The aim of this study was to assess the genotoxic effects of sediment elutriates of an aquatic ecosystem. Sediment samples were taken from Limache stream, located in central Chile. The tests were ...carried out on sediment elutriates. Genotoxicity was determined by bioassay with
Allium cepa
. The percentage of germination, root growth, mitotic index, and frequency of chromosome aberrations were determined. The results show a significant increase in chromosome aberrations and decrease of the mitotic index in
Allium cepa
in all the sediment elutriates compared to the control. No significant differences were observed in the percentages of germination or root growth among the sediment elutriates. A negative correlation was found between the mitotic index and chromosomal aberrations. In conclusion, genotoxic variables are more sensitive than growth variables. The sediments contain chemical agents in bioavailable concentrations that produce genotoxic effects.
Allium cepa
test proved to be a sensitive indicator of genotoxic contaminants in sediment elutriates of the Limache stream in central Chile.
The aim of this study was to determine the effect of soils from areas with mining activity on the stability of the lysosomal membrane and avoidance behavior in the worm
Eisenia fetida
. Texture, ...organic material, conductivity and pH were determined in soils. The total concentrations of Cu, Zn, Pb, Ni, As and Hg were determined in tissues of
E. fetida
and in soils. Neutral red retention time (NRRT) was determined in hemocytes, and behavior with the avoidance test, in the earthworm. Cu (1563 ± 58 mg kg
-1
) and Zn (135 ± 9 mg kg
-1
) had the highest mean concentrations in the soils, while Hg (0.01 ± 0.001 mg kg
-1
) had the lowest concentration in all the soils. The soil with the highest Cu concentration produced an avoidance of > 80%. Most of the soils produced a significant loss of the stability of the lysosomal membrane. The variables organic material and sand would facilitate habitat selection in
E. fetida
, In conclusion, the soils have chemical agents in bioavailable concentrations that provoke adverse cellular effects and evasion behavior. We propose the use of both response variables as early alerts in the evaluation of soils.
The estuaries of the Aconcagua and Maipo Rivers of central Chile are receptors of residues that contain metals from anthropic activities including agriculture, mining and smelters, which have ...different levels in the two basins. This study postulates that the exposition to metals is different in the two estuaries and that their sediments contain bioavailable chemical agents that produce oxidative stress. The aim of the study was to evaluate the effect of estuarine sediments on the polychaete Perinereis gualpensis using oxidative stress biomarkers and to determine the metal concentrations in sediments and their accumulation in P. gualpensis. Sediments and organisms were collected in December 2015 and January 2016 in the estuaries. The Catapilco estuary was used as control, since its basin has little anthropic activity. The metal concentrations of Fe Cu, Pb, Zn and Cd were determined in tissues of the organisms and in sediments. The granulometry, conductivity, redox potential, pH and organic matter in sediments were determined, as well as catalase activity and lipid peroxidation. The results show that the concentrations of metals in sediments were higher in the estuary of the Aconcagua River: Cu: 48 ± 2μgg−1; Fe: 154 ± 19mgg−1, Pb: 20 ± 3μgg−1 and Zn: 143 ± 20μgg−1. In tissues, Pb and Fe were higher in the estuary of the Maipo River, while Cd was detected only in the Catapilco River mouth. Catalase activity was greater in the estuary of the Aconcagua River and lipid peroxidation in the estuary of the Catapilco River. Significant regressions were found between biomarkers of oxidative stress and metal concentrations in tissues of P. gualpensis. In conclusion, the sediments of the studied estuaries contain bioavailable chemical agents that provoke oxidative stress in P. gualpensis, which may be a risk for the benthic communities of these ecosystems. This species is proposed to monitor metals bioavailability and oxidative stress in estuarine sediments.
