TSP-PM10-PM2.5-2型中流量大气颗粒物采集系统的开发和应用

自行开发并研制了TSP-PM10-PM2.5-2型中流量TSP、PM10、PM2.5大气颗粒物采集系统,是目前中国唯一可以采集TSP、PM10、PM2.5样品并提供足够的样品量进行大气颗粒物化学成分分析的中流量大气颗粒物采集器.该系统精心设计和加工的限流孔可以保持完全固定的流量,保证切割粒径的稳定,减小采样的误差并方便操作.该系统已经成功地应用于20多个城市和地区大气颗粒物的监测和研究中,为研究大气颗粒物的污染状况和来源提供了有效的技术手段和支持.     

珠三角地区大气PM_(2.5)理化特性季节规律与成因

基于珠三角大气超级站2013年8月至2014年3月PM2.5、PM2.5中主要水溶性无机离子组分及其重要气态前体物等参数的逐时在线监测结果,揭示当地大气PM2.5中二次无机组分与其气态前体物的相互作用,以及PM2.5理化特性与成因的季节差异。结果表明,观测期间,PM2.5、PM10的年平均质量浓度分别为64.2、105.1μg/m3,PM2.5在PM10中所占比例(PM2.5/PM10)平均为61.1%。SO2-4、NO-3、NH+4的年平均质量浓度分别为16.6、9.0、10.2μg/m3,3者之和(SNA)占PM2.5的比例(SNA/PM2.5)平均为55.8%,体现了二次转化对珠三角地区PM2.5污染的重要影响;不同季节,SNA/PM2.5为46.0%~64.3%,夏季最低,冬季最高,其中SO2-4、NH+4对PM2.5的贡献相对稳定,NO-3贡献的季节差异较大;秋、冬季各项观测参数浓度的日变化规律相对明显,夏季除HNO3和NH3外,多项观测参数在低浓度水平波动,日变化规律不明显;珠三角大气中具有足量气态NH3以中和硫酸盐和硝酸盐,PM2.5中NH+4、SO2-4、NO-3主要以(NH4)2SO4和NH4NO3形式存在;本研究站点夏季的硫氧化率和氮氧化率均高于广州市,这充分体现了该站点的区域性特征。     

Mutagenicity of particulate matter fractions in areas under the impact of urban and industrial activities

Organisms in the environment are exposed to a mixture of pollutants. Therefore the purpose of this study was to analyze the mutagenicity of organic and inorganic responses in two fractions of particulates (TSP and PM2.5) and extracts (organic and aqueous). The mutagenicity of organic and aqueous particulate matter extracts from urban-industrial and urban-residential areas was evaluated by Salmonella/microsome assay, through the microsuspension method, using strain TA98 with and without liver metabolization. Additionally, strains YG1021 and YG1024 (nitro-sensitive) were used for organic extracts. Aqueous extracts presented negative responses for mutagenesis and cytotoxicity was detected in 50% of the samples. In these extracts the presence of potential bioavailable metals was identified. All organic extracts presented mutagens with a higher potential associated with PM2.5. This study presents a first characterization of PM2.5 in Brazil, through the Salmonella/microsome assay. The evaluation strategy detected the anthropic influence of groups of compounds characteristically found in urban and industrial areas, even in samples with PM values in accordance with quality standards. Thus, the use of a genotoxic approach in areas under different anthropic influences will favor the adoption of preventive measures in the health/environment relation.     

昆山市夏秋季节大气PM2.5中水溶性无机阴离子的污染特征

对昆山市区域7个点位夏秋季的5中水溶性无机阴离子(SO2-4、NO-3、NO-2、Cl-、F-)的污染特征进行了调查,结果表明,昆山市夏季大气PM2.5中5种离子平均值排序为:ρ(SO2-4)ρ(Cl-)ρ(NO-3)ρ(F-)ρ(NO-2);秋季平均值排序为:ρ(SO2-4)ρ(NO-3)ρ(Cl-)ρ(F-)ρ(NO-2)。SO2-4、NO-3和Cl-3者的总量在PM2.5中占比20%。除F-以外各区域离子的平均值秋季比夏季要高。ρ(NO-3)/ρ(SO2-4)表明,固定污染源在昆山市大气颗粒物污染中仍然占很大比重,但大部分测点的比值接近1,说明移动源也是昆山大气颗粒物的重要污染源。     

