Science-policy in environmental and health risk assessment: if we cannot do without, can we do better?

How can empirical evidence of adverse effects from exposure to noxious agents, which is often incomplete and uncertain, be used most appropriately to protect human health? We examine several important questions on the best uses of empirical evidence in regulatory risk management decision-making raised by the US Environmental Protection Agency (EPA)'s science-policy concerning uncertainty and variability in human health risk assessment. In our view, the US EPA (and other agencies that have adopted similar views of risk management) can often improve decision-making by decreasing reliance on default values and assumptions, particularly when causation is uncertain. This can be achieved by more fully exploiting decision-theoretic methods and criteria that explicitly account for uncertain, possibly conflicting scientific beliefs and that can be fully studied by advocates and adversaries of a policy choice, in administrative decision-making involving risk assessment. The substitution of decision-theoretic frameworks for default assumption-driven policies also allows stakeholder attitudes toward risk to be incorporated into policy debates, so that the public and risk managers can more explicitly identify the roles of risk-aversion or other attitudes toward risk and uncertainty in policy recommendations. Decision theory provides a sound scientific way explicitly to account for new knowledge and its effects on eventual policy choices. Although these improvements can complicate regulatory analyses, simplifying default assumptions can create substantial costs to society and can prematurely cut off consideration of new scientific insights (e.g., possible beneficial health effects from exposure to sufficiently low 'hormetic' doses of some agents). In many cases, the administrative burden of applying decision-analytic methods is likely to be more than offset by improved effectiveness of regulations in achieving desired goals. Because many foreign jurisdictions adopt US EPA reasoning and methods of risk analysis, it may be especially valuable to incorporate decision-theoretic principles that transcend local differences among jurisdictions.

C-reactive protein, cardiovascular risk, and renal disease in a remote Australian Aboriginal community

Rates of cardiovascular and renal disease in Australian Aboriginal communities are high, but we do not know the contribution of inflammation to these diseases in this setting. In the present study, we sought to examine the distribution of C-reactive protein (CRP) and other markers of inflammation and their relationships with cardiovascular risk markers and renal disease in a remote Australian Aboriginal community. The study included 237 adults (58% of the adult population) in a remote Aboriginal community in the Northern Territory of Australia. Main outcome measures were CRP, fibrinogen and lgG concentrations, blood pressure (BP), presence of diabetes, lipids, albuminuria, seropositivity to three common micro-organisms, as well as carotid intima-media thickness (IMT). Serum concentrations of CRP [7 (5-13) mg/l; median (inter-quartile range)] were markedly increased and were significantly correlated with fibrinogen and lgG concentrations and inversely correlated with serum albumin concentration. Higher CRP concentrations were associated with lgG seropositivity to Helicobacter pylori and Chlamydia pneumoniae and higher lgG titre for cytomegalovirus. Higher CRP concentrations were associated with the following: the 45-54-year age group, female subjects, the presence of skin sores, higher body mass index, waist circumference, BP, glycated haemoglobin and greater albuminuria. CRP concentrations increased with the number of cardiovascular risk factors, carotid IMT and albuminuria independently of other risk factors. These CRP concentrations were markedly higher than described in other community settings and are probably related, in a large part, to chronic and repeated infections. Their association with markers of cardiovascular risk and renal disease are compatible with the high rates of cardiovascular and renal disease in this community, and provide more evidence of strong links between these conditions, through a shared background of infection/inflammation. This suggests that a strong focus on prevention and management of infections will be important in reducing these conditions, in addition to interventions directed at more traditional risk factors.

Noise trader risk and the welfare effects of privatization

Excessive volatility of asset prices like that generated in the 'noise trader' model of De Long et al. is one factor that plausibly might contribute to an explanation of the equity premium. We extend the De Long et al. model to allow for privatization of publicly-owned assets and assess the welfare effects of such privatization in the presence of excess volatility arising from noise traders' mistaken beliefs.

Why does dissimilarity matter? Exploring self-categorization, self-enhancement, and uncertainty reduction

Although relational demographers have based their arguments on self-categorization theory, they have paid little attention to the underlying processes associated with this theory. The authors examined whether demographic dissimilarity affects individuals' identification with groups by affecting the group's prototype valence and clarity and the individual's perceptions of self-prototypicality. The data showed that the proportion of women and non-Australians in 34 work groups negatively influenced prototype valence, prototype clarity, and self-prototypicality for all members of the group. These results provide support for the continued use of self-categorization theory by relational demographers.

