1. ¹The Neuropsychology Laboratory, Mental Health Research Institute, Parkville, VIC, Australia
2. ²School of Psychological Science, La Trobe University, Bundoora, VIC, Australia
3. ³Menzies School of Health Research, Charles Darwin University, Darwin, Australia
4. ⁴Northern Territory Clinical School, Flinders University, Darwin, Australia
5. ⁵Brain Research Unit, Drug and Alcohol Services, Westmead Hospital, Westmead, NSW, Australia

Correspondence: Dr S Cairney, Menzies School of Health Research, PO Box 41096, Casuarina, NT 0811, Australia. Tel: +61 8 8922 8196; Fax: +61 8 8927 5187; E-mail: Sheree.Cairney@menzies.edu.au

Received 21 April 2004; Revised 14 December 2004; Accepted 21 December 2004; Published online 16 February 2005.

Abstract

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.