Bioavailability and cellular effects of metals on Lumbricus terrestris inhabiting volcanic soils

Soil degradation kinetics of oxybenzone (Benzophenone-3) and toxicopathological assessment in the earthworm, Eisenia fetida

A preponderance of recent evidence indicates that oxybenzone and other personal-care product chemicals threaten the biota inhabiting various ecological niches. What is understudied is the ecotoxicological impact of oxybenzone, a UV filter in sunscreens and anti-aging products, to terrestrial/soil organisms that are keystone species in these habitats. In the present study, acute exposure (14-day) to oxybenzone resulted in earthworm mortality (LC₅₀ of 364 mg/kg) and growth rate inhibition. Environmentally relevant concentration of oxybenzone (3.64, 7.28 and 36.4 mg/kg) at exposures of 7-day, 14-day, 28-day induced oxidative stress and neurotoxicity followed by perturbations in reproduction processes and changes in vital organs. Decreased levels of superoxide dismutase (SOD) and catalase (CAT) activity were statistically lower than controls (p < 0.05) on day 14 for all three concentrations, while glutathione-s-transferase (GST) activity was significantly elevated from controls on days 7 and 14. On day 28, SOD and CAT activities were either not significantly different from the control or were higher, demonstrating a temporal multiphasic response of anti-oxidant enzymes. GST activity on day 28 was significantly reduced compared to controls. Acetylcholinesterase levels across the three-time points exhibited a complicated behaviour, with every exposure concentration being significantly different from the control. Chronic exposure negatively influences earthworm health status with elevated biomarker values analysed using IBRv2 index. This, in turn, impacted higher levels of hierarchical organization, significantly impairing reproduction and organismal homeostasis at the histological level and manifesting as decreasing cocoon formation and successful hatching events. Thus, the overall findings demonstrate that oxybenzone is toxic to Eisenia fetida at low-level, long-term exposure. Based on the concentration verification analysis and application of the EPA PestDF tool, oxybenzone undergoes single first-order kinetics degradation in OECD soil with DT50 and DT90 as 8.7-28.9 days, respectively.

Studies on the toxic effects of agrochemical pesticide (Monocrotophos) on physiological and reproductive behavior of indigenous and exotic earthworm species

Earthworms are an ideal biological model in toxicity assays and environmental monitoring studies. In the present study, the reproductive toxicity and histopathological effects of Monocrotophos pesticide on an exotic epigeic Eudrilus eugeniae and an indigenous epigeic Perionyx barotensis earthworm were studied. Earthworm species were exposed to different concentrations of pesticide like 450 ppm, 500 ppm, and 650 ppm for 45 days and the mortality rate and reproductive activity was recorded every 15 days of exposure. There was an increase in mortality and abnormal sperm (asthenospermia, necrospermia, and oligospermia) and defective cocoons in earthworms with increasing concentrations of the pesticide. Histopathological changes like rupture of chloragogenous tissue, longitudinal muscle, fused and extra-villous growth and necrotic cell rupture in earthworm's body wall (epidermis, circular and longitudinal muscles) were observed. Fluorescent probes have detected cell death in pesticide-treated earthworms when compared to the control group after 45 days. The present findings show that Monocrotophos pesticide on exposure to epigeic earthworm species causes significant reproductive toxicity and histopathological abnormalities and these changes could be used as a tool in environmental risk assessment of pesticides.Abbreviations: DDT: Dichlorodiphenyltrichloroethane; MCP: Monocrotophos; EPA: Environment Protection Act; SL: Soluble Liquid; C: N (Carbon: Nitrogen); C: P (Carbon: Phosphorus); LC: Lethal Concentration; PBS: Phosphate Buffer Solution; WHO: World Health Organization; H&E: Hematoxylin and Eosin; SV: seminal vesicles; O: ovary; GP: genital papillae; Ch: chloragogenous tissue; EL: epithelial layer; CM: circular muscle; LM: longitudinal muscle; CD: cell debris.

