Relationship between Urban and Rural Sulfate Levels

Abstract

The topic of global warming as a result of increased atmospheric CO₂ concentration is arguably the most important environmental issue that the world faces today. It is a global problem that will need to be solved on a global level. The link between anthropogenic emissions of CO₂ with increased atmospheric CO₂ levels and, in turn, with increased global temperatures has been well established and accepted by the world. International organizations such as the United Nations Framework Convention on Climate Change (UNFCCC) and the Intergovernmental Panel on Climate Change (IPCC) have been formed to address this issue. Three options are being explored to stabilize atmospheric levels of greenhouse gases (GHGs) and global temperatures without severely and negatively impacting standard of living: (1) increasing energy efficiency, (2) switching to less carbon-intensive sources of energy, and (3) carbon sequestration. To be successful, all three options must be used in concert. The third option is the subject of this review. Specifically, this review will cover the capture and geologic sequestration of CO₂ generated from large point sources, namely fossil-fuel-fired power gasification plants. Sequestration of CO₂ in geological formations is necessary to meet the President’s Global Climate Change Initiative target of an 18% reduction in GHG intensity by 2012. Further, the best strategy to stabilize the atmospheric concentration of CO₂ results from a multifaceted approach where sequestration of CO₂ into geological formations is combined with increased efficiency in electric power generation and utilization, increased conservation, increased use of lower carbonintensity fuels, and increased use of nuclear energy and renewables.

This review covers the separation and capture of CO₂ from both flue gas and fuel gas using wet scrubbing technologies, dry regenerable sorbents, membranes, cryogenics, pressure and temperature swing adsorption, and other advanced concepts. Existing commercial CO₂ capture facilities at electric power-generating stations based on the use of monoethanolamine are described, as is the Rectisol process used by Dakota Gasification to separate and capture CO₂ from a coal gasifier.

Two technologies for storage of the captured CO₂ are reviewed—sequestration in deep unmineable coalbeds with concomitant recovery of CH4 and sequestration in deep saline aquifers. Key issues for both of these techniques include estimating the potential storage capacity, the storage integrity, and the physical and chemical processes that are initiated by injecting CO₂ underground. Recent studies using computer modeling as well as laboratory and field experimentation are presented here. In addition, several projects have been initiated in which CO₂ is injected into a deep coal seam or saline aquifer. The current status of several such projects is discussed. Included is a commercial-scale project in which a million tons of CO₂ are injected annually into an aquifer under the North Sea in Norway. The review makes the case that this can all be accomplished safely with off-the-shelf technologies. However, substantial research and development must be performed to reduce the cost, decrease the risks, and increase the safety of sequestration technologies.

This review also includes discussion of possible problems related to deep injection of CO₂ . There are safety concerns that need to be addressed because of the possibilities of leakage to the surface and induced seismic activity. These issues are presented along with a case study of a similar incident in the past. It is clear that monitoring and verification of storage will be a crucial part of all geological sequestration practices so that such problems may be avoided. Available techniques include direct measurement of CO₂ and CH4 surface soil fluxes, the use of chemical tracers, and underground 4-D seismic monitoring.

Ten new hypotheses were formulated to describe what happens when CO₂ is pumped into a coal seam. These hypotheses provide significant insight into the fundamental chemical, physical, and thermodynamic phenomena that occur during coal seam sequestration of CO₂ .     

A Practical Relationship Between Government and Industry

The science of air pollution control is making significant advances and a practical working arrangement between all levels of government and industry must be achieved. Lawmakers, scientists, and industry must work side by side in combatting air pollution; there is no other approach that will give the problem the attention it deserves. How this might be accomplished is the subject of this article.     

