The World Health Report 2002 international organizations that clearly aim to be influential in public health, including the World Health Organization, other multilateral and specialized agencies of the United Na ions, and bilateral donor agencies. In addition, many international nongovernmental or- ganizations do play a major role in gathering evidence, disseminating information and advocating risk control policies in such areas as child labour, dangerous chemicals and the dumping of waste products IMPORTANCE OF MASS MEDIA IN RISK PERCEPTIONS nderstanding common risks to health is crucial for the future well-being of many people in all countries, but information on risks, risk factors and uncertainty are inherently difficult to communicate. However, the mass media clearly do have a powerful influence on people' s perceptions of risks and, in a global world, information on risks can be disseminated ery rapidly through satellite technologies. Although newspapers, magazines, radio and television are often criticized for inaccurate and biased reporting, in industrialized countrie ey remain the most influential sources for everyday information on risks to health(12) The rapid spread of these media in developing countries, together with improvements in literacy, means that this is also increasingly true in low and middle income countries How should the media evaluate and communicate the information on health risks such as HIVIAIDS or new vaccines, particularly if these are associated with scientific and ethical controversies? Such situations challenge the media to be responsible when dealing with complicated scientific issues and conflicting political goals(47). What information should be conveyed? How fully should uncertainties and controversies be explained to the public? With regard to health matters, the media perform two major functions-they can interpret scientific information and government policies to the public, and at the same time they e concerns the general public to a wider national audience. Media are also very much a part of the larger society in which they operate(47). The way the different media outlets report risks to health reflects their biases and organizational constraints, such as whether they are private entities or government agencies and whether they are a free press or allied with particular political or business interests. Since the media are organized to cover newsworthy events, they often seek out sensational and dramatic health episodes such as chemical accidents, exciting research discoveries epidemics of communicable diseases, and safety defects in new medicines. Other controversial debates, such as those between the pharmaceutical industry and the medical profession over access to treatment for HIVAIDS, often gain international attention. Media coverage tends to focus on human interest stories and news about dreaded diseases. In contrast, attention is not often given to common, chronic and low-level risks to healt such as passive exposure to tobacco smoke or poor levels of physical exercise. In addition, the media tend to avoid issues that may threaten prevailing social and cultural norms or moral and economic values Given the complex nature of many risks to health, media reporting has to rely on a variety of expert sources as well as on representatives of government ministries, private ompanies and special interest groups. Government press releases, national scientists and international scientific journals are often the main sources of information for the media Journalists tend to use the best organized sources and those which provide technical information simply in the form of non-technical press releases. In addition, international news organizations frequently syndicate risk stories around the world. Special interest and42 The World Health Report 2002 international organizations that clearly aim to be influential in public health, including the World Health Organization, other multilateral and specialized agencies of the United Na￾tions, and bilateral donor agencies. In addition, many international nongovernmental or￾ganizations do play a major role in gathering evidence, disseminating information and advocating risk control policies in such areas as child labour, dangerous chemicals and the dumping of waste products. IMPORTANCE OF MASS MEDIA IN RISK PERCEPTIONS Understanding common risks to health is crucial for the future well-being of many people in all countries, but information on risks, risk factors and uncertainty are inherently difficult to communicate. However, the mass media clearly do have a powerful influence on people’s perceptions of risks and, in a global world, information on risks can be disseminated very rapidly through satellite technologies. Although newspapers, magazines, radio and television are often criticized for inaccurate and biased reporting, in industrialized countries they remain the most influential sources for everyday information on risks to health (12). The rapid spread of these media in developing countries, together with improvements in literacy, means that this is also increasingly true in low and middle income countries. How should the media evaluate and communicate the information on health risks such as HIV/AIDS or new vaccines, particularly if these are associated with scientific and ethical controversies? Such situations challenge the media to be responsible when dealing with complicated scientific issues and conflicting political goals (47). What information should be conveyed? How fully should uncertainties and controversies be explained to the public? With regard to health matters, the media perform two major functions – they can interpret scientific information and government policies to the public, and at the same time they reflect the concerns of the general public to a wider national audience. Media are also very much a part of the larger society in which they operate (47). The way the different media outlets report risks to health reflects their biases and organizational constraints, such as whether they are private entities or government agencies and whether they are a free press or allied with particular political or business interests. Since the media are organized to cover newsworthy events, they often seek out sensational and dramatic health episodes such as chemical accidents, exciting research discoveries, epidemics of communicable diseases, and safety defects in new medicines. Other controversial debates, such as those between the pharmaceutical industry and the medical profession over access to treatment for HIV/AIDS, often gain international attention. Media coverage tends to focus on human interest stories and news about dreaded diseases. In contrast, attention is not often given to common, chronic and low-level risks to health, such as passive exposure to tobacco smoke or poor levels of physical exercise. In addition, the media tend to avoid issues that may threaten prevailing social and cultural norms or moral and economic values. Given the complex nature of many risks to health, media reporting has to rely on a variety of expert sources as well as on representatives of government ministries, private companies and special interest groups. Government press releases, national scientists and international scientific journals are often the main sources of information for the media. Journalists tend to use the best organized sources and those which provide technical information simply in the form of non-technical press releases. In addition, international news organizations frequently syndicate risk stories around the world. Special interest and