RAYMOND SINGER, PH.D.
A Professional Association
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Singer, R. (2001). Neurotoxicity evaluation of a new solvent. Archives of Clinical Neuropsychology, 16 (2001), 697.
Purpose: To evaluate a case of potential neurotoxicity from a new solvent, Foamflush, which is composed primarily of gamma butyrolactone and n-methyl pyrrolidone. Both of these substances are organic solvents. The product replaced the neurotoxic solvent methylene chloride and is designed to dissolve urethane foam. Foamflush is one of 70,000 chemicals in commercial use, most of which lack adequate, or any testing, for potential workplace neurotoxicity. Nevertheless, all organic solvents have the potential to cause neurotoxicity due to their action of dissolving organic materials, such as lipids in nervous system tissue, depending upon factors of exposure (amount, duration, intermittency, co-exposures, etc.), the exposed (constitution, prior exposures, current health status etc.), the dissolving strength of the solvent, and its capacity and opportunity to enter the human body.
Method: Exposure assessment, neuropsychological testing, personality assessment
Results: A woman worked for 3 years on an assembly line manufacturing foam automobile air filters. She had an almost perfect work attendance record, and was well regarded by co-workers and supervisors. On two occasions during her last months at this job, the hosing carrying the solvent, Foamflush, malfunctioned, and she was enveloped in a solvent mist. Immediate symptoms included headache, nausea, skin rash, shortness of breath, stomach pain, nervousness, blackouts, hoarseness, and slowing and slurring of speech. Shortly thereafter, she developed a disorder similar to Parkinson=s disease, with motor and cognitive dysfunction. She was diagnosed with extrapyramidal system dysfunction, tremor and headache. Upon examination 4 years post-exposure, symptoms consistent with permanent neurotoxicity were found with the Neurotoxicity Screening Survey. Estimated pre-morbid FSIQ was probably in the average range. Current FSIQ was 1st % (VIQ 2nd %, PIQ 1st %). She had extreme anxiety and depression on the Beck=s Inventories. Malingering was not found on 4 tests of this variable. Results on the NEO Personality Inventory indicated a possible Avoidant or Dependent personality disorder, conditions which were probably latent prior to exposure. Examination of the medical record found no alternate explanation of her illness.
Conclusion: Gamma butyrolactone and/or n-methyl pyrrolidone may cause permanent neurotoxicity in some people, depending upon various factors of exposure, etc.. In general, solvent-workers need to be informed of the potential for neurotoxic injury from their exposure, and then monitored using repeated neurobehavioral tests.