Bioconcentration of Pirimiphos-methyl in Killifish (Oryzias latipes)

Abstract

Killifish (Oryzias latipes) were exposed to an organophosphate pesticide, pirimiphos-methyl, in a flow-through system to determine the bioconcentration factor (BCF) following GLP (Good Laboratory Practice). This study was conducted at two different concentrations (1 and 10 μg/L) of 14 C-labeled pirimiphos-methyl for 28 days uptake and 14 days depuration according to the OECD 305 test guideline. The BCF ss for total radioactive residues in whole fish were 1,251 and 1,277 for low and high concentrations, respectively. The BCF k based on the uptake and depuration rate constants were 1,200 for both low and high concentrations. During the depuration phase, the accumulated test substance was rapidly depurated from fish. Greater than 95% of the residue at steady-state was depurated after 2 days. Although the measured BCF values were high, pirimiphos-methyl could be evaluated as a low risk from bioaccumulation by aquatic organisms due to the short depuration period and low amount of bound residue (1.5%). We suggest that in evaluating bioaccumulation, not only the BCF should be considered, but also depuration time and bound residue in aquatic organisms give an indication of the potential environmental risks.

Accumulation of current-use pesticides, cholinesterase inhibition and reduced body condition in juvenile one-sided livebearer fish (Jenynsia multidentata) from the agricultural Pampa region of Argentina

“…It is well known that these insecticides should not reach waterways as they are highly toxic to fish and other aquatic organisms. In Argentina, as in many other countries, these molecules are only registered for treating insects on stored Given that dichlorvos and pirimiphos-methyl allegedly have low bioconcentration potential and are rapidly eliminated from the body upon termination of exposure (Tsuda et al, 1992;Seo et al, 2009), their detection in fish tissues would reportedly be indicative of an ongoing exposition at the time of capture through either water or foodstuff. The fact that dichlorvos and pirimiphos-methyl were generally detected in fish from determined locations at specific dates is also consistent with this view (Smalling et al, 2015).…”

Bioconcentration and Metabolism of the New Herbicide Methiozolin in Ricefish (Oryzias latipes)

“…The fish were minced with Kelly scissors, and 2 mL of Soluene-350 was added per fish using a glass pipet. The samples were shaken at 250 rpm and 50 ± 1 °C for 2 h until they were completely dissolved, and 1.2 mL of acetic acid was then added to each sample . Scintillation cocktail (12 mL) was added to each dissolved fish sample, and its radioactivity was measured by LSC.…”

“…The fish lipid content was determined at the beginning of the uptake phase and end of the depuration phase. Fish samples were collected from the solvent control vessel, and the lipid content was measured following a previously reported chloroform/methanol extraction method. , Briefly, the samples were homogenized in 3 mL of methanol/chloroform (2:1 v/v), and 1 mL of chloroform was added. The samples were then filtered through GF/A glass microfiber paper (Whatman, Maidstone, England) and transferred into a 60 mL separation funnel.…”