Fipronil: Environmental Fate, Ecotoxicology, and Human Health Concerns

Environmental fate and toxicology of fipronil

“…The t 1/2 on average is 123 days, much longer than any aerobic soil system where both the fipronil and fipronildesulfinyl t 1/2 is only 5 days. 1,18) Two major products were formed under these water conditions: fipronil-sulfide and fipronil-amide.…”

“…For instance, the t 1/2 in a loam was found to be 34 days while in a sandy loam it ranged from 30 to 194 days. 1,18) The leaching of fipronil's degradation products under subSaharan soil conditions has also been studied. 14) Except for the very water-soluble fipronil-amide, the degradation products ( Fig.…”

“…33 days) in sterile soils. However, longer half lives have been reportedas long as 342 days in a loam, 1) and 126 days in sandy loams. 18) Similarly, the reported t 1/2 of fipronil in a sandy loam was 122 days, with fipronil-amide and fipronil-sulfone accounting for 27-38% and 14-24% of the total byproducts, respectively.…”

“…31) The LD 50 of fipronil to the honeybee Apis mellifera has been reported to be either 4 or 6.2 ng/bee. 1,33) At very low doses (e.g., 0.6 g a.i./ha) fipronil can effectively control adult grasshopper (Pyrgomorpha cognate) outbreaks; application rates of 1-2 g a.i./ha resulted in high mortality rates, with more than 90% of the insects disappearing within 3-10 days. 34) An increase in mortality in a shorter time period was also found with higher doses in the same study.…”

Citotoxicity of Fipronil on Hepatocytes Isolated from Rat and Effects of Its Biotransformation

“…The central nervous system and other organs, including the liver, can be affected by the treatment with fipronil. A study by Silva (2008) evaluated the effects of the prolonged exposure of the rats to the insecticide; swollen hepatocytes and increased liver weights were observed in the animals that were treated with an oral dose of 10 mg kg body weight -1 , which corresponded to one tenth of the LD 50 value established for the rats (Tingle et al 2003). In addition, the livers from the rats that were evaluated after exposure to different concentrations of fipronil (15, 25 and 50 mg kg body weight -1 ) revealed cytological, morphological and immunohistochemical changes in the hepatocytes with autophagic processes, steatosis and necrotic cell death .…”