制药企业密集区空气中VOCs污染特性及健康风险评价

为研究制药企业密集区产生的挥发性有机物(VOCs)对环境和人群健康的影响,在制药企业密集区周边8个点位采集168个样品,采用预浓缩-GC-MS法测定VOCs的含量,并通过美国环境保护署(US EPA)的健康风险评价模型,对制药企业密集区挥发性有机物(VOCs)污染进行评价.结果表明,制药企业密集区共检测出32种物质,总挥发性有机物(TVOC)浓度为2.04 mg·m-3,芳香烃类和酮类所占比例较高,分别占总VOCs浓度的43%和28%;大部分VOCs浓度是背景值的十倍或百倍.检测到的19种存在健康危害的VOCs不会对人体产生明显的非致癌健康危害;但1,3-丁二烯、氯仿、四氯化碳、苯和1,1,2-三氯乙烷等5种VOCs对人体有致癌健康危害.密集区总VOCs的累积致癌风险指数远超可接受数量级,说明制药企业密集区排放的VOCs对人体以致癌健康危害为主.

企业密集区土壤主要污染物的空间分布及其预测性初步探讨

用克里格空间插值方法研究了城乡民营企业密集区土壤中Cu、Pb、Zn、Cd、Ni、Cr、Hg、As和多氯联苯(PCBs)等9种污染物的空间分布特征,对比该区的企业布局,初步探讨了企业布局对土壤污染物浓度预测的可行性。结果表明,该区污染物的高浓度区主要分布在废旧拆解园区周边地区和小冶炼集中地带,且存在多污染物的复合污染。当在约1km2的范围内有金属类生产企业、电机生产企业或(和)电线电缆生产企业存在时,土壤中可能有Cu和Pb积累。电机、电线电缆和(或)自动喷雾器生产企业的密集分布可能出现土壤中Pb的累积。而金属类生产企业的空间布局与土壤中Cd、Ni和Cr的浓度间存在显著的相关关系。汽摩配生产企业和金属配件生产企业可能分别会带来土壤As和PCBs积累。

家具制造企业密集区空气中VOCs污染状况及健康风险评价

采用Tenax管吸附-热脱附-气相色谱法测定家具制造企业密集区空气中挥发性有机物(VOCs),并应用美国国家环保局(USEPA)的健康风险评价模型评估其对周边人群的影响。结果表明,家具制造企业密集区总VOCs的质量浓度为0.931 mg/m3,11种目标物中乙酸乙酯、丙酮和乙酸丁酯所占比例较高,分别占总VOCs的20.2%、10.7%和9.1%。该区总VOCs的累积非致癌风险指数为3.47×10-7,低于1,不会对人体产生明显的非致癌健康危害;其累积致癌风险指数为2.49×10-5,是可接受致癌风险值(1.0×10-6)的25倍,可能对人群存在致癌影响。

Industrial Spatial Agglomeration Using Distance-based Approach in Beijing, China

To study the difference of industrial location among different industries, this article is to test the spatial agglomeration across industries and firm sizes at the city level. Our research bases on a unique plant-level data set of Beijing and employs a distance-based approach, which considers space as continuous. Unlike previous studies, we set two sets of references for service and manufacturing industries respectively to adapt to the investigation in the intra-urban area. Comparing among eight types of industries and different firm sizes, we find that： 1） producer service, high-tech industries and labor-intensive manufacturing industries are more likely to cluster, whereas personal service and capital-intensive industries tend to be randomly dispersed in Beijing; 2） the spillover of the co-location of finns is more important to knowledge-intensive industries and has more significant impact on their allocation than business-oriented services in the intra-urban area; 3） the spatial agglomeration of service industries are driven by larger establishments, whereas manufac- turing industries are mixed.