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1.
采用平行同步采样法,于2012年雨季,对广州市大夫山森林公园林内外空气的总悬浮颗粒物(TSP)和细颗粒物(PM 2.5)样品进行了24 h收集,测定了TSP和PM 2.5的质量浓度并分析了样品中水溶性无机离子成分。结果表明:林内外PM 2.5的质量浓度平均值分别为(40.18±10.47)和(55.79±13.01) g/cm 3;林内外TSP的质量浓度分别为(101.32 ± 33.19)和(116.61±35.36) g/cm 3。林内与林外比,PM 2.5和TSP平均质量浓度都显著减少( P < 0.05),表明森林能显著改善空气环境质量。TSP和PM 2.5中SO 42-、Na +、NH 4+和NO 3-为水溶性无机离子主要成分,占总离子质量的80%以上,林外这些离子的浓度高于林内(NH 4+除外)。这4种离子雨季在空气中的主要存在方式为NaCl、Na 2SO 4、NH 4HSO 4和NH 4NO 3。计算表明,采样期间海盐对大夫山空气TSP和PM 2.5的水溶性组分中Na +和Cl -贡献最大,其它元素主要源自陆地源。林内外TSP和PM 2.5的 c(NO 3-)/ c(SO 42-)比值在0.3以下,表明固定源是大夫山森林公园空气主要污染贡献者,TSP中 c(NO 3-)/ c(SO 42-)的比值大于PM 2.5的比值,说明移动源对TSP的贡献大于PM 2.5。 相似文献
2.
The growth rate of Chromohalobacter salexigens DSM 3043 can be stimulated in media containing 0.3 M NaCl by a 0.7 M concentration of other salts of Na +, K +, Rb +, or NH 4+, Cl −, Br −, NO 3−, or SO 42− ions. To our knowledge, growth rate stimulation by a general high ion concentration has not been reported for any organism previously. 相似文献
3.
Particulate matter with an aerodynamic diameter <2.5 μm (PM 2.5) represents a severe environmental problem and is of negative impact on human health. Xi''an City, with a population of 6.5 million, is among the highest concentrations of PM 2.5 in China. In 2013, in total, there were 191 days in Xi’an City on which PM 2.5 concentrations were greater than 100 μg/m 3. Recently, a few studies have explored the potential causes of high PM 2.5 concentration using remote sensing data such as the MODIS aerosol optical thickness (AOT) product. Linear regression is a commonly used method to find statistical relationships among PM 2.5 concentrations and other pollutants, including CO, NO 2, SO 2, and O 3, which can be indicative of emission sources. The relationships of these variables, however, are usually complicated and non-linear. Therefore, a generalized additive model (GAM) is used to estimate the statistical relationships between potential variables and PM 2.5 concentrations. This model contains linear functions of SO 2 and CO, univariate smoothing non-linear functions of NO 2, O 3, AOT and temperature, and bivariate smoothing non-linear functions of location and wind variables. The model can explain 69.50% of PM 2.5 concentrations, with R 2 = 0.691, which improves the result of a stepwise linear regression (R 2 = 0.582) by 18.73%. The two most significant variables, CO concentration and AOT, represent 20.65% and 19.54% of the deviance, respectively, while the three other gas-phase concentrations, SO 2, NO 2, and O 3 account for 10.88% of the total deviance. These results show that in Xi''an City, the traffic and other industrial emissions are the primary source of PM 2.5. Temperature, location, and wind variables also non-linearly related with PM 2.5. 相似文献
4.