植物SOD活性变化与其抗污能力的关系

研究了模拟酸雨、ＳＯ２单独与复合污染对水杉、杉木、龙柏３种抗污能力不同的植物ＳＯＤ活性、细胞汁酸度、细胞膜透性的影响。结果表明，ＳＯＤ的活性经污染后变化规律在不同植物有所不同，而这种变化与其抗污能力有关。ＳＯＤ活性升高者，其抗污能力强，反之则弱，与本底值大小无关。     

综合食品基地土壤和蔬菜中重金属的调查

根据《淮安市绿色食品基地调查以及相关研究》课题资料研究表明，蔬菜对重金属的吸收特点因元素不同而有较大差异，而不同种类蔬菜之间的差异不大。     

The Silver Valley Lead Study:The Relationship between Childhood Blood Lead Levels and Environmental Exposure

This paper is directed to those persons concerned with the relationship between blood lead levels and environmental exposures to lead. Information presented in this paper represents one of the largest collections of epidemiologica! data relating blood lead levels to environmental exposures. The observed annual average ambient air lead concentration ranged from approximately 0.5 ng Pb/m³ to 23 ng Pb/m³, while lead in soil ranged from 50-24,600 ppm. Blood lead levels of children (ages 1-9 years) are related to a host of environmental variables via regression techniques. Blood lead levels were found to be most influenced by five variables. These variables are: ambient air lead, soil lead, age of the child, dustiness of the home, and occupational status of the parents. It is concluded, based upon the results of this study, that any environmental control strategy should address both the air and the soil. Soil levels in excess of 1000 ppm lead as well as air lead levels greater than 2 jug Pb/m³, 30 day average, were found to be unacceptable.     

The Relationship Between Atmospheric Transport and the Particle Scattering Coefficient at the Grand Canyon

Air trajectory and particle scattering data (bsp) for the period 1984-1989 are used to determine the relationship between atmospheric transport and visual air quality at the Grand Canyon National Park. Using cluster analysis, 72-hour back-trajectories arriving four times per day were grouped into distinct transport patterns. Northwesterly and southerly/southwesterly flow dominate in the winter and summer seasons, respectively. Comparisons of bsp values accompanying different transport patterns showed a clear relationship between air flow pathway and light scattering due to small particles during the non-summer months only. An index is defined which describes the percentage of annual trajectories belonging to specific transport routes delivering predominantly clear air to the GCNP.     

Relationship Between Biogenic Amines and Free Amino Acid Contents of Wines and Musts from Alentejo (Portugal)

The concentration of biogenic amines and free amino acids was studied in 102 Portuguese wines and 18 musts from Alentejo demarcated (D.O.C.) regions. Most wines were commercial, except for 38 monovarietals obtained by micro vinification. Musts from the varieties used to produce the latter wines were also studied. Both biogenic amines and free amino acids were analyzed by HPLC using fluorescence detection for their o-phthalaldehyde/fluorenylmethyl chloroformate (OPA/FMOC) derivatives. The most significant amines (average 10.8 mg/L for histamine+tyramine in red, and 7.4 mg/L for white wines) were found to be present at low levels and, although no important relationship between each individual biogenic amine could be obtained, the total amine content depends significantly on the assimilable amino acid content in wine.     

Exposure to Fine Particle Acidity and Sulfate in 24 North American Communities: The Relationship Between Single Year Observations and Long-Term Exposures

Abstract

Twenty-four communities in North America were monitored over one year for a variety of air pollutants as part of a crosssectional epidemiological study on the respiratory health effects of exposure to fine particle acidity. The relationships between these single-year observations and the long-term community levels of ambient sulfate and acidity were examined. In the health study it was assumed that the singleyear measurements were indicative of the lifetime or long-term exposures of the participants (eight?, nine?, and ten-year-olds). Therefore, a strong relationship between the long-term and single-year (24-community) particle acidity and sulfate concentrations was important.

Ambient sulfate data from a variety of alternate sources were obtained from monitoring sites close to 20 of the 24 communities. Long-term averages, which were determined for the warm season (May to September), were derived from a minimum of four complete years of monitoring data at each site. Long-term acidity concentrations were derived from these sulfate data because multi-year measurements of acidity were not available. These concentrations were calculated by multiplying the sulfate concentrations by the mean warm season acid-to-sulfate ratios observed during the 24-community study. For each community, 25 random estimates (determined by allowing the observed mean ratio to vary randomly by ±0.2) of the mean warm season acidity were used to determine the community-to-community differences in the long-term acid concentrations.

