Air Toxics and Health Risks in California: The Public Health Implications of Outdoor Concentrations

Of the 188 hazardous air pollutants (HAPs) listed in the Clean Air Act, only a handful have information on human health effects, derived primarily from animal and occupational studies. Lack of consistent monitoring data on ambient air toxics makes it difficult to assess the extent of low-level, chronic, ambient exposures to HAPs that could affect human health, and limits attempts to prioritize and evaluate policy initiatives for emissions reduction. Modeled outdoor HAP concentration estimates from the U.S. Environmental Protection Agency's Cumulative Exposure Project were used to characterize the extent of the air toxics problem in California for the base year of 1990. These air toxics concentration estimates were used with chronic toxicity data to estimate cancer and noncancer hazards for individual HAPs and the risks posed by multiple pollutants. Although hazardous air pollutants are ubiquitous in the environment, potential cancer and noncancer health hazards posed by ambient exposures are geographically concentrated in three urbanized areas and in a few rural counties. This analysis estimated a median excess individual cancer risk of 2.7E-4 for all air toxics concentrations and 8600 excess lifetime cancer cases, 70% of which were attributable to four pollutants: polycyclic organic matter, 1,3 butadiene, formaldehyde, and benzene. For noncancer effects, the analysis estimated a total hazard index representing the combined effect of all HAPs considered. Each pollutant contributes to the index a ratio of estimated concentration to reference concentration. The median value of the index across census tracts was 17, due primarily to acrolein and chromium concentration estimates. On average, HAP concentrations and cancer and noncancer health risks originate mostly from area and mobile source emissions, although there are several locations in the state where point sources account for a large portion of estimated concentrations and health risks. Risk estimates from this study can provide guidance for prioritizing research, monitoring, and regulatory intervention activities to reduce potential hazards to the general population. Improved ambient monitoring efforts can help clarify uncertainties inherent in this analysis.     

素质教育人力资源开发观--兼谈现代人力资源开发与传统人力资源开发

从人力资源开发的角度,重新审视素质教育问题,并与以前就教育而教育的研究相比,我们认为素质教育并不是与应试教育相对立的一种教育.我国目前的学校教育既担负着发展教育的功能又担负着选拔人才的功能,这是由我国现阶段的经济发展水平与市场经济的要求所决定的.中小学教育是人力资源开发的基础工程,职业教育与高等教育是人力资源开发的导向开发工程;要尽快建立人才测评的科学机制,实行教培用酬一体化的人力资源开发与管理体制,把学校教育纳入到人力资源开发的轨道中来,使学校教育服务于经济、服务于社会、服务于人的发展等功能得以真正实现.     

矿产资源竞争力及其影响因素分析

根据矿产资源开发的特点 ,对矿产资源竞争力的概念进行了论述 ,并对影响矿产资源竞争力的因素进行了分析 ,提出了对矿产资源竞争力评价的一些认识。     

Rapid Benefit-Risk Assessments: No Escape from Expert Judgments in Risk Management

The "human health impacts assessment" described by Cox and Popken (this issue) is intended to be a benefit-risk tool that avoids pitfalls of using expert judgments for policy analysis or during strict application of the precautionary principle in risk management. The proposed benefit-risk calculation uses numerous assumptions and suppositions to calculate a ratio of quality-adjusted life years (QALYs) lost for the number of human illness days prevented by the use of a food-animal antimicrobial drug, to the number of human illness days caused by the use of the antimicrobial drug. Assumptions about data--e.g., expert judgments on the representativeness of parameter estimates--are commonly used in risk assessment and risk management, including Cox and Popken's method. Cox and Popken apply the technique to specific examples of enrofloxacin and macrolides antimicrobial drugs, sometimes used in broiler chickens for human food. Although enthusiastically portrayed as a straightforward calculation of QALYs lost for two decision alternatives, Cox and Popken were silent on the pivotal expert judgment subsumed in their method: quality weights for illnesses caused by antimicrobial-resistant and antimicrobial-sensitive microbes are tacitly assumed to be equal. Yet, the costs in terms of prolonged illness, additional medications, repeat medical visits, and dread of more serious sequelae are expected to differ substantially for antimicrobial-resistant versus antimicrobial-sensitive illnesses. Despite their enthusiasm to the contrary, the "human health impacts assessment" by Cox and Popken is not immune from expert judgments in risk management.     

