Long-term deficits in adaptive behavior secondary to ethylene dichloride exposure.

Although the neurological effects of ethylene dichloride (EDC) have been fairly well explored, the literature offers little information concerning the long-term effects on adaptive functioning. A further understanding of adaptive capability would enhance the development of treatment programs, allow them to become more cost-efficient, supplement measures of cognitive ability, and facilitate estimates of neuropsychological intactness. The purpose of the present study was to explore the long-term effects of EDC on adaptive functioning. The results study suggest that adaptive capabilities are adversely affected secondary to EDC exposure, and limit a person's future health and welfare.

Ethylene dichloride (EDC) also known as 1,2-dichloroethane, was first discovered by a Dutch chemist in the late 1700s, but its usefulness as an organic solvent was not capitalized upon until the early part of the 20th century (Agency for Toxic Substances and Disease Registry [ATSDR], 2001). In the 1800's EDC was also briefly used as an anesthetic but quickly discontinued for this purpose because of its toxic side effects (Baker, Smith, & Landrigan, 1985; EPA, 2000). Since the mid-1940s, it has been used as a raw material in the production of other materials.

EDC is an organic solvent that is utilized in the manufacture of fumigants, solvents, cleaning fluids, pesticides, and more recently, plastics, especially PVC. Although large amounts of EDC are produced today, it is mostly used in the manufacture of other chemical products, such as vinyl chloride (ATSDR, 2001; EPA, 2000). Government regulations regarding the management of toxic chemicals, such as EDC, are voluminous but not necessarily comprehensive. There are ample regulations concerning the immediate management of spills, cleanup, manufacture, transportation and storage and there are even regulations addressing the long-term direct consequences of mismanagement of chemicals (NIOSH, 1978). These programs have contributed to the welfare of society by preventing spills and in their facilitation during cleanup. Taken together, these regulations and programs have resulted in a safer and cleaner environment (Whitford, Feinberg, Mysz, Rowan, Earl, Doering, Neltner, & Blessing, 2001). The investigation of long-term effects on psychological functioning is less well documented and the secondary effects on behavior have hardly been addressed at all in the literature and are not reflected in public policy (Thornton, 2000). At this time, the overall public policy regarding the realm of toxic chemicals does not address the phenomena of personal loss or deterioration resulting from toxic exposure.

Exposure to EDC can occur by skin contact, through respiration, or through ingestion. Most human contact is inadvertent and the consequences of contact while processing the chemical. Ingestion is typically intentional and usually fatal (ATSDR, 2001). In this study, individuals were exposed to EDC unintentionally while working at a clean-up site.

In 1985, the World Health Organization met to address concerns about toxic exposure among individuals who work with hazardous chemicals. Chronic Toxic Encephalopathy was subsequently coined and resulted in the development of a classification scheme to specify three categories of symptomatology (World Health Organization, 1985): Type I: Acute signs and symptoms that typically reverse when exposure is discontinued; Type IIA: Affective and behavioral features; Type IIB: Positive findings on physiological and neuropsychological examinations; Type III: Persistent and severe features involving damage to body organs that are often permanent or terminal.

To date, our research has delineated Type IIA and IIB symptomatology among individuals exposed to EDC (Davis, Dilks, Matzenbacher, & Christianson, 2003; Dilks & Matzenbacher, 2002). That research supported the hypothesis that exposure to EDC resulted in long-term deficits in executive functioning, such as judgment, insight, reasoning, and abstraction abilities. The research revealed permanent impairments in multiple realms of recent memory.…