Today - United Nations World Health Day - is the 64th anniversary of the founding of the World Health Organisation. In human terms, that is no longer seen as old because people live much longer, a factor in the choice of ageing and health as the global theme for this birthday. In the next few years, for the first time, the world will have more people aged over 60 than children under five. The issue resonates in Hong Kong, where the needs of an ageing population will impose an increasing burden on public spending for health and welfare services, as well as on a proportionately smaller workforce and the adult children of smaller families. WHO chief Dr Margaret Chan Fung Fu-chun, a former Hong Kong director of health, says the main health challenges for older people are non-communicable diseases such as heart disease, stroke, cancer, diabetes and chronic lung disease, often associated with lifestyle issues. She says people in low- and middle-income countries face up to four times the risk of death and disability from these diseases than people in rich countries. Though Hong Kong is home to great wealth, a low to middle average income puts it in the higher-risk category. But that does not stop us from adopting risk-reducing behaviour such as exercise, healthy eating, moderate use of alcohol and not smoking. The sooner we adopt these practices the better the chances of a healthy old age. Hong Kong is fortunate to have a world-class public health system, but its resources are under increasing strain and they already devour a large chunk of the government's budget for recurring spending. Chief executive-elect Leung Chun-ying has promised to enhance health-care financing. We trust he will also approach reform of health-care delivery with more urgency. This should include the integration of the public and private sectors to promote preventive health care through family doctors. And he could leave Hong Kong a healthier place if he showed more resolve than the present administration in stopping smoking in public places and adopting more stringent air pollution standards.