Analysis of oxidative stress and cellular aggregation in the coelomocytes of earthworms collected from metal contaminated sites of industrial and agricultural soils of West Bengal, India

Endogeic earthworm Metaphire posthuma (Valliant, 1868) is a common biological component of the tropical soil of India and other countries. The species is reported to influence fertility and porosity of soil and bear a high composting potential. Intensive agricultural, industrial, and mining activities increase the amount of toxic metals in soil causing physiological adversity in earthworm and other biotic components in soil. Coelomocytes, the chief immunoeffector cells of earthworm, perform diverse physiological functions under the challenge of toxins and pathogens. The experimental earthworms collected separately from soils with agricultural and tannery activities were subjected to quantitation of prooxidation and antioxidation parameters for estimation of oxidative stress. Total count, cellular aggregation, generation of reactive oxygen species (ROS), superoxide anion, nitric oxide, activities of phenoloxidase, superoxide dismutase, catalase and glutathione-s-transferase, and amount of total protein were estimated in the coelomocytes of M. posthuma as experimental end points of toxicity screening. Concentrations of cadmium, chromium, lead, and mercury were determined in the soil samples to assess the degree of toxic contamination. The increase in the amount of prooxidants and decrease in the activities of antioxidant enzymes indicated the signs of oxidative stress in the coelomocytes of the organism. Aggregation of circulating coelomocytes is considered as an immune response involved in pathogen encapsulation response as reported in many invertebrates. Decrease in coelomocyte aggregation in earthworm collected from contaminated sites suggested a state of inappropriate shift of the innate immune status. Toxin-induced oxidative stress and reductions in cell aggregation response are the signs of immunocompromisation of M. posthuma. Present findings bear a prospect of this experimental species as an indicator of soil pollution.

Biomarker responses in the earthworm, Dichogaster curgensis exposed to fly ash polluted soils

Earthworms are globally accepted as a model organism in terrestrial ecotoxicology for assessment of environmental pollution. This study evaluated and compared effects of fly ash polluted soils collected from two geographically different thermal power plants on biomarker responses in the earthworm, Dichogaster curgensis. To evaluate relationship between distance sampling and biomarker responses in the earthworm D. curgensis, soil samples at 0.5, 1 and 3km from thermal plant were analyzed for physico-chemical properties and metal concentrations. Biochemical alterations, lysosomal membrane stability, genotoxic effects, and histological changes were examined on 1, 7, and 14 d of exposure to fly ash contaminated soils collected from different thermal power plants. The activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde (MDA) levels were significantly increased, while glutathione reductase (GR) activity was found to be decreased in treated animals. Catalase (CAT) and glutathione-S- transferase (GST) activities were found to be increased initially up to 7d exposure and further decreased on 14d exposure. D. curgensis exposed to fly ash contaminated soils showed significant lysosomal membrane destabilization and DNA damage. Extensive histopathological changes were observed in the tissues of the body wall and intestinal tract of the exposed D. curgensis along with accumulation of heavy metals. These results demonstrate that soil pollution around thermal power plants has adverse biological effects of on the indicator organism D. curgensis and no correlation was found between distance and extent of biological biochemical responses.

Volcanogenic pollution and testicular damage in wild mice

Many evidences have surfaced the adverse effects of environmental pollutants on male reproduction. Volcanogenic pollution is understudied, although it is a well-known source of hazardous contaminants. This study aims to assess the effects of chronic exposure to volcanogenic pollution on wild mice testes by studying: (i) diameter of seminiferous tubules; (ii) relative volumetric density of different spermatogenic cells and interstitial space; (iii) damage in the seminiferous tubules and (iv) apoptotic level in the germinal epithelium. The mice from the polluted site showed higher levels of the selected heavy metals than those from the reference site. The mean diameter of seminiferous tubules and the relative volume occupied by spermatozoa and lumen in exposed mice were significantly lower than in the unexposed group. Contrarily, exposed mice showed a significantly higher relative volume occupied by interstitium, as well as, a higher degree of damage and a significantly higher number of apoptotic cells in the germinal epithelium. Results show that secondary manifestations of volcanic activity can pose a serious risk of testicular injury and therefore for male reproduction.

Establishment of toxicity thresholds in subpopulations of coelomocytes (amoebocytes vs. eleocytes) of Eisenia fetida exposed in vitro to a variety of metals: implications for biomarker measurements

