Handbook of Solvents - George Wypych - ChemTech - Ventech!

20.9 Toxicity of environmental solvent exposure for brain, lung and heart 1415
The focus on polyneuropathy in 14 studies 2 has usurped studies of central nervous system
(CNS) functions except for one showing increased latencies of visual and auditory
evoked potentials. 61 Neurophysiological and psychological assessments 62 show narcotic effects
that match those in animals. 2 Until restricted from foods n-hexane was used to extract
oil from soybean meal and exposed US workers. They had headache, dysesthesia, insomnia,
somnolence and memory loss but testing for appraise brain damage was not done.
Gasoline is a mixture of aliphatic straight and branched chains and aromatic hydrocarbons
with toxicity attributable to toluene, xylene and perhaps hexane and additives including
methyl ter butyl ether and tri-orthocresyl phosphate. 63
Effects of the lungs of inhaled solvents simplify to the consideration of agents affecting
airway cells that include n-hexane and PCBs. Both cause proliferation and transformation
of distal airway lining cells to produce mucus and obstruct airways 64-66 and cause
inflammatory cells to pour into the lungs distal alveolar spaces interfering with for gas exchange.
Cardiac effects of solvents are of three types A, alterations in rhythm B,
cardiomyopathy and C, hypertension directly and via renal changes as in interstitial nephritis,
glomerulonephritis and Goodpasture’s syndrome. 67
Alterations in heart rhythm have been attributed to anesthesia with TCE and were serious,
especially when administered in soda lime CO 2 absorbing anesthesia machines to stop
the use of TCE for anesthesia in the 1960’s. 4 Rhythm disturbances have also been observed
in some groups of workers exposed to TCE. Knowing this we did electrocardiograms
(ECG’s) on the Tucson TCE exposed population and found no arrhythmias. A loss of respiratory
variation in heart rate has been associated with exposure to organic solvents, including
carbon disulfide, acrylamide and alcohol but not toluene and with diabetes mellitus and
syndromes of autonomic nervous system dysfunction. 17,68,69 Later freons, volatile chlorofluorocarbons
were associated with arrhythmias and withdrawn from use to propel therapeutic
aerosols used for asthma. 70 Cardiomyopathy, heart muscle dysfunction and
enlargement have been associated with alcohol ingestion. Two epidemics were ascribed to
cobalt used to color beer. 9 But in the most common cardiac muscle disorder from alcohol,
cobalt is not incriminated.
Hypertension has been associated with solvent exposure in workers, an association
that needs further study. Associations with hypertension were absent in the authors studies
of TCE, toluene rich waste and PCBs discussed earlier.
Workers who used methylene chloride in making acetate film had sleepiness and fatigue
and decreased digit symbol substitution scores and lengthened reaction time. 71 Use of
methylene chloride in closed spaces has been fatal with brain edema, elevated blood levels
of carboxyhemoglobin and caused temporary right hemispheric paralysis and/or unconsciousness.
2 Chronic exposure has been associated with dementia, headache, dizziness and
disturbed gait. 72
Chloromethane exposures from foam production caused tremor and decreased attention
and ability to do arithmetic. 73 Environmental exposures from leaks in refrigerating
systems 2 caused deaths, convulsions, myoclonus and personality changes. One fishing boat
exposure of 15 men left profound neurological residuals, fatigue, depression and alcohol intolerance.
2 The effects resemble those of methyl bromide poisoning.
Methanol has profound and specific toxic effects on the optic nerve and vision causing
central blind spots and ingestion of methanol for the intoxicating effects of ethanol has