临安区域大气本底站CO_2浓度特征及其碳源汇变化研究

通过分析2006年8月～2009年7月临安区域大气本底站Flask瓶采样获得的CO2浓度特征,结合碳追踪模式的模拟结果,研究了长三角地区碳源汇变化对CO2浓度的影响.结果表明,临安区域大气本底站的CO2浓度分布在368.3×10-6～414.8×10-6之间,具有较明显的季节波动变化特征,冬季高、夏季低,浓度年较差接近...     

“十二五”地表水国家环境监测网络吉林省水环境国控监测点位布设的构想

根据国家环境质量监测网络,对“十二五”地表水环境质量监测断面调整工作要求,吉林省在辖区内所有水环境质量监测断面及采样点基础上,完成了松花江流域和辽河流域国控监测断面的优化调整工作。在此过程中,如何从国家尺度上,既能充分反映吉林省水环境质量状况,又能满足国家对地表水环境管理需求进行了深入思考。本文以吉林省为例,在确定国控监测断面及采样点的布设中．提出了自己的构想和建议。     

实用环境监测气体采集器设计与应用

手持式电动气体采集器解决了传统双联球气体采集时繁琐、计量不准等诸多问题,为快速、准确地获得监测数据提供保障。     

The market and shadow value of informal fish catch: a framework and application to Panama

Fisheries catches are known to be widely underreported, and much of their value flows in informal markets. Goods and services that are not directly sold in a market also have a corresponding economic value, here termed ‘shadow value’, which can apply to discarded fish—or those that are consumed but not sold (e.g., subsistence catches). Here, we estimate the monetary value of fisheries catches in Panama that are landed but not reported, or that are discarded at sea; this includes catches from artisanal and industrial fleets, as well as recreational and subsistence fisheries. Based on available data, we estimate that the market and shadow value of unreported catches in Panama in 2010 was around US$92 million, equal to approximately 43% of the total reported landed value. In the case of discarded fish, the shadow value represents the potential but entirely unrealized economic benefit of landing such fish; in the case of unreported landings, unreported market value represents only the first link in the potentially sophisticated informal seafood economy. One must be careful in considering these results for policy. It is possible that, rather than seeking to capture these ‘lost’ benefits, fish that are discarded or unreported should not have been caught at all, for example, if they are juveniles or of threatened species; conversely, unreported subsistence catches are crucial for food security throughout the world. These results help contextualize the scale of unreported fisheries in economic terms, and can inform subsequent policies and strategies to ensure social, ecological, and economic sustainability.     

Sources, distribution, and risk assessment of organochlorine pesticides in Nairobi City, Kenya

The distribution and sources of organochlorine pesticides (OCPs) in air and surface waters were monitored in Nairobi City using triolein-filled semipermeable membrane devices (SPMDs). The SPMDs were extracted by dialysis using n-hexane, followed by cleanup by adsorption chromatography on silica gel cartridges. Sample analysis was done by GC-ECD and confirmed by GC–MS. Separation of means was achieved by analysis of variance, followed by pair-wise comparison using the t-test (p≤ 0.05). The total OCPs ranged between 0.018 – 1.277 ng/m³ in the air and <LOD – 1391.000 ng/m³ in surface waters. Based on the results, the means of Industrial Area, Dandora and Kibera were not significantly different (p≤ 0.05), but were higher (p≤ 0.05) than those of City square and Ngong’ Forest. The results revealed non-significant (p≤ 0.05) contribution of long-range transport to OCP pollution in Nairobi City. This indicated possible presence of point sources of environmental OCPs in the city. The water-air fugacity ratios indicated that volatilization and deposition played an important role in the spatial distribution of OCPs in Nairobi City. This indicated that contaminated surface waters could be major sources of human exposure to OCPs, through volatilization. The incremental lifetime cancer risks (ILCR) determined from inhalation of atmospheric OCPs were 2.3745  ×  10^?13 – 1.6845  ×  10^?11 (adult) and 5.5404  ×  10^?13 – 3.9306  ×  10^?11 (child) in the order: Dandora > Kibera > Industrial Area > City Square > Ngong’ Forest. However, these were lower than the USEPA acceptable risks, 10^?6 – 10^?4. This study concluded that atmospheric OCPs did not pose significant cancer risks to the residents.     

