Jacint Nadal

Metal accumulation in three species of passerine birds (Emberiza cia, Parus major, and Turdus merula) subjected to air pollution from a coal-fired power plant

Metal accumulation in three passerine bird species, Great Tit (Parus major), Rock Bunting (Emberiza cia), and Blackbird (Turdus merula), was analyzed in a polluted zone where there is a coal-fired power plant (Cercs, Northeast Spain), and a non-polluted zone located 40 km from the source of pollution. Rainwater from the polluted area was acidic (pH 5.2) but the calcareous composition of the soil in this zone buffered the soil and water pools; there were no significant differences between soil pH in the two areas. Metal accumulation in organs and tissues was dependent upon the species and the diet. Blackbirds did not show any significant difference between sites, but Rock Buntings from the polluted zone had higher levels of Cr in feathers and Al in bone, and lower levels of Mn in muscle. Great Tits from the polluted zone showed significantly higher levels of Cr in feathers than those from the unpolluted area. Concerning interspecific differences, Blackbird accumulated significantly more metals than Great Tit or Rock Bunting: higher levels of Cd and Cu in the liver, higher levels of Cr, Pb, Zn and S in bone, and higher levels of S in muscle.

Metals in liver and kidneys and the effects of chronic exposure to pyrite mine pollution in the shrew Crocidura russula inhabiting the protected wetland of Doñana.

Historically impacted by anthropogenic activities, the nature reserve of Doñana (SW Spain) was affected by an unprecedented spillage of mud and acidic water from the Aznalcóllar pyrite mine in April 1998. Although several studies have addressed the influence of this spill on soils, water, and biota, there is little information on mammals, especially carnivorous species. We measured the concentrations of Fe, Mg, Pb, Hg, Cd, Zn, Cu, Mn, Mo, Co, and Cr in specimens of the greater white-toothed shrew, Crocidura russula, inhabiting the protected area affected by the mine spillage. We also examined other parameters to approach at the physiological effects of pollution. We found an increase in non-essential metals (Pb, Cd, and Hg), and morphometric, histological and genotoxic alterations. Age and gender were two significant factors explaining metal bioaccumulation: adults had higher Hg and Cd levels than juveniles, whereas males bioaccumulated more Pb and Co and less Mo than females. The micronucleus frequencies in blood erythrocytes were significantly higher in specimens from the polluted site than animals from the control site. Shrews from the impacted area also had hepatic alterations, namely increased liver-body ratio, focal necrosis, and signs of apoptosis in hepatocytes. Due to the relevance of small mammals in the diet of endangered species such as carnivorous birds and mammals, the findings of our study are of practical use for the management of the Doñana wildlife reserve and other protected Mediterranean wetlands.

Haematology, genotoxicity, enzymatic activity and histopathology as biomarkers of metal pollution in the shrew Crocidura russula

Haematological (WBC, RBC, Hgb and Hct) and genotoxicity (MNT) parameters, hepatic enzymatic activities (GST, GPx and GR), and a histopathological evaluation of liver, kidneys and gonads were assessed as general biomarkers of metal pollution in the shrew Crocidura russula inhabiting a pyrite mining area. Specimens exposed to metals presented a few significant alterations when compared with reference animals: GST activity decreased; micronuclei increased; and evident liver alterations related to metal exposure were observed. On the basis of all the parameters studied, age was an important factor that partly explained the observed variation, whereas sex was the least important factor. Significant correlations were also found between heavy metal concentrations and biomarkers evaluated, demonstrating the great influence of these metals in the metabolic alterations. To the best of our knowledge, these data constitute the first measurements of a battery of biomarkers in shrews from a mine site and are among the few available for insectivorous mammals.

Bioaccumulation of metals and effects of a landfill in small mammals Part III: Structural alterations.

