Visual Contrast Sensitivity in Children Exposed to Tetrachloroethylene

Abstract

This study examined relationships between indoor air, breath, and blood tetrachloroethylene (perc) levels and visual contrast sensitivity (VCS) among adult and child residents of buildings with or without a colocated dry cleaner using perc. Decreasing trends in proportions of adults or children with maximum VCS scores indicated decreased VCS at a single spatial frequency (12 cycles per degree [cpd]) among children residing in buildings with colocated dry cleaners when indoor air perc level averaged 336 μg/m³; breath perc level averaged 159.5 μg/m³; and blood perc level averaged 0.51 μg/L. Adjusted logistic regression indicated that increases in indoor air, breath, and blood perc levels among all child participants significantly increased the odds for decreased VCS at 12 cpd. Adult VCS was not significantly decreased by increasing indoor air, breath, or blood perc level. These results suggest that elevated residential perc exposures may alter children's VCS, a possible subclinical central nervous system effect.

Letter to the editor: “Review of the epidemiologic literature on residential exposure to perchloroethylene” by John A. Bukowski

“…The interested reader is encouraged to read our complete study report available at: http://www.health.ny.gov/environmental/ investigations/perc/perc_vision_report.pdf. A comprehensive description of recruitment and enrollment procedures has appeared in the scientific literature (McDermott et al, 2005); as has a comprehensive description of the influence of residential perc exposure on children's VCS (Storm et al, 2011). The alteration in VCS was very small, limited to visual images of a specific size, and occurred only in children's worse performing eyes.…”

Response to letter from J.E. Storm and colleagues concerning the paper “Review of the epidemiologic literature on residential exposure to perchloroethylene”

“…In the case of the NYSDOH (2010) study, significant effects on children are reported from exposures in the range of 0.1 mg/m 3 (100 µg/m 3 ), which is 680-1700-fold below the threshold suggested from occupational and chamber studies. Storm et al (2011; provide no reasonable rationale why normal, healthy children would have this degree of extreme sensitivity compared with normal, healthy adults.…”

“…This would appear to be yet another example of Storm et al (2012) presenting evidence that supports their view and marginalizing that which doesn't. It should also be pointed out that nowhere in their recent letter , published paper (Storm et al, 2011), or unpublished report (NYSDOH, 2010) does NYSDOH provide convincing evidence that the wider literature recognizes VCS as the gold standard and most sensitive neurologic test for solvent-induced effects.…”

“…In the published version (Storm et al, 2011), their color-vision testing is not even mentioned. Furthermore, contrary visual contrast sensitivity (VCS) findings from the NYSDOH (2010) report are largely missing from the published paper, to the point that tabular data in the published version no longer match corresponding tables in the report (Bukowski, 2012).…”

“…In the case of the NYSDOH (2010) study, more exposed subjects were contacted (45%) than were those who were not exposed (38%), suggesting some level of differential selection. Furthermore, subjects were paid for their participation (Storm et al, 2011), creating an incentive that further muddies the selection process. Storm et al's (2012) suggestion that their study does not suffer from selection bias is speculation that cannot be reliably tested.…”