Chronic Solvent Encephalopathy: How to screen working populations - Experiences from Finland

Introduction and objectives  Exposure to organic solvents in Finland and developed countries has decreased during the decades. However in Finland, the yearly incidence of chronic solvent encephalopathy (CSE) as occupational disease is still 5-10. Although, occupational health (OH) care screens for symptoms and signs of (CSE), previous findings suggest that this leaves out undetected cases (Kaukiainen et al, 2009). We studied whether workers with CSE can be found by questionnaire-based surveys to employees in union registers at professional fields with risk of CSE (Keski-Säntti et al, 2010).    

Patients and Methods  A questionnaire was sent to 3 600 employees in union registers. The professional fields with organic solvent exposure and CSE were painting and floor industry, printing press industry, boat construction/ other reinforced plastic laminating and metal industry. We screened possible neurotoxic symptoms by Euroquest and life-time solvent exposure by a structured questionnaire developed for this study. Other health-related causes of symptomatology were also inquired.    From the 1 719 respondents, 122 patients with both adequate exposure to organic solvents and suitable symptoms of CSE were invited for clinical examination. The clinical examination consisted of a thorough interview by a medical specialist in occupational health, a medical examination, general blood tests, and CERAD neuropsychological screening battery. 32 were not willing to participate, 10 did not show up, thus leaving 80 examined patients.    

Results and conclusions  From the 80 cases, we found 33 with suspicion of CSE, which were referred to official clinical investigations of occupational disease. In comparison to the cases found in a previous study on construction painters (Kaukiainen 2009), the proportion of cases in the current study is larger. The preliminary results suggest that CSE is under diagnosed in Finland. Focused screening of workers at risk seems warranted even in countries with adequate OH.