Acidic Air Pollution Research Articles

Calcium availability affects the intrinsic water-use efficiency of temperate forest trees

Intrinsic water-use efficiency (iWUE) of trees is an important component of the Earth’s coupled carbon and water cycles. The causes and consequences of long-term changes in iWUE are, however, still poorly understood due to the complex interplay between biotic and abiotic factors. Inspired by the role calcium (Ca) plays in plant transpiration, we explore possible linkages between tree ring-derived iWUE and Ca availability in five central European forest sites that were affected by acidic air pollution. We show that increasing iWUE was directly modulated by acid air pollution in conjunction with soil Ca concentration. Responses of iWUE to rising atmospheric CO2 concentrations accelerated across sites where Ca availability decreased due to soil acidity constraints, regardless of nitrogen and phosphorus availability. The observed association between soil acidity, Ca uptake, and transpiration suggests that Ca biogeochemistry has important, yet unrecognized, implications for the plant physiological upregulation of carbon and water cycles.

Differences in leaf gas exchange strategies explain Quercus rubra and Liriodendron tulipifera intrinsic water use efficiency responses to air pollution and climate change.

Trees continuously regulate leaf physiology to acquire CO2 while simultaneously avoiding excessive water loss. The balance between these two processes, or water use efficiency (WUE), is fundamentally important to understanding changes in carbon uptake and transpiration from the leaf to the globe under environmental change. While increasing atmospheric CO2 (iCO2 ) is known to increase tree intrinsic water use efficiency (iWUE), less clear are the additional impacts of climate and acidic air pollution and how they vary by tree species. Here, we couple annually resolved long-term records of tree-ring carbon isotope signatures with leaf physiological measurements of Quercus rubra (Quru) and Liriodendron tulipifera (Litu) at four study locations spanning nearly 100 km in the eastern United States to reconstruct historical iWUE, net photosynthesis (Anet ), and stomatal conductance to water (gs ) since 1940. We first show 16%-25% increases in tree iWUE since the mid-20th century, primarily driven by iCO2 , but also document the individual and interactive effects of nitrogen (NOx ) and sulfur (SO2 ) air pollution overwhelming climate. We find evidence for Quru leaf gas exchange being less tightly regulated than Litu through an analysis of isotope-derived leaf internal CO2 (Ci ), particularly in wetter, recent years. Modeled estimates of seasonally integrated Anet and gs revealed a 43%-50% stimulation of Anet was responsible for increasing iWUE in both tree species throughout 79%-86% of the chronologies with reductions in gs attributable to the remaining 14%-21%, building upon a growing body of literature documenting stimulated Anet overwhelming reductions in gs as a primary mechanism of increasing iWUE of trees. Finally, our results underscore the importance of considering air pollution, which remains a major environmental issue in many areas of the world, alongside climate in the interpretation of leaf physiology derived from tree rings.

Quasi-Classical Trajectory Dynamics Study of the Reaction OH + H2S→H2O + SH and Its Isotopic Variants: Comparison with Experiment

The hydrogen abstraction reaction OH + H2S→H2O + SH plays an important role in acid rain formation, air pollution and climate change. In this work, the product energy disposals of the reaction and its isotopic variants OD + H2S and OD + D2S are calculated on a new ab-initio-based ground electronic state potential energy surface (PES) using the quasi-classical trajectory method. The PES is developed by fitting a total of 72,113 points calculated at the level of UCCSD(T)-F12a/aug-cc-pVTZ and using the fundamental invariant-neural network method, resulting in a total RMSE of 4.14 meV. The product H2O formed in the OH + H2S reaction at 298 K is found to be largely populated in the first overtone states of its symmetric and asymmetric stretching modes, while the vibrational distributions of the products HOD and D2O in the isotopically substituted reactions are visibly different. The computed product vibrational state distributions agree reasonably well with experimental results and are rationalized by the sudden vector projection model.

