Sulfuric acid on Europa and the radiolytic sulfur cycle.
(9/445)
A comparison of laboratory spectra with Galileo data indicates that hydrated sulfuric acid is present and is a major component of Europa's surface. In addition, this moon's visually dark surface material, which spatially correlates with the sulfuric acid concentration, is identified as radiolytically altered sulfur polymers. Radiolysis of the surface by magnetospheric plasma bombardment continuously cycles sulfur between three forms: sulfuric acid, sulfur dioxide, and sulfur polymers, with sulfuric acid being about 50 times as abundant as the other forms. Enhanced sulfuric acid concentrations are found in Europa's geologically young terrains, suggesting that low-temperature, liquid sulfuric acid may influence geological processes. (+info)
Increases in heart rate during an air pollution episode.
(10/445)
This paper assesses whether air pollution increases resting heart rates in 2,681 men and women aged 25-64 years who participated in the MONICA (monitoring of trends and determinants in cardiovascular disease) Augsburg cohort. Increases in heart rate were observed during the air pollution episode in January 1985 compared with non-episode days adjusted for cardiovascular risk factors and meteorologic parameters. Consistently, heart rates were also elevated at high concentrations of sulfur dioxide, total suspended particulates, or carbon monoxide. Acceleration in heart rates indicates an altered autonomic control of the heart in association with air pollution, which may contribute to the observed health effects in association with air pollution. (+info)
Airway diseases and allergies in East and West German children during the first 5 years after reunification: time trends and the impact of sulphur dioxide and total suspended particles.
(11/445)
BACKGROUND: East-West comparison studies in Europe find higher prevalences of infectious airway diseases and lower prevalences of allergies in eastern areas. Pollution from sulphur dioxide (SO2) or total suspended particles (TSP) are discussed as causes of this difference. METHODS: In four differently polluted areas of East Germany where pollution decreased dramatically between 1989 and 1995 cross-sectional studies in about 7-year-old children were repeated every year between 1991 and 1995. In two differently polluted areas of West Germany studies with the same design were done in 1991 and 1994. In all, 19090 children participated in the study. Thirteen different questions about airway diseases and allergies were evaluated. Logistic regression was used to adjust for confounding. RESULTS: With the exception of pneumonia, all infectious airway diseases and irritations of the airways show a steeper temporal decrease in East than in West Germany or are positively associated with either SO2 or TSP in East Germany. For allergies and related symptoms no differences in time trends could be detected or no association with SO2 or TSP could be seen in East Germany. CONCLUSION: Most airway diseases were more frequent in East than in West Germany in 1991 and were associated with SO2 or TSP. The decrease in these pollutants between 1991 and 1995 has already had a favourable effect. An effect of SO2 or TSP pollution on allergies and related symptoms could not be detected. This pollution does not protect against the development of allergies. (+info)
Relationship between ambient sulfur dioxide levels and neonatal mortality near the Mt. Sakurajima volcano in Japan.
(12/445)
We examined the association between neonatal mortality and ambient sulfur dioxide (SO2) levels in the neighborhood of Mt. Sakurajima, Yamashita public health district of Kagoshima City, during the period between 1978 and 1988. The analysis using Poisson regression models showed that the monthly average level of SO2 was positively associated with the neonatal mortality (P = 0.002). When the SO2 levels were categorized into four groups to estimate the relative risk (RR) of neonatal mortality using the lowest exposure category as a reference, the RR increased with elevated exposure levels (P for trend < 0.001) and was the highest in the group with the highest level of exposure (RR = 2.2, 95% confidence interval; 1.2-4.1). Other than SO2, we also examined the number of eruptions, the amount of ashfall, and the average level of suspended particulate matter. None of these factors was associated with neonatal mortality. Although the present study suggests that increase in SO2 levels has had an adverse effect on neonatal mortality in the neighborhood of Mt. Sakurajima, it is difficult to determine the source of the SO2. Further studies are necessary to elucidate the mechanisms of the excess neonatal mortality probably associated with the volcanic SO2 levels. (+info)
Outdoor air pollution, low birth weight, and prematurity.
(13/445)
This study tested the hypothesis, suggested by several recent reports, that air pollution may increase the risk of adverse birth outcomes. This study analyzed all singleton live births registered by the Czech national birth register in 1991 in 67 districts where at least one pollutant was monitored in 1990-1991 (n = 108,173). Maternal exposures to sulfur dioxide (SO(2)), total suspended particles (TSP), and nitrous oxides (NO(x)) in each trimester of pregnancy were estimated as the arithmetic means of all daily measurements taken by all monitors in the district of birth of each infant. Odds ratios of low birth weight (< 2,500 g), prematurity (< 37 weeks of gestation), and intrauterine growth retardation (IUGR; < 10th percentile of birth weight for gestational age and sex) were estimated by robust logistic regression. The median (and 25th and 75th percentile) trimester exposures were 32 (18, 56) microg/m(3) for SO(2); 72 (55, 87) microg/m(3) for TSP; and 38 (23, 59) microg/m(3) for NO(x). Low birth weight (prevalence 5.2%) and prematurity (prevalence 4.8%) were associated with SO(2) and somewhat less strongly with TSP. IUGR was not associated with any pollutant. The effects on low birth weight and prematurity were marginally stronger for exposures in the first trimester, and were not attenuated at all by adjustment for socioeconomic factors or the month of birth. Adjusted odds ratios of low birth weight were 1.20 [95% confidence interval (CI), 1.11-1.30] and 1.15 (CI, 1.07-1.24) for a 50 microg/m(3) increase in SO(2) and TSP, respectively, in the first trimester; adjusted odds ratios of prematurity were 1.27 (CI, 1.16-1.39) and 1.18 (CI, 1.05-1.31) for a 50 microg/m(3) increase in SO(2) and TSP, respectively, in the first trimester. Low gestational age accounted for the association between SO(2) and low birth weight. These findings provide further support for the hypothesis that air pollution can affect the outcome of pregnancy. (+info)
Air pollution and hospital admissions for respiratory and cardiovascular diseases in Hong Kong.
