RESUMEN
Early efforts at remediation of contaminated soils involve overturn or removal of the uppermost soil horizons. We find that such disruption is counterproductive, as it actually increases the mobility of the heavy metals involved. In our study, we sought to replicate in a controlled manner this commonly used remediation strategy and measure Pb, Zn, Cu and As concentrations in all soil horizons-both prior to and 1 year after disruption by trenching. BCR analyses (sequential leaching) indicate that Pb is affected to the greatest degree and is most highly mobile; however, Zn and As remain insoluble, thus partially ameliorating the detrimental effect. Differences in vegetation cover (i.e. spruce vs. beech forest) have little influence on overall element mobility patterns. The Krusné hory (Ore Mts., Czech Republic) study area is one of the more heavily contaminated areas in Central Europe, and thus the results reported here are applicable to areas affected by brown-coal-burning power plants.
Asunto(s)
Lluvia Ácida/estadística & datos numéricos , Monitoreo del Ambiente , Metales Pesados/análisis , Contaminantes del Suelo/análisis , Suelo/química , Lluvia Ácida/análisis , República Checa , Contaminación Ambiental/análisis , Contaminación Ambiental/estadística & datos numéricos , Europa (Continente) , Bosques , Plomo/análisis , Zinc/análisisRESUMEN
Soil acidification caused by acid deposition has been significant in some forests in southern China. We present an approach for assessing the current stage maximum allowed load (SML) of acid deposition for terrestrial system in the country. The main idea was that soil base cation exchange as a finite buffer to acidity was included in the soil acidity mass balance calculation at current acidification stage. We calculated the SML for five forests in southern China. The usual critical loads for the same forests were also calculated by the steady state mass balance model for comparison. The results showed that the SML is a more tolerant limit than the critical load for the forests with soils not acidified seriously at current stage. However, the SML become a more stringent limit to acid deposition when the forest soils have acidified seriously to very low base cation saturation. In this case the SML assessment is beneficial for the soils recovering from a serious acidified state. Based on a national scale database, the SML mapping for non-agricultural soil system in China was carried out.
Asunto(s)
Lluvia Ácida/estadística & datos numéricos , Monitoreo del Ambiente , Modelos Teóricos , Suelo/química , ChinaRESUMEN
OBJECTIVE: To assess the association of indoor environmental risk factors with respiratory function among adults in an acid rain-plagued city in China where coal use is frequent. METHODS: The subjects were randomly selected in the winter season. Information on selected home environmental factors was collected through administered questionnaires. Additionally, pulmonary function tests, including Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 s (FEV1), FEV1/FVC and Peak Expiratory Flow Rate (PEFR) were also performed in participants. RESULTS: This study showed that, among a variety of risk factors, coal fuel use, cooking oil fumes and active and passive smoking exposure together with asthma in childhood were important factors for deterioration of pulmonary function among adults in the winter season (p < 0.05). Additionally, subjects whose kitchen was located in the living room or bedroom, who opened their windows only occasionally or never, who noted the presence of cooking oil fumes and pests, whose bedroom was shared by 3 or more residents and who kept pets tended to exhibit lower values of FVC, FEV1 and PEFR values compared with non-exposed counterparts (p < 0.05). CONCLUSIONS: This study demonstrated impaired pulmonary function among adults who were exposed to indoor risk factors, such as coal fires and cigarette smoking compared to non-users in the winter season and emphasizes the need for public health efforts to decrease exposure to indoor air pollution.
