Air pollution is one of the primary concerns of our society for its effect on human health and the environment. Among the policy measures that can be put in place to limit air pollutant emissions, end-of-pipe technologies and/or regulatory instruments may be implemented through legislative acts. Also, equally important are behavioural measures, requiring citizens’ active involvement. The success of any measure to limit pollutant emissions requires the acceptance by the citizens that, in turn, implies a correct perception of the main pollutant emission drivers. We present here the comparison between the public perception of air pollution sources and the real-world situation through a survey carried out in seven European countries and involving 16 101 respondents. Our study shows a dramatic underestimation of the contribution of the agri-food sector to air pollution. This result is common to all respondents in the seven countries examined and only to a small extent depends on gender, age and socio-economic status of the respondents. 相似文献
Freshwater resources are increasingly scarce due to human activities, and the understanding of water quality variations at different spatial and temporal scales is necessary for adequate management. Here, we analyze the hypotheses that (1) the presence of a wastewater treatment plant (WWTP) and (2) a polluted tributary that drains downstream from the WWTP change the spatial patterns of physicochemical variables (pH, turbidity, dissolved oxygen, and electrical conductivity) and nutrient concentrations (reactive soluble phosphorus, total phosphorus, nitrogen series, total nitrogen, and total dissolved carbon) along a mid-order river in SE Brazil and that these effects depend on rainfall regime. Six study sites were sampled along almost 4 years to evaluate the impacts of human activities, including sites upstream (1–3) and downstream (5–6) from the WWTP. The impacts were observed presenting an increasing trend from the source (site 1) towards Água Quente stream (site 4, the polluted tributary), with signs of attenuation at site 5 (downstream from both WWTP and site 4) and the river mouth (site 6). Input of nutrients by rural and urban runoff was observed mainly at sites 2 and 3, respectively. At sites 4 and 5, the inputs of both untreated and treated wastewaters increased nutrient concentrations and changed physicochemical variables, with significant impacts to Monjolinho River. Seasonal variations in the measured values were also observed, in agreement with the pluviometric indexes of the region. Univariate analyses suggested no effect of the WWTP for most variables, with continued impacts at sites downstream, but non-parametric multivariate analysis indicated that these sites were recovering to chemical characteristics similar to upstream sites, apparently due to autodepuration. Therefore, multivariate methods that allow rigorous tests of multifactor hypotheses can greatly contribute to determine effects of both point and non-point sources in river systems, thus contributing to freshwater monitoring and management. 相似文献
Rock ptarmigan (Lagopus muta) and willow ptarmigan (L. lagopus) are Arctic birds with a circumpolar distribution but there is limited knowledge about their status and trends across their circumpolar distribution. Here, we compiled information from 90 ptarmigan study sites from 7 Arctic countries, where almost half of the sites are still monitored. Rock ptarmigan showed an overall negative trend on Iceland and Greenland, while Svalbard and Newfoundland had positive trends, and no significant trends in Alaska. For willow ptarmigan, there was a negative trend in mid-Sweden and eastern Russia, while northern Fennoscandia, North America and Newfoundland had no significant trends. Both species displayed some periods with population cycles (short 3–6 years and long 9–12 years), but cyclicity changed through time for both species. We propose that simple, cost-efficient systematic surveys that capture the main feature of ptarmigan population dynamics can form the basis for citizen science efforts in order to fill knowledge gaps for the many regions that lack systematic ptarmigan monitoring programs.
Adjoint method is applied to various oil spill problems. A three-dimensional model for describing the dispersion of a quasi-passive substance (a pollutant or a nutrient) and its adjoint model are considered in a limited sea region. Direct and adjoint estimates are used to get dual (equivalent) estimates of the mean concentration of the substance in important zones of the region. The role of dual estimates is illustrated with a few examples. They include such oil spill problems as the search of the most dangerous point of the oil tanker route, the oil dispersion with a climatic velocity, and the dependence of the oil concentration estimates on the oil spill rate. One more example is the application of optimal bioremediation strategy for cleaning a few zones polluted by oil. In this case, instead of oil, the model describes the dispersion of a nutrient released to marine environment. Balanced, unconditionally stable second-order finite-difference schemes based on the splitting method for the solution of the dispersion model and its adjoint are suggested. The main and adjoint difference schemes are compatible in the sense that at every fractional step of the splitting algorithm, the one-dimensional split operators of both schemes satisfy a discrete form of Lagrange identity. In the special unforced and non-dissipative case, each scheme has two conservation laws. Every split one-dimensional problem is solved by Thomas’ factorization method. 相似文献
The formation of secondary organic aerosol from the gas-phase reaction of catechol (1,2-dihydroxybenzene) with ozone has been studied in two smog chambers. Aerosol production was monitored using a scanning mobility particle sizer and loss of the precursor was determined by gas chromatography and infrared spectroscopy, whilst ozone concentrations were measured using a UV photometric analyzer. The overall organic aerosol yield (Y) was determined as the ratio of the suspended aerosol mass corrected for wall losses (Mo) to the total reacted catechol concentrations, assuming a particle density of 1.4 g cm?3. Analysis of the data clearly shows that Y is a strong function of Mo and that secondary organic aerosol formation can be expressed by a one-product gas–particle partitioning absorption model. The aerosol formation is affected by the initial catechol concentration, which leads to aerosol yields ranging from 17% to 86%. The results of this work are compared to similar studies reported in the literature. 相似文献
Dissolved iron (Fe) distribution and speciation was determined in water samples (0–200?m) collected in a coastal area near Terra Nova Bay during the austral summer of 2014. Nutrients, dissolved oxygen, chlorophyll-a, phytoplankton composition and prokaryotic biomass distribution were investigated in combination with measurements of the physical properties of the water columns and its dynamics. The dFe value was above the limiting growth concentration, ranging from 0.52 to 4.51?nM, and it showed a spatial variability with a horizontal length scale of about 10?km, according to the variability of the water column physical properties and to iron sources. The organic ligands (L) maintained the concentrations of dFe at levels much higher than the inorganic solubility of Fe, keeping it available for phytoplankton and the log K’FeL values found (from 22.1 to 23.6) highlighted the presence of complexes of differing stabilities. 相似文献
The mineral and chemical composition of the liquid and lithogenous substances, consumed by the wild ungulate animals, at the kudurs of the Teletskoye Lake, Gorny Altai, Russia, was studied. It was investigated that all examined kudurits are argillous-aleurolitic and get in the interval from 1 to 100 μm with the predominance of the fraction 10 μm. By the mineral composition, the lithogenous kudurits present the quartz-feldspathic-hydromicaceous-chloritic mineral formations with the large content of the quartz particles (20–43%) and sodium-containing plagioclases (albite, 15–32 wt%). The lithogenous kudurits are the products of the reconstitution of the metamorphic cleaving stones as a result of the glacier abrasive effect, subsequent its aqueous deposits and then eolation in the subaerial conditions. The fontinal waters consumed at the kudurs are subsaline chloride-hydrocarbonate-sodium and sulphated-hydrocarbonate-calcium types. It essentially differs by the increased content of rare-earth elements in reference to the lake water. The acid (HCl, pH-1) extracts from the kudurits more actively extract calcium (10–35% of the gross contents; sodium extracts at the level of 1–3%). The most fluent in the microelements composition are Cu, Be, Sr, Co, Cd, Pb, Sc, Y and rare-earth elements. The transit of all these elements into the dissoluted form fluctuates about 10% from the gross contents. The reason of geophagy is related to tendency of herbivores to absorb mineralized subsoils enriched by the biologically accessible forms of rare-earth elements, arisen as a result of vital activity of specific microflora. 相似文献