Preliminary Findings on the Effects of Occupational Exposure to Mercury Vapor Below Safety Levels on Visual and Neuropsychological Functions

Barboni, Mirella Telles Salgueiro; Feitosa-Santana, Cláudia; Zachi, Elaine Cristina; Lago, Mayra Coan; Teixeira, Rosaní Aparecida Antunes; Taub, Anita; Costa, Marcelo Fernandes; Silveira, Luiz Carlos de Lima; Ventura, Dora Fix

doi:10.1097/jom.0b013e3181bca9ea

Cited by 30 publications

(17 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The variability in the data supports the need to use more than one testing procedure when evaluating the visual outcome of occupational neurotoxic exposures [13], [15], [28], [31], [32]. Visual system performance and cognitive changes are not straightforward and may unpredictably affect the testing performance.…”

Section: Discussionmentioning

confidence: 95%

“…The Cambridge Colour Test (CCT) is a computerized test [26] that proved to be an efficient tool in the detection and quantification of acquired color vision defects [13], [14], [27], [28], [29], [30], [31], [32]. The test uses pseudoisochromatic stimuli and a four-alternative forced choice psychophysical procedure, avoiding eventual biases known to occur in arrangement tests and other classes of color vision tests.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Long-Term Occupational Exposure to Organic Solvents Affects Color Vision, Contrast Sensitivity and Visual Fields

et al. 2012

Self Cite

View full text Add to dashboard Cite

The purpose of this study was to evaluate the visual outcome of chronic occupational exposure to a mixture of organic solvents by measuring color discrimination, achromatic contrast sensitivity and visual fields in a group of gas station workers. We tested 25 workers (20 males) and 25 controls with no history of chronic exposure to solvents (10 males). All participants had normal ophthalmologic exams. Subjects had worked in gas stations on an average of 9.6±6.2 years. Color vision was evaluated with the Lanthony D15d and Cambridge Colour Test (CCT). Visual field assessment consisted of white-on-white 24–2 automatic perimetry (Humphrey II-750i). Contrast sensitivity was measured for sinusoidal gratings of 0.2, 0.5, 1.0, 2.0, 5.0, 10.0 and 20.0 cycles per degree (cpd). Results from both groups were compared using the Mann–Whitney U test. The number of errors in the D15d was higher for workers relative to controls (p<0.01). Their CCT color discrimination thresholds were elevated compared to the control group along the protan, deutan and tritan confusion axes (p<0.01), and their ellipse area and ellipticity were higher (p<0.01). Genetic analysis of subjects with very elevated color discrimination thresholds excluded congenital causes for the visual losses. Automated perimetry thresholds showed elevation in the 9°, 15° and 21° of eccentricity (p<0.01) and in MD and PSD indexes (p<0.01). Contrast sensitivity losses were found for all spatial frequencies measured (p<0.01) except for 0.5 cpd. Significant correlation was found between previous working years and deutan axis thresholds (rho = 0.59; p<0.05), indexes of the Lanthony D15d (rho = 0.52; p<0.05), perimetry results in the fovea (rho = −0.51; p<0.05) and at 3, 9 and 15 degrees of eccentricity (rho = −0.46; p<0.05). Extensive and diffuse visual changes were found, suggesting that specific occupational limits should be created.

show abstract

Section: Discussionmentioning

confidence: 95%

Section: Methodsmentioning

confidence: 99%

Long-Term Occupational Exposure to Organic Solvents Affects Color Vision, Contrast Sensitivity and Visual Fields

et al. 2012

Self Cite

View full text Add to dashboard Cite

show abstract

“…Recent epidemiological studies evaluated exposure to different mercurials and found that even low levels of mercury cause subtle adverse effects on brain functions (Barboni et al 2009;Debes et al 2006) and may interfere with neurobehavioral development in children and affect also the immune system and cause progression of atherosclerosis and cardiovascular diseases in adults (Kjellström et al 1989;Shamlaye et al 1995;Vas and Monestier, 2008;Virtanen et al 2005). However, the mechanism of toxicity has not been well understood and studies with EtHg and TM are scarce in vivo and in vitro (Geir et al, 2009;Ida-Eto et al, 2013;Migdal et al, 2011;Mutkus et al, 2005;Pieper et al, 2014;Sharpe et al, 2012;Westphal et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

Toxicological effects of thiomersal and ethylmercury: Inhibition of the thioredoxin system and NADP+-dependent dehydrogenases of the pentose phosphate pathway

Rodrígues

Branco

et al. 2015

Toxicology and Applied Pharmacology

View full text Add to dashboard Cite

“…Color vision is a popular model system for information processing in neural circuits and human color perception has been successfully used as a model to assess the functional status of the central nervous system (Gobba and Cavalleri, 2003; Ventura et al, 2003, 2004, 2005, 2007; Silva et al, 2005; Costa et al, 2006, 2007; Feitosa-Santana et al, 2008, 2010; Moura et al, 2008; Barboni et al, 2009; Conway et al, 2010). Current understanding of the human color perception system can be considered extensive when compared to our understanding of other sensory systems.…”

Section: Introductionmentioning

confidence: 99%

Transcranial Direct Current Stimulation Modulates Human Color Discrimination in a Pathway-Specific Manner

Costa¹,

Nagy²,

Barboni³

et al. 2012

Front. Psychiatry

View full text Add to dashboard Cite

Previous research showed that transcranial direct current stimulation (tDCS) can modulate visual cortex excitability. However, there is no experiment on the effects of tDCS on color perception to date. The present study aimed to investigate the effects of tDCS on color discrimination tasks. Fifteen healthy subjects (mean age of 25.6 ± 4.4 years) were tested with Cambridge Color Test 2.0 (Trivector and ellipses protocols) and a Forced-choice Spatial Color Contrast Sensitivity task (vertical red-green sinusoidal grating) while receiving tDCS. Anodal, cathodal, and sham tDCS were delivered at Oz for 22 min using two square electrodes (25 cm2 with a current of 1.5 mA) in sessions separated by 7 days. Anodal tDCS significantly increased tritan sensitivity (p < 0.01) and had no significant effect on protan, deutan, or red-green grating discrimination. The effects on the tritan discrimination returned to baseline after 15 min (p < 0.01). Cathodal tDCS reduced the sensitivity in the deutan axis and increased sensitivity in the tritan axis (p < 0.05). The lack of anodal tDCS effects in the protan, deutan, and red-green grating sensitivities could be explained by a “ceiling effect” since adults in this age range tend to have optimal color discrimination performance for these hues. The differential effects of cathodal tDCS on tritan and deutan sensitivities and the absence of the proposed ceiling effects for the tritan axes might be explained by Parvocellular (P) and Koniocellular (K) systems with regard to their functional, physiological, and anatomical differences. The results also support the existence of a systematic segregation of P and K color-coding cells in V1. Future research and possible clinical implications are discussed.

show abstract

Preliminary Findings on the Effects of Occupational Exposure to Mercury Vapor Below Safety Levels on Visual and Neuropsychological Functions

Cited by 30 publications

References 36 publications

Long-Term Occupational Exposure to Organic Solvents Affects Color Vision, Contrast Sensitivity and Visual Fields

Long-Term Occupational Exposure to Organic Solvents Affects Color Vision, Contrast Sensitivity and Visual Fields

Toxicological effects of thiomersal and ethylmercury: Inhibition of the thioredoxin system and NADP+-dependent dehydrogenases of the pentose phosphate pathway

Transcranial Direct Current Stimulation Modulates Human Color Discrimination in a Pathway-Specific Manner

Contact Info

Product

Resources

About