Determining the level of organic acid air pollution in museum storage rooms by mass-balance modelling

• Mass-balance calculations can be used to predict the concentration of formic and acetic acid in air. • Lowering the temperature in storage reduces the emission of organic acids from objects. • Air can be cleaned by filtration and ventilation, but at a cost. • Low winter temperatures can be used for free to reduce energy consumption in storage buildings. • We demonstrate how to apply mass-balance modelling to any storage building. Formic acid and acetic acid are among the most critical indoor air pollutants causing damage to museum collections. Many museums, however, lack funds and expertise to conduct detailed environmental monitoring to survey the level of organic acids in the air of collection areas. We demonstrate how a mass-balance calculation, based on data obtained from estimated factors and from literature can be used instead. The model was applied on a real museum storage building located in Denmark, and compared with concentration measurements performed in it by passive sampling. The model seemed at first to overestimate the concentration as compared to the real measurements, which could mean that either the emission of organic acids from objects was over-estimated, or the removal by surfaces was under-estimated, or both. However, taking that into account, it is demonstrated how the model can be used to examine the behaviour of different air quality control scenarios, in this case the effectiveness of: adjusting room temperature, applying internal air filtration, or varying the air exchange (ventilation) rate. For each case, the result was evaluated against the implication on energy consumption. The mass-balance calculations points to temperature as the most useful control method of the three, at least from a temperate climate zone point of view, as cold winter temperatures can be used to reduce the temperature within unoccupied storage buildings without applying mechanical control. The least energy-efficient method would be to dilute the pollutants by ventilation. To attain the same reduction in organic acid concentration by ventilation, as could be achieved with a decrease in temperature from normal indoor room conditions to cool conditions (13 °C less), the air exchange rate would need to be increased by almost three room volumes per hour. This would, however, for filtration alone increase the energy use by 6.3 kWh per cubic metre of storage space, annually, as compared to the free cooling provided by not heating during winter, at least for a building located in a temperate climate zone. To investigate the general magnitude of the organic acid pollution levels, which may be expected in typical storage rooms, a Monte Carlo simulation based on literature data was carried out and showed that for most situations the concentration can be expected to be well below the safe levels suggested in literature. A step-by-step guide for applying the mass-balance model to any storage building is provided. Further research, however, is needed in order to refine the model as well as to expand it to include other building types and climate zones.

Changes in forest nitrogen cycling across deposition gradient revealed by δ15N in tree rings

Tree rings provide valuable insight into past environmental changes. This study aimed to evaluate perturbations in tree ring width (TRW) and δ15N alongside soil acidity and nutrient availability gradients caused by the contrasting legacy of air pollution (nitrogen [N] and sulphur [S] deposition) and tree species (European beech, Silver fir and Norway spruce). We found consistent declines of tree ring δ15N, which were temporarily unrelated to the changes in the TRW. The rate of δ15N change in tree rings was related to the contemporary foliar carbon (C) to phosphorus (P) ratio. This observation suggested that the long-term accumulation of 15N depleted N in tree rings, likely mediated by retained N from deposition, was restricted primarily to stands with currently higher P availability. The shifts observed in tree-ring δ15N and TRW suggest that acidic air pollution rather than changes in stand productivity determined alteration of N and C cycles. Stable N isotopes in tree rings provided helpful information on the trajectory of the N cycle over the last century with direct consequences for a better understanding of future interactions among N, P and C cycles in terrestrial ecosystems.

Mode-specific quantum dynamics study of OH + H2S → H2O + SH reaction

The hydrogen abstraction reaction from H2S by OH is of key importance in understanding of the causes of acid rain, air pollution, and climate change. In this work, the reaction OH+H2S → H2O+SH is investigated on a recently developed ab initio-based globally accurate potential energy surface by the time-dependent wave packet approach under a reduced-dimensional model. This reaction behaves like a barrier-less reaction at low collision energies and like an activated reaction with a well-defined barrier at high collision energies. Exciting either the symmetric or antisymmetric stretching mode of the molecule H2S enhances the reactivity more than exciting the bending mode, which is rationalized by the coupling strength of each normal mode with the reaction coordinate. In addition, the modespecific rate constant shows a remarkable non-Arrhenius temperature dependence.

