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881.
882.
室外空气污染对成人呼吸系统健康影响的分析 总被引:7,自引:0,他引:7
报告在广州、武汉、兰州、重庆市 8所小学共 80 0 0余名学生父母患呼吸系统疾病的病症率受空气污染影响的分析结果。每个城市城区污染点的成人感冒咳嗽和咳痰、未感冒咳嗽和咳痰、支气管炎等病症的发生率均高于相应城市的郊区对照点 ,且男性比女性更高。呼吸系统的病症率与空气 PM1 0 、PM2 .5 污染呈正相关。调整了混杂因子的影响后 ,这种相关关系仍保持不变。结论是 :空气中 PM1 0 的污染与成人 (男女 )的感冒或未感冒时咳嗽、男性未感冒时咳痰、哮喘、支气管炎有明显正相关关系 ;空气 SO2 污染与成人 (男女 )感冒时咳嗽、咳痰呈显著正相关 ;空气中 NOx 污染对成人呼吸系统病症率的影响相对较弱 相似文献
883.
秦淮河上游水体大型底栖无脊椎动物群落结构及水质生物评价 总被引:5,自引:1,他引:4
2009年4月用D形网半定量采样法调查秦淮河上游25个点位的大型底栖无脊椎动物群落多样性,共获得63个大型底栖无脊椎动物分类单元;其中,水生昆虫5目12科30属,软体动物9科11属19种,寡毛纲2科7属9种。结果表明,生物指数(Biotic Index,BI)比Shannon-Wiener多样性指数的评价结果更接近实际情况,BI与ρ(TN)(r=0.44,p0.05)和ρ(NH3-N)(r=0.40,p0.05)之间显著相关,Shannon-Wiene多样性指数与ρ(TN)(r=-0.19,p0.05)和ρ(NH3-N)(r=0.44,p0.05)无显著性相关。生物评价表明秦淮河上游水质受到严重污染,句容地区的水质要优于南京。 相似文献
884.
The analysis of heavy metals is very important for assessing the feasibility of the agricultural utilization for the municipal
sludge. In this paper, a four-step sequential extraction method was applied to extract heavy metals (Cu, Zn, Mn, Cr, and Ni)
in municipal sludges from seven individual wastewater treatment plants located in Jilin and Heilongjiang Province, China,
for estimating the mobility and bioavailability of the metal ions in the agricultural application. The total concentrations
of heavy metals and their chemical fractions after the sequential extraction were determined. Principal component analysis
(PCA) was applied to analyze the relations of heavy metals fractions in the municipal sludges. Experimental results indicated
that the total concentrations of Cu, Zn, Cr, and Ni in all sludge samples were below the threshold values set out by the Chinese
legislation (GB18918-2002). Specially, Zn had a high bioavailability and mobility, Cu and Cr had potential bioavailability,
while Mn mainly existed in the residual fraction of municipal sludge. On the other hand, Ni had different mobility in different
municipal sludge. PCA results were confirmed by the environmental behavior of heavy metals. 相似文献
885.
Spatial and seasonal distribution of nitrogen in marsh soils of a typical floodplain wetland in Northeast China 总被引:3,自引:0,他引:3
Bai J Wang Q Deng W Gao H Tao W Xiao R 《Environmental monitoring and assessment》2012,184(3):1253-1263
Horizontal and profile distributions of nitrogen in marsh soils in different seasons were studied in a typical site within
the Erbaifangzi wetland in Northeast China. Results showed that there was higher spatial heterogeneity for nitrate nitrogen
(NO3--_{3}^{-}-N) and ammonium nitrogen (NH4+_{4}^{+}–N), as well as available nitrogen (AN), in surface soils in July compared to that in September. Relative to July, the mean
nitrogen contents in surface soils were slightly higher in September; however, in November, soils contained significantly
lower NO3--_{3}^{-}-N and NH4+_{4}^{+}–N, higher AN, organic nitrogen (Org-N), and total nitrogen (TN). Except for mineral nitrogen, no significant differences
were observed between Org-N and TN contents in September and November. Nitrogen contents generally declined exponentially
with depth along soil profiles in three sampling dates (July, September, and November), except for a significant accumulation
peak of NO3--_{3}^{-}-N at the 20–30 cm depth in September. However, NH4+_{4}^{+}–N contents showed a vertical alternation of “increasing and decreasing” in both July and September, while nearly kept constant
with depth in November. The depth ranking of nitrogen showed the shallowest distribution for AN, followed by Org-N and TN,
while deeper distributions for NO3--_{3}^{-}-N and NH4+_{4}^{+}–N. TN, Org-N, and AN were significantly correlated with soil organic matter and total phosphorus. Soil pH values were significantly
correlated with TN and AN contents in surface soils. Clay contents showed significant correlations with nitrogen contents
except for NO3--_{3}^{-}-N in surface soils and NH4+_{4}^{+}–N in profile soils. However, soil moisture was not significantly correlated with nitrogen contents among all soil samples. 相似文献
886.
