Airborne pollen of allergenic herb species in Toledo (Spain)

This study analysed airborne pollen counts for allergenic herb taxa in Toledo (central Spain), a major tourist city receiving over 2 million visitors per year, located in the region of Castilla-La Mancha. The taxa selected were Chenopodiaceae–Amaranthaceae, Plantago, Poaceae and Urticaceae, all of which produce allergenic pollen giving rise to serious symptoms in pollen-allergy sufferers. Aerobiological data were recorded over a 6-year period (2005 to 2010) using the sampling and analysis procedures recommended by the Spanish Aerobiology Network. The abundance and the temporal (annual, daily and intradiurnal) distribution of these pollen types were analysed, and the influence of weather-related factors on airborne pollen counts was assessed. Pollen from herbaceous species accounted for 20.9% of total airborne pollen in Toledo, the largest contributor being Poaceae, with 8.5% of the total pollen count; this family was also the leading cause of respiratory allergies. Examination of intradiurnal variation revealed three distinct distribution patterns: (1) peak daily counts for Chenopodiaceae–Amaranthaceae and Plantago were recorded during the hottest part of the day, i.e. from 1400 to 1600 hours; (2) Urticaceae displayed two peaks (1400–1600 and 2200 hours); and (3) Poaceae counts remained fairly stable throughout the day. Two main risk periods were identified for allergies: spring, with allergies caused by Urticaceae, Plantago and Poaceae pollen, and summer, due to Chenopodiaceae–Amaranthaceae pollen.     

Phytoremediating a copper mine soil with Brassica juncea L., compost and biochar

The soils at a depleted copper mine in Touro (Galicia, Spain) are chemically degraded. In order to determine the effect of amendments and vegetation on the chemical characteristics of a mine soil and on the plant uptake of metals, a greenhouse experiment was carried out for 3 months. A settling pond soil was amended with different percentages of a compost and biochar mixture and vegetated with Brassica juncea L. The results showed that the untreated settling pond soil was polluted by Cu. Amendments and planting mustards decreased the pseudototal concentration of this metal, reduced the extreme soil acidity and increased the soil concentrations of C and TN. Both treatments also decreased the CaCl₂-extractable Co, Cu and Ni concentrations. However, the amendments increased the pseudototal concentration of Zn in the soil, provided by the compost that was used. The results also showed that mustards extracted Ni efficiently from soils, suggesting that B. juncea L. is a good phytoextractor of Ni in mine soils.     

The ERICA Tool

The ERICA Tool is a computerised, flexible software system that has a structure based upon the ERICA Integrated Approach to assessing the radiological risk to biota. The Tool guides the user through the assessment process, recording information and decisions and allowing the necessary calculations to be performed to estimate risks to selected animals and plants. Tier 1 assessments are media concentration based and use pre-calculated environmental media concentration limits to estimate risk quotients. Tier 2 calculates dose rates but allows the user to examine and edit most of the parameters used in the calculation including concentration ratios, distribution coefficients, percentage dry weight soil or sediment, dose conversion coefficients, radiation weighting factors and occupancy factors. Tier 3 offers the same flexibility as Tier 2 but allows the option to run the assessment probabilistically if the underling parameter probability distribution functions are defined. Results from the Tool can be put into context using incorporated data on dose-effects relationships and background dose rates.     

Female house martins (Delichon urbica) reduce egg androgen deposition in response to a challenge of their immune system

Female birds deposit in the yolks of eggs substantial amounts of androgens, such as testosterone and androstenedione. These androgens have been shown to speed up nestling development, induce a fast development of ornaments and increase dominance in adults. Experiments in several species have reported that females invest greater amounts of androgens in the eggs fathered by attractive males, suggesting that yolk androgen is a costly investment for either the offspring or the mother. There is some evidence that nestling immunocompetence may be partially suppressed by high levels of yolk androgens, but it is not known whether this is also the case for females. We tested this hypothesis in the house martin by inducing an immune challenge through an injection of sheep red blood cells, a standard challenge of the humoral immune system. Experimental birds laid eggs with lower amounts of yolk androstenedione than controls, and there was a similar non-significant trend for testosterone. Furthermore, the probability of laying a replacement clutch was higher for birds that had laid a first clutch with relatively high levels of yolk testosterone. These results suggest that yolk androgen deposition is limited by immune costs in the female, and that only females in good condition may afford to invest high levels of androgen in eggs in this species.     

