxication and requires emergency hospital treatment. Previously, in chronic petrol sniffers, we showed neurological, saccadic, and cognitive abnormalities that were more severe in petrol sniffers with a history of hospitalization for lead encephalopathy, and that correlated with blood lead levels and the length of time of sniffing petrol. Ex-petrol sniffers showed a qualitatively similar but quantitatively less severe pattern of impairment. Petrol sniffing was stopped completely in one of the study communities by modifying social, occupational, and recreational opportunities. After 2 years, we obtained biochemical and neurobehavioral (neurological, saccade, and cognitive) data from all available participants of the earlier study including 10 nonsniffers and 29 chronic petrol sniffers, with six of these individuals previously receiving hospital treatment for lead encephalopathy. Here, we report that blood lead was reduced and that neurobehavioral impairments improved, and in many cases normalized completely. The most severe petrol-related neurobehavioral impairment was observed among individuals who had longer histories of abuse and higher blood lead levels, and among petrol sniffers with a history of lead encephalopathy. Those with the greatest extent of neurobehavioral impairment showed the greatest degree of improvement with abstinence, but were less likely to recover completely. This is the first direct evidence that neurological and cognitive impairment from chronic petrol sniffing ameliorates with abstinence and may recover completely.

Patterns of petrol sniffing and other drug use in young men from an Australian Aboriginal community in Arnhem Land, Northern Territory

Petrol sniffing and use of other drugs were examined among 48 males aged 13-32 years resident in a remote Aboriginal community in Arnhem Land. The study group consisted of 13 non-sniffers, 13 ex-sniffers and 22 current sniffers. Unemployment was highest among those with a history of petrol sniffing. Employment and family influence emerged as major reported reasons for individuals stopping petrol sniffing. The findings of the study suggest that strategies to reduce petrol sniffing should not only focus on education, employment, skills training and recreation, but should further encourage Aboriginal communities to utilize family relationships to dissuade young people from the practice. Unlike ex-sniffers and current sniffers, non-sniffers tended to be abstainers from tobacco, kava and alcohol. Of the selected study group, 52% smoked >or=25 cigarettes per day. On the basis of the research findings, the local community Council has implemented employment, skills training and recreation strategies to reduce petrol sniffing in this age group. A reduction in tobacco consumption in both adults and young people has also been targeted through health education programmes developed by the community health clinic and the school.

A study of the use of free nicotine patches by indigenous people

Objective: To assess use of free nicotine patches by Indigenous people when offered a brief intervention for smoking cessation, and to assess changes in smoking behaviour at six months.

Health effects of kava use in an eastern Arnhem Land Aboriginal community

Abstract

Validity and utility of community health workers' estimation of kava use.

Objective : Estimating illicit substance use in epidemiological studies is challenging, particularly across ethical, cultural and language barriers. While developing the methods for a case‐control study of the effects of heavy kava consumption among Aboriginal people in remote Northern Territory (NT), we examined the validity and utility of alternative methods for estimating exposure.

Saccade dysfunction associated with chronic petrol sniffing and lead encephalopathy

Background: In chronic petrol sniffers, recent exposure to high levels of leaded petrol may give rise to a lead encephalopathy characterised by tremor, chorea, ataxia, hyperreflexia, convulsive seizures, and death. Neurological abnormalities associated with lead encephalopathy involve the cortex, basal ganglia, cerebellum, and brain stem. Objective: To use saccadic eye movement tasks as an experimental tool to determine which CNS changes are associated with chronic petrol sniffing and which with a history of lead encephalopathy, and to what extent these changes are reversible. Methods: Saccade function was assessed in chronic petrol sniffers with a history of lead encephalopathy (encephalopathic sniffers), chronic petrol sniffers who had never suffered lead encephalopathy (chronic sniffers), individuals who had sniffed petrol in the past but had not done so for more than six months (ex-sniffers), and individuals who had never sniffed petrol (non-sniffers). Results: Chronic sniffers showed increased latency of visually guided saccades and antisaccades and increased antisaccade errors which suggested cortical and basal ganglia dysfunction. These abnormalities returned to normal in ex-sniffers. Encephalopathic sniffers showed the same abnormalities as chronic sniffers but with greater severity and additional saccadic signs including dysmetria, gaze evoked nystagmus, and saccade slowing which usually indicate cerebellar and brain stem dysfunction. Conclusions: Chronic petrol abuse is associated with cortical and basal ganglia abnormalities that are at least partially recoverable with abstinence. Additional long term cerebellar and brain stem abnormalities are associated with lead encephalopathy.

Kava in Arnhem Land: a review of consumption and its social correlates

The debate about the effects and public health importance of the way Aboriginal people drink kava has been confounded by claims, based on anecdote, of imputed health effects. Anecdote and comment have promoted the perception that dosage levels among Aboriginal people are much greater than in Pacific island societies. In this paper we review published data about kava consumption, and evaluate it with respect to information collected from observation of one Aboriginal community in Arnhem Land (Northern Territory) where people tend to consume kavaat a steady tempo; 37g of kava powder containing around 3800mg of kava lactones in 670ml of water in an hour. The highest levels of consumption in Arnhem Land have been reported to be up to 900g/week of kava powder with heavy consumers drinking at least 610g/week, levels comparable to estimates for Pacific-island societies. The significance of a steady drinking tempo means that an individuals weekly kava consumption relates directly to the amount of time spent drin...

Cannabis: a Trojan horse for nicotine?

[Extract] The recent report published by the AMA and APMA into Indigenous tobacco issues raised important questions regarding the implementation of effective strategies to reduce high levels of tobacco smoking and related harm in this population. We are currently working on separate projects within the Top End of the Northern Territory to support smoking cessation in the Aboriginal population and also to develop interventions to reduce harm associated with excessive cannabis use by Aboriginal youth.

An Evaluation of Unleaded Petrol as a Harm Reduction Strategy for Petrol Sniffers in an Aboriginal Community

OBJECTIVE In mid 1989, leaded petrol was replaced by unleaded petrol to reduce lead toxicity in petrol sniffers in Maningrida, a remote Aboriginal community in Northern Australia. RETROSPECTIVE REVIEWS: Hospital admissions between 1987 and 1992 due to petrol sniffing were compared for Maningrida and a community using only leaded petrol. RESULTS Admissions from Maningrida decreased significantly following introduction of unleaded petrol (chi 2 on 2df = 22.25, p < 0.001). Lead and hydrocarbon exposures were also compared for three groups from Maningrida (27 sniffers using only unleaded petrol; 15 exsniffers and 13 nonsniffers) and 24 individuals admitted to hospital for petrol sniffing related illness from other communities using only leaded petrol. Median blood lead levels for hospitalized sniffers (using only leaded petrol). Maningrida sniffers (using only unleaded petrol), exsniffers and nonsniffers were 5.06, 1.87, 1.24 and 0.17 microM/L respectively. There were significant differences between blood lead level, delta-aminolevulinic acid dehydratase activity, and free erythrocyte protoporphyrin for sniffers of leaded and unleaded petrol, whereas these indices were not significantly different for current sniffers and exsniffers in Maningrida. Hydrocarbons were only detectable in the blood of active sniffers (toluene < or = 0.5 micrograms/mL; benzene < or = 0.17 micrograms/mL blood; n-hexane not detected). CONCLUSIONS The elimination of tetraethyl lead from petrol resulted in a significant decrease in hospitalization of petrol sniffers.