Joint toxicity of a pyrethroid insecticide, cypermethrin, and a heavy metal, lead, to the benthic invertebrate Chironomus dilutus

Abstract

Abstract-Insecticides and heavy metals are frequently detected in the environment, but few studies have assessed the joint toxicity of organic and inorganic contaminants. Joint toxicity of a pyrethroid insecticide, cypermethrin, and a heavy metal, Pb 2þ , was evaluated in the present study. An antagonistic toxic response was observed when the benthic invertebrate Chironomus dilutus was simultaneously exposed to the two contaminants in both water and sediment exposures. Pre-exposure bioassays with midges were also conducted, and toxicity of cypermethrin was significantly reduced for midges that were pre-exposed to Pb 2þ . In addition, the impact of Pb 2þ on the bioavailability of cypermethrin to midges was measured using Tenax extraction. No significant difference was noted in the amount of Tenax-extractable cypermethrin when different amounts of Pb 2þ were added to sediment. Results suggested that altered organism sensitivity may contribute to the observed antagonistic interaction between cypermethrin and Pb 2þ

Addition of contaminant bioavailability and species susceptibility to a sediment toxicity assessment: Application in an urban stream in China

“…Elevated levels of heavy metals, especially lead, have been detected in sediment in Guangzhou urban waterways (Cheung et al, 2003). Mehler et al (2011c) noted an antagonistic interaction between cypermethrin and lead to C. dilutus, and deemed that the co-existence of lead in sediment might reduce cypermethrin toxicity to C. dilutus in some field sediments. So, antagonistic interactions between cypermethrin and lead might also be one of the reasons for the unexpectedly low toxicity to H. azteca in Chebei Creek sediments.…”

Influence of bioturbation on bioavailability and toxicity of PAHs in sediment from an electronic waste recycling site in South China

“…Another sediment sample collected from a drinking water reservoir in Conghua, Guangdong was used as a control sediment. A previous study (Mehler et al, 2011a) showed this control sediment was non-toxic to benthic organisms and contained limited contamination. Total sediment OC was measured using an Elementar Vario ELIII (Hanau, Germany) after removing the inorganic carbonates with 1 mol/l HCl.…”

“…The extraction was repeated twice, and the combined extracts were filtered, solvent exchanged to 2 ml of dichloromethane, and cleaned with gel permeation chromatography (LabTech, Beijing, China) following the method described by Mehler et al (2011a). After cleanup, the eluents were concentrated, solvent exchanged to 0.5 ml of hexane and analyzed using GC/MS after the addition of 500 ng of internal standards.…”

Does cadmium affect the toxicokinetics of permethrin in Chironomus dilutus at sublethal level? Evidence of enzymatic activity and gene expression

“…When organisms were exposed to a mixture of chemicals, one constituent may affect the uptake, biotransformation, distribution and elimination of the others, and this would lead to joint interaction among chemicals and subsequently change toxicity (Belden and Lydy, 2000;Mehler et al, 2011). Thus, alteration in toxicokinetic parameters may serve as a good indicator for the mechanism of joint toxicity.…”

“…On the contrary, alteration of toxicokinetics may also cause antagonism. Antagonistic interaction between permethrin and cadmium as well as cypermethrin and lead in C. dilutus was attributed to enhanced biotransformation of pyrethroids with the addition of metals (Chen et al, 2015;Mehler et al, 2011). Joint toxicity between chemicals may depend on their exposure levels (Banks et al, 2003).…”