Handbook of Solvents - George Wypych - ChemTech - Ventech!

20.9 Toxicity of environmental solvent exposure for brain, lung and heart 1411
list 1990) Thus here we had an example of a probable environmental exposure to TCE with
a superimposed occupational one. 4
TCE leakage had produced these same effects in Joplin, MO neighbors of a company
manufacturing ball bearings and cleaning with this solvent. The companies decision to
clean and reuse TCE rather than dump it ameliorated the effects. 4 In San Gabriel and San
Fernando Valleys in California similar observations confirm adverse effects from TCE contamination
of groundwater and air. Clearly the observations were replicated and each time
TCE was associated with reasonable timing and proximity. More than half of the federal
superfund sites in the US are contaminated with TCE suggesting 800 potential replications.
29 Experience with several patients have shown me that the effects of dichloroethylene
and of 1,1,1-trichloroethane are indistinguishable from those of TCE.
Toluene is the most toxic and best studied of the aromatic ring compound solvents.
Both acute and chronic effects were observed by 1961 from inhaling “huffing” toluene 30,31
or lacquer thinner, 32 especially in children sniffing airplane glue. 30 Chronic impairment was
shown shoemakers 33 and rotogravure printing workers 34 using neurobehavioral testing. Toluene
exposed experimental animals, mainly rats and mice showed enhanced motor activity,
abnormal movements, altered sleep patterns and electroencephalograph (EEG) changes
from an integrative brain loop, the hippocampus. 2 Occupational exposures produced memory
disturbances, poorer performance on block design assembly, embedded figures, visual
memory and eye-hand coordination. CT scans showed some generalized brain swelling 34
that correlated with impaired psychological functions. 35 Women working in electronic assembly
had environmental air levels of toluene of 88 ppm compared to 13 ppm for controls
and comparable differences in blood levels. These workers were less apt at placing pegs in a
grooved board, at trail making, digit symbol, visual retention and reproduction and verbal
memory. 36 They were tested during the day after being away from exposure for at least 16
hours.
Protracted sniffing of solvents alone or in glue has produced intention tremor and
titubating gait 30 consistent with cerebellar degeneration which continued after 5 years with
ataxia, EEG slowing and cerebral atrophy. 31 Polyneuropathy was observed in 2 glue sniffers
in Japan whose exposures were to n-hexane and toluene. 37 Many such descriptions 2 outweigh
one epidemiological study that found no differences in performance when comparing
12 glue sniffing boys, ages 11 to 15, mean 13.8 years and 21 controls, ages 11 to 15, mean
12.6 years. Four non-standard tests and the Benton visual retention and design reproduction
test were used but the exposed group was 1.2 years older and should have outperformed
younger controls whose skills were less developed. 38
Some published data are difficult to interpret. For example, 26 men were exposed in
tanks and holds of two merchant vessels being painted (solvents) and sprayed with malathion
20% and pyrethrin 1.5%, with piperonyl butoxide in toluene. They showed losses of
concentration, unawareness of danger and unconsciousness at toluene levels estimated as
10,000 to 12,000 ppm and up to 30,000 ppm below waist level. 39 Additive effects of the
neurotoxic insecticides were not discussed.
Effects of toluene in 52 men and paint solvents in 44 men were contrasted with unexposed
men. Painters had impaired reading scores, trails B, visual search, block design,
grooved pegboard, simple reaction time and verbal memory. 40 Toluene exposed men had
only abnormal reading scores reduced significantly, although scores on all tests were lower.