Asunto(s)
Lluvia Ácida/estadística & datos numéricos , Contaminación del Aire Interior/estadística & datos numéricos , Culinaria/estadística & datos numéricos , Exposición a Riesgos Ambientales/estadística & datos numéricos , Trastornos Respiratorios/epidemiología , Pruebas de Función Respiratoria/estadística & datos numéricos , Contaminación por Humo de Tabaco/estadística & datos numéricos , Adolescente , Adulto , Animales , Asma , China/epidemiología , Comorbilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mascotas , Prevalencia , Factores de Riesgo , Estaciones del Año , Adulto JovenRESUMEN
Critical loads (CLs) and dynamic critical loads (DCLs) are important tools to guide the protection of ecosystems from air pollution. In order to quantify decreases in acidic deposition necessary to protect sensitive aquatic species, we calculated CLs and DCLs of sulfate (SO4(2-))+nitrate (NO3-) for 20 lake-watersheds from the Adirondack region of New York using the dynamic model, PnET-BGC. We evaluated lake water chemistry and fish and total zooplankton species richness in response to historical acidic deposition and under future deposition scenarios. The model performed well in simulating measured chemistry of Adirondack lakes. Current deposition of SO4(2-)+NO3-, calcium (Ca2+) weathering rate and lake acid neutralizing capacity (ANC) in 1850 were related to the extent of historical acidification (1850-2008). Changes in lake Al3+ concentrations since the onset of acidic deposition were also related to Ca2+ weathering rate and ANC in 1850. Lake ANC and fish and total zooplankton species richness were projected to increase under hypothetical decreases in future deposition. However, model projections suggest that lake ecosystems will not achieve complete chemical and biological recovery in the future.
Asunto(s)
Lluvia Ácida/estadística & datos numéricos , Monitoreo del Ambiente , Lagos/química , Animales , Biodiversidad , Ecosistema , Peces/clasificación , Peces/crecimiento & desarrollo , New York , Nitratos/análisis , Sulfatos/análisis , Contaminantes Químicos del Agua/análisis , Zooplancton/clasificación , Zooplancton/crecimiento & desarrolloRESUMEN
To understand the general characteristics of pH distribution and pollution in precipitation at Mt. Huang, statistical analyses were conducted for the routine measurements of pH and conductivity (K) at Mt. Huang during 2006-2011. The results showed that: (1) Over the period of study, the annual volume weighted mean (VWM) precipitation pH varied from 4.81 to 5.57, with precipitation acidity strengthening before 2009 and weakening thereafter. The precipitation acidity showed evident seasonal variations, with the VWM pH lowest in winter (4.78), and highest in summer (5.33). The occurrence frequency of acid rain was 46% , accounting for 45% of total rainfalls and with the most frequent pH falling into weak acid to neutral rain. (2) The annual VWM K varied from 16.91 to 27.84 microS x cm(-1), with no evident trend. As for ions pollution, the precipitation was relatively clean at Mt. Huang, with the most frequent K range being below 15 microS x cm(-1), followed by 15-25 microS x cm(-1). From February 2010 to December 2011, precipitation samples were collected on daily basis for ions analysis, as well as pH and K measurement in lab. Detailed comparisons were conducted between the two sets of pH and K, one set from field measurement and the other from lab measurement. The results indicated: (1) The lab measured pH (K) was highly correlated with the field pH (K); however, the lab pH tended to move towards neutral comparing with the corresponding field pH, and the shift range was closely correlated with the field pH and rainfall. The shift range of K from field to lab was highly correlated with the total ion concentration of precipitation. The field K showed evident negative correlation with the field pH with a correlation coefficient of -0.51. (2) When sampling with nylon-polyethylene bags, the statistics showed smaller bias between two sets of pH, with higher correlation coefficient between two sets of K. Furthermore, the lab K also showed evident negative correlation with the lab pH. Comparing with the observations at other alpine sites in central to eastern China, the natural precipitation at Mt. Huang was weaker in acidity and contains lower ion concentration.
