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The article offers the author's insights regarding the cultural issues among risk assessment, precautionary principle, public health, and sustainability using the writings of Adam Finkel as basis. He mentions that risk assessment often builds on the opportunity provided by new science including molecular biology instead of focusing on the information needed to address a problem. Moreover, he adds that the move toward sustainability is consistent with a public health culture.

Sediment metal concentrations in embayments of Sydney Harbour, acquired from the literature and from samples collected for this study, were used to generate contaminant probability density distributions using AQUARISK. The sediment metal concentrations often exceeded Australia's interim sediment quality guidelines. Similarly, estuarine spiked sediment toxicity test literature provided adverse biotic effects concentration data to generate species sensitivity distributions using AQUARISK. Although the harbor is subject to other inorganic and organic contamination, we have used sediment metals to demonstrate an approach for ecological risk mapping and environmental management prioritization. Sufficient spiked sediment toxicity test data were found for only three metals—Cd, Cu, and Zn—and some tests were likely to overestimate toxicity. The estimates of the hazardous concentration to 5% of species (the 50th percentile of the 95% species protection level) were 5, 12, and 40 mg/kg DW of total sediment metal for Cd, Cu, and Zn, respectively. These values were generally low when compared with the interim sediment quality guidelines due to the overestimation of toxic effects in the literature data. The parameters for the species sensitivity distributions have been combined with the measured sediment metal concentrations in Homebush Bay to generate risk maps of the estimated species impact for each metal as well as for all three metals collectively assuming proportional additivity. This has demonstrated the utility of comparing contaminants on a consistent scale—ecological risk. [ABSTRACT FROM AUTHOR]

A screening level human health risk assessment (HHRA) was applied to evaluate the human health implications of consuming selenium found in fish tissues collected downstream of coal mines in southeastern British Columbia, Canada. The study evaluated the potential for adverse human health effects associated with selenium, and considered known and potential benefits of selenium and fish ingestion. The results indicated that risks of selenosis due to consumption of selenium-contaminated fish in the region are negligible. Conclusions were strengthened by consideration of the potential benefits of selenium to human health, including: selenium essentiality for maintenance of good health; potential cancer prevention properties due to its role as an antioxidant; potential benefits for cardiovascular health; and other positive health benefits. The findings indicated that some aspects of the traditional framework for HHRA (e.g., application of safety factors to "err on the side of safety") are inappropriate for the assessment of selenium-contaminated fish. Due to both deficiency and toxicity in the selenium dose-response relationship, application of compounding conservatism in risk assessment may lead to recommended intakes of fish that are contrary to the public health interest. The need for balancing risk types, for incorporating positive responses in risk assessments, and the linkage to the precautionary principle, are discussed. [ABSTRACT FROM AUTHOR]

The history of environmental decision-making in the United States is primarily one of antagonism, conflict, and litigation. Four sectors of American society are typically at odds over why and how to solve environmental problems—government regulators, businesses proponents, environmental advocates, and members of affected communities. Dissimilar worldviews are at the heart of most environmental disputes, and people in the four sectors tend to have diverse perspectives and philosophies that affect how they interpret and respond to environmental issues. To promote integrated, cost-effective decisions, the public health paradigm (prevention first, intervention second, treatment third), as embodied in the Precautionary Principle and the concept of Sustainable Development, should be mutually adopted as a joint framework for prioritizing solutions to pressing environmental problems. The core public health principle of prevention first is a simple yet powerful tenet that can help foster better environmental choices that are more effective, efficient, and equitable. [ABSTRACT FROM AUTHOR]

An important part of the Precautionary Principle is that taking action is justified for protecting public health even when there is some scientific uncertainty. We examine here the two components of this central feature of the precautionary principle, scientific uncertainty and decision making. In order to operationalize the principle we should examine the consequences of its decision rules and how they perform under various conditions. The performance of decision rules in disease screening is measured by the sensitivity and specificity of the rule, but the consequences for the patient are given by the positive and negative predictive values, determined not only by the performance of the rule by the prevalence of the disease in the population. We look at positive and negative predictive value of the Precautionary Principle from the standopoint of the costs to one or other parts of society, show that the usual rule which tends to maximize sensitivity in favor of specificity may have unexpected consequences, and demonstrate that it is sometimes possible to trade sensitivity and specificity off against each other in a way the improves both positive and negative predictive value, or worse, degrades both.We conclude by asking if certain strategies are better for one or the other kinds of uncertainty. [ABSTRACT FROM AUTHOR]