Coelomocytes comprise the immune system of earthworms and due to their sensitivity responding to a wide range of pollutants have been widely used as target cells in soil ecotoxicology. Recently, in vitro assays with primary cultures of coelomocytes based in the neutral red uptake (NRU) assay have been developed as promising tools for toxicity assessment chemical in a reproducible and cost-effective manner. However, NRU showed a bimodal dose-response curve previously described after in vivo and in vitro exposure of earthworm coelomocytes to pollutants. This response could be related with alterations in the relative proportion of coelomocyte subpopulations, amoebocytes and eleocytes. Thus, the aims of the present work were, first, to establish the toxicity thresholds that could be governed by different cell-specific sensitivities of coelomocytes subpopulations against a series of metals (Cu, Cd, Pb, Ni), and second to understand the implication that coelomocyte population dynamics (eleocytes vs. amoebocytes) after exposure to pollutants can have on the viability of coelomocytes (measured by NRU assay) as biomarker of general stress in soil health assessment. Complementarily flow cytometric analyses were applied to obtain correlative information about single cells (amoebocytes and eleocytes) in terms of size and complexity, changes in their relative proportion and mortality rates. The results indicated a clear difference in sensitivity of eleocytes and amoebocytes against metal exposure, being eleocytes more sensitive. The bimodal dose-response curve of NRU after in vitro exposure of primary cultures of coelomocytes to metals revealed an initial mortality of eleocytes (decreased NRU), followed by an increased complexity of amoebocytes (enhanced phagocytosis) and massive mortality of eleocytes (increased NRU), to give raise to a massive mortality of amoebocytes (decrease NRU). A synergistic effect on NRU was exerted by the exposure to high Cu concentrations and acidic pH (elicited by the metal itself), whereas the effects on NRU produced after exposure to Cd, Ni and Pb were due solely to the presence of metals, being the acidification of culture medium meaningless.

Histological Alterations in the Body Wall of the Tropical Earthworm Eudrilus eugeniae Exposed to Hexavalent Chromium

The tropical earthworm Eudrilus eugeniae was chronically exposed to hexavalent chromium (Cr) in its substrate over a concentration range from 0.24 to 893 mg kg(-1). Histological alterations in the body wall epithelium included cell fusion, reduction in thickness of the epithelial layer, a marked increase in pyknotic nuclei and epithelial sloughing. Similar changes were noted in the circular and longitudinal muscles with damage being indicated by the prominent inter-muscular cell spaces and disintegration. Many of these noted alterations intensified with increasing levels of exposure. It is significant that some of the changes recorded here were evident even at the lowest concentration of 0.24 mg kg(-1), an environmentally relevant concentration. Hence, the observed trends could be taken as an early warning to the imminent threats of heavy metal pollution to epigeic earthworm species.

Zonation in the digestive tract of Eisenia fetida: implications in biomarker measurements for toxicity assessment

Eisenia fetida is a model species for soil health assessment and different biomarkers that detect either the presence of bioavailable contaminants or their biological effect have been developed. These parameters are performed in a target tissue or whole earthworm, without considering the marked zonation in histological organisation, enzyme activities and gene expression pattern existing along the body. Thus, the present work was aimed at (a) characterising the morphofunctional heterogeneity along the digestive tract of E. fetida in tissue morphology and turnover, lysosomal enzyme markers (β-glucuronidase, β-GUS; hexosaminidase, HEX), lipofuscin contents (LPF) and metallothionein (MT) and catalase (CAT) gene expression; and (b) determining whether the responsiveness to Cd exposure varies among tissues and along the digestive tract. HEX and β-GUS exhibited a heterogeneous distribution pattern along and across the digestive tract and Cd exposure caused a marked decrease of HEX and an increase of β-GUS activity. Likewise, the significant decrease of cell turnover and the induction of MT transcription were was zone-dependent. Therefore, in was concluded that the consideration of the zonation when applying biomarker for toxicity assessment would reduce the intrinsic variability that results from overlooking the marked morphofunctional heterogeneity that exists in annelids along their body axis.

Evidence of DNA damage in humans inhabiting a volcanically active environment: a useful tool for biomonitoring

The present study was designed to evaluate whether chronic exposure to a volcanically active environment might result in genotoxic and cytotoxic effects in human oral epithelial cells. A study group of 120 individuals inhabiting a volcanically active environment (exposed group; Furnas village) and a reference group of 122 individuals inhabiting a village without manifestations of volcanic activity (Santo António village) were examined in this study. Individuals from Furnas village inhabit a volcanically active environment marked by several degassing manifestations, including fumarolic fields, thermal and cold CO₂ springs and soil diffuse degassing areas. For each individual, 1000 buccal epithelial cells were analyzed for the frequency of micronucleated cells (MNC) and the frequency of cells with other nuclear anomalies (ONA: pyknosis, karyolysis and karyorrhexis), by using the micronucleus assay. Information on life-style factors and an informed consent were obtained from each participant. The frequencies of MNC and of ONA per 1000 cells in the exposed group (4.3‰ and 23.5‰, respectively) were significantly higher than in the reference group (1.7‰ and 7.7‰, respectively). The risk of having a high frequency of MNC or ONA was 2.4 and 3.1-fold higher in exposed individuals compared to reference group. The analyzed confounding factors (age, gender, smoking status, alcohol consumption, and mouthwash use) did not show any significant association with the frequency of MNC or ONA. The higher risk of DNA damage in individuals inhabiting a volcanically active environment is for the first time clearly highlighted with this biomonitoring study. Given that MNC in oral epithelia are recognized as a predictive biomarker of cancer risk within a population of healthy subjects, these findings could contribute to explain the high incidence rates of lip, oral cavity and pharynx cancers previously referred for Furnas village inhabitants.

