Abstract

This study aimed to evaluate the toxicological effect of food cooked or water boiled with a fan-assisted top-lit-updraft rice husk fuelled gasifier stove named Paul Olivier 150 (PO150). Distilled water was boiled for 1 h using this stove in an opened pot and closed room. This water was then cooled to room temperature before being administered to rats with body weights ranging from 70 to 110 g. Two types of tests were performed: acute and sub-chronic toxicity test. For the acute toxicity study, a unique dose of 2 ml/100 g body weight (bw) of boiled water was administered orally to the rats. The animals were observed for toxic symptoms and mortality daily for 14 days. In a sub-chronic toxicity study, the boiled water, at doses of 0.5, 1 and 2 ml/100 g bw were orally administered daily for 28 days to rats. After these 28 days, the rats were sacrificed, blood samples were collected for haematological, biochemical and histological examination. The control rats were administered distilled water. The sample of distilled water boiled with rice husk fuelled gasifier stove showed no evidence of single dose toxicity (2 ml/100 g) when studying acute toxicity. For the sub-chronic toxicity study, boiled water at doses of 0.5, 1 and 2 ml/100 g showed significant difference in some parameters such as creatinine in males (71.81 mg/dL), uric acid (2.75 mg/dL) and total bilirubin (0.08 mg/dL), monocytes (0.49 10³/µL) and granulocytes in females (2.70 10³/µL) compared to the control group (64.16 mg/dL, 2.25 mg/dL, 0.19 mg/l, 0.37 10³/µL, and 1.80 10³/µL for each parameter respectively) but the data was below the threshold levels to be considered to have  toxic effects. These showed that cooking in an open pot with a rice husk fuelled PO150 gasifier stove does not cause toxicity at the doses studied.

Key words: Acute toxicity, sub-chronic toxicity, biochemical analysis, hematological parameters, histopathology, rice husk.