The perception of risks for environment and health deriving from globalization processes and an uncontrolled use of modern technologies is growing everywhere. The greater the capacity of controlling living conditions, the larger is the possibility of misusing this power. In environmental and occupational health research we tend to reduce the complexity of the observed phenomena in order to facilitate conclusions. In social and political sciences complexity is an essential element of the context, which needs to be continuously considered. The Precautionary Principle is a tool for facing complexity and uncertainty in health risk management. This paper is aimed at demonstrating that this is not only a problem of technical risk assessment. Great attention should also be paid to improve risk communication. Communication between the stakeholders (experts, decision makers, political and social leaders, media, groups of interest and people involved) is possibly the best condition to be successful in health risk management. Nevertheless, this process usually runs up against severe obstacles. These are not only caused by existing conflicts of interest. Differences in values, languages, perceptions, resources to have access to information, and to express one's own point of view are other key aspects. [ABSTRACT FROM AUTHOR]

Ecuador is a Latin American country with one of the biggest biodiversities. At the same time, social and environmental problems are also big. Poverty, political and social problems as well as questions like old transport systems, imported hazards from industrialized countries and lack of information and weak health care systems are the framework of this situation. The most common problems are the use of heavy metals in many activities without safety and health protection, a low technological oil production during two decades, intensive use of pesticides in agriculture, and some other chemical risks. A limited capacity to develop prevention strategies, reduced technical and scientific skills, and the absence of a reliable information and control system, lead to a weak response mechanism. The Precautionary Principle could help to stimulate prevention, protection and to have a new tool to improve the interest in environment and health problems. Reinforcing the presence of international organizations like WHO and ILO, establishing bridges among scientific organizations from developed and developing countries and introducing the Precautionary Principle in the legislation and daily practices of industry and agriculture could lead to an improvement in our environment and health. [ABSTRACT FROM AUTHOR]

The European Commission has published a Communication on the Precautionary Principle and a White Book on Governance. These provide us (as research civil servants of the Commission) an institutional framework for handling scientific information that is often incomplete, uncertain, and contested. But, although the Precautionary Principle is intuitively straightforward to understand, there is no agreed way of applying it to real decision-making. To meet this perceived need, researchers have proposed a vast number of taxonomies. These include ignorance auditing, type one-two-three errors, a combination of uncertainty and decision stakes through post-normal science and the plotting of ignorance of probabilities against ignorance of consequences. Any of these could be used to define a precautionary principle region inside a multidimensional space and to position an issue within that region. The rôle of anticipatory research is clearly critical but scientific input is only part of the picture. It is difficult to imagine an issue where the application of the Precautionary Principle would be non-contentious. From genetically-modified food to electro-smog, from climate change to hormone growth in meat, it is clear that: 1) risk and cost-benefit are only part of the picture; 2) there are ethical issues involved; 3) there is a plurality of interests and perspectives that are often in conflict; 4) there will be losers and winners whatever decision is made. Operationalisation of the Precautionary Principle must preserve transparency. Only in this way will the incommensurable costs and benefits associated with different stakeholders be registered. A typical decision will include the following sorts of considerations: 1) the commercial interests of companies and the communities that depend on them; 2) the worldviews of those who might want a greener, less consumerist society and/or who believe in the sanctity of human or animal life; 3) potential benefits such as enabling the world's poor to improve farming; 4) risks such as pollution, gene-flow, or the effects of climate change. In this paper we will discuss the use of a combination of methods on which we have worked and that we consider useful to frame the debate and facilitate the dialogue among stakeholders on where and how to apply the Precautionary Principle. [ABSTRACT FROM AUTHOR]