Asunto(s)
Lluvia Ácida/estadística & datos numéricos , Conductividad Eléctrica , Monitoreo del Ambiente , Lluvia/química , Contaminantes Atmosféricos/química , Altitud , China , Concentración de Iones de HidrógenoRESUMEN
The negative health effects of simulated acid mists and fluoranthene on juvenile Japanese red pine were investigated, and the methods of protection from these pollutants were examined. The needle gas exchange, chlorophyll fluorescence, chemical contents and visual damage to needles caused by acid mist applied alone or its conjunction with fluoranthene were investigated over 60 d and 20 d, respectively. Acid mist at pH 2 and 3 caused physiological and visual damage, which was enhanced by the addition of fluoranthene to the mist. However, fluoranthene and acid mist at pH 4 and 5 showed only minor effects. These findings indicate that acid mist may be more harmful to pine trees if it occurs in conjunction with polycyclic aromatic hydrocarbons. Moreover, suppression of the singular and additive effects of these compounds was achieved using mannitol, which may be widely applicable to suppression of reactive oxygen species-mediated plant damage.
Asunto(s)
Contaminantes Atmosféricos/toxicidad , Antioxidantes/farmacología , Restauración y Remediación Ambiental/métodos , Fluorenos/toxicidad , Manitol/farmacología , Lluvia Ácida/efectos adversos , Lluvia Ácida/estadística & datos numéricos , Clorofila/metabolismo , Japón , Estrés Oxidativo/efectos de los fármacos , PinusRESUMEN
A laboratory repacked soil-leaching column experiment was conducted to study the effects of simulated acid rain or EDTA by themselves or in combination, on migration and chemical speciation distribution of Pb and its alternative rare metals including Ag, Bi, In, Sb, and Sn. Experimental results demonstrate that leaching with simulated acid rain promoted the migration of Bi, In and Pb, and their migration reached down to 8 cm in the soil profile, no enhancement of Sb, Ag or Sn migration was observed. Addition of EDTA significantly enhanced the migration of all six metals, especially Bi, In and Pb. The migration of metals was in the order Pb>Bi>In>Sb>Sn>Ag. The individual and combined effects of acid rain and EDTA increased the environmental risk of metals, by increasing the soluble content of metals in soil solutions and the relative distribution of the exchangeable fraction. Leaching risks of Bi, In and Pb were higher than other three metals.
Asunto(s)
Lluvia Ácida/análisis , Ácido Edético/química , Metales/análisis , Modelos Químicos , Contaminantes del Suelo/análisis , Suelo/química , Lluvia Ácida/estadística & datos numéricos , Silicatos de Aluminio/química , Arcilla , Metales/química , Contaminantes del Suelo/químicaRESUMEN
Acid atmospheric emissions within Europe and North America have decreased strongly since 1985 and most recent acidification studies have focused on the changes occurring within ecosystems as a result of this decreased deposition. This current study documents a soil acidification trend under ambient N deposition conditions over a 13 year period, suggesting that acidification continues to be a process of concern at this Calluna vulgaris dominated heathland with an acidic sandy soil. The annual manipulation of climatic conditions on this heathland simulated the predicted summer rainfall reduction (drought) and resulted in a long term retardation of the soil acidification trend. The pH of the soil solution significantly decreased over the course of the trial for both treatments, however, in the final 2 years the decline continued only in the Control treatment. This retardation is primarily associated with the reduction in rainfall leading to lower drainage rates, reduced loss of cations and therefore reduced lowering of the soil acid neutralizing capacity (ANC). However, a change in the underlying mechanisms also indicated that N transformations became less important in the Drought treatment. This change corresponded to an increase in groundcover of an air-pollution tolerant moss species and it is hypothesized that this increasing moss cover filtered an increasing quantity of deposited N, thus reducing the N available for transformation. A soil acidification lag time is expected to increase between the two treatments due to the cumulative disparity in cation retention and rates of proton formation. To the authors' knowledge, this is the first study in which such acidification trends have been demonstrated in a field-scale climate manipulation experiment.