Overall, the long-term and 24-community warm season sulfate concentrations were correlated with an R2, determined from linear regression, of 0.92 (slope = 0.90±0.13). With only two exceptions, regardless of which of these exposure estimates were used, the communities that were determined to experience high (>8 μg m^?3), moderate (4-8 μg m^?3) and low (<4 μg m^?3) sulfate exposures did not change. Similarly, few communities crossed exposure classes when the long-term and short-term acid concentrations were compared. However, due to the increased uncertainty arising from the lack of information on the long-term acid-to-sulfate ratio, the average correlation (R²) between the long-term and 24-community exposure estimates (the mean of the 25 separate random estimates for each community) was 0.85 (slope = 0.94).     

The Relationship Between Total Suspended Particulate Matter (TSP) and British Smoke Measurements in London: Development of a Simple Model

Abstract

This article develops an empirical relationship between the British Smoke (BS) measurement, coefficient of haze (CoH), and Total Suspended Particulate Matter (TSP) for London winter periods of the early 1950s and 1960s. A bounded nonlinear model of form BS = TSP³ / (TSP² + [200 μg/m³]² ) fits the available BS/TSP data and meets the urban boundary conditions that BS→0 as TSP→ 0, and BS→ TSP as TSP→∞. A derivation is presented for the form of the equation from basic principles. Equations of a similar form may be useful on a site- and season-specific basis for developing relations between other fractions of PM.     

Levels and trends of brominated flame retardants in the Arctic

Polybrominated diphenyl ethers (PBDEs) containing two to seven bromines are ubiquitous in Arctic biotic and abiotic samples (from zooplankton to polar bears (Ursus maritimus) and humans; air, soil, sediments). The fully brominated decabromodiphenyl ether (BDE-209), hexabromocyclododecane (HBCD), tetrabromobisphenol A (TBBPA) and polybrominated biphenyls (PBBs) are also present in biotic and abiotic samples. Spatial trends of PBDEs and HBCD in top predators are similar to those seen for polychlorinated biphenyls (PCBs) and indicate western Europe and eastern North America as source regions. Concentrations of tetra- to heptaBDEs have increased significantly in North American and Greenlandic Arctic biota and in Greenland freshwater sediments paralleling trends seen further south. For BDE-209, increasing concentrations in Greenlandic peregrine falcons (Falco peregrinus) and in dated lake sediment cores in the Canadian Arctic have been seen during the 1990s. BDE-47, -99, -100 and -153 are observed to biomagnify in Arctic food webs. summation operatorPBDE concentrations in Arctic samples are lower than in similar sample types from more southerly regions and are one or more orders of magnitude lower than summation operatorPCB concentrations except for some levels for air. Air and harbor sediment results for PBDEs indicate that there are local sources near highly populated areas within the Arctic. Findings of PBBs on moss and TBBPA on an air filter, and that both are found in biota at high trophic levels indicates that these compounds may also reach the Arctic by long-range atmospheric transport. Based on the evidence of their presence in the Arctic and indications that most if not all are undergoing long-range transport, these brominated flame retardants (BFRs) have characteristics that qualify them as POPs according to the Stockholm Convention.     

Carbon Monoxide Levels in Kitchens and Homes with Gas Cookers

It always has been assumed that only a small amount of CO will be produced by a gas stove when mixture of air and gas are well adjusted and that that small amount will be dissipated by the home’s ventilation and by a combination of a fan and hood over the stove. However, preparation of meals may substantially increase CO. The immediate air supply may be progressively diminished when more than one burner is used and air supply may be partially cut off by vessels placed over the gas flame. The purpose of this investigation was to determine the amount of CO that may be expected to be produced during normal cooking. The experiment measured CO levels, using multiple burners with and without cooking vessels, and the rate of dissipation of the accumulated gas under various conditions of ventilation.     

