Effects of Mosquito Coil Smoke Inhalation on the Haematological, Biochemical, and Histopathological Parameters of Wistar Rats (Rattus norvegicus)

Abstract

Malaria remains the most important mosquito-borne parasitic disease in sub – Saharan Africa and one of the ways of reducing the risk of the disease is by preventing mosquito–human contact. Mosquito coil (MC) is a coiled substance having one or more insecticides that slowly burns to emit smoke that repels mosquitoes. Some emissions from mosquito coil smoke (MCS) have however been reported to have various health implications. In this study, we investigated the effect of MCS inhalation on the haematological, biochemical, and histopathological parameters of Wistar rats. Twenty adults male Wistar rats weighing between 160 and 180g were divided into four groups of five rats each. Group I (G1) served as unexposed control while groups 2 – 4 (G2, G3, G4) were exposed to MCS for 2, 4, and 6 hours respectively each day for eight weeks. At the end of the exposure period, the rats were weighed and sacrificed. Blood samples were collected for haematological and biochemical parameters while kidney, liver and lung samples were harvested for histopathology. There was a significant increase (P<0.5) in the Packed Cell Volume (PCV) and electrolyte level of exposed rats compared to the control. Histopathological evaluation of the kidney showed severe congestion of the renal cortex and moderate diffused degeneration of the renal tubules. Sections of the exposed liver showed mild to moderate periportal cellular infiltration, mild congestion of interstitial capillaries, and mild diffuse hydropic degeneration of hepatocytes. Similarly, sections of exposed lungs revealed severe congestion and oedema of the lungs, moderate diffuse proliferation of alveoli pneumocyte, multiple foci of congestion, and oedema with haemorrhage into the alveoli. These findings suggest that exposure to MCS may have toxic effects on the haematological, biochemical, and histopathological parameters of Wistar rats. Friendlier mosquito control alternatives like Long Lasting Insecticidal–treated Nets should therefore be encouraged.