Fengyu Liu Wei Li Fusheng Li Shiguo Sun 《Environmental monitoring and assessment》2013,185(5):4153-4158
Considering of the basic properties and also the two nitrogen atoms in the structure, hydrazine hydrate was employed to be an amine additive candidate, to build a Ru(bpy) 3 2+ /hydrazine electrochemiluminescence (ECL) system, and ECL of Ru(bpy) 3 2+ has been employed for the determination of hydrazine hydrate in the paper. The result demonstrated that the logarithmic ECL increasing (ΔECL?=?ECLafter addition of hydrazine???ECLbefore addition of hydrazine) versus the logarithmic concentration of hydrazine hydrate is linear over a concentration range of 1.0?×?10?9 to 1.0?×?10?5?mol/L, on both glassy carbon and Pt electrodes in a pH 9 phosphate buffer. The hydrazine hydrate detection limit was down to 1.0?×?10?9?mol/L, comparatively lower than other detection methods. To check its applicability, the proposed method was applied to the determination of hydrazine hydrate added into a tap water sample with good reproducibility and stability. All these provide a possibility to develop a novel ECL detection method for hydrazine in water. 相似文献
887.
Dynamics of the lakes in the middle and lower reaches of the Yangtze River basin, China, since late nineteenth century 总被引:1,自引:0,他引:1
Lijuan Cui Changjun Gao Xinsheng Zhao Qiongfang Ma Manyin Zhang Wei Li Hongtao Song Yifei Wang Shengnan Li Yan Zhang 《Environmental monitoring and assessment》2013,185(5):4005-4018
The middle and lower reaches of the Yangtze River basin have the most representative and largest concentration of freshwater lakes in China. However, the size and number of these lakes have changed considerably over the past century due to the natural and anthropogenic impact. The lakes, larger than 10 km2 in size, were chosen from relief maps and remotely sensed images in 1875, 1950, 1970, 1990, 2000, and 2008 to study the dynamics of lakes in the middle and lower reaches of the Yangtze River basin and to examine the causes and consequences of these changes. Results indicated that there was a dramatic reduction in lake areas, which decreased by 7,841.2 km2 (42.64 %) during the study period (1875–2008), and the number of lakes in this region changed moderately. Meanwhile, a large number of lakes in the middle and lower reaches of the Yangtze River basin were directly converted into paddy fields, ponds, building lands, or other land-use types over the study period. Therefore, all kinds of lake reclamation should be identified as the major driving factors for the loss of lake in this region. Furthermore, flooding, soil erosion, and sedimentation were also the main factors which triggered lake changes in different periods. Some wetland conservation and restoration projects have been implemented since the 1970s, but they have not reversed the lake degradation. These findings were of great importance to managers involved in making policy for the conservation of lake ecosystems and the utilization of lake resources. 相似文献
888.
环境标准样品是监测过程中重要的质量控制手段,中国受天然基体标准样品制备技术的制约,尚未拥有自己的沉积物中多环芳烃标准样品。为制备符合中国重点流域沉积物类型及多环芳烃浓度水平的沉积物标准样品,对中国6个重点流域的沉积物进行了采样,获得了制备多环芳烃标准样品的原料。分析常温及冷冻2种干燥方式对多环芳烃的影响,为制备大批量多环芳烃标准样品提供数据支持。对11个点位样品采用气相色谱质谱法测定16种优控多环芳烃化合物浓度,结果表明,样品均匀性良好,样品中多环芳烃检出率在99%以上,江河沉积物样品中多环芳烃浓度区间为664~2.91×103μg/kg,湖泊样品最高值达到1.25×105μg/kg,其主要污染源是化学燃料的燃烧。为中国制备水系沉积物中多环芳烃标准样品积累了技术基础。 相似文献
889.
石家庄市冬季大气中VOCs污染特征分析 总被引:5,自引:3,他引:2
为弄清石家庄市冬季大气中VOCs的污染特征,采用美国环保局TO-15方法对石家庄市冬季大气中VOCs组成进行了定性和定量分析。在此基础上,进行了VOCs的月度变化分析、春节期间的变化分析,并进行了VOCs与空气质量指数AQI、PM2.5等之间的相关性分析;根据VOCs组成及变化情况和相关性,分析了其可能的来源。结果表明,石家庄市冬季大气中VOCs的质量浓度为145.7~1 410.7μg/m3,VOCs组分主要有丙酮、二氯甲烷、苯、乙酸乙酯、甲苯、1,2-二氯丙烷、三氯甲烷。春节期间,大气中VOCs的浓度有大幅的下降,比日常均值下降了40.9%。AQI较高时,大气中VOCs浓度有所升高。石家庄市冬季大气中丙酮、二氯甲烷、乙酸乙酯等主要来源于医药化工生产活动,苯、甲苯主要来源于煤燃烧。 相似文献
890.