BackgroundHeavy fine particulate matter (PM 2.5) air pollution occurs frequently in China. However, epidemiological research on the association between short-term exposure to PM 2.5 pollution and respiratory disease morbidity is still limited. This study aimed to explore the association between PM 2.5 pollution and hospital emergency room visits (ERV) for total and cause-specific respiratory diseases in urban areas in Beijing. MethodsDaily counts of respiratory ERV from Jan 1 to Dec 31, 2013, were obtained from ten general hospitals located in urban areas in Beijing. Concurrently, data on PM 2.5 were collected from the Beijing Environmental Protection Bureau, including 17 ambient air quality monitoring stations. A generalized-additive model was used to explore the respiratory effects of PM 2.5, after controlling for confounding variables. Subgroup analyses were also conducted by age and gender. ResultsA total of 92,464 respiratory emergency visits were recorded during the study period. The mean daily PM 2.5 concentration was 102.1±73.6 μg/m 3. Every 10 μg/m 3 increase in PM 2.5 concentration at lag 0 was associated with an increase in ERV, as follows: 0.23% for total respiratory disease ( 95% confidence interval [CI]: 0.11%-0.34%), 0.19% for upper respiratory tract infection (URTI) ( 95%CI: 0.04%-0.35%), 0.34% for lower respiratory tract infection (LRTI) ( 95%CI: 0.14%-0.53%) and 1.46% for acute exacerbation of chronic obstructive pulmonary disease (AECOPD) ( 95%CI: 0.13%-2.79%). The strongest association was identified between AECOPD and PM 2.5 concentration at lag 0-3 (3.15%, 95%CI: 1.39%-4.91%). The estimated effects were robust after adjusting for SO 2, O 3, CO and NO 2. Females and people 60 years of age and older demonstrated a higher risk of respiratory disease after PM 2.5 exposure. ConclusionPM 2.5 was significantly associated with respiratory ERV, particularly for URTI, LRTI and AECOPD in Beijing. The susceptibility to PM 2.5 pollution varied by gender and age. 相似文献
5.
BackgroundA large number of studies about effects of air pollutants on cardiovascular mortality have been conducted; however, those investigating association between air pollutants and cardiovascular morbidity are limited, especially in developing countries. MethodsA time-series analysis on the short-term association between outdoor air pollutants including particulate matter (PM) with diameters of 10 µm or less (PM 10), sulfur dioxide (SO 2) and nitrogen dioxide (NO 2) and cardiovascular morbidity was conducted in Tianjin, China based on 4 years of daily data (2008–2011). The morbidity data were stratified by sex and age. The effects of air pollutants during the warm season and the cool season were also analyzed separately. ResultsEach increase in PM 10, SO 2, and NO 2 by increments of 10 µg/m 3 in a 2-day average concentration was associated with increases in the cardiovascular morbidity of 0.19% with 95 percent confidence interval (95% CI) of 0.08–0.31, 0.43% with 95% CI of 0.03–0.84, and 0.52% with 95% CI of −0.09–1.13, respectively. The effects of air pollutants were more evident in the cool season than those in the warm season, females and the elderly were more vulnerable to outdoor air pollution. ConclusionsAll estimated coefficients of PM 10, SO 2 and NO 2 are positive but only the effect of SO 2 implied statistical significance at the 5% level. Moreover, season, sex and age might modify health effects of outdoor air pollutants. This work may bring inspirations for formulating local air pollutant standards and social policy regarding cardiovascular health of residents. 相似文献
6.
The effect of NaCl and Na 2SO 4 salinity on NO 3− assimilation in young barley ( Hordeum vulgare L. var Numar) seedlings was studied. The induction of the NO 3− transporter was affected very little; the major effect of the salts was on its activity. Both Cl − and SO 42− salts severely inhibited uptake of NO 3−. When compared on the basis of osmolality of the uptake solutions, Cl − salts were more inhibitory (15-30%) than SO 42− salts. At equal concentrations, SO 42− salts inhibited NO 3− uptake 30 to 40% more than did Cl − salts. The absolute concentrations of each ion seemed more important as inhibitors of NO 3− uptake than did the osmolality of the uptake solutions. Both K + and Na + salts inhibited NO 3− uptake similarly; hence, the process seemed more sensitive to anionic salinity than to cationic salinity. Unlike NO3− uptake, NO3− reduction was not affected by salinity in short-term studies (12 hours). The rate of reduction of endogenous NO3− in leaves of seedlings grown on NaCl for 8 days decreased only 25%. Nitrate reductase activity in the salt-treated leaves also decreased 20% but its activity, determined either in vitro or by the `anaerobic' in vivo assay, was always greater than the actual in situ rate of NO3− reduction. When salts were added to the assay medium, the in vitro enzymic activity was severely inhibited; whereas the anaerobic in vivo nitrate reductase activity was affected only slightly. These results indicate that in situ nitrate reductase activity is protected from salt injury. The susceptibility to injury of the NO3− transporter, rather than that of the NO3− reduction system, may be a critical factor to plant survival during salt stress. 相似文献
7.
