Thu, Nov. 14, 2002
On-the-job exposure to organic solvents may increase a person's risk of developing multiple sclerosis (MS), an inflammatory condition of the central nervous system, new study findings from Norway suggest.
No one knows what causes MS, which occurs when the body's immune system mistakenly attacks the protective myelin sheath surrounding nerve fibers in the brain and spine. Symptoms of MS include muscle weakness and stiffness, balance and coordination problems, numbness and vision disturbances.
Previous studies have suggested that a history of exposure to organic solvents may increase one's MS risk. To further investigate the association, lead author Dr. Trond Riise and colleagues from the University of Bergen studied nearly 12,000 people identified as working as painters in a 1970 census. The researchers followed the group until the end of 1986.
Painters are known to be routinely exposed to various organic solvents such as toluene, white spirit and xylene, the authors note in their report in the November issue of the journal Epidemiology.
For comparison sake, Riise's team also followed 36,899 construction workers and 9,314 food processing workers for the same period, who were not believed to have been exposed to organic solvents.
At the end of the study period, a review of disability pensions revealed that 9 painters, 12 construction workers and 6 food workers were diagnosed with MS, the researchers report.
"The risk of receiving a disability pension because of MS among painters was twice as high as among the combined group of workers in construction and food processing," the authors write.
Since occupational exposure to organic solvents is the major difference between the two groups, Riise and colleagues conclude that their "findings are therefore consistent with the hypothesis that exposure to organic solvents might increase the risk of developing MS."
The investigators call for more research on the association between the chemicals and MS risk.
SOURCE: Epidemiology 2002;13:718-720.
© 2002 Reuters Ltd