Histopathological changes in the earthworm Eisenia andrei associated with the exposure to metals and radionuclides

Earthworms were exposed for 56 d to a contaminated soil, from an abandoned uranium mine, and to the natural reference soil LUFA 2.2. Histological changes in earthworm's body wall (epidermis, circular and longitudinal muscles) and gastrointestinal tract (chloragogenous tissue and intestinal epithelium) were assessed, after 0, 14 and 56 d of exposure. Results have shown alterations in all the studied tissues after 14 d of exposure (except for the intestinal epithelium), yet more severe effects were registered after 56 d of exposure. Herein we report histopathological alterations as a good biomarker for the evaluation of soil quality. We also demonstrate that morphological changes in the body wall and gastrointestinal tract, are important endpoints that could be added to earthworm's standardized tests, for the evaluation of soil toxicity, as part of the risk assessment of contaminated areas.

Bioaccumulation of trace metals in the submarine hydrothermal vent crab Xenograpsus testudinatus off Kueishan Island, Taiwan

The concentrations of ten trace metals were determined in the gills, muscles, hepatopancreas, and exoskeleton tissues of Xenograpsus testudinatus that lives around shallow and acidic hydrothermal vents off Kueishan Island, northeastern Taiwan. The analytical results demonstrate that the metal concentrations vary significantly with the type of crab tissue. The concentrations of Al, Cd, Co, Cu, Fe, Ni, and Zn are highest in the gills, whereas the concentration of Mn is highest in the exoskeleton. Cr and Pb concentrations are similar across the different tissues. The enhanced accumulation of most metals in the gills suggests the metal accumulation via the respiration pathway rather than the uptake of food. The results also reveal that the distribution patterns of metals in tissues are similar in the hepatopancreas and muscles, but very different in both the gills and the exoskeleton, perhaps because of the different pathways of metal utilization in the different crab tissues.

Morphometry of the epidermis of an invasive megascoelecid earthworm (Amynthas gracilis, Kinberg 1867) inhabiting actively volcanic soils in the Azores archipelago

For the first time, the structure, dimensions, and composition of the epidermis of an invasive earthworm species that has successfully colonized hostile conditions in actively volcanic soil on São Miguel (Azores) have been measured. Metal concentrations in actively volcanic (Furnas) and volcanically inactive (Fajã) soils were similar; however, Furnas soil was characterised by elevated temperature (10°C differential), relative hypoxia, extremely high CO(2) tension, and accompanying acidity. The epidermis of earthworm's resident at Fajã was approximately twice the thickness of the epidermis of conspecifics resident in Furnas soil. Reference worms transferred to Furnas soil for 14 days experienced an epidermal thinning of approximately 51%. In comparison, when Furnas earthworms were transferred to mesocosms at the relatively benign Fajã site, their epidermal thickness increased by approximately 21% over 14 days. Earthworms resident in Furnas soil had higher goblet cell counts than the residents of volcanically inactive soil on a neighbouring island (S. Maria). Transferring worms from S. Maria to mesocosms at Furnas induced a significant increase in goblet cell counts. Clearly, the active volcanic environment at Furnas poses a multifactorial stress challenge to the epigeic A. gracilis colonizer.

Metal concentration and structural changes in Corallina elongata (Corallinales, Rhodophyta) from hydrothermal vents

Shallow-water hydrothermal activity is widely present at Azores archipelago. Organisms in such environments present great potential as sentinels of the effects derived from chronically exposure to increased temperature, metal concentrations and reduced pH. This study aimed to evaluate metal concentration in Corallina elongata collected at locations exposed and not exposed to shallow-water hydrothermal activity and evaluate changes in its calcareous structure. Elemental concentration was determined and morphometric analysis was performed by scanning electron microscopy. Thicker cell walls and a bleached appearance were observed on C. elongata specimens from the hydrothermally active location, as well as increased concentrations of elements associated to volcanic activity. This study reports on metal accumulation and morphometric changes in the calcareous structure of C. elongata from a hydrothermally active location, adding new data for further research on such habitats and communities, providing an insight on how coralline algae might be affected by ocean acidification.