Net uptakes of K + and NO 3− were monitored simultaneously and continuously for two barley ( Hordeum vulgare) cultivars, Prato and Olli. The cultivars had similar rates of net K + and NO 3− uptake in the absence of NH 4+ or Cl −. Long-term exposure (over 6 hours) to media which contained equimolar mixtures of NH 4+, K +, Cl −, or NO 3− affected the cultivars very differently: (a) the presence of NH 4+ as NH 4Cl stimulated net NO 3− uptake in Prato barley but inhibited net NO 3− uptake in Olli barley; (b) Cl − inhibited net NO 3− uptake in Prato but had little effect in Olli; and (c) NH 4+ as (NH 4) 2SO 4 inhibited net K + uptake in Prato but had little effect in Olli. Moreover, the immediate response to the addition of an ion often varied significantly from the long-term response; for example, the addition of Cl − initially inhibited net K + uptake in Olli barley but, after a 4 hour exposure, it was stimulatory. For both cultivars, net NH 4+ and Cl − uptake did not change significantly with time after these ions were added to the nutrient medium. These data indicate that, even within one species, there is a high degree of genotypic variation in the control of nutrient absorption. 相似文献
8.
Ricinus communis was used to test the Ben Zioni-Dijkshoorn hypothesis that NO 3 uptake by roots can be regulated by NO 3 assimilation in the shoot. The rate of the anion charge from assimilated NO 3− (and SO 42−) was followed in its distribution between organic acid anion accumulation and HCO 3− efflux into the nutrient solution. In plants adequately supplied with NO 3−, HCO 3− efflux accounted for between 56 and 63% of the anion charge. When the plants were subjected to a low NO 3 regime HCO 3− excretion accounted for only 23% of the charge. A comparison of mature plants growing for a 10-day period at the two levels of NO 3 nutrition revealed that the uptake of NO 3− at the higher level was increased 3-fold, whereas K uptake was unaltered. To trace ion movement within the plant, the ionic constituents of xylem and phloem sap were determined. In xylem sap these constituents were found to be predominantly K +, Ca 2+, and NO 3−, whereas in the phloem sap they were mainly K + and organic acid anions. Results have been obtained which may be interpreted as providing direct evidence of NO 3 uptake by roots regulated by NO 3 reduction in the tops, the process being facilitated by the recirculation of K + in the plant. 相似文献
9.
Experiments were designed to study the importance of organic acids as counterions for K + translocation in the xylem during excess cation uptake. A comparison was made of xylem exudate from wheat seedlings treated 72 hours with either 1.0 millimolar KNO 3 or 0.5 millimolar K 2SO 4, both in the presence of 0.2 millimolar CaSO 4. Exudation from KNO 3 plants had twice the volume and twice the K + and Ca 2+ fluxes or rate of delivery to shoots, as K 2SO 4 plants. Malate flux was 25% higher in K 2SO 4 than in KNO 3 exudate. Malate was the principal anion accompanying K + or Ca 2+ in K 2SO 4 treatment, while in the KNO 3 treatment, NO 3− was the principal anion. The contribution of SO 42− was negligible in both treatments. In a second experiment, exudate was collected every 4 hours during the daytime throughout a 72-hour treatment with KNO 3. Malate was the only anion present in exudate at first, just after the CaSO 4 pretreatment had ended. Malate concentration decreased and NO 3− concentration increased with time and these concentrations were negatively correlated. By 62 hours, NO 3− represented 80% of exudate anions. K + and NO 3− concentrations in exudate were strongly correlated with K + and NO 3− uptake, respectively. The first 36 hours of absorption from KNO 3 solution resembled the continuous absorption of K 2SO 4, in that malate was the principal counterion for translocation of K +. 相似文献
10.
Six-year (2005–2010) evolution of water chemistry (Cl −, NO 3
−, SO 4
2−, HCO 3
−, Na +, K +, Ca 2+ and Mg 2+) and their interactions with morphological properties (i.e., slope and area), land cover, and hydrological seasonality were examined to identify controlling factors and processes governing patterns of stream water quality in the upper Han River, China. Correlation analysis and stepwise multiple regression models revealed significant correlations between ions (i.e., Cl −, SO 4
2−, Na + and K +) and land cover (i.e., vegetation and bare land) over the entire catchment in both high- and low-flow periods, and in the buffer zone the correlation was much more stronger in the low-flow period. Catchment with steeper slope (>15°) was negatively correlated with major ions, largely due to multicollinearity of basin characteristics. Land cover within the buffer zone explained slightly less of major elements than at catchment scale in the rainy season, whereas in the dry season, land cover along the river networks in particular this within 100 m riparian zone much better explained major elements rather than this over the entire catchment. Anthropogenic land uses (i.e., urban and agriculture) however could not explain water chemical variables, albeit EC, TDS, anthropogenic markers (Cl −, NO 3
−, SO 4
2), Na +, K + and Ca 2+ significantly increased during 2005–2010, which was corroborated by principal component analyses (PCA) that indicated anthropogenic inputs. Observations demonstrated much higher solute concentrations in the industrial-polluted river. Our results suggested that seasonal evolution of water quality in combined with spatial analysis at multiple scales should be a vital part of identifying the controls on spatio-temporal patterns of water quality. 相似文献
11.
