Background:Hydrogen cyanide is the chemical responsible for tissue hypoxia. Chronic exposure to HCN may cause neurological, respiratory, cardiovascular and thyroid defects. Onset of symptoms depends on dose and duration of exposure. Large scale of Cassava processing could be disastrous due to discharge of hydrocyanic acid into the air. Cassava processing is the major industrial work in and around Salem. Hence the present study is taken to assess the effects of HCN exposure in Cassava workers.Materials and Methods:Thirty-nine workers from a Cassava processing unit at Salem and age-matched controls of the same economic status were taken up for this study. Clinical history was obtained with a questionnaire and their Blood sugar, lipid profile, serum total protein, urea, creatinine, AST, ALT and T3, T4, TSH were estimated using a fasting blood sample and AIP was calculated. Statistical analysis was done by student t test.Results:Our study reveals a significant increase in triglyceride in Cassava workers when compared to the control. Atherogenic index of plasma (AIP) is statistically highly significant. A significant decrease was seen in T4.Conclusion:An increase in TGL and AIP shows a higher degree of cardiovascular risk. A decrease in T4 suggests an insufficient iodine uptake by thyroid gland. Hence a periodic medical evaluation should be done on such workers for their safety and to prevent the health hazard.