Clinical signs and organ pathology in rats exposed to graded doses of pyrethroids- containing mosquito coil smoke and aerosolized insecticidal sprays

Abstract

Morphological changes in tissues/organs of weanling Albino rats exposed to graded doses of popular brands of pyrethroids-containing insecticidesmosquito coil and aerosolized spray were studied over a period of 18 days. Rats were exposed to 0.4, 0.8, 1.2 and 1.6mg/kg BW of active ingredients in aerosolized insecticidal spray for 15, 30, 45 and 60 seconds, in two divided doses daily for 18 days. Control rats were not exposed. Early clinical signs include irritability, head shaking and scratching of nostrils; these later gave way to sneezing, gurgling, fine muscular tremors, ruffled fur, lethargy and depression. No self-death was recorded in all the exposed and control groups. Gross changes were not apparent in most organs, but for pulmonary oedema and slight hepatomegaly and palor of kidneys in rats exposed to high doses of the fumes sacrificed on days 12, 15 and 18 post-exposure. Histopathology revealed varying degrees of vacuolar degeneration and necrosis of hepatocyctes, myocardiac degeneration, glomerular and tubular degeneration and necrosis, meningitis, neuronophagia, demyelination of neuronal axons and exudative pnuemonia. Others include blood vascular damage, haemorrhages, vasculitis and thrombosis in many organs, and Kuppfer and intestinal goblet cells hyperplasia. The severity of the lesions was dose and time dependent. The lesions observed suggest interference with tissue energy metabolism and widespread vascular damage and multi-organ degeneration and necrosis. The implications of the consistent and uncontrolled use of pyrethroids-containing insecticides on farm and market produce and in human inhabitants and their effects on public health and biodiversity conservation are discussed.(Afr. J. Biomed. Res. 11: 97 -104)

Efectos toxicológicos del uso prolongado e intenso de emisiones de espirales contra mosquitos en ratas y sus implicaciones sobre el control de la malaria

“…Histopathological evaluation of mosquito coil effect had shown the impact on the kidney, 16 weeks post exposure, which demonstrates full congestion around the glomerular tuft, the study agrees with Taiwo et al 2008 which demonstrated glomerula and tubular degeneration, necrosis, thrombosis and vasculitis to mosquito coil and varying insecticidal spray fumes in experimental rats. The study is also in line with earlier published work of Garba et al 2007a which demonstrated serve multifocal congestion, cystic dilation in the medulla of kidney tissue exposed to pyrethroid based mosquito coil.…”

“…The elevated activities of AST, ALT ALP enzymes observed in rats exposed to both transfluthrin and d-allethrin insecticides suggest hepatic damage or dysfunction; high concentrations of these enzymes in hepatic tissues of dogs, cats and primates have been linked to hepatocellular damage (Kaneko & Cornelius 1980, Hall et al 2001). This was confirmed by histopathological examination of rats exposed to transfluthrin and d-allethrin mosquito coil smoke for eight, 12 and 16 weeks in this study, which indicates generalized intracellular accumulations and severe sinusoidal congestion, which also have been demonstrated (Garba et al 2007b, Taiwo et al 2008, Aslam et al 2010). This study therefore demonstrates potential damage to the liver arising from the use of transfluthrin and d-allethrin mosquito coil.…”

“…Oedema could have resulted from the inflammatory processes taking place as a result of irritation of various organs by toxic chemicals from coil smoke. Other pathological manifestation that has been associated with pyrethroid mosquito coil but not observed in this study, includes exudative pneumonia, anthracosis, thrombosis and vasculitis, as observed by Taiwo et al 2008. The sneezing that resulted at the initial stage of exposure could be the result of irritants released in the coils smoke such as aldehydes, sulphates and polycyclic aromatic hydrocarbons such as acenaphthene, penanthrene, benzo(a)pyrene (EPA 1998, Liu et al 2003.…”

“…Histopathological investigations have demonstrated that mosquito fumes leads to focal dociliation of the tracheal epithelium, metaplasia of the epithelial cells and morphological alteration of the alveolar macrophages (Liu & Sun 1988, Liu & Wong 1987, Cheng et al 1992, Chang & Lin 1998. Kidney tissues of exposed rats have revealed severe multifocal congestion, cystic dilation in the medulla, interstitial mononuclear cellular infiltration and wide spread fibrosis (Garba et al 2007a, Taiwo et al 2008, while damage to spleen revealed severe sinusoids hyperplasia and regression of red and white pulps (Garba et al 2007b).…”

Ameliorative effect of N-acetyl cysteine on alpha-cypermethrin-induced pulmonary toxicity in male rats

“…Literature report illustrated that free radical‐mediated oxidative stress was responsible for the toxicity of pesticides (Abdollahi et al, ). CYP can induce degenerative changes in various organs including the lung, liver, brain, kidney, and heart (Taiwo et al, ). In the present experiment, α‐CYP induced a significant increase in the level of MDA in lung tissues.…”