Not all the changes that have occurred in this century have been good for health.

The most obvious of the health-damaging behavior that have shown an increase is cigarette smoking.

Changes in society with improved transport systems, more advanced information and industrial technology, increased leisure, and very widespread possession of televisions and videos in homes has led to less physical exercise being taken, and thus an increase in risk for such diseases as coronary heart disease, stroke and arthritis.

Abortion and fertility are also issues of public health, as well as ethical concern. In the past abortion was illegal, and practiced illicitly with undocumented consequences. It has been legal since 1968, with a sharp increase in the first 4 years. Whether it is now more common than in earlier years we know not. Other methods of contraception, such as the Pill have been introduced, and have revolutionized this area of health care and society. Recent advances in reproductive medicine too have opened possibilities in the treatment of infertility, which have vast ethical implications yet to be fully addressed by the profession, politicians and society at large.