The aim of this study was to determine the cytotoxic and genotoxic effects of copper on the bivalve
Perumytilus purpuratus
. The individuals were exposed to three copper concentrations: 1, 30 and ...45 μg L
−1
for 24, 48 and 96 h. Lysosomal membrane stability in hemocytes was determined through the neutral red retention time (NRRT) and micronucleus (MN) frequency tests in hemocytes and gills. The results show that the NRRT decreased significantly at 30 μg L
−1
after 48 h of exposure. The frequency of MN was significantly greater in gills after 24 h in all concentrations tested. Copper is cytotoxic from 30 μg L
−1
and genotoxic from 1 μg L
−1
. The use of these biomarkers of effects in
P. purpuratus
is proposed as an early warning tool for monitoring in environmental assessment of coastal ecosystems impacted by mining activities.
Several previous studies highlighted the importance of using field-collected soils—and not artificially-contaminated soils—for ecotoxicity tests. However, the use of field-collected soils presents ...several difficulties for interpretation of results, due to the presence of various contaminants and unavoidable differences in the physicochemical properties of the tested soils. The objective of this study was to estimate thresholds of metal toxicity in topsoils of 24 agricultural areas historically contaminated by mining activities in Chile. We performed standardized earthworm reproduction tests (OECD 222 and ISO 11268-2) with Eisenia fetida. Total soil concentrations of Cu, As, Zn, and Pb were in the ranges of 82–1295mgkg−1, 7–41mgkg−1, 86–345mgkg−1, and 25–97mgkg−1, respectively. In order to differentiate between the effects of different metals, we used regression analysis between soil metal concentrations and earthworm responses, as well as between metal concentrations in earthworm tissues and earthworm responses. Based on regression analysis, we concluded that As was a metal of prime concern for Eisenia fetida in soils affected by Cu mining activities, while Cu exhibited a secondary effect. In contrast, the effects of Zn and Pb were not significant. Soil electrical conductivity was another significant contributor to reproduction toxicity in the studied soils, forcing its integration in the interpretation of the results. By using soils with electrical conductivity ≤0.29dSm−1 (which corresponds to EC50 of salt toxicity to Eisenia fetida), it was possible to isolate the effect of soil salinity on earthworm reproduction. Despite the confounding effects of Cu, it was possible to determine EC10, EC25 and EC50 values for total soil As at 8mgkg−1, 14mgkg−1 and 22mgkg−1, respectively, for the response of the cocoon production. However, it was not possible to determine these threshold values for juvenile production. Likewise, we were able to determine EC10, EC25 and EC50 of earthworm tissue As of 38mgkg−1, 47mgkg−1, and 57mgkg−1, respectively, for the response of the cocoon production. Finally, we determined the no-observed effect concentration of tissue As in E. fetida of 24mgkg−1. Thus, earthworm reproduction test is applicable for assessment of metal toxicity in field-collected soils with low electrical conductivity, while it might have a limited applicability in soils with high electrical conductivity because the salinity-induced toxicity will hinder the interpretation of the results.
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•Cocoon and juvenile production was correlated with total soil As.•Cocoon production was correlated with earthworm tissue As.•In soils affected by Cu mining, As was a metal of prime concern.•Copper exhibited a secondary toxicity effect to Eisenia fetida.•Soil salinity was a confounding toxicity factor.
The aim of this study was to determine metal distribution in different tissues in early life stages of Atlantic salmon. The concentrations of the metals Al, Cd, Cu, Fe, Mn, Pb and Zn in liver, gills, ...muscle of fish and water from a salmon farm in the Region de los Lagos of southern Chile were determined. Results show that Cd and Pb had the lowest concentrations, while Zn the highest concentration, followed by Cu, Fe and Mn. Cu and Fe had the highest concentrations in liver, while Mn and Zn were the highest in gills. Cu and Fe in liver were higher in pre-smolts than in fingerlings. Cu had the highest bioaccumulation factor in pre-smolts, both in liver and gills. In conclusion the metals tend to bioaccumulate selectively in different tissues of
Salmo salar
. Liver is the most relevant for Cu and Fe, and liver and gills for Zn.
