Epidemiologic investigation of an occupational illness of tobacco harvesters in southern Brazil, a worldwide leader in tobacco production

Objectives As part of smoking surveillance, the authors conducted an epidemiologic investigation in southern Brazil to identify the occurrence of Green Tobacco Sickness and risk factors for illness and to recommend control and prevention measures. Methods A 1:2 case-control study matched by subjects' smoking habits. The study population was residents of Candelaria, Rio Grande do Sul state, who farm tobacco and provided a urine sample for cotinine measurement by high-performance liquid chromatography. Confirmed cases were persons with compatible clinical presentation (headache, nausea, vomit, dizziness or weakness) and cotinine level >10 ng/ml. Controls were persons without compatible signs or symptoms. The association measure was the matched OR with 95% CIs and p<0.05. Results Of 33 confirmed cases, 64% were men, average age was 33 years (SD +/- 11.8 years) and 57% were landowners. Cases have had similar illness in the past and were likelier to be workers hired by farmers-landowners than controls. Multivariate analysis yielded independent association between these variables and illness, controlled for age and sex. Contact with pesticides and working with wet tobacco leaves were not associated with illness. Conclusions The authors confirmed Green Tobacco Sickness in southern Brazil; the authors recommend investigation of its prevalence in tobacco-growing regions and monitoring of and education about the disease and its prevention by occupational health authorities.