Exposure to Organic Solvents Used in Dry Cleaning Reduces Low and High Level Visual Function

Abstract

PurposeTo investigate whether exposure to occupational levels of organic solvents in the dry cleaning industry is associated with neurotoxic symptoms and visual deficits in the perception of basic visual features such as luminance contrast and colour, higher level processing of global motion and form (Experiment 1), and cognitive function as measured in a visual search task (Experiment 2).MethodsThe Q16 neurotoxic questionnaire, a commonly used measure of neurotoxicity (by the World Health Organization), was administered to assess the neurotoxic status of a group of 33 dry cleaners exposed to occupational levels of organic solvents (OS) and 35 age-matched non dry-cleaners who had never worked in the dry cleaning industry. In Experiment 1, to assess visual function, contrast sensitivity, colour/hue discrimination (Munsell Hue 100 test), global motion and form thresholds were assessed using computerised psychophysical tests. Sensitivity to global motion or form structure was quantified by varying the pattern coherence of global dot motion (GDM) and Glass pattern (oriented dot pairs) respectively (i.e., the percentage of dots/dot pairs that contribute to the perception of global structure). In Experiment 2, a letter visual-search task was used to measure reaction times (as a function of the number of elements: 4, 8, 16, 32, 64 and 100) in both parallel and serial search conditions.ResultsDry cleaners exposed to organic solvents had significantly higher scores on the Q16 compared to non dry-cleaners indicating that dry cleaners experienced more neurotoxic symptoms on average. The contrast sensitivity function for dry cleaners was significantly lower at all spatial frequencies relative to non dry-cleaners, which is consistent with previous studies. Poorer colour discrimination performance was also noted in dry cleaners than non dry-cleaners, particularly along the blue/yellow axis. In a new finding, we report that global form and motion thresholds for dry cleaners were also significantly higher and almost double than that obtained from non dry-cleaners. However, reaction time performance on both parallel and serial visual search was not different between dry cleaners and non dry-cleaners.ConclusionsExposure to occupational levels of organic solvents is associated with neurotoxicity which is in turn associated with both low level deficits (such as the perception of contrast and discrimination of colour) and high level visual deficits such as the perception of global form and motion, but not visual search performance. The latter finding indicates that the deficits in visual function are unlikely to be due to changes in general cognitive performance.

Chronic Exposure to Solvents Among Construction Painters

“…This discrepancy among studies may be explained by differences in solvent exposures and in some cases less control for other factors known to affect visual contrast sensitivity (e.g., alcohol use, diabetes). (55, 58) Therefore, in contrast with the conclusions of previous reviews(13) the current study did not reveal an association between chronic solvent exposure and indicators of either cognitive, motor, or visual contrast function.…”

“…Overall multivariate analyses for the domains of attention, working memory, and visual memory did not support that exposed subjects exhibited a consistent pattern of impaired neurobehavioral function in any domain. Although several previous studies reported reduced visual contrast sensitivity as an indicator of solvent induced neurotoxicity(51, 55–58), the current study also did not reveal any significant differences in contrast sensitivity at any spatial frequency. This discrepancy among studies may be explained by differences in solvent exposures and in some cases less control for other factors known to affect visual contrast sensitivity (e.g., alcohol use, diabetes).…”

Risk, Reliability and Resilience: Phytolith Evidence for Alternative ‘Neolithization’ Pathways at Kharaneh IV in the Azraq Basin, Jordan

“…However, the analysis of this unique macrobotanical evidence has concentrated largely on those plant remains that later became the first domesticates (i.e. wild cereals and grasses) [ 28 – 30 ].…”

Relationship between Neurocognitive Performance and Body Composition of Men and Women Exposed to Organic Solvents

“…En general, los solventes orgánicos pueden afectar el desempeño neurocognitivo y los efectos de la exposición crónica dependen de la precisión del test neurocognitivo y del índice de composición corporal. Boon, & Khuu, 2015;Lotti, Bleecker, & Aminoff, 2015), as well as changes in motor, sensory and neurocognitive functions (Morrow & Scott, 2002;Sabbath et al, 2014). A decline in cognitive ability may be a predictor of the development of a number of neurodegenerative disorders such as dementias, for example (Blazer, Yaffe, & Liverman, 2015).…”