Applying the Precautionary Principle to public health requires a re-evaluation of the methods of inference currently used to make claims about disease causation from epidemiologic and other forms of scientific evidence. In current thinking, a well-established, near-certain causal relationship implies highly consistent statistically significant results across many different studies, large relative risk estimates, extensive understanding of biological mechanisms and dose-response relationships, positive prevention trial results, a clear temporal relationship between cause and effect, and other conditions spelled out in terms of the widely-used causal criteria. The Precautionary Principle, however, states that preventive measures are to be taken when cause and effect relationships are not fully established scientifically. What evidentiary conditions, as reflected in the causal criteria, will be certain enough to warrant precautionary preventive action? This paper argues that minimum evidentiary requirements for causation need to be articulated if the Precautionary Principle is to be successfully incorporated into public health practice. Two precautionary changes to criteria-based methods of causal inference are examined: reducing the number of criteria and weakening the rules of inference accompanying the criteria. Such changes point in the direction of identifying minimum evidentiary conditions, but would be premature without better understanding how well current methods of causal inference work. [ABSTRACT FROM AUTHOR]

Ethics tells us: do good and do no harm and invokes the norms of justice, equity and respect for autonomy in protecting and promoting health and well-being. The Precautionary Principle, a contemporary re-definition of Bradford Hill's case for action, gives us a common sense rule for doing good by preventing harm to public health from delay: when in doubt about the presence of a hazard, there should be no doubt about its prevention or removal. It shifts the burden of proof from showing presence of risk to showing absence of risk, aims to do good by preventing harm, and subsumes the upstream strategies of the DPSEEA (Driving Forces Pressure Stress Exposure Effect Action) model and downstream strategies from molecular epidemiology for detection and prevention of risk. The Precautionary Principle has emerged because of the ethical import of delays in detection of risks to human health and the environment. Ethical principles, the Precautionary Principle, the DPSEEA model and molecular epidemiology all imply re-emphasizing epidemiology's classic rôle for early detection and prevention. Delays in recognizing risks from past exposures and acting on the findings (e.g., cigarette smoking and lung cancer, asbestos, organochlorines and endocrine disruption, radiofrequency, raised travel speeds) were examples of failures that were not only scientific, but ethical, since they resulted in preventable harm to exposed populations. These may delay results from, among other things, external and internal determinants of epidemiologic investigations of hazard and risk, including misuse of tests of statistical significance. Furthermore, applying the Precautionary Principle to ensure justice, equity, and respect for autonomy raises questions concerning the short-term costs of implementation to achieve long-term goals and the principles that guide compensation. [ABSTRACT FROM AUTHOR]

The Precautionary Principle is founded on the use of comprehensive, coordinated research to protect human health in the face of uncertain risks. Research directed at key data gaps may significantly reduce the uncertainty underlying the complexities of assessing risk to mixtures. The National Institute of Environmental Health Sciences (NIEHS) has taken a leadership rôle in building the scientific infrastructure to address these uncertainties. The challenge is to incorporate the objectives as defined by the Precautionary Principle with the knowledge gained in understanding the multifactorial nature of gene-environment interactions. Through efforts such as the National Center for Toxicogenomics, the National Toxicology Program, and the Superfund Basic Research Program, NIEHS is translating research findings into public health prevention strategies using a 3-pronged approach: (1) identify/evaluate key deviations from additivity for mixtures; (2) develop/apply/link advanced technologies and bioinformatics to quantitative tools for an integrated science-based approach to chemical mixtures; (3) translate/disseminate these technologies into useable, practical means to reduce exposure and the risk of disease. Preventing adverse health effects from environmental exposures requires translation of research findings to affected communities and must include a high level of public involvement. Integrating these approaches are necessary to advance understanding of the health relevance of exposure to mixtures. [ABSTRACT FROM AUTHOR]

In ‘Hard’ science, scientists correctly operate as the ‘guardians of certainty,’ using hypothesis testing formulations and value judgements about error rates and time discounting that make classical inferential methods appropriate. But these methods can neither generate most of the inputs needed by decision makers in their time frame, nor generate them in a form that allows them to be integrated into the decision in an analytically coherent and transparent way. The need for transparent accountability in public decision making under uncertainty and value conflict means the analytical coherence provided by the stochastic Bayesian decision analytic approach, drawing on the outputs of Bayesian science, is needed. If scientific researchers are to play the rôle they should be playing in informing value-based decision making, they need to see themselves also as ‘guardians of uncertainty,’ ensuring that the best possible current posterior distributions on relevant parameters are made available for decision making, irrespective of the state of the certainty-seeking research. The paper distinguishes the actors employing different technologies in terms of the focus of the technology (knowledge, values, choice); the ‘home base’ mode of their activity on the cognitive continuum of varying analysis-to-intuition ratios; and the underlying value judgements of the activity (especially error loss functions and time discount rates). Those who propose any principle of decision making other than the banal ‘Best Principle,’ including the ‘Precautionary Principle,’ are properly interpreted as advocates seeking to have their own value judgements and preferences regarding mode location apply. The task for accountable decision makers, and their supporting technologists, is to determine the best course of action under the universal conditions of uncertainty and value difference/conflict. [ABSTRACT FROM AUTHOR]