Air pollutants and subsequent risk of chronic kidney disease and end-stage renal disease: A population-based cohort study

Air pollutants have been reported to be a possible risk factor of chronic kidney disease (CKD). However, epidemiologic results regarding acidic gases and CKD have yet to be elucidated. We linked the Taiwan Air Quality Monitoring Database (TAQMD) to the Longitudinal Health Insurance Database. An observational cohort of 161,970 Taiwan citizens who had not been diagnosed with CKD was formed. The concentrations of air pollutant were classified into four levels based on quartile. Multivariable and univariable Cox proportional hazard regression models were used to assess the risk of developing CKD and end-stage renal disease (ESRD). Compared with Q1-level SO2, exposure to the Q4 level was at a 1.46-fold risk of developing CKD (95% confidence interval [CI] = 1.28–1.65) and 1.32-fold risk of ESRD (95% CI = 1.03–1.70). Compared with Q1-level NOx, exposure to the Q4 level was at a 1.39-fold higher risk of developing CKD (95% CI = 1.22–1.58) and 1.70-fold risk of ESRD (95% CI = 1.33–2.18). Compared with Q1-level NO, exposure to the Q4 level was at a 1.48-fold risk of CKD (95% CI = 1.30–1.68) and 1.54-fold risk of ESRD (95% CI = 1.20–1.98). Compared with Q1-level particles <2.5 μm (PM2.5), exposure to the Q4 level were at a 1.74-fold risk of CKD (95% CI = 1.53–1.98) and 1.69-fold risk of ESRD (95% CI = 1.32–2.16). Exposure to particulate and acidic gas air pollution was observed to be associated with an increased risk of CKD and ESRD.

Disentangling the effects of acidic air pollution, atmospheric CO2 , and climate change on recent growth of red spruce trees in the Central Appalachian Mountains.

In the 45years after legislation of the Clean Air Act, there has been tremendous progress in reducing acidic air pollutants in the eastern United States, yet limited evidence exists that cleaner air has improved forest health. Here, we investigate the influence of recent environmental changes on the growth and physiology of red spruce (Picea rubens Sarg.) trees, a key indicator species of forest health, spanning three locations along a 100km transect in the Central Appalachian Mountains. We incorporated a multiproxy approach using 75-year tree ring chronologies of basal tree growth, carbon isotope discrimination (∆13 C, a proxy for leaf gas exchange), and δ15 N (a proxy for ecosystem N status) to examine tree and ecosystem level responses to environmental change. Results reveal the two most important factors driving increased tree growth since ca. 1989 are reductions in acidic sulfur pollution and increases in atmospheric CO2 , while reductions in pollutant emissions of NOx and warmer springs played smaller, but significant roles. Tree ring ∆13 C signatures increased significantly since 1989, concurrently with significant declines in tree ring δ15 N signatures. These isotope chronologies provide strong evidence that simultaneous changes in C and N cycling, including greater photosynthesis and stomatal conductance of trees and increases in ecosystem N retention, were related to recent increases in red spruce tree growth and are consequential to ecosystem recovery from acidic pollution. Intrinsic water use efficiency (iWUE) of the red spruce trees increased by ~51% across the 75-year chronology, and was driven by changes in atmospheric CO2 and acid pollution, but iWUE was not linked to recent increases in tree growth. This study documents the complex environmental interactions that have contributed to the recovery of red spruce forest ecosystems from pervasive acidic air pollution beginning in 1989, about 15years after acidic pollutants started to decline in the United States.

Investigating the Effect of Arbuscular Mycorrhizal Fungi (Glomus etonicatum) and Air Pollutants on Growth Parameters of Maize (Zea mays L.)