The leachates from the Garraf landfill located in a protected site (NE Spain) contain several potentially toxic substances such as heavy metals. Here we report the histopathological alterations produced by this pollution in wild specimens of an omnivorous species, the wood mouse, Apodemus sylvaticus, and an insectivorous species, the greater white-toothed shrew, Crocidura russula. Hepatic tissue presented the most severe alterations in both the species, namely cell cycle arrest (apoptosis and necrosis), inflammation, preneoplasic nodules, vacuolation and microsteatosis. The kidneys were altered more in the mice (presenting tubular necrosis and dilatation, inflammation, and cylinders) than in the shrews, suggesting that different metabolic pathways render shrews more tolerant to renal toxicity induced by pollutants. No pollution-related alterations were observed in lung, spleen, pancreas, gonads, oesophagus, intestine, or adrenals. We conclude that the two species could be used in conjunction as bioindicators to assess the effects of environmental pollution at different trophic levels.

Effects of air pollution on passerine birds and small mammals

The effects produced by emissions from coal-fired power plants, including mainly SO2, NOx and particulates, on natural populations and caged specimens of birds and small mammals were studied. The field-captured species used to evaluate these effects were passerine birds:Parus major (coal tit) andEmberiza cia (rock bunting), and the rodentApodemus sylvaticus (wood mouse). In parallel to this study on animals captured in the field, we used other animals,Mus musculus (house mouse) andCarduelis carduelis (goldfinch) which were placed in cages near the source of pollution. Some of the animals were killed and their tracheas were removed and prepared for conventional optic studies (1000x) and electron microscopy (TEM and SEM). The results show that atmospheric air pollutants from coal-fired power plants produce alterations in the tracheal epithelium. In passerine birds, an increase in the mucus which covers the tracheal epithelium, shortening of the cilia, and increase in the number of secretory granules and vesicles were observed. In mammals, variation of the uniformity of the pseudostratified epithelium with a wide stratum of mucus, shortening of the cilia, and increase in the number of secretory granules were observed.

Effects of air pollution on hematological parameters in passerine birds

The effects of atmospheric air pollution on some hematological, and bioquimic parameters, of passerine birds were analyzed. The studies were undertaken in the area of Cercs (polluted area in Spain), where there is a coal-fired power plant that emanates SO2, NOx, and particles, and the area of St. Jaume de Frontanya (nonpolluted area) located 40 km from the area of Cercs with similar climatology, relief, and altitude, but without air pollution. The results showed that there was a significant decrease in the erythrocyte count, and an increase in erythrocyte size in specimens from the polluted area. An increase in prealbumines and a decrease in β-globulines in Emberiza cia was observed, while an increase in transaminases (GOT and GPT), and a decrease in weight in Turdus merula from the polluted zone was observed.

Ecological Factors Associated with European Bat Lyssavirus Seroprevalence in Spanish Bats

Bats have been proposed as major reservoirs for diverse emerging infectious viral diseases, with rabies being the best known in Europe. However, studies exploring the ecological interaction between lyssaviruses and their natural hosts are scarce. This study completes our active surveillance work on Spanish bat colonies that began in 1992. Herein, we analyzed ecological factors that might affect the infection dynamics observed in those colonies. Between 2001 and 2011, we collected and tested 2,393 blood samples and 45 dead bats from 25 localities and 20 bat species. The results for dead confirmed the presence of EBLV-1 RNA in six species analyzed (for the first time in Myotis capaccinii). Samples positive for European bat lyssavirus-1 (EBLV-1)–neutralizing antibodies were detected in 68% of the localities sampled and in 13 bat species, seven of which were found for the first time (even in Myotis daubentonii, a species to date always linked to EBLV-2). EBLV-1 seroprevalence (20.7%) ranged between 11.1 and 40.2% among bat species and seasonal variation was observed, with significantly higher antibody prevalence in summer (July). EBLV-1 seroprevalence was significantly associated with colony size and species richness. Higher seroprevalence percentages were found in large multispecific colonies, suggesting that intra- and interspecific contacts are major risk factors for EBLV-1 transmission in bat colonies. Although bat-roosting behavior strongly determines EBLV-1 variability, we also found some evidence that bat phylogeny might be involved in bat-species seroprevalence. The results of this study highlight the importance of life history and roost ecology in understanding EBLV-1–prevalence patterns in bat colonies and also provide useful information for public health officials.

