Santiago Llacuna

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.

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.

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.

Hematological and biochemical parameters in pollution-exposed mice.

The selection of a model in life sciences research, especially when dealing with environmental effects of pollution, poses the dilema of prioritizing one of the terms of the dialectic pair “realism vs. control of experimental parameters”. This fact suggests the need for a multiple, diversificate approach.