Sulfur Dioxide In Air Research Articles

Did the Clean Air Act cause the remarkable decline in sulfur dioxide concentrations?

Over the last three decades, ambient concentrations of sulfur dioxide (SO 2 ) air pollution have declined by approximately 80%. This paper tests whether the 1970 Clean Air Act and its subsequent amendments caused this decline. The centerpiece of this legislation is the annual assignment of all counties to SO 2 nonattainment or attainment categories. Polluters face stricter regulations in nonattainment counties. There are two primary findings. First, regulators pay little attention to the statutory selection rule in their assignment of the SO 2 nonattainment designations. Second, SO 2 nonattainment status is associated with modest reductions in SO 2 air pollution, but a null hypothesis of zero effect generally cannot be rejected. This finding holds whether the estimated effect is obtained with linear adjustment or propensity score matching. Overall, the evidence suggests that the nonattainment designation played a minor role in the dramatic reduction of SO 2 concentrations over the last 30 years.

Did the Clean Air Act cause the remarkable decline in sulfur dioxide concentrations?

Over the last three decades, ambient concentrations of sulfur dioxide (SO 2) air pollution have declined by approximately 80%. This paper tests whether the 1970 Clean Air Act and its subsequent amendments caused this decline. The centerpiece of this legislation is the annual assignment of all counties to SO 2 nonattainment or attainment categories. Polluters face stricter regulations in nonattainment counties. There are two primary findings. First, regulators pay little attention to the statutory selection rule in their assignment of the SO 2 nonattainment designations. Second, SO 2 nonattainment status is associated with modest reductions in SO 2 air pollution, but a null hypothesis of zero effect generally cannot be rejected. This finding holds whether the estimated effect is obtained with linear adjustment or propensity score matching. Overall, the evidence suggests that the nonattainment designation played a minor role in the dramatic reduction of SO 2 concentrations over the last 30 years.

Childhood Asthma Hospitalizations and Ambient Air Sulfur Dioxide Concentrations in Bronx County, New York

The association between asthma hospitalizations and ambient sulfur dioxide (SO2) concentrations was examined in a case-control study in Bronx County, New York. Cases comprised 2629 children aged 0-14 yr who were admitted to hospitals for asthma. There were 2236 controls who were admitted for reasons other than asthma. Daily ambient SO2 concentrations were categorized into quartiles of both average and maximum levels and various exposure windows (i.e., day of admission and 1-, 2-, and 3-d lags). Cases were exposed to higher daily average concentrations of SO2 than controls. The authors compared the highest exposure quartile with the lowest, and the odds ratios were 1.66, 1.90, 2.05, and 2.21 (all p < 0.01 for same-day, 1-, 2-, and 3-d lags, respectively), with a similar finding for daily SO2 maximum exposure. The results suggest a consistent positive association between SO2 exposure and hospitalizations for childhood asthma.

Temporal changes and fluxes of sulphur and calcium in wet and dry deposition, internal circulation as well as in run-off and soil in a forest at Gårdsjön, Sweden

Sulphur dioxide in air as well as dry deposition of sulphur dioxide to a forest has decreased by a factor of 20 during the last two decades. It was earlier found that the internal circulation of calcium in Norway spruce follows the dry deposition of sulphur dioxide. The sulphur and calcium fluxes from 1992 were calculated from wet deposition, throughfall and a surrogate surface. Earlier fluxes from 1981 to 1991 were calculated using assumptions of the dry deposition of non-marine sulphate and calcium. The new estimates confirm the earlier studies that the internal circulation of calcium in a coniferous forest is directly related to the dry deposition of sulphur dioxide to the canopies and that the internal circulation of calcium decreases at the same rate as the deposition of sulphur decreased during the last two decades. The deposition fluxes were also compared to run-off and uptake of calcium in the forest as well as on modelled weathering rates from severely acidified forested catchments near the coast and inland and the soil pool. A reconstruction of changes in the soil pool of calcium over the last 100 years indicate that the soil pool has decreased by ca. 70% in catchments with complete harvest of the forest and ca. 40% if branches and needles are left on the ground. In a natural forest without acid deposition the soil pool of calcium would have increased by 6%. Estimates for the 21st century show that harvesting of stems + branches and needles may almost empty the soil pool of calcium in the next 100 years. Increased nitrogen deposition has increased forest growth, which indirectly increased uptake of calcium by the trees and indirectly caused a further decrease of the soil pool of calcium.

On-line collection/concentration and detection of sulfur dioxide in air by flow-injection spectrophotometry coupled with a chromatomembrane cell.