An Integrated Model of Infection Risk in a Health-Care Environment

Certain respiratory tract infections can be transmitted by hand-to-mucous-membrane contact, inhalation, and/or direct respiratory droplet spray. In a room occupied by a patient with such a transmissible infection, pathogens present on textile and nontextile surfaces, and pathogens present in the air, provide sources of exposure for an attending health-care worker (HCW); in addition, close contact with the patient when the latter coughs allows for droplet spray exposure. We present an integrated model of pertinent source-environment-receptor pathways, and represent physical elements in these pathways as "states" in a discrete-time Markov chain model. We estimate the rates of transfer at various steps in the pathways, and their relationship to the probability that a pathogen in one state has moved to another state by the end of a specified time interval. Given initial pathogen loads on textile and nontextile surfaces and in room air, we use the model to estimate the expected pathogen dose to a HCW's mucous membranes and respiratory tract. In turn, using a nonthreshold infectious dose model, we relate the expected dose to infection risk. The system is illustrated with a hypothetical but plausible scenario involving a viral pathogen emitted via coughing. We also use the model to show that a biocidal finish on textile surfaces has the potential to substantially reduce infection risk via the hand-to-mucous-membrane exposure pathway.     

Applying fuzzy logic to personnel assessment: a case study

The main results of a research project spanning over several years are presented in this paper. The aim of the research was the improvement of the effectiveness of personnel assessment within a large Italian corporation operating in the research sector. The first step of the research consisted of the analysis of the raters’ behavior, so as to elicit the judgement categories and prototypes they used in the judgement formulation, based on the rating method adopted in the corporation. The second step consisted of improving the rating method using fuzzy logic. The corporate management tested the new rating method and found it more efficient and reliable than the previous one.     

Sensitivity Analysis, Monte Carlo Risk Analysis, and Bayesian Uncertainty Assessment

Standard statistical methods understate the uncertainty one should attach to effect estimates obtained from observational data. Among the methods used to address this problem are sensitivity analysis, Monte Carlo risk analysis (MCRA), and Bayesian uncertainty assessment. Estimates from MCRAs have been presented as if they were valid frequentist or Bayesian results, but examples show that they need not be either in actual applications. It is concluded that both sensitivity analyses and MCRA should begin with the same type of prior specification effort as Bayesian analysis.     

中小企业业务绩效考核模式构建

中小企业特别是快速成长的中小企业,销售部门的作用与地位特别重要,进而处于一线的业务员的作用与地位就特别重要。对中小企业的业务员的业务进行绩效考核一方面有利于进一步提高企业的整体业绩,另一方面有利于留住优秀的业务人员。目前,我国中小企业业务员的业务绩效考核还存在着许多的误区,因而建立科学的业绩考核标准十分重要。本文通过对我国中小企业业务员业务绩效考核的探讨,旨在为中小企业找到一种适合自身发展的业务员业务绩效考核模式提供一点思路。     

Implicit and Self-Attributed Dependency Needs in Homeless Men and Women

Recent metaanalyses indicate that women consistently obtain higher scores than men do on self-report dependency measures, but not on projective dependency tests (R. F. Bornstein, 1995, 1996). To explore this issue in a heretofore unexamined population, we analyzed archival data from 85 homeless participants (40 women and 45 men) enrolled in a vocational rehabilitation program, using the MMPI Dependency (Dy) Scale (L. Navran, 1954) and the Rorschach Oral Dependency (ROD) Scale (J. M. Masling, L. Rabie, & S. H. Blondheim, 1967). Consistent with earlier results, there were no gender differences in projective dependency scores, but contrary to earlier results, there were also no gender differences in self-reports of dependency. These findings suggest that stressful conditions like homelessness may mitigate the impact of gender on self-reported dependency.     

Patterns of entry to community‐based services for families with children with developmental disabilities: implications for social work practice

The purpose of the present study was to understand, from parents' perspectives, the process of entry to community‐based services for children with developmental disabilities and to explore the relationship between patterns of entry and parent‐reported needs and priorities for service. Qualitative interviews were conducted with 43 mothers and 29 fathers of children with developmental disabilities approximately 6 months after the families entered community‐based childhood disability support services in Manitoba, Canada. Analysis of the coded interview data resulted in the identification of three process factors influential in the entry of families to community‐based support services: recognition of problems in child development, formal diagnosis of child disability and linkage between diagnostic services and the community‐based support system. Analysis of these processes identified four patterns of service entry associated with differing family needs for service: early entry, prompt entry, delayed entry and atypical entry. The results can be understood as a typology useful for social workers in the assessment of family needs and priorities at the point of entry to community‐based services.