| Apartment Residents' and Day Care Workers' Exposures to Tetrachloroethylene and Deficits in Visual Contrast Sensitivity Judith S. Schreiber,1 H. Kenneth Hudnell,2 Andrew M. Geller,2 Dennis E. House,2 Kenneth M. Aldous,3 Michael S. Force,3 Karyn Langguth,4 Elizabeth J. Prohonic,4 and Jean C. Parker5 1State of New York, Office of Attorney General, Albany, New York, USA; 2Office of Research and Development, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA; 3New York State Department of Health, Wadsworth Center, Albany, New York, USA; 4New York State Department of Health, Center for Environmental Health, Troy, New York, USA; 5Office of Research and Development, National Center for Environmental Assessment, U.S. Environmental Protection Agency, Washington, DC, USA Abstract Tetrachloroethylene (also called perchloroethylene, or perc) , a volatile organic compound, has been the predominant solvent used by the dry-cleaning industry for many years. The U.S. Environmental Protection Agency (EPA) classified perc as a hazardous air pollutant because of its potential adverse impact on human health. Several occupational studies have indicated that chronic, airborne perc exposure adversely affects neurobehavioral functions in workers, particularly visual color discrimination and tasks dependent on rapid visual-information processing. A 1995 study by Altmann and colleagues extended these findings, indicating that environmental perc exposure at a mean level of 4,980 µg/m3 (median=1,360 µg/m3) alters neurobehavioral functions in residents living near dry-cleaning facilities. Although the U.S. EPA has not yet set a reference concentration guideline level for environmental exposure to airborne perc, the New York State Department of Health set an air quality guideline of 100 µg/m3. In the current residential study, we investigated the potential for perc exposure and neurologic effects, using a battery of visual-system function tests, among healthy members of six families living in two apartment buildings in New York City that contained dry-cleaning facilities on the ground floors. In addition, a day care investigation assessed the potential for perc exposure and effects among workers at a day care center located in the same one-story building as a dry-cleaning facility. Results from the residential study showed a mean exposure level of 778 µg/m3 perc in indoor air for a mean of 5.8 years, and that perc levels in breath, blood, and urine were 1-2 orders of magnitude in excess of background values. Group-mean visual contrast sensitivity (VCS) , a measure of the ability to detect visual patterns, was significantly reduced in the 17 exposed study participants relative to unexposed matched-control participants. The groups did not differ in visual acuity, suggesting that the VCS deficit was of neurologic origin. Healthy workers in the day care investigation were chronically exposed to airborne perc at a mean of 2,150 µg/m3 for a mean of 4.0 years. Again, group-mean VCS, measured 6 weeks after exposure cessation, was significantly reduced in the nine exposed workers relative to matched controls, and the groups did not differ significantly in visual acuity. These results suggested that chronic, environmental exposure to airborne perc adversely affects neurobehavioral function in healthy individuals. Further research is needed to assess the susceptibility of the young and elderly to perc-induced effects, to determine whether persistent solvent-induced VCS deficits are a risk factor for the development of neurologic disease, and to identify the no observable adverse effect level for chronic, environmental, perc exposure in humans. Key words: color discrimination, human exposure, perchloroethylene, tetrachlorethylene, vision, visual contrast sensitivity. Environ Health Perspect 110:655-664 (2002) . [Online 24 May 2002] http://ehpnet1.niehs.nih.gov/docs/2002/110p655-664schreiber/ abstract.html Address correspondence to H.K. Hudnell, MD-74B, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 USA. Telephone: (919) 541-7866. Fax: (919) 541-4849. E-mail: hudnell.ken@epa.gov We thank S. House and D. Sharron of the New York State Department of Health for their assistance in sample collection and data analysis ; R. Narang of the Wadsworth Laboratory of NYSDOH, D. Ashley of the Centers for Disease Control and Prevention, and W. Dekant of the University of Wurzburg, Germany, for sample analysis ; and D. Monahan of Mt. Sinai Medical Center for blood sample collections. We also thank reviewers of the paper for the U.S. EPA clearance process--P. Bushnell, C. Scott, R. Hetes, within EPA's Office of Research and Development, and F. Gobba, Universita di Modena e Reggio Emilia, Italy--for their insightful comments and suggestions. We express our appreciation to the families who participated in the study for their generous cooperation. This work was supported by U.S. EPA Cooperative Agreement CR824400-01. This manuscript was reviewed by the National Health and Environmental Effects Research Laboratory, U.S. EPA, and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the agency, nor does mention of trade names or commercial products constitute endorsement or recommendation. This manuscript was reviewed by the Office of the New York State Attorney General and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the Attorney General's Office. J.S. Schreiber collected the data discussed in this article while employed at the New York State Department of Health prior to employment with the Attorney General's Office. Received 15 August 2001 ; accepted 2 January 2002. The full version of this article is available for free in HTML or PDF formats. |