Effects of air pollution on hematological and plasma parameters in Apodemus sylvaticus and Mus musculus.

The effects of atmospheric air pollution on some hematological and plasma parameters, activity, and food and water consumption in Apodemus sylvaticus (wood mouse) and Mus musculus (mouse) were studied. The studies were undertaken in the area of Cercs (polluted area in Spain), where there is a coal-fired power plant that emanates SO2, NOx, and particles, and the area of St. Jaume de Frontanyà (nonpolluted area), located 40 km from the area of Cercs, with similar climatology, relief, and altitude, but without air pollution. Apodemus sylvaticus were captured in the field and Mus musculus were placed in cages in both studied areas. The results showed that there is a significant decrease in hematocrit, and a significant increase in leucocyte number, mean corpuscular hemoglobin concentration, osmolality, and γ-globulin in Mus musculus, and a decrease in albumin (%) and albumin/globulin index in Apodemus sylvaticus. A negative correlation between hematocrit values and pollution was found. In mice placed in cages in the polluted area a slight but significant decrease in water and food consumption, and slower activity, was observed. The results suggest that pollution could induce a decrease in water and food consumption, which may be due to an observed reduction in activity.

A study of the ciliar tracheal epithelium on passerine birds and small mammals subjected to air pollution: ultrastructural study.

A study was made of the ciliar tracheal epithelium on passerine birds and small mammals subjected to NOx, SO2 emissions and particulates from a coal-fired power plant. The results were compared to those of a non-polluted area, very similar in vegetation, relief, and climatology. We studied Carduelis carduelis (goldfinch), Emberiza cia (rock bunting), Parus major (great tit), Turdus merula (blackbird), and Apodemus sylvaticus (wood mouse). All animals were captured in the wild. We also used goldfinch (Carduelis carduelis) captured in the wild and mice (Mus musculus) from our laboratory. These species were placed in protected cages near the source of pollution for 5 and 12 months. The images of the tracheal epithelium surface and the observation of tracheal sections at transmission and scanning electron microscopy showed a variation in the percentage of ciliated and non-ciliated cells, and a variation in the organization, orientation, and morphology of the cilia in animals from the polluted zone.

Trace metal concentrations in tissues of two tinamou species in mining areas of Bolivia and their potential as environmental sentinels.

Mining has a long history in the Bolivian Andes and has left many tailing piles, from which trace metals may reach surface waters, soils, and biota. The potential of tinamous (Birds: Tinamidae) as sentinels has never been tested before, although their biological and ecological characteristics mean they could well be appropriate bioindicators. We captured 13 and nine individuals of the Ornate Tinamou (Nothoprocta ornata) from two polluted sites (P1 and P2) and 10 and five from control unpolluted sites (NP1 and NP2) and used, for comparative purposes, four specimens bred in captivity. We also captured six specimens of Darwin’s Nothura (Nothura darwinii) from the polluted site, P2. We determined the concentration of As, Cd, Pb, and Sb in feathers, liver, and kidney and conducted histological analyses of liver and kidney. For the Ornate Tinamou, a site effect was found for all trace metals in all tissues, with the highest concentrations at polluted sites. At the P2 site, no differences between the two tinamou species were detected except in some cases where Darwin’s Nothura shows near-double concentrations. In some cases, mean and/or individual values of trace metal concentrations reached toxicity levels at the polluted sites. Thesaurismosis in proximal convoluted renal tubules, probably related to Cd exposure, was observed in 30% of the samples from the P1 site. Significant correlations were observed between all tissues for all trace metals and also for all trace metals in each tissue. Because the species studied are ubiquitous and relatively abundant, we recommend monitoring programs based on feather analysis.