A simple and rapid procedure for SO2 determination in air was developed by using a flow injection analysis (FIA) system coupled with a 3-hole chromatomembrane cell (CMC). The CMC was applied for the on-line collection/concentration of SO2 from air into a solution of 2 g l(-1) triethanolamine (TEA) solution as an absorbing solution: SO2 was converted to SO3(2-) in the alkaline absorbing solution. The solution containing absorbed SO2 was introduced into the carrier stream of the FIA system. The amount of SO3(2-) in the absorbing solution was measured by spectrophotometry with a mixed reagent of pararosaniline and formaldehyde, and was converted to the concentration of SO2 in the air sample. A calibration graph prepared by using standard sodium sulfite aqueous solutions was adopted for the determination of SO3(2-) in the absorbing solution. The SO2 concentration in indoor air examined was found to be 22.7 +/- 0.2 ppbv using 20 ml of air sample with the air flow rate of 5 ml min(-1), where the relative standard deviation was 1.7%. The detection limit for aqueous solutions and air samples were 6.9 x 10(-8) M and 0.48 ppbv, respectively. The measuring time for one sample was about 10 min when a 20 ml air sample was used. The interferences from common anionic species, formaldehyde and acetaldehyde, were also examined.

Health effects of a sulphur dioxide air pollution episode

A sulphur dioxide (SO(2)) episode occurred in the United Kingdom in 1998. The worst affected area was the city of Nottingham. Emergency hospital admissions in Nottingham in the episode week were compared with those in the previous week. A statistically significant increase in admissions for all respiratory diseases occurred in the episode week (odds ratio (OR) = 1.40, 95 per cent confidence interval (CI) = 1.00-1.94). Ten of the 25 excess admissions were for asthma, although the excess for asthma alone was not statistically significant (OR = 1.90, 95 per cent CI = 0.87-4.15). The excess admissions for respiratory diseases could have been caused by exposure to SO(2), to other pollutants present in increased concentrations during the pollution episode, or by seasonal variations in the frequency of asthma symptoms, or prevailing weather conditions. This study shows how simple analyses of routinely collected health data can be used to assess public health impacts of pollution episodes.

Atmospheric sulfur deposition and the sulfur nutrition of crops at an agricultural site in Jiangxi province of China

During the period From November 1998 to October 1999, the air sulfur dioxide (SO 2 ) and sulfate (SO 2− 4 ) concentrations were measured and rain water was collected on farmland at Yingtan, a typical red soil area in the Jiangxi province of China. Based on hourly meteorological data and surface resistance data from the literature, the dry deposition velocities of SO 2 and SO 2− 4 were computed using a three-layer resistance analogy model, and sulfur dry deposition was calculated. The wet deposition was obtained from precipitation amount and sulfur concentrations in rainwater. The average dry deposition velocities of SO 2 and SO 2− 4 on farmland were found to be 0.38 ± 0.16 cm s −1 (monthly average 0.16–0.55 cm s −1 ) and 0.20 ± 0.12 cm s −1 (monthly average 0.15–0.27 cm s −1 ), respectively. The annual total sulfur deposition for the study region is about 103 kg S ha −1 , of which 83% is dry deposition. The uncertainties due to measurement and the dry deposition model are less than 30%. It is also found that atmospheric deposition plays a key role in sulfur circulation within the agrecosystem, accounting for more than 90% of the total sulfur input to farmland DOI: 10.1046/j.1435-6935.2003.00076.x

A LONG-RANGE ATMOSPHERIC TRANSPORT MODEL (HY-SPLIT) FOR ENVIRONMENTAL EMERGENCY RESPONSE (EER): EVALUATION OF DRIVING MODELS

The Eta and Aviation (AVN) driving models of HY-SPLIT are evaluated by means of a case study of the sulphur fire plume at Somerset West (34° 04’ S, 18° 48’ E) which caused sulphur dioxide (SO2) air pollution over Macassar on 16 - 17 December 1995. The HY-SPLIT model is verified by comparing it with the Lagrangian kinematic trajectory (LKT)model. Plume dispersions and depositions of the HY-SPLIT model for the Eta and AVN driving models are compared with Eta model winds. Eta model winds for a grid point close to the fire are verified against radiosonde data and synoptic observations. Results indicate that the finer-resolution regional Eta model has the higher accuracy.

Colorimetric Determination of Sulphur Dioxide and Sulphites in Various Environmental Samples

AbstractRhodamine‐B has been proposed as a simple and sensitive colorimetric reagent for the estimation of sulphur dioxide in air. The air sample containing sulphur dioxide is passed through the absorbing solution of aqueous potassium iodate and N‐chlorosuccinimide to liberate iodine. The liberated iodine bleaches the pinkish red coloured rhodamine‐B dye, which measured at 555 nm. Beer's law was obeyed in the range of 0.5–5.0 μg, of sulphite per 25 mL (0.02–0.2 ppm) equivalent to 0.4–4.0 μg of sulphur dioxide (0.016–0.16 ppm). The molar absorptivity and Sandell's sensitivity were found to be 4.56 × 105 l mol−1 cm−1 and 0.00017 μg cm−2, respectively. The method has been suitably modified and successfully applied to the determination of sulphites in water after liberation of sulphur dioxide in acidic medium.