佛山市臭氧浓度时间变化特征及主要影响因子

对佛山市2011—2014年O_3监测数据进行分析,结果表明,ρ(O_3)日变化呈现明显的单峰特征,2011—2014年O_3日最大8小时滑动均值(O3-8 h)的年评价值没有出现显著的下降趋势,超标值多出现在8—10月。夏季O3-8 h与日平均气温的相关系数较高,O_3污染多发生在气温30℃,相对湿度为50%~70%的气象条件下。相对湿度60%,气温为20~25℃,也可能出现O3污染。10℃时,不同的温度条件下,O_3与PM_(2.5)存在正相关关系。在不同的季节时段,O_3-8 h基本随着ρ(NO_2)/ρ(NO)增大而增大。     

青岛市采暖期PM2．5与大气能见度的关系

利用青岛市大气综合观测站的研究性监测数据,分析了2011年采暖期PM2.5和能见度的相关性,结果表明：①能见度在≤3km时,对应的PM2.5浓度超出0．250mg／m^3,属于严重污染;②PM2.5浓度对能见度的影响存在一临界区域,当PM2.5浓度低于该临界区时能见度会随PM2.5浓度减少迅速改善,临界值大致位于PM2.5浓度为0．100mg／m^3处;③相对湿度小于85％时,能见度与PM2.5浓度呈显著负相关。其中,相对湿度在60％-70％时,能见度与PM2.5浓度之间的相关性最好,PM2.5对能见度的影响最直接。     

淮南市秋季大气可吸入颗粒物中多环芳烃的污染特征分析

2007年秋季在淮南市五个采样点采集大气可吸入颗粒物样品,用色谱-质谱法分析多环芳烃中16种优控污染物.结果显示,交通区PAHs浓度最高;PAHs以四环为主,二环所占比例最小;PM10与ΣPAHs成显著正相关关系,与苯并[a]芘成显著正相关;采用比值法对准南市PM10中的PAHs进行来源分析,得到PAHs主要来源于交通源及燃煤排放.     

Spatial distribution of aerosol pollution based on MODIS data over Beijing, China

With the help of regression analysis,the relationships were detected between aerosol's contribution to apparent reflectance(ACR) derived from Moderate Resolution Imaging Spectroradiometer(MODIS)on board Terra and hourly PM_(10)mass concentration measured at 30 ground-based locations in Beijing for the August of 2003 and 2004.It was shown that there was a good correlation between the ACR and PM_(10)(linear correlation coefficient,R=0.56).On the basis of this relationship,spatial distribution and possible sources of PM_(10)derived from MODIS were analyzed and two frequently heavily-polluted regions were found,namely downtown of the city and the district near Xishan Mountain.These two regions coincidently are also urban heat island centers.The foundings of this paper will be greatly useful for environmental monitoring and urban planning for Beijing,especially for the 2008 Olympic game to be held in Beijing.     

PM10浓度时间序列多时间尺度分析的小波方法

文章利用Morlet小波函数进行小波变换,以乌鲁木齐市的大气污染物时间序列为例,分析了当地PM10的多时间尺度的演变特性。研究结果显示,其年际变化和季节性变化的时间尺度在尺度空间中分布不均匀,受气象和污染源因素影响,具有较明显的局部化特征。     

Effects of age and sex ratios on offspring recruitment rates in translocated black rhinoceros

Success of animal translocations depends on improving postrelease demographic rates toward establishment and subsequent growth of released populations. Short‐term metrics for evaluating translocation success and its drivers, like postrelease survival and fecundity, are unlikely to represent longer‐term outcomes. We used information theory to investigate 25 years of data on black rhinoceros (Diceros bicornis) translocations. We used the offspring recruitment rate (ORR) of translocated females—a metric integrating survival, fecundity, and offspring recruitment at sexual maturity—to detect determinants of success. Our unambiguously best model (AICω = 0.986) predicted that ORR increases with female age at release as a function of lower postrelease adult rhinoceros sex ratio (males:females). Delay of first postrelease reproduction and failure of some females to recruit any calves to sexual maturity most influenced the pattern of ORRs, and the leading causes of recruitment failure were postrelease female death (23% of all females) and failure to calve (24% of surviving females). We recommend translocating older females (≥6 years old) because they do not exhibit the reproductive delay and low ORRs of juveniles (<4 years old) or the higher rates of recruitment failure of juveniles and young adults (4–5.9 years old). Where translocation of juveniles is necessary, they should be released into female‐biased populations, where they have higher ORRs. Our study offers the unique advantage of a long‐term analysis across a large number of replicate populations—a science‐by‐management experiment as a proxy for a manipulative experiment, and a rare opportunity, particularly for a large, critically endangered taxon such as the black rhinoceros. Our findings differ from previous recommendations, reinforce the importance of long‐term data sets and comprehensive metrics of translocation success, and suggest attention be shifted from ecological to social constraints on population growth and species recovery, particularly when translocating species with polygynous breeding systems.