(14/445)
OBJECTIVE: To investigate short term effects of concentrations of pollutants in ambient air on hospital admissions for cardiovascular and respiratory diseases in Hong Kong. METHODS: Retrospective ecological study. A Poisson regression was performed of concentrations of daily air pollutant on daily counts of emergency hospital admissions in 12 major hospitals. The effects of time trend, season, and other cyclical factors, temperature, and humidity were accounted for. Autocorrelation and overdispersion were corrected. Daily concentrations of nitrogen dioxide (NO2), sulphur dioxide (SO2), ozone (O3), and particulate matter < 10 microns in aerodynamic diameter (PM10) were obtained from seven air monitoring stations in Hong Kong in 1994 and 1995. Relative risks (RR) of respiratory and cardiovascular disease admissions (for an increase of 10 micrograms/m3 in concentration of air pollutant) were calculated. RESULTS: Significant associations were found between hospital admissions for all respiratory diseases, all cardiovascular diseases, chronic obstructive pulmonary diseases, and heart failure and the concentrations of all four pollutants. Admissions for asthma, pneumonia, and influenza were significantly associated with NO2, O3, and PM10. Relative risk (RR) for admissions for respiratory disease for the four pollutants ranged from 1.013 (for SO2) to 1.022 (for O3), and for admissions for cardiovascular disease, from 1.006 (for PM10) to 1.016 (for SO2). Those aged > or = 65 years were at higher risk. Significant positive interactions were detected between NO2, O3, and PM10, and between O3 and winter months. CONCLUSIONS: Adverse health effects are evident at current ambient concentrations of air pollutants. Further reduction in air pollution is necessary to protect the health of the community, especially that of the high risk group. (+info)
Interstrain variation in murine susceptibility to inhaled acid-coated particles.
(15/445)
Epidemiologic studies have demonstrated a positive correlation between concentration of acid aerosol and increased morbidity and mortality in many urban environments. To determine whether genetic background is an important risk factor for susceptibility to the toxic effects of inhaled particles, we studied the interstrain (genetic) and intrastrain (environmental) variance of lung responses to acid-coated particle (ACP) aerosol in nine strains of inbred mice. A flow-past nose-only inhalation system was used to expose mice to ACPs produced by the cogeneration of a carbon black aerosol-sulfur dioxide (SO(2)) mixture at high humidity. Three days after a single 4-h exposure to ACPs or filtered air, mice underwent bronchoalveolar lavage, and cell differentials and total protein were determined as indexes of inflammation and epithelial permeability, respectively. To determine the effect of ACPs on alveolar macrophage (AM) function, lavaged AMs were isolated from exposed animals and Fc receptor-mediated phagocytosis was evaluated. Compared with air-exposed animals, there was a slight but significant exposure effect of ACPs on the mean number of lavageable polymorphonuclear leukocytes in C3H/HeJ and C3H/HeOuJ mice. ACP exposure also caused a significant decrease in AM phagocytosis. Relative to respective air-exposed animals, Fc receptor-mediated phagocytosis was suppressed in eight of nine strains. The order of strain-specific effect of ACPs on phagocytosis was C57BL/6J > 129/J > SJL/J > BALB/cJ > C3H/HeOuJ > A/J > SWR/J > AKR/J. There was no effect of ACP exposure on AM phagocytosis in C3H/HeJ mice. The significant interstrain variation in AM response to particle challenge indicates that genetic background has an important role in susceptibility. The effects of ACPs on AM function, inflammation, and epithelial hyperpermeability were not correlated (i.e., no cosegregation). This model may have important implications concerning interindividual variation in particle-induced compromise of host defense. (+info)
Detection of SO in Io's exosphere.
(16/445)
The Galileo orbiter's close pass by Io in 1995 produced evidence for extensive mass loading of the plasma torus through the ionization of SO2. On 11 October 1999, Galileo passed even closer to Io, this time across the upstream side relative to the flow of magnetospheric plasma that corotates with Jupiter. On the first flyby, ion cyclotron waves gave direct evidence for the production of SO2+ ions. On the second flyby, ion cyclotron waves associated with SO+ were stronger and more persistent. Moreover, SO+ emissions were seen closer to Io than SO2+ emissions, suggesting that the exosphere was spatially inhomogeneous. The location of the waves suggests a fan-shaped region of ion pickup extending in the anti-Jupiter direction. Because the wave spectra were different even where the 1995 and 1999 trajectories crossed, we infer that Io's exosphere is temporally variable. (+info)