Week-old wheat seedlings absorbed at least 40% NO 3− from NaNO 3 when preloaded with K + than when preloaded with Na + or Ca 2+. Cultures of Triticum vulgare L. cv. Arthur were grown for 5 days on 0.2 m m CaSO 4, pretreated for 48 hours with either 1 m m CaSO 4, K 2SO 4, or Na 2SO 4, and then transferred to 1 m m NaNO 3. All solutions contained 0.2 m m CaSO 4. Shoots of K +-preloaded plants accumulated three times more NO 3− than shoots of the other two treatments. Initially, the K +-preloaded plants contained 10-fold more malate than either Na +- or Ca 2+-preloaded seedlings. During the 48-hour treatment with NaNO 3, malate in both roots and shoots of the K +-preloaded seedlings decreased. Seedlings preloaded with K + reduced 25% more NO 3− than those preloaded with either Na + or Ca 2+. These experiments indicate that K + enhanced NO 3− uptake and reduction even though the absorption of K + and NO 3− were separated in time. Xylem exudate of K +-pretreated plants contained roughly equivalent concentrations of K + and NO 3−, but exudate from Na + and Ca 2+-pretreated plants contained two to four times more NO 3− than K +. Therefore K + is not an obligatory counterion for NO 3− transport in xylem. 相似文献
12.
Ricinus communis L. plants were grown in nutrient solutions in which N was supplied as NO 3− or NH 4+, the solutions being maintained at pH 5.5. In NO 3−-fed plants excess nutrient anion over cation uptake was equivalent to net OH − efflux, and the total charge from NO 3− and SO 42− reduction equated to the sum of organic anion accumulation plus net OH − efflux. In NH 4+-fed plants a large H + efflux was recorded in close agreement with excess cation over anion uptake. This H + efflux equated to the sum of net cation (NH 4+ minus SO 42−) assimilation plus organic anion accumulation. In vivo nitrate reductase assays revealed that the roots may have the capacity to reduce just under half of the total NO 3− that is taken up and reduced in NO 3−-fed plants. Organic anion concentration in these plants was much higher in the shoots than in the roots. In NH 4+-fed plants absorbed NH 4+ was almost exclusively assimilated in the roots. These plants were considerably lower in organic anions than NO 3−-fed plants, but had equal concentrations in shoots and roots. Xylem and phloem saps were collected from plants exposed to both N sources and analyzed for all major contributing ionic and nitrogenous compounds. The results obtained were used to assist in interpreting the ion uptake, assimilation, and accumulation data in terms of shoot/root pH regulation and cycling of nutrients. 相似文献
13.
ObjectiveLimited information is available regarding spatiotemporal variations of particles with median aerodynamic diameter < 2.5 μm (PM 2.5) at high resolutions, and their relationships with meteorological factors in Beijing, China. This study aimed to detect spatiotemporal change patterns of PM 2.5 from August 2013 to July 2014 in Beijing, and to assess the relationship between PM 2.5 and meteorological factors. MethodsDaily and hourly PM 2.5 data from the Beijing Environmental Protection Bureau (BJEPB) were analyzed separately. Ordinary kriging (OK) interpolation, time-series graphs, Spearman correlation coefficient and coefficient of divergence (COD) were used to describe the spatiotemporal variations of PM 2.5. The Kruskal-Wallis H test, Bonferroni correction, and Mann-Whitney U test were used to assess differences in PM 2.5 levels associated with spatial and temporal factors including season, region, daytime and day of week. Relationships between daily PM 2.5 and meteorological variables were analyzed using the generalized additive mixed model (GAMM). ResultsAnnual mean and median of PM 2.5 concentrations were 88.07 μg/m 3 and 71.00 μg/m 3, respectively, from August 2013 to July 2014. PM 2.5 concentration was significantly higher in winter ( P < 0.0083) and in the southern part of the city ( P < 0.0167). Day to day variation of PM 2.5 showed a long-term trend of fluctuations, with 2–6 peaks each month. PM 2.5 concentration was significantly higher in the night than day ( P < 0.0167). Meteorological factors were associated with daily PM 2.5 concentration using the GAMM model ( R
2 = 0.59, AIC = 7373.84). ConclusionPM 2.5 pollution in Beijing shows strong spatiotemporal variations. Meteorological factors influence the PM 2.5 concentration with certain patterns. Generally, prior day wind speed, sunlight hours and precipitation are negatively correlated with PM 2.5, whereas relative humidity and air pressure three days earlier are positively correlated with PM 2.5. 相似文献
14.
