Working across sectors for public health.

Hippocrates wrote about the relationship between environmental conditions and health status in Airs, waters and places in about 460 BC, where he identified environmental factors affecting human health that “doctors must know to pursue their calling”. Working across different sectors in public health is therefore not a new idea. The routes through which people are exposed to environmental hazards such as traffic-related air pollution or lead, for example, cut through many sectors, all of which need to be involved if change is to be achieved. The benefits of cross-disciplinary dialogue were recognized in the AlmaAta Declaration in 1978 (1). Nevertheless, health professionals are still more comfortable looking at patients than at the broader determinants of their health. Identifying environmental causes of diseases and implementing the measures needed to remove them is not easy, especially at local level where sectors are involved over which health policy-makers have little or no control. Such work may expose them to unfamiliar territories, budgets, vocabularies and political priorities, as well as dialogue with industry, nongovernmental organizations, planning authorities and legislators. To facilitate this cross-sectoral cooperation, fundamental in environment and health, the WHO European Region has brought health ministers together with their counterparts in environment in quinquennial ministerial conferences, starting in 1989. The aim is to make public health a key objective for other sectors, with health impact assessment as a routine management tool. The ethical and political value of human health as a driving force persuades other sectors to give it consideration, particularly because environmental hazards do not affect everyone in the same way: people living in poverty are more exposed (2, 3). In addition, the economic argument is persuasive: at a time when the health sector is under political pressure to deliver services, it is financially attractive to reduce the demand on health services by removing