Levels and speciation of arsenic in the atmosphere in Beijing, China

Arsenic levels and speciation in the total suspended particles (TSPs) were quantitatively determined by high performance liquid chromatography on-line coupled with hydride generation atomic fluorescence spectrometry in Beijing, China from February 2009 to March 2011. The high TSP levels fluctuated between 0.07 and 0.79 mg m⁻³, with a mean level of 0.32 ± 0.17 mg m⁻³. The total arsenic concentrations ranged from 0.03 to 0.31 μg m⁻³ (mean: 0.13 ± 0.06 μg m⁻³) in Beijing‘s air. The concentrations of As(III) and As(V) ranged from 0.73 to 20 ng m⁻³ (mean: 4.7 ± 3.6 ng m⁻³) and from 14 to 2.5 × 10² ng m⁻³ (mean: 67 ± 35 ng m⁻³), respectively. As levels and speciation demonstrated relative higher levels in spring and autumn and lower values in summer and winter. As(V) accounted for 81-99% of the extractable species in the TSP samples which showed that As(V) was the major fraction of the extractable As. Organoarsenic species, monomethylarsonate (MMA) and dimethylarsinate (DMA) were not found in all samples. Higher values of enrichment factors demonstrated that arsenic in TSP mainly come from anthropogenic sources. High As and its species levels in air and respiratory exposure (0.30-0.84 μg d⁻¹) attributed to higher excess cancer risk ((4.2 ± 2.0) × 10⁻⁴) for people in Beijing.     

A Study of Ozone Levels in a Maritime and Land Environment

During the summer of 1976, a comparison was made between ozone measurements for a coastal industrial concentration area (Norfolk/Virginia Beach, Virginia) and an offshore station (Chesapeake Light Station, 15 miles out to sea). The anticipated dominance of high offshore ozone readings with offshore flow was not observed. A surprising number of high O₃ concentrations were observed at both the offshore and land sites with northeasterly and easterly winds. This suggests that the phenomenon of long range transport of contaminants from highly urbanized centers in the northeast to the mid-Atlantic states via an offshore sea route must be given careful consideration. The body of information presented in this paper points out the need for a clearer understanding of the complex urban/rural O₃ problem coupled with transport effects before costly control strategies are to be implemented.     

Differences between Weekday and Weekend Air Pollutant Levels in Southern California

Abstract

Ambient air quality data were analyzed to empirically evaluate the effects of reductions of volatile organic compounds (VOCs) and oxides of nitrogen (NO_x) emissions on weekday and weekend levels of ozone (O₃; 1991–1998) and particulate NO₃ ^- (1980–1999) in southern California. Despite significantly lower O₃ precursor levels on weekends, 20 of 28 South Coast Air Basin (SoCAB) sites (28 of all 78 southern California sites) showed statistically significant higher mean O₃ levels on Sundays than on weekdays (p < 0.01); 49 of the remaining 50 sites showed no significant differences between mean weekday and Sunday peak O₃ levels. We also observed no statistically significant differences between mean weekday and weekend concentrations of particulate NO₃ ^- or nitric acid (HNO₃, the precursor of particulate NO₃ ^-). Averaged over sites, the mean Sunday NO_x and nonmethane hydrocarbon concentrations were 25–41% and 16–30% lower, respectively, than on weekdays. Site-to-site differences between weekend and weekday mean peak hourly O₃ levels were related to whether O₃ formation was limited by the availability of NO_x. A thermodynamic equilibrium model predicts that particulate NO₃ ^- levels would decrease in response to a reduction of HNO₃, and that particulate ammonium NO₃ ^- formation was not limited by the availability of ammonia. The similarity of mean weekday and weekend levels of NO₃ ^- therefore did not result from limitations on the formation of particulate NO₃ ^- from its precursor, HNO₃.     