水质监测频率与极端气候对高原湖泊入湖河流氮磷通量估算的影响

河流是流域氮磷营养盐的主要输出途径之一,准确掌握其通量变化和驱动因素对流域营养盐管理具有重要意义.本研究以滇池主要入湖河流宝象河为例,基于周水质观测数据和逐日水量数据,构建了河流氮磷通量LOADSET模型.估算了宝象河不同时间尺度（日、季、年）TN和TP的通量,评估了4种低频水质采样和极端气候指数对河流氮磷通量计算的影响.结果表明：①2018年宝象河的TN和TP年通量分别为270.49 t和11.19 t,存在显著的年内差异,夏季是通量最高的季节,分别占TN和TP年通量的40.78%和41.96%.②基于LOADEST模型的低频水质采样的氮磷估算结果与高频采样差异较小,宝象河TN、TP通量估算受采样频率影响较小.③宝象河的TN和TP通量变化受连续5日最大降水量、平均最低气温、平均最高气温、最低气温、最低气温极大值、最高气温极小值和平均温差7种极端气候指数的显著影响.     

北京市家具生产企业职业危害抽样调查

本文从北京市家具生产企业最多的区县中,有针对性地选择其中的18家企业进行现场抽样调查,并对其中的11家进行现场检测,研究北京市家具生产企业职业危害现状,通过现场调查和检测结果表明:北京市家具生产企业的管理者对职业危害的重视程度有所提高,但是从业者的自我保护意识仍然淡漠;生产环境不令人满意,作业场所粉尘超标严重;毒物浓度得到较好控制,主要毒物为苯及苯的同系物。该研究可为有关管理部门制定管理政策提供依据。     

SO2采样方式改变后的质量分析

环境空气SO2采样由每天采样3次,每次采样30分钟的瞬时采样变成24小时的连续采样,其测定浓度都降低了。其原因主要有,监测点位重新布设后,有些采样点位向郊区转移、进气管接胶管采样、进气管有水、采样流量变小及延迟化验分析等,都影响采样结果。     

中国表层土壤有机质空间分布模拟分析方法研究

气候变化背景下,对土壤有机碳的研究是目前大尺度上土壤性质研究的热点。基于第二次全国土壤普查5 374个典型土壤剖面数据,分析表层土壤有机质(20 cm)与环境因素的相关关系,利用多元回归模型和HASM模型结合的方法模拟中国国家尺度上表层土壤有机质含量的空间分布格局,探讨该方法的模拟误差,为国家尺度上有机碳的估算提供方法参考。研究结果表明,对350个检验点模拟结果的平均绝对误差和平均相对误差为15.61 g.kg-1和56.59%,与普通克里格法相比分别降低了1.61 g.kg-1和20.84%;对样点分布较少以及无样点的西北地区和台湾省的模拟结果也更符合实际情况。建模样点减少一半的情况下,模拟结果的平均绝对误差和平均相对误差仅分别增加了0.14 g.kg-1和1.07%。因此,论文方法可作为模拟国家尺度上有机质空间分布相对有效的方法,同时如何使模型解释更多的土壤有机质空间变异将是进一步提高模拟精度的关键。     

Seasonal trend of ambient PCDD/Fs in Tianjin City, northern China using active sampling strategy

The spatial concentrations, seasonal trends, profiles and congener pairs of ambient polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were investigated within a seasonally active sampling scheme during Jun 2008 and Jan 2009 in Tianjin City, northern China. The PCDD/F concentrations ranged 14.2-172 fg I-TEQ/m³ (average 69.3 fg I-TEQ/m³) in summer and (89.8-1.01) × 10³ fg I-TEQ/m³ (average 509 fg I-TEQ/m³) in winter, respectively, except for the E-waste dismantling site where much higher values were observed (1.04 × 10³ fg I-TEQ/m³ in summer and 7.123 × 10³ fg I-TEQ/m³ in winter). The results indicated a significantly seasonal trend with higher TEQ values in winter as compared with summer, which could be related to increased emission sources and seasonal variations of the atmospheric boundary layer height. 2,3,4,7,8-PeCDF was the dominant contributor to the total PCDD/F toxic equivalents, and 2,3,7,8-TCDD was detected at almost all the sampling sites in winter. Most of the similarly substituted PCDD/F congener pairs exhibited high correlations, suggesting that they might have similar environmental fate or sources. But different seasonal and spatial distributions of PCDD/F concentrations indicated that the emission sources might be intermittent.