Due to increased use of agrochemicals and growing concerns about ecotoxicology, the development of new insecticides, moving away from those with neurotoxic and broad spectrum effects towards insecticides that are safer for the environment and nontarget beneficial species, has been a research priority. Novaluron stands out among these newer insecticides, is an insect growth regulator that is used for the control of insect pests in crops grown close to mulberry plantations. Mulberry serves as food for the silkworm Bombyx mori, which is a nontarget insect of great economic importance to silk production. We investigated the lethal and sublethal effects of Novaluron on the development of B. mori. Larvae were segregated into experimental groups: the control groups (CGs) and the treatment groups (TGs), which were treated with the Novaluron concentration of 0.15 mL/L. Following exposure, we analyzed: larval mortality, changes in the insect life cicle and cytotoxic effects on the midgut cells. This is the first report about the Novaluron’s effects on B.mori. We detected rupture in the integument, complete cessation of feeding, late development, incomplete ecdysis and production of defective cocoons. After 240 h of exposure, there was 100% mortality in TG larvae exposed in the 3rd instar and 20% mortality from larvae exposed in the 5th instar. Cytotoxic effects was observed, such as dilation of cells, emission of cytoplasmic protrusions, extreme rarefaction of the cytoplasm and nuclei, dilation of the endoplasmic reticulum in addition to changes in mitochondria, the presence of large digestive vacuoles and intercellular spaces and the presence of active caspase. Novaluron exposure impairs the midgut and may affect the physiological functions of this organ. Novaluron additionally compromises several phases of insect development, indicating the importance of toxicology studies that utilize different life stages of nontarget species to evaluate the safe use of insecticides.

Silver (Ag) is amongst the most well studied nanomaterials (NMs), although most studies have only dealt with a single AgNM at a time and one biological endpoint. We here integrate the results of various testing-tools (endpoints) using a terrestrial worm, the standard ecotoxicological model organism Enchytraeus crypticus. Exposure spanned both water and soil exposure, it covered all life stages (cocoons, juveniles and adults), varying exposure durations (1-2-3-4-5-21 days), and covered 5 biological endpoints: hatching success, survival, reproduction, avoidance and gene expression (qPCR target genes GABA and Acetyl cholinesterase). We tested 4 Ag materials: PVP coated (PVP-AgNM), non-coated (NC-AgNM), the JRC reference Ag NM300K and AgNO₃. Results showed that short-term exposure via water to assess impact on cocoons’ hatching predicted longer term effects such as survival and reproduction. Moreover, if we extended the exposure from 11 to 17 day this allowed discrimination between hatch delay and impairment. Exposure of juveniles and adults via water showed that juveniles were most sensitive with survival affected. Across materials the following toxic ranking was observed: AgNO₃ ≥ Ag NM300K ≫ NC-AgNM ≥ PVP-AgNM. E. crypticus avoided AgNO₃ in a dose-response manner, avoiding most during the first 24 h. Avoidance of Ag NM300K and NC-AgNM only occurred during the first 24 h and the PVP coated AgNM were not avoided at all. The up-regulation of the GABA triggering anesthetic effects, indicated the high ecological impact of Ag materials in soil: Ag affects the GABAergic system hence organisms were not able to efficiently avoid and became intoxicated, this caused impacts in terms of survival and reproduction.

Aluminum/iodine pentoxide (Al/I₂O₅) composites are currently receiving much attention for their capabilities as potential anthrax combatants. Their high halogen gas release, coupled with high temperature evolution from combustion, renders them effective in bacterial deactivation. Despite extensive research on the energetic capacities of these compounds, limited information is currently available in relation to their potential environmental (non-target) effects. We evaluated the effects of Al/I₂O₅ on aquatic (Daphnia magna) and terrestrial (Eisenia fetida, Acheta domesticus) invertebrates, as well as alfalfa (Medicago sativa) seed germination. Polytetrafluoroethylene (PTFE, or DuPont Teflon® MP1150) was examined concurrently to assess whether observations were general to halogen, or element specific. Our observations were based on mortality and reproduction (hatchability) for the terrestrial and aquatic assays. In all Al/I₂O₅ assays, mortality was concentration dependent, ranging from 0% mortality in the control samples to partial and complete mortality in the contaminated cases. The PTFE assays showed no mortality at all contaminant concentrations. At a maximum Al/I₂O₅ contaminant concentration of 1000 μg/g (ppm), 100% mortality was observed in cricket assay conducted in sand within 72 h exposure and earthworm assay conducted in soil within 4 days exposure. In the aquatic assay, a water concentration of 200 μg/mL (ppm) caused 100% mortality to D. magna in less than 12 h. The effect of aluminum/iodine pentoxide on earthworm cocoon hatching success was also determined. At soil concentrations ≤ 400 μg/g, hatching success for earthworm cocoons was equivalent to control (un-contaminated) soil; above this concentration, hatching success was reduced by a factor of 2. Alfalfa germination tests were performed at a single contaminant concentration of 1000 μg/g. This soil concentration was completely inhibitory to seed germination.

This study aimed to evaluate the removal of polychlorinated biphenyls, with a vermicomposting system, using the following as components: the earthworm Eisenia fetida, peat moss and rabbit excrement and a compound called decachlorobiphenyl, for a period of 91 days under non-sterile conditions. The results obtained were a removal of decachlorobiphenyl 79.6 % with an initial concentration of 100 mg L⁻¹, 89.7 % with 150 mg L⁻¹and 95.38 % with 200 mg L⁻¹; the earthworms bioaccumulated less than 5 mg L⁻¹in all concentrations of decachlorobiphenyl analysed without apparent toxic effect. Weight gain was observed in earthworms that assimilated contaminant during vermicomposting, as the number of cocoons produced in contrast to the control in which both the weight and the number of cocoons were lower. To our knowledge, this is the first study which suggests that vermicomposting may be a suitable mechanism for removal of decachlorobiphenyl with high recalcitrance from contaminated sediment or soils.

