土壤污染防治立法的效果导向及其实现

从规范的内容、规制形式等方面分析,土壤污染防治专门立法应当坚持效果导向,要与调整土壤污染源的大气、水、固体废物、化学品等上游制度,以及食品、人居安全等下游制度实现效力对接与协同,并超越当前效果乏力的实施模式。未来立法的效果导向实现需要围绕“土壤质量保持”这个核心,坚持在红线思维指导下确立国家、经营者和公众的权利（力）义务,区分底土与表层土壤的权利属性,创新我国土地权利结构。     

气垫导轨实验的拓展

针对传统的气垫导轨实验起点低,过于简单这一缺憾,提出了一种新的实验原理及实验方法,使其内容得以拓展.     

不可压缩地下水水质污染模型广义解的唯一性

不可压缩地下水水质污染问题的数学模型由一类非线性抛物－椭圆耦合方程组的初边值问题描述,本文用积分估计法证明这一模型广义解的唯一性。     

Radon Risk Information and Voluntary Protection: Evidence from a Natural Experiment

This study examines the perceived risks and mitigating behavior of Maine households who received new information on their exposures to significant health risks from indoor radon. The observed responses of these households illustrate conceptual issues related to designing an effective risk information program. Despite the involvement of generally well-motivated homeowners and well-intentioned researchers and government officials, we conclude that the risk information approach used in Maine failed to induce appropriate, cost-effective voluntary protection. The results indicate that, after receiving radon test results, information on associated health risks, and suggestions on how to reduce exposures: perceived risks tended to understate objective risks by orders of magnitude, and there was no statistically significant relationship between mitigating behavior and objective risks. These results suggest that the formation of risk perceptions and subsequent behavioral adjustments involve complex interactions among information, contextual, socioeconomic, and psychological variables. Therefore, government programs that seek to reduce health and safety risks with information programs, instead of using more conventional enforced standards, must be crafted very carefully to accommodate this complex process.     

Linking Indoor Air and Pharmacokinetic Models to Assess Tetrachloroethylene Risk

Physiologically based pharmacokinetic (PBPK) models describing the uptake, metabolism, and excretion of xenobiotic compounds are now proposed for use in regulatory health-risk assessments. In this study we investigate the extent of PCE metabolism arising from domestic respiratory exposure to tetrachloroethylene (PCE) from ground water, as predicted using a PBPK model. Indoor exposure patterns we use as input to the PBPK model are realistic ones generated from a three-compartment model describing volatilization of PCE from domestic water into household air. Values we use for the metabolic parameters of the PBPK model are estimated from data on urinary metabolites in workers exposed to PCE. It is shown that for respiratory PCE exposure due to typical levels of PCE in ground water, use of time-weighted average air concentrations with a steady-state PBPK model yields estimates of total metabolized PCE similar to those obtained using completely dynamic modeling, despite considerable uncertainty in key exposure- and metabolic-model parameters. These findings suggest that, for PCE, risk estimation taking pharmacokinetics into account may be accomplished using a simple analytic approach.     

Modelling spatio-temporal air pollution data from a mobile monitoring station

ABSTRACT

Environmental data is typically indexed in space and time. This work deals with modelling spatio-temporal air quality data, when multiple measurements are available for each space-time point. Typically this situation arises when different measurements referring to several response variables are observed in each space-time point, for example, different pollutants or size resolved data on particular matter. Nonetheless, such a kind of data also arises when using a mobile monitoring station moving along a path for a certain period of time. In this case, each spatio-temporal point has a number of measurements referring to the response variable observed several times over different locations in a close neighbourhood of the space-time point. We deal with this type of data within a hierarchical Bayesian framework, in which observed measurements are modelled in the first stage of the hierarchy, while the unobserved spatio-temporal process is considered in the following stages. The final model is very flexible and includes autoregressive terms in time, different structures for the variance-covariance matrix of the errors, and can manage covariates available at different space-time resolutions. This approach is motivated by the availability of data on urban pollution dynamics: fast measures of gases and size resolved particulate matter have been collected using an Optical Particle Counter located on a cabin of a public conveyance that moves on a monorail on a line transect of a town. Urban microclimate information is also available and included in the model. Simulation studies are conducted to evaluate the performance of the proposed model over existing alternatives that do not model data over the first stage of the hierarchy.     

Optimal Tests for No Contamination in Reliability Models

Inferences on mixtures of probability distributions, in general,and of life distributions, in particular, are receiving considerableimportance in recent years. The likelihood ratio procedure oftesting for the null hypothesis of no contamination is oftenvery cumbersome and lacks its usual asymptotic properties. Recently,SenGupta (1991) has introduced the notion of an `L-optimal' testfor such testing problems. The idea is to recast the originalseveral parametric hypotheses representation of the null hypothesisin terms of only a single hypothesis involving an appropriatelychosen parametric function. This approach is shown to be bothmathematically elegant and operationally simple for a quite generalclass of mixture distributions which contains, in particular,all mixtures of the one-parameter exponential family and alsoa very rich subclass of mixtures useful in life-testing and reliabilityanalysis. It is also illustrated through two examples—onebased on real-life data and the other on a simulated sample.     

Stringency of Workplace Air Contaminant Exposure Limits: A Case Study of OSHA Risk Management

Political context may play a large role in influencing the efficiency of environmental and health regulations. This case study uses data from a 1989 update of the Occupational Safety and Health Administration (OSHA) Permissible Exposure Limits (PELs) program to determine the relative effects of legislative mandates, costly acquisition of information by the agency, and pressure applied by special interest groups upon exposure standards. The empirical analysis suggests that federal agencies successfully thwart legislative attempts to limit agency discretion, and that agencies exercise bounded rationality by placing greater emphasis on more easily obtained information. The 1989 PELs were less significantly related to more costly information, contained safety factors for chemicals presenting relatively more ambiguous risks, and the proposed standard stringencies showed evidence of being influenced by vying industry and labor interests.     

幼儿园室内物质环境评价效果调查研究

对98名教师和80名幼儿进行问卷调查和访谈,研究发现,教师在室内墙面环境花费的精力和时间颇多,但效果不太明显;相比于其他级类幼儿园,示范幼儿园的教师对特征的感知水平较高,对工作负担的感知水平较低;评价标准的清晰度、评价结果的有用性与工作负担之间存在显著正相关,评价结果的应用支持与教师的实践改善之间存在显著正相关。建议明晰幼儿园室内物质环境评价的目的定位,提高评价标准的清晰度和关键性,优化评价结果的应用制度。     

包头市城区大气环境质量现状评价及其预测

运用大气综合污染指数及污染物负荷分担率的分析方法对包头市2007年的大气质量现状进行了评价;基于2007年的包头大气环境监测数据,运用灰色系统的GM(1,1)模型对包头市未来五年内的大气环境进行了预测.结果表明,2007年包头市的PM10及SO2的污染仍处于较高水平,今后几年,SO2和PM10的污染超标情况还会时有发生,这需要政府、企业、广大市民以及研究机构共同关注并不断探索控制的新路子.