The association of daily sulfur dioxide air pollution levels with hospital admissions for cardiovascular diseases in Europe (The Aphea-II study).

The objective of this study is to assess the short-term effect of sulfur dioxide (SO(2)) air pollution levels on hospital admissions for cardiovascular diseases. Daily mean hospital admissions for cardiovascular diseases, ischemic heart diseases (IHDs), and stroke in seven European areas (the cities of Birmingham, London, Milan, Paris, Rome, and Stockholm, and in The Netherlands) participating in the multicenter European study of air pollution (Aphea-II), were measured. Time series analysis of daily hospital admission counts was performed using poison autoregressive models. A summary regression coefficient for all cities was provided. Daily numbers of all cardiovascular admissions except stroke, and particularly IHDs, rose significantly with an increase of daily SO(2)levels of the same day and day before. After adjusting for PM(10)(i.e. particles with size <10 microm), the association of SO(2)with IHD admissions remained significant (i.e. an increase of 0.7%; 95% confidence interval=0.1-1.3, per each 10 microg/m(3)increase of SO(2)) among subjects younger than 65 years, but not among subjects older than 65. In the older group the increase was only significant for particles (1.3%; CI 0.7-1.8, per each increase in 10 microg/m(3)of PM(10)). This study provides new evidence for the effects of urban air pollution on cardiac diseases in Europe, and suggests that SO(2)pollution may play an independent role in triggering ischemic cardiac events. From a Public Health perspective these results suggest that reduction in SO(2)levels in European cities could imply a reduction of admissions for IHDs.

Photochemical Oxidation of Sulfur Dioxide in Air in the Presence of Ozone

The photochemical conversion of small amounts of SO2 into SO3 and, finally, H2SO4 aerosol in an atmospheric air flow with small admixtures of ozone has been studied experimentally. Ozone admixtures increase the SO2 oxidation rate by a factor of 2.5 to 3.0 when the SO2 concentration in air is 0.07 mol %. Theoretical estimations predict a stronger effect of ozone. This discrepancy between the observed and calculated data may be due to the flow temperature rise caused by irradiation.

Development of a monitoring tape for the spectrophotometric determination of sulfur dioxide in air.

Development of a monitoring tape for the spectrophotometric determination of sulfur dioxide in air.

Performance of dicalcium silicate coatings in hot-corrosive environment

Thermally sprayed dicalcium silicate coatings have been developed for increased stability in highly corrosive environments at temperatures up to 900°C. In this study, the performance of dicalcium silicate based coatings was compared to yttria partially stabilized zirconia (Y-PSZ) coatings. The coatings were exposed to a V 2O 5-15 wt. % Na 2SO 4 slag at 700 and 900°C. At 700°C, gaseous sulfidation was stimulated by an addition of 0.5 vol.% sulfur dioxide in air. The results demonstrated that dicalcium silicate coatings exhibited superior endurance against hot corrosion induced by the V 2O 5-Na 2SO 4 slag. The mechanism of protection was related to stable calcium vanadate compounds, which formed on the surface and prevented the corrosive species from immediate penetration into the coating microstructure. In the presence of an SO 2/air atmosphere, a CaSO 4 reaction layer formed. Diffusion of SO 2 further facilitated sulfidation within the coatings. However, the dicalcium silicate materials withstood combined attack by gaseous SO 2 and V 2O 5-Na 2SO 4 slag without debonding. In this case, the zirconia coating deteriorated and spalled.

Spectrophotometric Determination of Sulfur Dioxide in Air, Using Thymol Blue

A simple and sensitive spectrophotometric method was developed for the determination of trace amounts of sulfur dioxide. The method is based on the reaction of SO2 with a known excess of ICI as the oxidant. The unreacted ICI iodinates thymol blue under acidic conditions. The lambdamax of thymol blue is at 545 nm under acidic conditions, and on lodination lambdamax shifts to 430 nm. This shift results in a decrease in the absorbance at 545 nm. The amount of uniodinated thymol blue present depends on the concentration of unreacted ICI, which in turn depends on the SO2 concentration. The system obeys Beer's law in the range 0-30 microg SO2 in a final volume of 25 mL, having a molar absorptivity of 3.2 x 10(4) L/mol cm with a relative standard deviation (RSD) of 2% at 24 microg SO2 (n = 10). The uniodinated dye can be extracted into 5 mL isoamyl alcohol under acidic conditions for measurement of absorbance. The extraction method obeys Beer's law in the range 0-5 microg SO2, having a molar absorpitivity of 4.16 x 10(4) L/mol x cm with an RSD of 1.9% at 4 microg SO2 (n = 10). The method has been successfully applied to the determination of atmospheric SO2.