Geographic patterns of natal dispersal in barn swallows <Emphasis Type="Italic">Hirundo rustica</Emphasis> from Denmark and Spain

Dispersal is an important factor that determines the degree of gene flow and, hence, the degree of differentiation among populations. Using two long-term datasets on natal philopatry and short-distance dispersal in barn swallows Hirundo rustica from Denmark and Spain, we evaluated the fitness costs and benefits and test a number of predictions about the functional significance of dispersal. The proportion of philopatric individuals was more than six times larger in Spain than in Denmark, with a higher rate of philopatry in males than in females. Dispersal propensity decreased in both populations during the course of the study. Males from the more philopatric Spanish population lived longer when philopatric rather than dispersing while that was not the case for either sex of the less philopatric Danish population. There were large differences in dispersal propensity among cohorts and breeding sites, suggesting that sites differed in their suitability as sites for immigrants. We found no evidence consistent with the mate competition hypothesis suggesting that males in better condition or with larger condition-dependent secondary sexual characters were more likely to be philopatric. These findings suggest that there is a high degree of intraspecific variation in dispersal propensity between populations, probably relating to local differences in costs and benefits of philopatry and dispersal.     

Ecotoxicological Assessment of the Impact of Residual Heavy Metals on Soil Nematodes in the Guadiamar River Basin (Southern Spain)

On 25 April 1998, as a consequence of the breaking of a dam containing the tailings of a pyrite mine, a land strip of approximately 43 km in length was covered with a layer of black sludge, containing high levels of heavy metals, along the Guadiamar River Basin (southern Spain). In this investigation we carried out an ecotoxicological assessment (field and laboratory studies) of the impact of residual heavy metals (Cu, Pb, Zn, Ni) on soil nematodes in the impacted riparian zone, two years after the huge mine spillage. Concentrations of residual heavy metals were significantly (P<0.05) higher at the impacted sampling sectors (S-2, S-3, S-4, S-5) than at the unpolluted (reference) sampling sector (S-1). Nickel however exhibited the lowest increases at the impacted sectors. As a consequence, correlation coefficients between concentrations of heavy metals and values of ecological indices were not significant for Ni. In contrast, copper, lead and zinc exhibited significant (P<0.05) negative correlation coefficients with ecological indices, particularly with diversity indices (including the~number of taxa). In addition, the toxicity of Cu and Pb to nematode test species (Aphelenchus avenae and Cephalobus persegnis) during short-term toxicity bioassays was much higher than the toxicity of Zn and Ni. We conclude that residual heavy metals were still influencing adversely the community of soil nematodes in the impacted riparian zone of the Guadiamar River Basin. Cu, Pb and, to a lesser extent, Zn would be major responsible for the observed impact.     

Comparative effect of compost and technosol enhanced with biochar on the fertility of a degraded soil

A large number of studies on the reclamation of mine soils focused on the problem caused by metals and did not explore in depth the issue of nutrients and vegetation after the application of organic materials. The aim of this study was to compare the effect of two treatments made of wastes and vegetated with Brassica juncea L. on the fertility of a settling pond mine soil. The first treatment was compost, biochar, and B. juncea (SCBP) and the second treatment was technosol, biochar, and B. juncea (STBP). This study evaluated the effect of the treatments on the soil nutrient concentrations and fertility conditions in the soil amendment mixtures, after 11 months of greenhouse experiment. Total carbon and nitrogen concentrations were higher in treatment SCBP than in treatment STBP after 7 months but, after 11 months, carbon concentration was higher in STBP. The used technosol could have forms of carbon more stable than compost, which could be released slower than in the compost-amended soils. Both compost and technosol mixed with biochar also increased the concentration of calcium, potassium, magnesium, and sodium in exchangeable form in the mine soil.     

