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4724096 
Journal Article 
Abstract 
A longitudinal study of memory impairments secondary to ethylene dichloride exposure 
Dilks, L; Matzenbacher, D; Marceaux, J; Mayeaux, B 
2005 
1 
Neurotoxicology and Teratology
ISSN: 0892-0362
EISSN: 1872-9738 
27 
6 
909-910 
English 
WOS:000233767400035 
Introduction: Ethylene dichloride (EDC) is an organic solvent used in the manufacture of pesticides, fumigants, paints and plastics. EDC is classified as a neurotoxin, a carcinogen and a DNAmutating agent. Research indicated exposure levels greater than one part per million over a 10 h period can cause physical and psychological impairments; however, some researchers argue that the effects of exposure are transient and likely to subside once exposure to organic solvents is terminated. Previous research by the authors indicates that individuals exposed to EDC sustained long-term memory impairments. The current study re-evaluated these individuals 10 years postexposure to assess stability, improvement, or deterioration.

Methods: (Participants) Twelve individuals exposed to EDC while working at a cleanup site between 1994 and 1996 underwent neuropsychological evaluations in 2000 and again in 2004. Individuals varied in age from 33 years to 53 years, with a mean age of 44.58 years. All participants were male. (Measures and Procedures) In 2000 eleven individuals were administered the Wechsler Memory Scale, Third Edition at a clinic in Lake Charles, LA. The same eleven individuals were evaluated in 2004 using the same instrument at the same location. All assessments were conducted according to standardized procedures by trained assessment specialists.

Results: t-tests conducted on 2000 and 2004 assessment data indicated a significant improvement in auditory delayed memory (t = -3.338; p =0.003) and in visual delayed memory (t = -2.256; p =0.034). The other six realms of memory assessed by the WMS-III, including auditory immediate, visual immediate, immediate memory, auditory recognition delayed, general memory and working memory, demonstrated no significant change from 2000 to 2004.

Discussion: The results of the 2000 neuropsychological evaluations suggested that exposure to EDC had a significant and permanent adverse influence on memory functioning at more than 6 years post-exposure. A follow up evaluation conducted at 10 years post-exposure supported this original observation. Any further advance in cognitive reorganization or improvement in functioning appears unlikely. 
Adult; drug effects; Ethylene Dichlorides; Humans; Longitudinal Studies; Male; Memory; methods; Middle Aged; Neuropsychological Tests; Solvents; toxicity 
24th Annual Meeting of the Behavioral Toxicology Society 
Saint Petersburg Beach, Florida 
June 25–28, 2005