Tomato plants ( Lycopersicon esculentum L. var. Ailsa Craig) were grown in water culture in nutrient solution in a series of 10 increasing levels of nitrate nutrition. Using whole plant data derived from analytical and yield data of individual plant parts, the fate of anion charge arising from increased NO 3 assimilation was followed in its distribution between organic anion accumulation in the plant and OH − efflux into the nutrient solution as calculated by excess anion over cation uptake. With increasing NO 3 nutrition the bulk of the anion charge appeared as organic anion accumulation in the plants. OH − efflux at a maximum accounted for only 20% of the anion charge shift. The major organic anion accumulated in response to nitrate assimilation was malate. The increase in organic anion accumulation was paralleled by an increase in cation concentration (K +, Ca 2+, Mg 2+, Na +). Total inorganic anion levels (NO 3−, SO 42−, H 2PO 4−, Cl −) were relatively constant. The effect of increasing NO 3 nutrition in stimulating organic anion accumulation was much more pronounced in the tops than in the roots. 相似文献
15.
Active transport of SO 42− and SeO 42− has been evaluated during 60-hour contact of barley roots with nutrient solutions containing either 35SO 42− or 75SeO 42−, or both ions, at 0.1 milli-equivalent per liter. In the SO 42− solution the time course of active transport follows a straight line; if SeO 42− is also present transport is strongly inhibited after 20 to 30 hours for both ions. The S-Se uptake ratio remains 1.4 during the 60 hours; S-Se ratio shifts from 3.0 to 3.3 in proteins and falls to 0.6 in free amino acids. S-Se discrimination is mainly operating at the level of amino acid incorporation into proteins. The presence of Se-amino acids blocks this incorporation and brings about an accumulation of free amino acids; at the same time carrier activity is inhibited. The addition of methionine or Se-methionine causes a 60 to 80% inhibition of the active transport. 相似文献
16.
Ricinus communis L. was used to test the Dijkshoorn-Ben Zioni hypothesis that NO 3− uptake by roots is regulated by NO 3− assimilation in the shoot. The fate of the electronegative charge arising from total assimilated NO 3− (and SO 42−) was followed in its distribution between organic anion accumulation and HCO 3− excretion into the nutrient solution. In plants adequately supplied with NO 3−, HCO 3− excretion accounted for about 47% of the anion charge, reflecting an excess nutrient anion over cation uptake. In vivo nitrate reductase assays revealed that the roots represented the site of about 44% of the total NO 3− reduction in the plants. To trace vascular transport of ionic and nitrogenous constituents within the plant, the composition of both xylem and phloem saps was thoroughly investigated. Detailed dry tissue and sap analyses revealed that only between 19 and 24% of the HCO 3− excretion could be accounted for from oxidative decarboxylation of shoot-borne organic anions produced in the NO 3− reduction process. The results obtained in this investigation may be interpreted as providing direct evidence for a minor importance of phloem transport of cation-organate for the regulation of intracellular pH and electroneutrality, thus practically eliminating the necessity for the Dijkshoorn-Ben Zioni recycling process. 相似文献
17.