The present study aimed to examine the interactions of mycorrhiza and air pollutant and acid rain on indicators such as chlorophyll, protein and carotenoids, as well as on maize (Zea mays) in a completely randomized design with 10 replications and in greenhouse conditions from February 2016 to April 2017. Experimental variants were classified in four groups including maize (Zea mays) colonized with Glomus etonicatum irrigated with acid rain water and normal water with pH=7 and control plants irrigated with acid rain water and normal water. Results from analysis of variance (by SPSS software) revealved that the effect of mycorrhizal inoculation on indicators such as the height of plant, the number of leaves, fresh leaf weight, dry leaf weight, root weight, the number of fruits, the amount of chlorophyll a, b, total chlorophyll, carotenoids and protein, were significant (p<0.05). Inoculation with Glomus etonicatum caused a significant increase in the mentioned indicators compared to the control ones. The highest amount was observed in plants inoculated with mycorrhiza and irrigated with normal water and the lowest amount was observed in control plants irrigated with acid rain water. Further, the results indicated that even the amount of these indicators in mycorrhiza plants irrigated with acidic water was significantly higher than that of the control plants irrigated with normal water. In general, inoculation with Glomus etonicatum could increase the growth and photosynthesis of plants, even under acid rain and air pollution, compared with non-mycorrhiza plants and in normal condition.

Composition of weathering crusts on sandstones from natural outcrops and architectonic elements in an urban environment.

This work presents mineralogical and chemical characteristics of weathering crusts developed on sandstones exposed to various air pollution conditions. The samples have been collected from sandstone tors in the Carpathian Foothill and from buildings in Kraków. It has been stated that these crusts differ in both fabric and composition. The sandstone black crust from tors is rich in organic matter and composed of amorphous silica. Sulphate incrustations accompanied by dust particles have been only sometimes observed. Beneath the black crust, a zone coloured by iron (oxyhydr)oxides occurs. The enrichment of the surface crust in silica and iron compounds protects the rock interior from atmospheric impact. The sandstones from architectonic details are also covered by a thin carbon-rich black crust, but they are visibly loosened. Numerous salts, mainly gypsum and halite, crystallise here, thus enhancing deterioration of the rock. Moreover, spherical particles originated from industrial emissions are much more common. Gypsum in natural outcrops, forms isolated and well-developed crystals, whilst these found on the architectonic details are finer and densely cover the surface. Such diversity reflects various concentrations of acid air pollutants in solutions.

Chemical Properties and Nutrient Loadings of Rainwater during Farming Season

Recently, special attention has been given to acid rain and its problem to environment such as acid precipitation and air pollution in East Asia. In the present study, rainwater samples were collected from Apr to Nov in 2012. The samples were chemically characterized for the assessment of emission sources. Suwon and Yeoju regions, typical agricultural areas in South Korea, were chosen for study sites. Ion composition and cation-affected neutralization were determined to evaluate the contribution of cations to the acidity of rainwater. Ion and electrical conductivity between the measured and the estimated showed high correlation. The cations observed in Suwon and Yeoju were <TEX>$Na^+$</TEX> > <TEX>$NH_4{^+}$</TEX> > <TEX>$K^+$</TEX> > <TEX>$Ca^{2+}$</TEX> > <TEX>$Mg^{2+}$</TEX> > <TEX>$H^+$</TEX> and <TEX>$Na^+$</TEX> > <TEX>$K^+$</TEX> > <TEX>$NH_4{^+}$</TEX> > <TEX>$Ca^{2+}$</TEX> > <TEX>$Mg^{2+}=H^+$</TEX>, respectively. The anions of all sites were <TEX>$SO{_4}^{2-}$</TEX> > <TEX>$NO_3{^-}$</TEX> > <TEX>$Cl^-$</TEX>. While the amounts of sulfate, one of the major dissolved components of rainwater, were 77.6 and 75.6 ueq <TEX>$L^{-1}$</TEX> in Suwon and Yeoju, the ones of NSS-<TEX>$SO{_4}^{2-}$</TEX> (Non-Sea Salt sulfate) were 83 and 82% in Suwon and Yeoju, respectively. The comparison of observed pH values (<TEX>$pH_{obs}$</TEX>) with the theoretical pH values (<TEX>$pH_{the}$</TEX>) showed that the neutralization of rain water considerably went along during the study periods. The highest amounts of rainfall throughout the year in Suwon and Yeoju were 572.3 and 484.6 mm in July, and its corresponding nitrogen loadings in Suwon and Yeoju were 5.28 and 3.50 kg <TEX>$ha^{-1}$</TEX>, respectively. The major ion contents for crop growth with <TEX>$SO{_4}^{2-}$</TEX>, <TEX>$Ca^{2+}$</TEX>, <TEX>$K^+$</TEX> and <TEX>$Mg^{2+}$</TEX> were 51.7, 5.2, 11.8 and 1.8 kg <TEX>$ha^{-1}$</TEX> in Suwon and 34.2, 4.0, 4.2 and 1.1 kg <TEX>$ha^</TEX><TEX>{-1}$</TEX> in Yeoju.