In creating a legal agenda in service of the Precautionary Principle, the idea of precaution requires more inventories and better monitoring of the condition of public and workforce health than at present. Rectifying problems of the past to better serve the aims of precaution will require more affirmative pre-market and much more post-market knowledge-generation by those who create and use potentially toxic substances, improved pre-market review of substances, better responses to early warnings, and quicker protective post-market responses to evidence of toxicity. This paper conceptualizes a model pre-market screening law to highlight the need for primary prevention measures and to provide philosophic ideas for improving post-market laws and addressing a large universe of existing substances that have been poorly characterized. Although retrospective personal injury law does not have good mechanisms for precaution, even this can be more protective than it is at present by enhancing causes of action for reasonable fear of disease and medical monitoring, and moving to create new causes of action for failure to develop and disseminate information needed to assess the toxicity of substances. [ABSTRACT FROM AUTHOR]

Aim. Before intergovernmental consensus under the Rio Declaration in 1992, ignorance of type I errors had been disfavoured in science. However, the Precautionary Principle (PP) counsels the avoidance of type II errors, rather than of type I errors. We need a new academic code for the PP. Material and methods. The risk of extinction has usually been evaluated based on conservative estimates of the present population size. I define the weight of evidence as the extinction risk of Japanese vascular plants based on unbiased estimates. Catch quotas in the fisheries are usually decided by precautionary approach. I calculate the long-term yield and risk of stock collapse under a simple stock dynamics model. Results. The weight of evidence depends on the frequency of grids with size unknown. In a few plant species, rankings based on conservative estimates have differed from rankings based on unbiased estimates. In fishery management, a catch quota based on a precautionary approach proved neither sufficient nor necessary to avoid stock collapse. The precautionary approach is one of the reasons that prevent us from maximizing a sustainable yield. Conclusions. We need to clarify the endpoint of risks, and check whether it is necessary to adopt a PP. We can obtain the weight of evidence that is measured under unbiased estimates, while the risk based on a PP is measured under conservative estimates. [ABSTRACT FROM AUTHOR]

The central challenge from the Precautionary Principle to statistical methodology is to help delineate (preferably quantitatively) the possibility that some exposure is hazardous, even in cases where this is not established beyond reasonable doubt. The classical approach to hypothesis testing is unhelpful, because lack of significance can be due either to uninformative data or to genuine lack of effect (the Type II error problem). Its inversion, bioequivalence testing, might sometimes be a model for the Precautionary Principle in its ability to ‘prove the null hypothesis.’ Current procedures for setting safe exposure levels are essentially derived from these classical statistical ideas, and we outline how uncertainties in the exposure and response measurements affect the No Observed Adverse Effect Level (NOAEL), the Benchmark approach and the “Hockey Stick” model. A particular problem concerns model uncertainty: usually these procedures assume that the class of models describing dose/response is known with certainty; this assumption is however often violated, perhaps particularly often when epidemiological data form the source of the risk assessment, and regulatory authorities have occasionally resorted to some average based on competing models. The recent methodology of Bayesian model averaging might be a systematic version of this, but is this an arena for the Precautionary Principle to come into play? [ABSTRACT FROM AUTHOR]