Influence of clay content on bioavailability of copper in the earthworm Eisenia fetida

We investigated the effect of clay content on the bioavailability of copper to the earthworm Eisenia fetida, in the laboratory for 28 days using OECD artificial soil adjusted to 5%, 20% and 40% clay. Mortality, growth, cocoon production and internal copper concentrations were assessed in worms, and total, DTPA and CaCl(2) extractable copper in the substrates were also determined. The results showed that with increased clay content, there was significant reduction in internal Cu concentration of worms as well as toxicity of copper as shown by data for growth and mortality. However, internal copper concentrations of worms could not explain fully the observed toxicity in this study probably because of Cu regulation. Among the three extraction methods, DTPA extraction revealed the strongest relationship between partitioning and toxicity of Cu in this study. DTPA extract is thus a promising surrogate measure of bioavailability of Cu to earthworms. It is concluded that clay content has significant influence on the bioavailability of copper to earthworms and other similar species.

Bioavailability of heavy metals and their effects on the midgut cells of a phytopaghous insect inhabiting volcanic environments

Organisms living in volcanic environments are chronically exposed to metals, either as particles or associated with gases, from volcanic emissions, being therefore potential sentinels of the effects derived from such exposure. Concentrations of Ca, Cd, Cu, Mg, Mn, Pb, Rb, and Zn were measured in soil, grass (Lolium perenne), and larvae of Pseudaletia uninpuncta captured in sites exposed and non-exposed to volcanic activity. The midgut epithelial cell morphometry and apoptosis of P. unipuncta larvae were also analyzed. Larvae from the site with volcanic activity showed higher levels of Cu, Mn, Rb and Zn. Metals such as Pb, Cd and Mg levels of P. unipuncta larvae were similar between sites. Apoptosis was higher in cells from digestive epithelium of larvae exposed to volcanic activity. Soils and grass not exposed to volcanic activity showed higher levels for most of the analyzed elements with the exception of Rb. Such result when compared with metal levels of larvae may reveal that bioavailability of elements differs between sites. The higher levels of Cd, Zn and Mg in soils and grass from the site with no volcanic activity are probably related to the severe artificial fertilization in the studied pastures. Such result, when compared with metal levels of larvae, suggest that the bioavailability of metals differs between sites.

Essential and non-essential trace metals in scalp hair of men chronically exposed to volcanogenic metals in the Azores, Portugal

Volcanoes produce and release large amounts of toxicants, and the concentration of metals in hair can be used as a biomarker of exposure to trace metals. In order to investigate whether humans exposed to volcanic emissions demonstrate higher concentrations of essential and non-essential trace metals, scalp hair of men (3-89 years) living in two areas of the Azores, one exposed to volcanic emissions and the other not, was sampled, and their content in Cd, Cu, Pb, Rb, Se, and Zn was quantified by using High Resolution Inductively Coupled Plasma Mass Spectrometry. In average, men exposed to volcanic emissions presented higher concentrations of Cd (96.9 ppb), Cu (16.2 ppm), Pb (3417.6 ppb), Rb (216.3 ppb), and Zn (242.8 ppm), but not Se (469.6 ppb). Also, strong and significant correlations were found between Cd-Rb and Pb-Rb in the exposed men. In conclusion, humans living chronically exposed to volcanic emissions show high concentrations of essential and non-essential trace metals in scalp hair, and is suggested that this type of exposure may be as harmful as living close to industrial facilities.

Biological response of earthworm, Eisenia foetida (Savigny) to an organophosphorous pesticide, profenofos

Acute toxicity, morphological alterations and histological effects of an organophosphorus insecticide, profenofos (PFF) to earthworm, Eisenia foetida were evaluated by direct contact through a filter paper. The 24 and 48 h LC(50) was 4.56 and 3.55 microg cm(-2), respectively. Morphological and histological observations showed body ruptures, bloody lesions, and internal excessive formation of glandular cell mass and disintegration of circular and longitudinal muscles, which failed to regulate the internal coelomic pressure, leading to fragmentation in earthworms. Neurotoxic potentiality of PFF was assessed by measuring acetylcholinesterase (AChE). AChE basal K(m) and V(max) values were 0.26 mM and 0.15 micromol min(-1) mg(-1) protein, respectively. PFF alters the in vitro K(m) value, resulting in a competitive type of inhibition. The inhibitory constant K(i) was 2.52x10(-6) M. Morphological alterations and histological effects should be monitored in addition to AChE inhibition to assess OP pesticide contamination in soil ecosystems.

