Earthworm ecotoxicological assessments of pesticides used to treat seeds under tropical conditions

Ecotoxicological laboratory tests (lower-tier tests) are fundamental tools for assessing the toxicity of pesticides to soil organisms. In this study, using these tests under tropical conditions, we quantified the impact of the insecticides imidacloprid, fipronil, and thiametoxam, and the fungicides captan and carboxin + thiram, all of which are used in the chemical treatment of crop seeds, on the survival, reproduction, and behavior of Eisenia andrei (Oligochaeta). With the exception of imidacloprid, none of the pesticides tested caused mortality in E. andrei in artificial soils. The LC₅₀ of imidacloprid was estimated as 25.53 mg active ingredient kg^?1 of dry soil. Earthworm reproduction rates were reduced by imidacloprid (EC₅₀ = 4.07 mg kg^?1), fipronil (EC₂₀ = 23.16 mg kg^?1), carboxin + thiram (EC₅₀ = 56.38 mg kg^?1), captan (EC₅₀ = 334.84 mg kg^?1), and thiametoxam (EC₅₀ = 791.99 mg kg^?1). Avoidance behavior was observed in the presence of imidacloprid (AC₅₀ = 0.11 mg kg^?1), captan (AC₅₀ = 33.54 mg kg^?1), carboxin + thiram (AC₅₀ = 60.32 mg kg^?1), and thiametoxam (AC₅₀ = >20 mg kg^?1). Earthworms showed a preference for soils with the insecticide fipronil. Imidacloprid was the most toxic of the substances tested for E. andrei. The avoidance test was the most sensitive test for most pesticides studied, but results varied between pesticides. These results offer new insights on the toxicity of pesticides used to treat seeds in tropical regions. However, they should be complemented with higher-tier tests in order to reduce the uncertainties in risk assessment.     

Pollution from polychlorodibenzo‐p‐dioxins and furans: The case of several foundry plants in the Lombardy region

In 1991 a co‐operation between Public Health Office (U.S.S.L.) n° 18 of Brescia and the Chemical Section Laboratories of U.S.S.L. n° 38 of Milan concerning the possible environmental impact of foundry industrial activities performing metallic scraps recovering, has been undertaken.

Soil and surfaces have been classified in conformity with the National Toxicological Consultative Commission (C.C.T.N.) recommendation dated 12/02/1988'; owing to the characteristics of the processed material, besides heavy metals, polychlorodibenzo‐p‐dioxins (PCDDs), polychlorodibenzofurans (PCDFs) and polychlorobiphenyls (PCBs) have been looked for.

The particulate matter collected from the filters positioned over the arc furnaces in 14 foundry plants has been characterized and classified, according both to C.C.T.N.¹ and to the Interministerial Board regulation dated 27/07/1985 for the first application of the Republic President Decree Law (D.P.R.) n° 915/1982, concerning wastes classification, based, in this case, on these toxic chlorinated compounds concentrations. From the very beginning, high levels of PCDDs and PCDFs have been detected, corroborating the very few literature data from foundry plants². The results obtained on 14 different foundries allow us to draw already some information, acceptable from the point of view of the statistical validity, about the pollution produced by this industry.     

Elektronenmikroskopische Untersuchungen an den epitheloiden Zellen der Hoyer-Grosserschen Organe

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