Complexity, conflict and uncertainty: Issues in collaboration between child protection and mental health services

This paper provides an analysis of data from a state-wide survey of statutory child protection workers, adult mental health workers, and child mental health workers. Respondents provided details of their experience of collaboration on cases where a parent had mental health problems and there were serious child protection concerns. The survey was conducted as part of a large mixed-method research project on developing best practice at the intersection of child protection and mental health services. Descriptions of 300 cases were provided by 122 respondents. Analyses revealed that a great deal of collaboration occur-red across a wide range of government and community-based agencies; that collaborative processes were often positive and rewarding for workers; and that collaboration was most difficult when the nature of the parental mental illness or the need for child protection intervention was contested. The difficulties experienced included communication, role clarity, competing primary focus, contested parental mental health needs, contested child protection needs, and resources. (C) 2004 Elsevier Ltd. All rights reserved.

Disease risk and mortality prediction in intensive care patients with pneumonia. Australian and New Zealand practice in intensive care (ANZPIC II)

This study of ventilated patients investigated pneumonia risk factors and outcome predictors in 476 episodes of pneumonia (48% community-acquired pneumonia, 24% hospital-acquired pneumonia, 28% ventilator-associated pneumonia) using a prospective survey in 14 intensive care units within Australia and New Zealand. For community acquired pneumonia, mortality increased with immunosuppression (OR 5.32, CI 95% 1.58-17.99, P < 0. 01), clinical signs of consolidation (OR 2.43, CI 95% 1.09-5.44, P = 0. 03) and Sepsis-Related Organ Failure Assessment (SOFA) scores (OR 1.19, CI 95% 1.08-1.30, P < 0. 001) but improved if appropriate antibiotic changes were made within three days of intensive care unit admission (OR 0.42, CI 95% 0.20-0.86, P = 0.02). For hospital-acquired pneumonia, immunosuppression (OR 6.98, CI 95% 1.16-42.2, P = 0.03) and non-metastatic cancer (OR 3.78, CI 95% 1.20-11.93, P = 0.02) were the principal mortality predictors. Alcoholism (OR 7.80, CI 95% 1.20-1750, P < 0.001), high SOFA scores (OR 1.44, CI 95% 1.20-1.75, P = 0.001) and the isolation of high risk organisms including Pseudomonas aeruginosa, Acinetobacter spp, Stenotrophomonas spp and methicillin resistant Staphylococcus aureus (OR 4.79, CI 95% 1.43-16.03, P = 0.01), were associated with increased mortality in ventilator-associated pneumonia. The use of non-invasive ventilation was independently protective against mortality for patients with community-acquired and hospital-acquired pneumonia (OR 0.35, CI 95% 0.18-0.68, P = 0.002). Mortality was similar for patients requiting both invasive and non-invasive ventilation and non-invasive ventilation alone (21% compared with 20% respectively, P = 0.56). Pneumonia risks and mortality predictors in Australian and New Zealand ICUs vary with pneumonia type. A history of alcoholism is a major risk factor for mortality in ventilator-associated pneumonia, greater in magnitude than the mortality effect of immunosuppression in hospital-acquired pneumonia or community-acquired pneumonia. Non-invasive ventilation is associated with reduced ICU mortality. Clinical signs of consolidation worsen, while rationalising antibiotic therapy within three days of ICU admission improves mortality for community-acquired pneumonia patients.

Motivations for group membership: The role of subjective importance and uncertainty reduction

An experiment was conducted to investigate the idea that an important motive for identifying with social groups is to reduce subjective uncertainty, particularly uncertainty on subjectively important dimensions that have implications for the self-concept (e.g., Hogg, 1996; Hogg & Mullin, 1999). When people are uncertain on a dimension that is subjectively important, they self-categorize in terms of an available social categorization and, thus, exhibit group behaviors. To test this general hypothesis, group membership, task uncertainty, and task importance were manipulated in a 2 x 2 x 2 between-participants design (N = 128), under relatively minimal group conditions. Ingroup identification and desire for consensual validation of specific attitudes were the key dependent measures, but we also measured social awareness. All three predictions were supported. Participants identified with their group (H1), and desired to obtain consensual validation from ingroup members (H2) when they were uncertain about their judgments on important dimensions, indicating that uncertainty reduction motivated participants towards embracing group membership. In addition, identification mediated the interactive effect of the independent variables on consensual validation (H3), and the experimental results were not associated with an increased sense of social awareness and, therefore, were unlikely to represent only behavioral compliance with generic social norms. Some implications of this research in the study of cults and totalist groups and the explication of genocide and group violence are discussed.