Asunto(s)
Lluvia Ácida , Cambio Climático , Sequías , Monitoreo del Ambiente/métodos , Modelos Teóricos , Suelo/análisis , Lluvia Ácida/estadística & datos numéricos , Cambio Climático/estadística & datos numéricos , Sequías/estadística & datos numéricos , Monitoreo del Ambiente/estadística & datos numéricos , Predicción , Países BajosRESUMEN
Evidence from a multi-date regional-scale analysis of both high-flow and annual-average water quality data from Galloway, south-west Scotland, demonstrates that forest land cover continues to exacerbate freshwater acidification. This is in spite of significant reductions in airborne pollutants. The relationship between freshwater sulphate and forest cover has decreased from 1996 to 2006 indicating a decrease in pollutant scavenging. The relationship between forest cover and freshwater acidity (pH) is, however, still present over the same period, and does not show conclusive signs of having declined. Furthermore, evidence for forest cover contributing to a chlorine bias in marine ion capture suggests that forest scavenging of sea-salts may mean that the forest acidification effect may continue in the absence of anthropogenic pollutant inputs, particularly in coastal areas.
Asunto(s)
Lluvia Ácida/análisis , Contaminantes Atmosféricos/análisis , Agua Dulce/química , Sulfatos/análisis , Árboles/crecimiento & desarrollo , Contaminantes Químicos del Agua/análisis , Lluvia Ácida/prevención & control , Lluvia Ácida/estadística & datos numéricos , Contaminación del Aire/estadística & datos numéricos , Monitoreo del Ambiente , Agricultura Forestal , Tecnología de Sensores Remotos , Escocia , Agua de Mar/química , Calidad del AguaRESUMEN
There is an increasing concern over the impact of human-related emissions on the acid precipitation in China. However, few measurements have been conducted so far to clarify the acid-neutralization of precipitation on a regional scale. Under a network of 10 sites across Northern China operated during a 3-year period from December 2007 to November 2010, a total of 1118 rain and snow samples were collected. Of this total, 28% was acid precipitation with pH < 5.6. Out of these acid samples, 53% were found heavily acidic with pH value below 5.0, indicating significantly high levels of acidification of precipitation. Most of the acidity of precipitation was caused by H2SO4 and HNO3, their relative contribution being 72% and 28%, respectively. However; the contribution of HNO3 to precipitation acidity will be enhanced due to the increasing NO(x) and stable SO2 emissions in future. Neutralization factors for K+, NH4+, Ca2+, Na+, and Mg2+ were estimated as 0.06, 0.71, 0.72, 0.15, and 0.13, respectively. The application of multiple regression analysis further quantified higher NH4+ and Ca2+ contribution to the neutralization process, but the dominant neutralizing agent varied from site to site. The neutralization was less pronounced in the rural than urban areas, probably due to different levels of alkaline species, which strongly buffered the acidity. Presence of high concentrations of basic ions was mainly responsible for high pH of precipitation with annual volume-weighted mean (VWM) values larger than 5.6 at several sites. It was estimated that in the absence of buffering ions, for the given concentration of SO4(2-) and NO3-, the annual VWM pH of precipitation would have been recorded around 3.5 across Northern China. This feature suggested that emissions of particles and gaseous NH3 played very important role in controlling the spatial variations of pH of precipitation in the target areas.
Asunto(s)
Lluvia Ácida/estadística & datos numéricos , Lluvia Ácida/análisis , Cationes/química , China , Concentración de Iones de Hidrógeno , Nitratos/química , Sulfatos/químicaRESUMEN
Lakes in the Adirondack region of New York have partially recovered in response to declining deposition, but information on stream recovery is limited. Here we report results of Adirondack stream monitoring from the early 1980s to 2008. Despite a 50% reduction in atmospheric deposition of sulfur, overall increases in pH of only 0.28 and ANC of 13 µeq L(-1) were observed in 12 streams over 23 years, although greater changes did occur in streams with lower initial ANC, as expected. In the North Tributary of Buck Creek with high dissolved organic carbon (DOC) concentrations, SO(4)(2-) concentrations decreased from 1999 to 2008 at a rate of 2.0 µmol L(-1) y(-1), whereas in the neighboring South Tributary with low DOC concentrations, the decrease was only 0.73 µmol L(-1) y(-1). Ca(2+) leaching decreased in the North Tributary due to the SO(4)(2-) decrease, but this was partially offset by an increase in Ca(2+) leaching from increased DOC concentrations.