Economic inequality and the environment

This paper analyzes the relationship between the level of income inequality and the quality of the environment (as measured by sulfur dioxide air pollution levels) in the US for the years 1947–1996, using a vector error correction model. We find that air pollution levels do appear to be negatively significantly correlated with the level of income inequality (as measured by the Gini coefficient), that is, income inequality decreases as pollution increases. Furthermore, the quality of the environment appears to affect different portions of the observed income graduation differently. For the lowest two quintiles, higher pollution is associated with an increase in their share of total US income, while for the highest quintile, higher pollution is associated with a decrease in their share of total US income.

Trends in the atmospheric and hydrological cycle of sulphur at catchments in the Czech Republic

The study is focused on the river basin of the upper Elbe and especially on the highly polluted area of northwestern Bohemia which is a part of the so-called Black Triangle area. A ten-year data set (1989–1998) of sulphur emissions, ambient air quality, atmospheric deposition and surface run-off has been evaluated. Substantial sulphur downward trend has been stated both for emissions and deposition which correlate well together. Relations between surface run-off and total deposition are discussed. Run-off chemistry of individual river basins is influenced by sulphur deposition and weathering of sulphur-rich heaps of lignite mines to a different degree. The ambient air quality has been improved in the Czech Republic, ambient air sulphur dioxide concentrations dropped and the total sulphur deposition has decreased to 50% of its value in 1989.

Spatially Explicit Characterization of Acidifying and Eutrophying Air Pollution in Life‐Cycle Assessment

Abstract: Simple models are often used to assess the potential impact of acidifying and eutrophying substances released during the life cycle of products. As fate, background depositions, and ecosystem sensitivity are not included in these models, environmental life‐cycle assessment of products (LCA) may produce incorrect results for these impact categories. This paper outlines the spatially explicit regional air pollution information and simulation model (RAINSLCA), which was developed for the calculation of acidification and terrestrial eutrophication potentials of ammonia (NH3) and nitrogen oxide (NOx) air emissions and acidification potentials for sulfur dioxide (SO2) air emissions for Europe and a number of European regions, taking fate,

EMMA model: an advanced operational mesoscale air quality model for urban and regional environments

Mesoscale air quality models are an important tool to forecast and analyse the air quality in regional and urban areas. In recent years an increased interest has been shown by decision makers in these types of software tools. The complexity of such a model has grown exponentially with the increase of computer power. Nowadays, medium workstations can run operational versions of these modelling systems successfully. Presents a complex mesoscale air quality model which has been installed in the Environmental Office of the Madrid community (Spain) in order to forecast accurately the ozone, nitrogen dioxide and sulphur dioxide air concentrations in a 3D domain centred on Madrid city. Describes the challenging scientific matters to be solved in order to develop an operational version of the atmospheric mesoscale numerical pollution model for urban and regional areas (ANA). Some encouraging results have been achieved in the attempts to improve the accuracy of the predictions made by the version already installed.

Chemiluminescence Determination of Sulfite and Sulfur Dioxide Using Tris(1,10-Phenanthroline)Ruthenium-KMnO4 System

The emission produced by sulfite after oxidation by potassium permanganate in acidic solution in the presence of Ru(phen)3 2+ is used to determine 1.0 × 10−7 to 2.5 × 10−5 mol/L sulfite. The limit of detection is 4.5 × 10−9 mol/L and the relative standard deviation is 3.1% for a 1 × 10−5 mol/L sulfite solution (n=8). The method was also applied satisfactorily to the determination of sulfur dioxide in air by using triethanolamine (TEA) as absorbent material.

Colorimetric Determination of Sulfur Dioxide in Air Using a Droplet Collector of Malachite Green Solution

The measurement of sulfur dioxide in air at the parts-per-billion level is described. The experimental arrangement consists of two optical fibers placed on opposite sides of a liquid droplet of malachite green solution. After light has been passed through the droplet, the transmitted light is measured by a referenced photodetection arrangement. The light used in this absorption process is from a monochromatic source (λ max625 nm). This arrangement permits the variation of color in the droplet to be measured. The sulfur dioxide in the sample is collected by the droplet; it reacts with malachite green resulting in a colorless dye. The decoloration of the solution is proportional to the concentration of sulfur dioxide sampled. The signal depends on the sample flow rate. The present technique is simple, inexpensive, and permits a fast and near real time measurement while consuming very little reagent.