The Precautionary Principle is in sharp political focus today because (1) the nature of scientific uncertainty is changing and (2) there is increasing pressure to base governmental action on more “rational” schemes, such as cost-benefit analysis and quantitative risk assessment, the former being an embodiment of ‘rational choice theory’ promoted by the Chicago school of law and economics. The Precautionary Principle has been criticized as being both too vague and too arbitrary to form a basis for rational decision making. The assumption underlying this criticism is that any scheme not based on cost-benefit analysis and risk assessment is both irrational and without secure foundation in either science or economics. This paper contests that view and makes explicit the rational tenets of the Precautionary Principle within an analytical framework as rigorous as uncertainties permit, and one that mirrors democratic values embodied in regulatory, compensatory, and common law. Unlike other formulations that reject risk assessment, this paper argues that risk assessment can be used within the formalism of tradeoff analysis—a more appropriate alternative to traditional cost-benefit analysis and one that satisfies the need for well-grounded public policy decision making. This paper will argue that the precautionary approach is the most appropriate basis for policy, even when large uncertainties do not exist, especially where the fairness of the distributions of costs and benefits of hazardous activities and products are a concern. Furthermore, it will offer an approach to making decisions within an analytic framework, based on equity and justice, to replace the economic paradigm of utilitarian cost-benefit analysis. [ABSTRACT FROM AUTHOR]

As technology advances rapidly, so do applications with potential adverse implications on human health. The possible threats include risks that can be substantial, far-reaching and irreversible, and currently available methods of investigation, designed to deal with direct exposure-disease associations, are not always suitable. Growing interest is being paid to health effects that may be the consequence of distal, “upstream” determinants. Considering the complex chain of events that links such determinants with health can be extremely difficult, and exposes severe limitations in science. Thus, there is often a mismatch between what is known and what would be required to inform rational, evidence-based decision making, which is increasingly called for. It has become apparent how production and use of scientific evidence in decision making must be accompanied by precaution, especially in those circumstances, more and more common in recent times, where there is an uncertain possibility that serious health consequences might take place. Several cautionary approaches have been proposed, but the Precautionary Principle (PP) has been the object of especially intense debate in recent years. Developed in the field of environmental health, the PP has been clarified, and has been applied or called for in several instances in public health. Although a unique definition is not available, the principle has been characterised, and criteria for its application have been proposed. However, many questions remain open on general as well as specific issues. In this paper, we address some of the questions that are relevant for the PP to support rational decision making in environment and health and more in general to strengthen its contribution towards human health protection. [ABSTRACT FROM AUTHOR]

The Precautionary Principle implies the adoption of a set of rules aimed at avoiding possible future harm associated with suspected, but not ascertained, risk factors. Several philosophical, economical and societal questions are implied by precaution-based public health decision making. The purpose of the present paper is to specify the scope of the principle examining the notion of uncertainty involved, and the implication of different approaches to the decision making process. The Bayesian-utilitarian approach and the approach based on the maximin principle will be considered, and the different meaning of prudence in the two settings will be discussed. In a Bayesian-utilitarian approach the small number of attributable cases will end up in a low average expected value, easily regarded as acceptable in a cost-benefit analysis. In a maximin approach, on the other hand, the issue will be to consider the high etiologic fraction of a rare disease in the highest category of exposure. In the light of the aforementioned cautions in interpretation, the core difference between the two approaches has to do with the choice between averaging knowledge or equitably distributing technological risks. [ABSTRACT FROM AUTHOR]

The greater the potential for disastrous, large-scale, or catastrophic impacts on health, the greater the case for precaution. The imperative for precautionary action, critical also for downstream determinants of health, is at least as compelling where macro-level concerns about the sustainability of life on Earth are at issue. In this context, I propose that a higher threshold of uncertainty is needed where large-scale harms to health and well-being are possible. Initial efforts must focus on the training of researchers and risk managers for competencies in complexity, and in systems approaches to transdisciplinary enquiry. Revisiting the intent behind Bradford Hill on causation is an essential first step. Focus on the more proximate causes of diseases, such as those related either to occupational exposures or to more downstream environmental exposures, is left to others in this collection. [ABSTRACT FROM AUTHOR]

Scientific research is of proven value to protecting public health and the environment from current and future problems. We explore the extent to which the Precautionary Principle is a threat to this rôle for science and technology. Not surprisingly for a relatively simple yet still incompletely defined concept, supporters of the Precautionary Principle come from different viewpoints, including a viewpoint that is at least uneasy with the rôle of science, and particularly its use in risk assessment. There are also aspects of the Precautionary Principle that inherently restrict obtaining and using science. The Hazardous Air Pollutant (HAP) provisions in the US Clean Air Act Amendments are an example of the Precautionary Principle, which both shifted the burden of proof so that the onus is now on showing a listed compound is harmless, and required maximum available control technology (MACT) instead of a primarily risk-based approach to pollution control. Since its passage in 1990 there has been a decrease in research funding for studies of HAPs. Other potential problems include that once MACT regulations are established, it may be difficult to develop new technological approaches that will further improve air pollution control; that by treating all regulated HAPs similarly, no distinction is made between those that provide a higher or lower risk; and that there is a perverse incentive to use less well studied agents that are not on the existing list. As acting on the Precautionary Principle inherently imposes significant costs for what is a potentially erroneous action, additional scientific study should be required to determine if the precautionary action was successful. If we are to maximize the value of the Precautionary Principle to public health and the environment, it is crucial that its impact not adversely affect the potent preventive rôle of science and technology. [ABSTRACT FROM AUTHOR]

