Dirk Jungmann, C. Bandow, T. Gildemeister
Feb 12, 2009
Citations
1
Influential Citations
16
Citations
Journal
Journal of Soils and Sediments
Abstract
Background, aim, and scopeFenoxycarb is an insect growth regulator widely used to control a variety of pests. As a juvenile hormone analogue, it interacts with the natural hormones involved in insect development, inhibiting metamorphosis to the adult stage. Adverse effects of fenoxycarb on non-target organisms have been repeatedly observed and its rapid dissipation from water to the organic fraction of the sediment is known. The aim of this work was to investigate the impact of fenoxycarb on the development of sediment-dwelling larvae of the midge Chironomus riparius after exposure to spiked sediment.Materials and methodsThree spiked-sediment toxicity tests were carried out based on OECD Guideline 218 using various sediment composition and food sources.ResultsThe endpoints mean emergence time, development rate, and sex ratio were not influenced by fenoxycarb exposure. The emergence ratio showed a concentration-dependent decrease in all experiments. The lowest no observed effect concentration (NOEC) value was calculated as 0.125 µg kg−1. The results imply that food quantity and quality might influence the toxicity of fenoxycarb to the midges.DiscussionA comparison of the NOEC with predicted environmental concentration in sediments (PECsed) leads to toxicity exposure ratios between 0.3 and 7.8, depending on the chosen scenario, which is an indication that fenoxycarb may be a risk for sediment-dwelling organisms.Recommendations and perspectivesThe findings are in contrast to results derived from risk assessment using effect data of water exposure and PECsurface water. Therefore, the risk assessment for sediment-dwelling organisms needs further refinement.