The aim of this study was to evaluate the effect on seaweeds Scytosiphon lomentaria and Ulva rigida of coastal waters of sites with mining activity, using oxidative stress biomarkers and heavy metal ...determination both in water and in tissue. The greatest bioaccumulation factors in S. lomentaria and U. rigida were founded for iron and arsenic in Quintay. Bioaccumulation factor in S. lomentaria in descending order was Fe> Cu> Zn> Cd> Cr> As> Mo and in U. rigida, in descending order, was Fe> Cu> Cd> Zn> Cr> Mo> As. Both species had higher antioxidant activity levels in areas with high mining activities. The concentration of metals in waters such as copper and arsenic in S. lomentaria, and iron, arsenic, and cadmium in U. rigida were related with oxidative stress biomarkers measured in both species. The use of both species is proposed to monitor the bioavailability and oxidative damage in coastal areas with mining activity. This work will generate a significant knowledge about the impact of mining wastes on macroalgal community in the area of north-central Chile.
Use of avoidance tests is a quick and cost-effective method of assessing contaminants in soils. One option for assessing earthworm avoidance behavior is a two-section test, which consists of ...earthworms being given the choice to move between a test soil and a control substrate. For ecological relevance, tested soils should be field-contaminated soils. For practical reasons, artificial soils are commonly used as the control substrate. Interpretation of the test results compromised when the test soil and the artificial substrate differ in their physico-chemical properties other than just contaminants. In this study we identified the physico-chemical properties that influence avoidance response and evaluated the usefulness of adjusting these in the control substrate in order to isolate metal-driven avoidance of field soils by earthworms. A standardized two-section avoidance test with Eisenia fetida was performed on 52 uncontaminated and contaminated (Cu >155mgkg−1, As >19mgkg−1) agricultural soils from the Aconcagua River basin and the Puchuncaví Valley in Chile. Regression analysis indicated that the avoidance response was determined by soil organic matter (OM), electrical conductivity (EC) and total soil Cu. Organic matter content of the artificial substrate was altered by peat additions and EC by NaCl so that these properties matched those of the field soils. The resultant EC80 for avoidance (indicative of soils of “limited habitat”) was 433mg Cu kg−1 (339 – 528mgkg−1 95% confidence intervals). The earthworm avoidance test can be used to assess metal toxicity in field-contaminated soils by adjusting physico-chemical properties (OM and EC) of the artificial control substrate in order to mimic those of the field-collected soil.
•Avoidance was affected by organic matter (OM) and electrical conductivity (EC).•Adjusting OM and EC suppresses the effect of these factors on avoidance response.•The improved method allows determining toxicity thresholds of total Cu in the soil.
Soils near mining centers usually have high heavy metal (HM) levels. It
has been found that some plants associated with arbuscular mycorrhizal
fungi (ANT) improve growth and tolerance to HM in soils. ...This symbiosis
is a biological resource for degraded soil recovery. The objective of
this study was to determine the effect of inoculating AMF ( Glomus
spp.) on alfalfa ( Medicago sativa L.) growth in agricultural soils
with different copper (Cu) levels for degraded soil recovery. To this
effect, alfalfa seeds were grown in soils from the Catemu and
Casablanca valleys and inoculated with ANT. Plant height, stem
diameter, and number of leaves were measured weekly. Dry matter,
mycorrhizal colonization, and Cu concentration in alfalfa plant tissues
were measured after 81 days. Inoculation increased plant height by 24%,
stem diameter by 11%, and number of leaves by 34%. Inoculation had a
significant effect (p ≤ 0.05) on alfalfa plants that were grown
in soil with the highest Cu concentration, but had no effect on Cu
accumulation in alfalfa plant tissues. A direct relationship was
observed between Cu accumulation in alfalfa and Cu concentration in
soils. It was concluded that alfalfa inoculated with Glomus spp. is
applicable to the soil recovery process whenever soil properties can
ensure inoculum effectiveness on alfalfa growth, and avoid toxicity by
excessive Cu in alfalfa plant tissues.
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