Inhaling paint and varnish fumes may increase the risk of multiple sclerosis (MS), research has shown.
On their own, the solvents raised the likelihood of developing MS by 50pc when compared with no exposure.
Adding MS susceptibility genes to the equation led to an almost seven-fold increase in risk, a study found.
As well as this, a triple whammy of smoking, genetic risk factors and solvent exposure caused the relative risk to soar 30 times over.
Lead researcher Dr Anna Hedstrom, from the Karolinska Institute in Stockholm, Sweden, said: "These are significant interactions where the factors have a much greater effect in combination than they do on their own.
"More research is needed to understand how these factors interact to create this risk.
"It's possible that exposure to solvents and smoking may both involve lung inflammation and irritation that leads to an immune reaction in the lungs," she added.