Does the use of pharmaceuticals for bullfrog farming pose health risks to humans?

As global food demand is projected to rise in the future due to population growth, animal husbandry has been increasingly promoted worldwide. Yet, pharmaceuticals are extensively used for animal husbandry to prevent disease outbreaks, possibly posing human health risks via consumption of pharmaceutical-contaminated animals. Using a typical bullfrog farm as the study site, this study assessed the accumulation of pharmaceuticals in bullfrogs at different ages (juveniles vs. adults) from different origins (cultured vs. wild). The health risk of bullfrog consumption was then evaluated with the consideration of different cooking methods (steaming, pan-frying and deep-frying). Different types of pharmaceuticals were detected in the culture ponds, where sulfonamides (SAs) and fluoroquinolones (FQs) were predominant in water and sediment (> 60 % of total pharmaceutical concentration), respectively. Regardless of ages and origins, the intestine and stomach of bullfrogs had higher pharmaceutical concentrations than their muscle, skin and liver. Wild bullfrogs tended to accumulate more pharmaceuticals, particularly FQs, than cultured bullfrogs. Nevertheless, the health risk of bullfrog consumption was low (HR < 1), especially when the bullfrogs were well cooked by steaming that reduced pharmaceutical concentrations. This risk can be further lowered by avoiding the consumption of internal organs. Taken together, this study provides useful guidance for the public to minimize dietary intake of persistent pollutants and suggests that proper use of pharmaceuticals is promising for producing safe animal food products on a large scale, possibly serving as an important solution to the future increase in global food demand.