BackgroundPanel studies have shown adverse effects of air pollution from biomass burning on children''s health. This study estimated the effect of current levels of outdoor air pollution in the Amazonian dry season on peak expiratory flow (PEF). MethodsA panel study with 234 schoolchildren from 6 to 15 years old living in the municipality of Tangará da Serra, Brazil was conducted. PEF was measured daily in the dry season in 2008. Mixed-effects models and unified modelling repeated for every child were applied. Time trends, temperature, humidity, and subject characteristics were regarded. Inhalable particulate matter (PM 10), fine particulate matter (PM 2.5), and black carbon (BC) effects were evaluated based on 24-hour exposure lagged by 1 to 5 days and the averages of 2 or 3 days. Polynomial distributed lag models (PDLM) were also applied. ResultsThe analyses revealed reductions in PEF for PM 10 and PM 2.5 increases of 10 µg/m 3 and 1 µg/m 3 for BC. For PM 10, the reductions varied from 0.15 (confidence interval (CI)95%: −0.29; −0.01) to 0.25 l/min (CI95%: −0.40; −0.10). For PM 2.5, they ranged from 0.46 (CI95%: −0.86 to −0.06) to 0.54 l/min (CI95%:−0.95; −0.14). As for BC, the reduction was approximately 1.40 l/min. In relation to PDLM, adverse effects were noticed in models based on the exposure on the current day through the previous 3 days (PDLM 0–3) and on the current day through the previous 5 days (PDLM 0–5), specially for PM 10. For all children, for PDLM 0–5 the global effect was important for PM 10, with PEF reduction of 0.31 l/min (CI95%: −0.56; −0.05). Also, reductions in lags 3 and 4 were observed. These associations were stronger for children between 6 and 8 years old. ConclusionReductions in PEF were associated with air pollution, mainly for lagged exposures of 3 to 5 days and for younger children. 相似文献
18.
China has recently made available hourly air pollution data from over 1500 sites, including airborne particulate matter (PM), SO 2, NO 2, and O 3. We apply Kriging interpolation to four months of data to derive pollution maps for eastern China. Consistent with prior findings, the greatest pollution occurs in the east, but significant levels are widespread across northern and central China and are not limited to major cities or geologic basins. Sources of pollution are widespread, but are particularly intense in a northeast corridor that extends from near Shanghai to north of Beijing. During our analysis period, 92% of the population of China experienced >120 hours of unhealthy air (US EPA standard), and 38% experienced average concentrations that were unhealthy. China’s population-weighted average exposure to PM 2.5 was 52 μg/m 3. The observed air pollution is calculated to contribute to 1.6 million deaths/year in China [0.7–2.2 million deaths/year at 95% confidence], roughly 17% of all deaths in China. 相似文献
19.
1. The influence of Cl −, Br −, NO 3− and F − ions on the visible-absorption spectrum of deionized aspartate aminotransferase was investigated. 2. Except for F −, these anions caused an increase of the extinction at 430mμ with a concomitant decrease of that at 362mμ. 3. The affinity constants for Cl − and NO 3− ions were calculated by a procedure based on the assumption that the anion stabilizes the protonated form of the enzyme chromophore (λ max. 430mμ). 4. The true p K of the chromophore of the enzyme was found to be 5·25. 相似文献
20.
Background and ObjectiveHigh concentrations of air pollutants have been linked to increased incidence of stroke in North America and Europe but not yet assessed in mainland China. The aim of this study is to evaluate the association between stroke hospitalization and short-term elevation of air pollutants in Wuhan, China. MethodsDaily mean NO 2, SO 2 and PM 10 levels, temperature and humidity were obtained from 2006 through 2008. Data on stroke hospitalizations (ICD 10: I60–I69) at four hospitals in Wuhan were obtained for the same period. A time-stratified case-crossover design was performed by season (April-September and October-March) to assess effects of pollutants on stroke hospital admissions. ResultsPollution levels were higher in October-March with averages of 136.1 µg/m 3 for PM 10, 63.6 µg/m 3 for NO 2 and 71.0 µg/m 3 for SO 2 than in April-September when averages were 102.0 µg/m 3, 41.7 µg/m 3 and 41.7 µg/m 3, respectively ( p<.001). During the cold season, every 10 µg/m 3 increase in NO 2 was associated with a 2.9% (95%C.I. 1.2%–4.6%) increase in stroke admissions on the same day. Every 10 ug/m 3 increase in PM 10 daily concentration was significantly associated with an approximate 1% (95% C.I. 0.1%–1.4%) increase in stroke hospitalization. A two-pollutant model indicated that NO 2 was associated with stroke admissions when controlling for PM 10. During the warm season, no significant associations were noted for any of the pollutants. ConclusionsExposure to NO 2 is significantly associated with stroke hospitalizations during the cold season in Wuhan, China when pollution levels are 50% greater than in the warm season. Larger and multi-center studies in Chinese cities are warranted to validate our findings. 相似文献
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