Chemical characterization of rainwater over Suwon region during farming and non-farming periods

Recently, special attention has been givento acid rain and its problem to environment such as acid precipitation and air pollution in East Asia.In the present study, rainwater samples werecollected from Apr to Oct (farming period) and from Nov to Mar (non-farming period) in 2009 ~ 2011. The samples were chemically characterized for the assessment of emission sources. Suwon region, a typical agricultural area in Gyeonggi province (South Korea) was chosen as a study site. The content of ionic species and theirtemporal variation were used forfactor analysis, which was used to presume the natural and anthropogenic sources depending upon the farming and non-farming periods. The cationsobserved during farming and non-farming periods were > Na+> Ca2+> K+> H+> Mg2+and Na+> N >Ca2+> H+= Mg2+> K+, respectively. The anions during farming and non-farming periods were > > Cl- and > > Cl-, respectively. While the amounts of sulfate, one of the major dissolved components of rainwater were 113.5 and 177.0 ueq.L-1, the ones of NSS- (Non-Sea Salt sulfate) were 93.7 and 87.1% during farming and non-farming periods, respectively. The comparison of observed pH values (pHobs) with the theoretical pH values (pHthe) showed that the neutralization of rainwater considerably went along during farming and non-farming periods. The highest amountof rainfall throughout the year was310.5 mmin August and its corre sponding nitrogen loading was5.03 kg·ha-1. The major ion contents for crop growth, , Ca2+, K+, Mg2+, were 49.4, 5.5, 18.1,1.4 kg·ha-1from April to October. The major contributions to the existing chemical ions in rainwaters during farming and non-farming periods were from the natural sources (sea and soil) and the anthropogenic sources (human and animal waste, vehicular emission + fossil fuels combustion), respectively.

An analysis of Acid Fog and Air Pollution at Mt. Akagi (2)

An analysis of Acid Fog and Air Pollution at Mt. Akagi (2)

An Analysis of Acid Fog and Air Pollution at Mt. Akagi Focusing on transportation of polluted air mass

An Analysis of Acid Fog and Air Pollution at Mt. Akagi Focusing on transportation of polluted air mass

Classroom Illustrations of Acidic Air Pollution Using Nylon Fabric

In 1970, deposition of fly ash from a coal burning power plant in downtown Peoria produced minor damage in the vicinity of its smokestack, including runs in ladies nylon stockings. In this article, we review the historical event and discuss the chemistry behind the depolymerization of the nylon, as well as laboratory experiments demonstrating how sulfur-containing acidic vapors, such as those from the combustion of sulfur compounds in coal, attack nylon fibers.

Ozone, nitric acid, and ammonia air pollution is unhealthy for people and ecosystems in southern Sierra Nevada, California

Two-week average concentrations of ozone (O 3), nitric acid vapor (HNO 3) and ammonia (NH 3) were measured with passive samplers during the 2002 summer season across the central Sierra Nevada Mountains, California, along the San Joaquin River drainage. Elevated concentrations of the pollutants were determined with seasonal means for individual sites ranging between 62 and 88 ppb for O 3, 1.0–3.8 μg m −3 for HNO 3, and 2.6–5.2 μg m −3 for NH 3. Calculated O 3 exposure indices were very high, reaching SUM00-191 ppm h, SUM60-151 ppm h, and W126-124 ppm h. Calculated nitrogen (N) dry deposition ranged from 1.4 to 15 kg N ha −1 for maximum values, and 0.4–8 kg N ha −1 for minimum values; potentially exceeding Critical Loads (CL) for nutritional N. The U.S., California, and European 8 h O 3 human health standards were exceeded during 104, 108, and 114 days respectively, indicating high risk to humans from ambient O 3.