The Precautionary Principle aims to anticipate and minimize potentially serious or irreversible risks under conditions of uncertainty. Thus it preserves the potential for future developments. It has been incorporated into many international treaties and pieces of national legislation for environmental protection and sustainable development. However the Precautionary Principle has not yet been applied systematically to novel Information and Communication Technologies (ICTs) and their potential environmental, social, and health effects. In this article we argue that pre- caution is necessary in this field and show how the general principle of precaution can be put in concrete terms in the context of the information society. We advocate precautionary measures directed towards pervasive applications of ICT (Pervasive Computing) because of their inestimable potential impacts on society. [ABSTRACT FROM AUTHOR]

In order to give adequate support to risk managers, new risk assessment methods should be developed that are (1) scientifically sound, (2) simplified, and (3) suited for precautionary risk management. In this Perspective we propose that the notion of a precautionary default can be a useful tool in the development of such methods. A precautionary default is a cautious or pessimistic assumption that is used in the ab-sence of adequate information and that should be replaced when such information is obtained. Furthermore, we point out some promising research areas for the devel-opment of such indicators, viz. connections between chemical characteristics such as persistence and effect parameters, monitoring of contaminants in polar regions, monitoring of contaminants in breast milk, application of results from (human) toxicology in ecotoxicology and vice versa, (eco)toxicological test systems that are sensitive to effects on reproduction, and the application of bioinformatic methods to complex data, both in genomic research and in ecotoxicology. We conclude that precautionary decision-making does not require less science, but to the contrary it requires more science and improved communication between scientists and risk managers. [ABSTRACT FROM AUTHOR]

The article reports on the principle of precaution. The principle of precaution is a highly important and challenging issue for all involved in planning a sustainable development model from the economic, social and environmental viewpoint. The precautionary approach has evolved its merely preventive-prudential yardstick into the founding principle by which to govern the uncertainty of science. Precaution means taking preventive action against potential damage even if the causal connection is not proven and scientific evidence is still lacking.

The article discussed implications of the Precautionary Principle (PP) for public health practice and research. The overall aim of the PP is to provide an approach to acting in the face of uncertainty. Like a single definition of the PP will probably not suffice, the various procedural aspects of the PP are currently being explored and discussed. This aspect is of particular interest at our conference. There is a need for an in-depth analysis of the role of the PP within the greater realm of decision-making in environmental health.

The article presents information on proceedings convened in Bologna by the Collegium Ramazzini to discuss the Precautionary Principle. The purpose in convening this conference was to consider the paradigm of traditional risk assessment, to illuminate its shortcomings, and to asses how Collegium Ramazzini can go beyond risk assessment to better prevent disease, death and disability through application of the precautionary principal. The Collegium Ramazzini serves as a bridge between the world of science and the world of public policy, so that scientific data can illuminate, shape, and guide the work of legislation and policymaking.

The article discusses the Precautionary Principle. It is argued that science must be free to identify the problems, set priorities, decide its own programmes, assess the results as they come in; above all it must establish relations with society, and society must make use of its contribution. These relations, however, must not undermine its independence: in other words, the relationship is one of interaction and interdependence, not dependency. In this context, the Precautionary Principle approach to governing the regaining of a just equilibrium between development, environment and health represents an adequate approach augured by many.

The article focuses on the use of Precautionary Principle for protecting human health and sustainability of the environment. Current regulatory practice permits the marketing of many products and technologies on the assumption that they cause no unacceptable harm, thus placing the burden of proving harm on public authorities. Under the Precautionary Principle, by contrast, products and technologies must be assessed to show that they are acceptably safe before they are introduced for use, as is currently the case for most pharmaceuticals and pesticides.