Size Changes in Honey Bee Larvae Oenocytes Induced by Exposure to Paraquat at Very Low Concentrations
Honey bee larvae were exposed to Paraquat at different concentrations in the food: 0, 0.001, 0.01, 0.1 and 1 g/kg. This study is the first which reports an effect of a pesticide at the very low concentration of 1 ng/kg, a concentration below the detection limits of the most efficient analytic methods. It shows that chemicals, including pesticides, are likely to have a potential impact at such exposure levels. Embryonic and post-embryonic developments are crucial phases during which environmental physiological disruptors may cause irreversible damages to the individuals A few studies have focused on the toxicity of pesticides to brood and the effects have mainly been investigated on adult bees, with special attention to insecticides and fungicides The effects of Paraquat demonstrated here raise the question of the impacts of quaternary ammonium herbicides, and especially pyridinium active substances, on the development of the honey bee. However, considering that the Paraquat-induced effects in bees are also observed in mammalian brain cells [50], it is legitimate to think that they could also occur in other cell types and at different developmental stages. The most important point is that concentrations around ng/kg are able to induce damages in living organisms and especially in honey bees.
http://www.plosone.org/article/info%...l.pone.0065693