Effects of deltamethrin, dimethoate, and chlorpyrifos on survival and reproduction of the collembolanFolsomia candidaand the predatory miteHypoaspis aculeiferin two African and two European soils

Abstract

Indiscriminate use of pesticides is rampant in most parts of Africa, but only scanty ecotoxicological data exist for the protection of soil organisms-and these data were usually obtained under temperate conditions, including the use of Organisation for Economic Co-operation and Development (OECD) standard test protocols. In order to assess the effects of 3 commonly used pesticides (deltamethrin, dimethoate, chlorpyrifos) on soil fauna in Africa, noncontaminated natural soils were collected from Nigeria and Tunisia. In addition, 2 common test soils, OECD artificial soil and European (Landwirtschaftliche Untersichungs-und Forschungsanstalt [LUFA]) 2.3 soil, were used in OECD standard reproduction tests. Two microarthropod species, the springtail Folsomia candida and the predatory mite Hypoaspis aculeifer, were exposed in these 4 soils spiked individually with the 3 insecticides. Results show that the collembolan F. candida was more sensitive than the mite H. aculeifer for all 3 insecticides. The toxicity of each insecticide in the 4 soils differed, with few exceptions, by less than an order of magnitude. However, the pattern of toxicity was not consistent, that is, the lowest toxicity was often but not always found in OECD artificial soil. Soil-and pesticide-specific patterns of toxicity to F. candida and H. aculeifer might be related to the physicochemical properties of the soils and thus the availability of the 3 pesticides. Following the rules laid down in the European Union for the registration of pesticides and using standard European exposure scenarios, neither an acute nor a chronic risk of dimethoate and chlorpyrifos can be excluded (with few exceptions) in all 4 soils. Lower risks were identified for deltamethrin. For pesticide used in Africa, an environmental risk assessment based on data gained in tests with at least 1 additional natural field soil, preferably of African origin, should be performed using the same risk assessment principles as in the European Union. Integr Environ Assess Manag 2018;14:92-104. C 2017 SETAC

Species Sensitivity to Toxic Substances: Evolution, Ecology and Applications

“…A complexity that may arise when using the presence of gene family representatives as simple determinants of sensitivity include cases where orthologs retain sequence homology but have evolved divergent roles outside the target function or tissue. As an example, earthworms have comparatively lower sensitivities to the organophosphate chlorpyrifos (Ma and Bodt, 1993) than soil arthropod species such as springtails (Broerse and van Gestel, 2010;Jegede et al, 2017;Kamoun et al, 2018). Earthworms do not lack the target acetylcholinesterases in the nervous system.…”

Photocatalytic degradation of an organophosphorus pesticide using a ZnO/rGO composite

“…Dimethoate is a typical OPP that has high toxicity and a wide insecticidal range to many kinds of pests, especially to chewing and piercing-sucking insects. Exposure to dimethoate may have many different adverse effects on humans, such as carcinogenic, 6 neurological, 7 reproductive, 8 and endocrine effects. 9 The removal of OPPs by various techniques including photocatalysis, 10,11 adsorption, [12][13][14] biodegradation, [15][16][17] chemical oxidation, 18,19 and electrochemical oxidation 20 has been investigated.…”

“…Dimethoate is a typical OPP that has high toxicity and a wide insecticidal range to many kinds of pests, especially to chewing and piercing-sucking insects. Exposure to dimethoate may have many different adverse effects on humans, such as carcinogenic, 6 neurological, 7 reproductive, 8 and endocrine effects. 9 …”

The fungicide mancozeb affects soil invertebrates in two subtropical Brazilian soils

“…Even that artificial soils already normally has been indicated as showing lower toxicity values than reference natural soils in Europe (De Silva et al, 2009). Kamoun et al (2018) indicates that toxicity of the pesticides deltamethrin, dimethoate, and chlorpyrifos to F. candida was higher in natural tropical soils than in OECD soil. Differences in natural soils of the present study could be one of the reasons for this higher toxicity.…”

“…This subject was already defined as an important specific protection goal (EFSA, 2010) to maintain soil services and so, it already was highlighted in current legislation of European Union (EC, 2009a). Also, beyond ecotoxicity tests with different organisms, testing contrasting soils (artificial, tropical, subtropical, temperate) its important, since specific conditions, like temperature, rainfall regime, organic matter content, and others, could influence pesticides toxicity (Chelinho et al, 2011;Kamoun et al, 2018).…”