Levels of polychlorinated dibenzo-p-dioxins and dibenzofurans in soil samples from Spain

Soil analyses were carried out to evaluate the contamination caused by PCDDs and PCDFs in different soil samples. Monitoring was undertaken at different locations throughout Spain, from 1993 to 1999. A total of 230 samples were analysed. The levels ranged from 0.10 pg I-TEQ/g to 1.08 ng I-TEQ/g. Differences in dioxin levels were observed as a function of the sampling site, with levels at the industrial sites exceeding those at the control sites.     

Levels and trends of brominated flame retardants in the European environment

In this paper, we review those data which have recently become available for brominated flame retardants (particularly the brominated diphenyl ethers (BDEs) and hexabromocyclododecane (HBCD)) in samples from the European environment. Environmental compartments studied comprise the atmosphere, sediments and soils, sewage sludges, and a variety of biological samples and food chains. This is currently a very active research area, and we cite over 70 studies reported in the literature during 2003-04. Findings include that the input of BDEs (especially BDE209) to the Baltic Sea by atmospheric deposition now exceeds that of PCBs by a factor of almost 40 times. Sewage sludge samples from both industrial and background locations show concentrations of BDEs, HBCD and tetrabromobisphenol-A (TBBP-A) that are of a similar order, indicating that the major source is from diffuse leaching from products into wastewater streams from users, households and industries generally. Point-sources from industries using BFRs (e.g. the textile industry) also generate local hot-spots. Sediment core studies identified the presence of two of the three PBDE formulations. The penta-mix formulation was clearly present from the beginning of the 1970s, but the deca-mix only appeared in the late 1970s. BDE183, BDE209 and HBCD were detected in peregrine falcons from Sweden and other birds feeding on terrestrial food chains. BDEs are found widely distributed in fish, including those from high mountain lakes in Europe, as a consequence of long-range atmospheric transport and deposition. A temporal trend study in archived freeze-dried mussels from the Seine estuary, France, indicated an exponential increase in BDE concentrations during the period 1982-1993, which levelled off in 1999 and 2001 and then began to decline after 2002. HBCD was detected in liver and blubber samples from harbour seals and harbour porpoises from the Wadden and North Seas, though very few animals yielded positive values for TBBP-A. There are difficulties in comparing data on summation operatorBDE from studies in which different suites of BDE congeners have been determined, and we suggest a common suite which will allow the study of all three commercial PBDE formulations.     

Levels and trends of PCDD/Fs and PCBs in human milk in Finland

Word Health Organization, WHO/EURO, has coordinated two rounds of follow-up studies on levels of PCDDs, PCDFs, and PCBs in human milk which were analyzed as two pooled samples from each participating country, one from urban and the other one from rural area. Finland has taken part to both of those studies and we are now reporting results of all the second round randomly sampled human milk samples (84 samples) from Southern (20) and Eastern (64) Finland. The levels of PCDD/Fs and PCBs in human milk in Southern Finland were considerably higher than in Eastern Finland. The level of PCDD/Fs in human milk in Southern Finland was the same as in the Central Europe but the level in Eastern Finland was similar to levels in Norway and eastern parts of Europe. The concentrations of PCDD/Fs and PCBs showed a significant decrease from 1987 to 1994. Declining of PCDD/Fs and PCBs was 36 and 49% in primiparae mothers' milk, respectively. This decrease in concentrations of PCDD/F and PCB was slightly greater in Eastern than in Southern Finland.     

Levels of dioxins and furans in urban surface soil in Trondheim, Norway

A study was conducted on polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in surface soil in order to determine the concentration levels and possibly distinguishing between known and potential sources. The concentration levels are low (0.16-14 ng I-TEQ kg(-1)). The results show a clear pattern where the highest concentration levels were found in the oldest parts of the city. A number of sources were recognised in the soil samples through congener profiles, not all of them active, although similar congener profiles make it extremely difficult to distinguish between different sources. Estimations show that the municipal solid waste incinerator (MSWI) and domestic wood burning are the largest PCDD/F pollution sources within the area.