High acidity tolerance in lichens with fumarprotocetraric, perlatolic or thamnolic acids is correlated with low pK a1 values of these lichen substances

The depsidone fumarprotocetraric acid as well as the depsides perlatolic and thamnolic acids are lichen secondary metabolites. Their first dissociation constants (pK a1) in methanol were determined to be 2.7 for perlatolic acid and 2.8 for fumarprotocetraric and thamnolic acids by UV spectroscopy. Lower pK a1 values are, so far, not known from lichen substances. Several lichens producing at least one of these compounds are known for their outstanding tolerance to acidic air pollution. This is demonstrated by evaluating published pH preferences for central European lichens. The low pK a1 values suggest that strong dissociation of the studied lichen substances is a prerequisite for the occurrence of lichens with these compounds on very acidic substrata, as protonated lichen substances of different chemical groups, but not their conjugated bases, are known to shuttle protons into the cytoplasm and thereby apparently damage lichens.

Foliar loading and metabolic assimilation of dry deposited nitric acid air pollutants by trees

Dry deposition of nitric acid vapor (HNO(3)) is a major contributor to eutrophication of natural ecosystems. Although soil fertilization by nitrogen deposition is considered to be the primary pathway for changes in plant nutrient status and shifts in ecological structure, the aerial portion of plants offer many times the surface area in which to collect atmospheric HNO(3). As much as 60% of deposited nitrogen may be retained in the canopy and not land on the soil surface below. Although uptake and assimilation appears to contribute to retention, only a small percentage of dry deposition is recovered in assimilated N pools. To test the importance of biological activity on the process and measurements of dry deposition, we used controlled environmental chambers to compare deposition to living and freeze-dried foliage of four tree species using (15)N-labeled HNO(3). In living trees, assimilation was determined by (15)N incorporation into free amino acids and proteins in leaves and roots. From 10% to 60% of the retained HNO(3) was incorporated into the biologically active nitrogen pool. The remainder was bound to foliar surfaces in an insoluble form in either living or freeze-dried foliage. The importance of the boundary layer conditions emerged as a primary factor controlling dry deposition characteristics and measurements.Trade names and commercial enterprises or products are mentioned solely for information. No endorsements by the U.S. Department of Agriculture are implied.

Innovative Plasma Processes for Consolidation of Biodeteriorated Ancient Papers

AbstractDeterioration of paper materials is mainly due to the degradation of cellulose caused by a lot of factors such as chemical attack due to acidic hydrolysis, oxidative agent, light, air pollution and biological attack due to presence of microorganisms like bacteria and fungi. Various technologies exist to limit the degradation of the paper materials but in a few cases are unsuited or produce no good results. Plasma technology is an innovative process which can be an alternative to the conventional methods. The plasma treatment produces a synergetic result of sterilization and coating of the paper. This technology is environmentally friendly and can be used for industrial applications. The aim of this project is the increasing of the paper tensile strength and paper conservation by means of several different plasma treatments.

Investigation of the effects of plasma treatments on biodeteriorated ancient paper

Deterioration of paper-based materials is mainly due to the degradation of cellulose caused by a lot of factors such as chemical attack due to acidic hydrolysis, oxidative agent, light, air pollution and biological attack and also due to the presence of microorganisms like bacteria and fungi. It is therefore desirable to focus the research activities on restoration and conservation techniques to develop appropriate treatments. 1 1 CNR Patent, n° Mi2004A000068, 21/01/2004. The aim of this paper is the removal or reduction of the microbial contamination and paper consolidation by means of plasma treatment. For plasma processes, different gas mixtures are utilised, and the different gas mixtures are compared as a function of pressure, power, and treatment time. To demonstrate the efficiency of the sterilisation treatment, two fungi: Aspergillus niger and Penicillium funiculosum, commonly found in libraries and archives were spread on naturally aged paper (19th century). Microorganisms were let to grow by using the organic compounds found in the historical records as a sole source of carbon and energy. The microbial abatement was measured before and after the plasma treatment by using the standard plate count method. Surface chemical and morphological characterisation of paper before and after plasma treatment has been carried out by X-ray photoelectron spectroscopy (XPS) and ATR infrared spectroscopy (ATR FTIR). The tensile strength of the plasma-treated papers was also determined.