Bioavailable metals and cellular effects in the digestive gland of marine limpets living close to shallow water hydrothermal vents

The pressure exerted by shallow water hydrothermal vents on edible gastropods and their cellular responses triggered by these stresses are almost unknown. The aims of this study were to evaluate the bioavailability of metals in the Macaronesian endemic limpet Patella candei gomesii living close to shallow water hydrothermal vents, and the structural differences in their digestive gland as well as the levels of apoptosis in that organ. Limpets were sampled in four sites, two with the presence of hydrothermalism and the other two without it. Whole body concentrations of several metals (Ca, Cd, Cs, Co, Cu, Fe, Hg, Mg, Mn, Pb, Rb, Se, Sr, and Zn) were obtained, morphometry analysis of the digestive gland and TUNEL test for apoptosis were also performed. Results revealed that the presence of shallow water hydrothermal vents is a source of chronic metal stress to limpets, imposing modifications in the morphometry and cell composition of the digestive gland of those limpets that may constitute cell and tissue adaptations to the environment they live in. This study sets up new baseline data for further research on the influence of shallow water hydrothermal vents over communities living in these habitats.

Effect of temperature on heavy metal toxicity to earthworm Lumbricus terrestris (Annelida: Oligochaeta)

Earthworms (Lumbricus terrestris) acclimated at 2 degrees C above their habitat temperature (10-12 degrees C) showed about 5% increase in basal rate of oxygen consumption, which increased to about 38% in 14-16 degrees C- and 40% in 16-18 degrees C-, but decreased by 84% in 20-22 degrees C-acclimated worms. Temperature also increased the blood hemoglobin (Hb) concentration, which decreased slightly in 20-22 degrees C-acclimated worms. The worms acclimated at 20-22 degrees C showed their blood to be hypovolemic than that of 10-12 degrees C worms indicating dehydration. Pre-exposure of 10-14 degrees C-acclimated worms to sublethal concentrations of zinc, copper, and lead did not significantly affect the rate of respiration. However, at higher temperatures all these metals inhibited oxygen consumption; zinc, lead, and cadmium by approximately 11% and copper by approximately 18% of that at 14-16 degrees C. At 20-22 degrees C, the respiration was further inhibited, 36% by copper, 18% by cadmium, and approximately 10% by lead and zinc. Copper, lead, and zinc decreased the temperature-enhanced increase in blood Hb concentration at all temperatures. In 20-22 degrees C-acclimated worms heavy metal exposure slightly lowered the oxygen affinity of Hb as well as caused shifts in carbon monoxide difference spectra. The acute toxicity of these metals was not affected by a 2 degrees C rise in acclimation temperature but increased by 17% (lead), 33% (copper), and 5% (zinc) in 14-16 degrees C- and by 40% (lead), 149% (copper), and 132% (zinc) in 20-22 degrees C-acclimated worms. The increase in toxicity of metals caused by high temperatures may be due to limiting the scope of aerobic metabolism (oxygen extraction, transport, and utilization) via quantitative and qualitative effects on Hb. This terrestrial species appears to be tolerant of slight increases in habitat temperature, such as that expected with current global climate change.

Apoptosis, metallothionein, and bioavailable metals in domestic mice (Mus musculus L.) from a human-inhabited volcanic area

The influence of extreme environments of volcanic origin over vertebrates and the cellular responses that these may give are almost unknown. The main objectives were to evaluate the exposure of mice to metals in the interior of houses of a small village settled inside a volcanic crater (Furnas, Azores), and the levels of apoptosis and metallothionein in the organs (lung, liver, and kidney) of those animals. Adult mice (Mus musculus) were captured in two areas, one with volcanic activity and the other without it over the last three centuries. In the excised organs, analysis of metals (Al, Cd, Pb, Zn), TUNEL assay for apoptosis, and immunohistochemistry for metallothionein were undertook. Mice from the area with volcanic activity presented higher levels of apoptosis and metallothionein than those from the area without volcanic activity. Such results were in agreement with the differences in metal burdens of the three organs, and interestingly these concentrations were similar to or higher than others found in heavily polluted areas outside the Azores. Thus, there may be a high risk of harmful effects for organisms, including humans, inhabiting areas with volcanism, where hazardous gases and metals in the air are very common during the entire day or even all year round.