Biological and behavioral responses of the tropical earthworm Perionyx excavatus towards different concentrations of abamectin were evaluated. Abamectin significantly reduced the biomass and reproduction (cocoon production) of P. excavatus as well as inducing histopathological alterations in the cuticle. Biomass loss was recorded in P. excavatus exposed to abamectin at a concentration as low as 0.1 mg active ingredient (a.i.) kg⁻¹, while atrophy, another physiological response, was observed at an abamectin concentration of 0.21 μg cm⁻² in a filter paper test. Cocoon production was significantly reduced in the presence of abamectin, and no cocoons were produced at doses of 20 mg a.i. kg⁻¹ or higher, while abamectin at 50 mg a.i. kg⁻¹ induced extreme pathology, characterized by the loss of the integrity of the whole body wall and intestine of P. excavatus. Histopathological alterations can be used as a biomarker to evaluate the toxicological impact of exposure to abamectin.

We studied the efficiency of water treatment by water hyacinth (Eichhornia crassipes) from heavy metals (Zn, Cd, Pb, Cu), as well as a possibility of using water hyacinth biomass obtained during treatment for vermicomposting by Eisenia fetida and the vermicompost quality in a model experiment. The results showed that the concentration of heavy metals in the trials with water hyacinth decreased within 35 days. We introduced water hyacinth biomass to the organic substrate for vermicomposting, which promoted a significant weight gain of earthworms and growth in their number, as well as a 1.5- to 3-fold increase in coprolite production. In the trial with 40 % of Eichhornia biomass in the mixture, we observed a 26-fold increase in the number and a 16-fold weight gain of big mature individuals with clitellum; an increase in the number of small individuals 40 times and in the number of cocoons 140 times, as compared to the initial substrate. The utilization of water hyacinth biomass containing heavy metals in the mixture led to a 10-fold increase in the number of adult individuals and cocoons, which was higher than in control. We found out that adding 10 % of Eichhornia biomass to the initial mixture affected slightly the number of microorganisms and their species diversity in the vermicompost. Adding Eichhornia biomass with heavy metals reduced the total number of microorganisms and sharply diminished their species diversity. In all trials, adding water hyacinth in the mixture for vermicomposting had a positive impact on wheat biometric parameters in a 14-day laboratory experiment, even in the trial with heavy metals.

In this study, particles produced from sericin-alginate blend were used as non-conventional bioadsorbent for removing Cr(III) and Cr(VI) from aqueous solutions. Besides chromium mitigation, the use of sericin-alginate particles as bioadsorbent aims to offer an environmental solution of added value for sericin, which is a by-product from silk industry. Sericin-alginate particles in natura and loaded with Cr(III) and Cr(VI) were characterized using N₂ physical adsorption analysis, optical microcopy, mercury porosimetry, helium pycnometry, scanning electron microscope coupled with energy dispersive X-ray spectrometer, Fourier transform infrared spectrometer, and X-ray diffraction. Kinetic studies on the removal of Cr(III) (at pH = 3.5) and Cr(VI) (at pH = 2) indicate the ion exchange mechanism with Ca(II) and the predominance of external mass transfer resistance. Cr(VI) uptake occurs through an adsorption-coupled reduction process, and bioadsorption equilibrium is reached after ~ 1000 min. Cr(III) bioadsorption occurs faster (~ 210 min). The Cr(VI) bioadsorption is endothermic, as bioadsorption capacity increases with temperature: 0.0783 mmol/g (20 °C), 0.1960 mmol/g (30 °C), 0.4570 mmol/g (40 °C), and 0.7577 mmol/g (55 °C). The three-parameter isotherm model of Tóth best represents the equilibrium data of total chromium. From Langmuir isotherm model, the maximum bioadsorption capacity is higher for total chromium, 0.25 mmol/g (30 °C), than for trivalent chromium, 0.023 mmol/g (30 °C). The comparison of bioadsorption capacities with different biomaterials confirms sericin-alginate particles as potential bioadsorbent of chromium.

Analyses of fine particulates (PM2.5) from the upper Assam oil fields of India indicated considerable presence of higher hydrocarbons (C₂₂–C₃₅) and heavy metals, Cd, Co, Cr, Cu, Ni, Pb, and Zn. This has raised serious concern for the sustainability of the exotic Muga (Antheraea assama) silk production, which has been a prime activity of a large number of people living in the area. The Muga worm feeds on the leaves of Machilus bombycina plant, and the impacts of air quality on its survival were further investigated by analyzing the leaves of the plant, the plantation soil, and the Muga cocoons. PM2.5 content in the air was much more during the winter due to near calm conditions and high humidity. Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and gas chromatography-mass spectrometer (GC-MS) analysis of PM2.5 showed the presence of higher alkanes (C₂₂–C₃₅) that could be traced to crude oil. Cr, Ni, and Zn were found in higher concentrations in PM2.5, M. bombycina leaves, and the plantation soil indicating a common origin. The winter has been the best period for production of the silk cocoons, and the unhealthy air during this period is likely to affect the production, which is already reflected in the declining yield of Muga cocoons from the area. SEM and protein analyses of the Muga silk fiber produced in the oil field area have exhibited the deteriorating quality of the silk. This is the first report from India on hydrocarbons and associated metals in PM2.5 collected from an oil field and on their possible effects on production of silk by A. assama.