Water Footprint of 65 Mid‐ to Large‐Sized U.S. Cities and Their Metropolitan Areas

Conventional indicators of water use for urban areas account primarily for direct water use. In contrast, our objective here is to employ the water footprint (WF) concept and methodology to include the virtual or indirect water use to assess the production‐side and consumption‐side WF of 65 United States (U.S.) cities. The 65 cities include the largest metropolitan areas and some of the major mid‐sized cities in the U.S. We use metropolitan areas to define our city boundaries as this is the native spatial resolution of the main datasets used. To estimate the urban WFs, we integrated large and disparate datasets, including commodity flow (agricultural, livestock, and industrial commodities), water use, and socioeconomic data. By analyzing the estimated WF values, we found indirect water use accounts on average for 66% of the WF of consumption. We found some cities are net virtual water exporters (11 of 65) because they rely heavily on direct water uses or are heavy producers of industrial commodities. Also, WF patterns vary widely across the U.S. but regional patterns seem to emerge. For example, the dense cities of the U.S. northeast megaregion have a significantly low per capita WF relative to the other cities, while cities in the Gulf Coast megaregion have a significantly higher industrial WF of production and consumption. Furthermore, there is inequality in the WF of consumption where a few cities account for a disproportionate share of the total U.S. urban water uses.     

Modeling wintertime particulate matter formation in central California

A wintertime episode during the 2000 California Regional PM Air Quality Study (CRPAQS) was simulated with the air quality model CMAQ–MADRID. Model performance was evaluated with 24-h average measurements available from CRPAQS. Modeled organic matter (OM) was dominated by emissions, which were probably significantly under-represented, especially in urban areas. In one urban area, modeled daytime nitrate concentrations were low and evening concentrations were high. This diurnal profile was not explained by the partition of nitrate between the gas and particle phases, because gaseous nitric acid concentrations were low compared to PM nitrate. Both measured and simulated nitrate concentrations aloft were lower than at the surface at two tower locations during this episode. Heterogeneous reactions involving NO₃ and N₂O₅ accounted for significant nitrate production in the model, resulting in a nighttime peak. The sensitivity of PM nitrate to precursor emissions varied with time and space. Nitrate formation was on average sensitive to NO_x emissions. However, for some periods at urban locations, reductions in NO_x caused the contrary response of nitrate increases. Nitrate was only weakly sensitive to reductions in anthropogenic VOC emissions. Nitrate formation tended to be insensitive to the availability of ammonia at locations with high nitrate, although the spatial extent of the nitrate plume was reduced when ammonia was reduced. Reductions in PM emissions caused OM to decrease, but had no effect on nitrate despite the role of heterogeneous reactions. A control strategy that focuses on NO_x and PM emissions would be effective on average, but reductions in VOC and NH₃ emissions would also be beneficial for certain times and locations.     

The Estimation of Personal Exposures to Air Pollutants for a Community-Based Study of Health Effects in Asthmatics—Design and Results of Air Monitoring

In order to provide reliable pollutant and meteorological exposure estimates for an epidemiological study of asthmatics residing in two Houston neighborhoods, a dedicated three-tier air monitoring system was established. This consisted of fixed site ambient air monitoring at the center of each study area, a mobile van performing simultaneous indoor and outdoor measurements at selected residences of study participants, and a limited amount of direct personal monitoring for half of the participants. Monitored pollutants Included all criteria pollutant gases, as well as aeroallergens, aldehydes, TSP, and IP. Laboratory analyses provided concentrations of sulfate, nitrate, and trace elements. Continuous measurements of several meteorological parameters also were obtained. Intensive quality assurance and data validation efforts resulted in a high percentage of valid data for most pollutants. Ozone was the only measured pollutant that exceeded the NAAQS during the six-month (May to October) study period. The monitoring scheme allowed important pollutant concentration differences to be detected between day and night, between Indoors and outdoors, and among various indoor environments. The use of these monitoring data in combination with personal activity and household characteristics data to generate estimates of personal exposures for the epidemiological analysis will be described in a subsequent paper.