Detecting chronic solvent encephalopathy in occupations at risk

Abstract Chronic solvent encephalopathy (CSE) is under-reported worldwide due to difficulties in recognition and differences in national legislation. Although its occurrence in developed countries has declined, new cases continue to be detected. Our aim was to determine whether CSE can be detected in risk trades, using a stepwise screening procedure. Another aim was to evaluate if this method detects more cases than present occupational health service (OHS) practices do in Finland, a country with decreasing exposures, high OHS coverage and an annual rate of around forty cases of suspected CSE and seven cases of occupational CSE. The studied fields, based on the national occurrence of CSE, were industrial and construction painting, floor layering, the printing press industry, boat construction, reinforced plastic laminating and the metal industry. We obtained contact information from trade union registers and municipal OHS. A postal survey including the Euroquest (EQ) neurotoxic symptom questionnaire, Beck's Depression Inventory (BDI) and the Alcohol Use Disorders Identification Test-Consumption (Audit-C), and questions on exposure and medical conditions, was sent to 3,640 workers in the age range of 30–65 years in two Finnish provinces. The survey resulted in 1,730 responses (48%). This was followed by a clinical examination, with methods applicable to OHS, of subjects fulfilling the criteria: three or more EQ memory and concentration symptoms and sufficient exposure, a BDI score ≤ 18, an AUDIT-C score ≤ 8, and no evident medical condition explaining their symptoms. Of 338 respondents with memory and concentration symptoms, 129 subjects fulfilled all the criteria, of which 83 participated in clinical examinations. We found 38 CSE compatible cases. The study shows that more CSE compatible cases can be detected when the screening is directed towards the occupational fields at greatest risk. This stepwise method is more effective for finding CSE compatible cases than regular OHS activity. The number of cases was similar to the total annual occurrence, of new CSE-suspected cases, although the sample represented approximately 18% of the abundantly exposed workforce in Finland. Combining of exposure and medical differential diagnostics to neurotoxic symptom questionnaire, decreases the amount of cases needing clinical examinations. This two-step procedure can be carried out with methods suitable for OHS and other primary health care, both in industrialized and developed countries.