ABSTRACT
The increased production and expanding demand for cellulosic products have required companies to provide solutions for the proper disposal of generated residues without compromising soil quality. In this context, the current research aimed at evaluating the ecotoxicological impacts of dregs application in subtropical soils. The experiments were carried out with the earthworm Eisenia andrei, the springtail Folsomia candida, and the potworm Enchytraeus crypticus in two subtropical soils (Neosol and Cambisol) collected in the southern region of Brazil. The considerable differences in texture and organic matter content motivated the choosing of these soils. The reproductive rate of all organisms was influenced, with varying EC50 values depending on the soil type. However, more pronounced effects were observed for Neosol. The springtail F. candida proved to be the most sensitive to contamination (EC50 = 5.8 g kg-1 for Neosol and 48.5 g kg-1 for Cambisol), followed by the earthworm E. andrei (EC50 = 62.4 g kg-1 for Neosol and 129.5 g kg-1 for Cambisol) and the potworm E. crypticus (EC50 = 67.2 g kg-1 for Neosol and 230.4 g kg-1 for Cambisol). As a result, while dregs can be used to correct soil acidity, they have been shown to have negative effects on important organisms responsible for functions critical to maintaining ecosystem quality.
Subject(s)
Oligochaeta , Paper , Soil Pollutants , Soil , Animals , Oligochaeta/drug effects , Soil Pollutants/toxicity , Soil Pollutants/analysis , Soil/chemistry , Brazil , Industrial Waste , Ecotoxicology , Environmental MonitoringABSTRACT
Mercury (Hg) is a highly toxic nonessential trace metal. Despite its natural occurrence in the Earth's Crust, its concentrations have been steadily increasing in the environment due to anthropogenic sources. Recent studies have showed great concern about soil fauna, once the potential adverse effects of mercury concentrations in the environment of these invertebrates are still poorly understood, especially when linked to forest soils and tropical biota. Different collembolan species can show distinct toxicity effects to the contaminants, impairing its developing lifelong and affecting its diversity and abundance in the environment. Laboratory studies were performed to evaluate the ecotoxicity of Hg(II) to collembolan species collected in Brazil, Proisotoma minuta (autochthonous) and Folsomia candida (allochthonous), as a tool to predict effects in ecological risk assessment of tropical regions. Behavioral, acute and chronic tests were carried under temperatures of 20°C and 24°C using two test soils, natural and artificial, spiked with increasing mercury concentrations. F. candida was more sensitive to mercury contamination than P. minuta, presenting the most restrictive values of EC50 and LC50. Reproduction was a considerably more sensitive endpoint than avoidance and mortality. The 28-day lower EC50 values were found in chronic tests for F. candida in natural soil to 24°C (3.32mgHgkg(-1)), while for P. minuta was in tropical artificial soil to 20°C (4.43mgHgkg(-1)). There were similarity for each collembolan species to respond at the Hg(II) effects when exposed at 20°C and 24°C. F. candida can be suitable as a bioindicator species to mercury ecotoxicity tests in tropical forest soils.
Subject(s)
Arthropods/drug effects , Environmental Monitoring , Mercury/toxicity , Soil Pollutants/toxicity , Toxicity Tests , Animals , Biological Assay , Brazil , Ecotoxicology , Rainforest , Reproduction/drug effects , Risk AssessmentABSTRACT
Trogolaphysa formosensis sp. nov. (holotype male deposited in DBEZ from Brazil, state of Rio Grande do Norte State, municipality of Bani Formosa), a new springtail from the Atlantic Forest domain, Rio Grande do Norte, Brazil, is described and illustrated. This species is diagnosed by unique coloration pattern, presence of 8+8 eyes, reduced number of setae on metatrochanteral organ, unguiculi truncated and dorsal chaetotaxy. Trogolaphysa formosensis sp. nov. is the first species of the genus from Brazil with all eye lenses. All other Brazilian species present 0+0 or 2+2 eyes. It is also the first species of Trogolaphysa described from the Northeast Region of Brazil.
Subject(s)
Animals , Arthropods/anatomy & histology , Arthropods/classification , Species Specificity , Brazil , SoilABSTRACT
Trogolaphysa formosensis sp. nov. (holotype male deposited in DBEZ from Brazil, state of Rio Grande do Norte State, municipality of Bani Formosa), a new springtail from the Atlantic Forest domain, Rio Grande do Norte, Brazil, is described and illustrated. This species is diagnosed by unique coloration pattern, presence of 8+8 eyes, reduced number of setae on metatrochanteral organ, unguiculi truncated and dorsal chaetotaxy. Trogolaphysa formosensis sp. nov. is the first species of the genus from Brazil with all eye lenses. All other Brazilian species present 0+0 or 2+2 eyes. It is also the first species of Trogolaphysa described from the Northeast Region of Brazil.(AU)