Asunto(s)
Ríos/química , Contaminantes Químicos del Agua/análisis , Contaminación Química del Agua/estadística & datos numéricos , Lluvia Ácida/análisis , Lluvia Ácida/estadística & datos numéricos , Atmósfera/química , Carbono/análisis , Monitoreo del Ambiente , Concentración de Iones de Hidrógeno , New York , Dióxido de Azufre/análisis , Contaminantes Químicos del Agua/químicaRESUMEN
The critical load (CL) of acidic atmospheric deposition represents the load of acidity deposited from the atmosphere to the earth's surface at which harmful acidification effects on sensitive biological receptors are thought to occur. In this study, the CL for forest soils was estimated for 27 watersheds throughout the United States using a steady-state mass balance approach based on both national and site-specific data and using different approaches for estimating base cation weathering. Results suggested that the scale and source of input data can have large effects on the calculated CL and that the most important parameter in the steady-state model used to estimate CL is base cation weathering. These results suggest that the data and approach used to estimate weathering must be robust if the calculated CL is to be useful for its intended purpose.
Asunto(s)
Contaminación Ambiental/estadística & datos numéricos , Modelos Químicos , Nitratos/análisis , Sulfatos/análisis , Lluvia Ácida/análisis , Lluvia Ácida/estadística & datos numéricos , Atmósfera/química , Contaminación Ambiental/análisis , Nitrógeno/análisis , Contaminantes del Suelo/análisis , Azufre/análisisRESUMEN
Acid deposition models are inherently simplified representations of real world behaviour and their performance is best evaluated by comparison with observations. National and international acid rain policy assessments handle observed and modelled deposition fields in different ways. Here, both the observed and modelled deposition fields are seen as uncertain and the Generalised Likelihood Uncertainty Estimation (GLUE) framework is used to choose acceptable sets of model input parameters that minimise the differences between them. These acceptable sets of model parameters are then used to estimate deposition budgets to the UK and to provide a probabilistic treatment of excess deposition over environmental quality standards (critical loads).
Asunto(s)
Lluvia Ácida/estadística & datos numéricos , Contaminación del Aire/estadística & datos numéricos , Simulación por Computador , Modelos Estadísticos , Lluvia Ácida/análisis , Movimientos del Aire , Contaminación del Aire/análisis , Monitoreo del Ambiente/métodos , Monitoreo del Ambiente/estadística & datos numéricos , Eutrofización , Modelos Químicos , Política Pública , Incertidumbre , Reino UnidoRESUMEN
Determination of airborne ammonia started in the early 1980s, as a part of air pollution monitoring of industrial plants. Due to high emissions, the city of Rijeka was one of the most polluted in Croatia in the mid-1980s. Considerable reductions in SO2 and NO(x) emissions led to lower airborne levels of these pollutants in the mid 1990s. In spite of the coke plant closure in 1994, there was only a weak decline in airborne ammonia over the period 1980--2005, with annual means in the range of 12-20 microg m(-3) at urban Site 1 and 6-28 microg m(-3) at suburban Site 2. Similar behaviour has been observed with ammonium in bulk rainwater samples since 1996. Higher and approximately equal deposition of nitrogen as ammonium (N-NH4+) were obtained for the urban Site 1 and the mountainous Site 4, but with different causative facts. Ammonium's contribution to total nitrogen (NO3(-)+NH4+) deposition is approximately two thirds, even for a remote Site 3.