Legal measures in support of prevention in Switzerland.

The Swiss health system results from a balance between federal and cantonal (state) legislation. Federal laws were instituted to combat infectious disease, certain other severe or widespread diseases, and alcohol and drug abuse; for the protection against harmful agents or substances; and on health and accident insurance. Cantonal implementation permits adaptation to local situations. In the case of health protection, this interplay of federal standards setting and cantonal implementation has been generally successful, but situations in the areas of immunization and breast cancer screening are presented, where, in the absence of uniform legislative guidance, cultural and political diversity has led to regionally different approaches. Varying levels of preventive action have resulted in measurable differences in mortality and morbidity. Lessons for other countries are discussed, where decentralization of preventive and health care services is being considered.

Effect of short-wave (6-22 MHz) magnetic fields on sleep quality and melatonin cycle in humans: the Schwarzenburg shut-down study.

This paper describes the results of a unique "natural experiment" of the operation and cessation of a broadcast transmitter with its short-wave electromagnetic fields (6-22 MHz) on sleep quality and melatonin cycle in a general human population sample. In 1998, 54 volunteers (21 men, 33 women) were followed for 1 week each before and after shut-down of the short-wave radio transmitter at Schwarzenburg (Switzerland). Salivary melatonin was sampled five times a day and total daily excretion and acrophase were estimated using complex cosinor analysis. Sleep quality was recorded daily using a visual analogue scale. Before shut down, self-rated sleep quality was reduced by 3.9 units (95% CI: 1.7-6.0) per mA/m increase in magnetic field exposure. The corresponding decrease in melatonin excretion was 10% (95% CI: -32 to 20%). After shutdown, sleep quality improved by 1.7 units (95% CI: 0.1-3.4) per mA/m decrease in magnetic field exposure. Melatonin excretion increased by 15% (95% CI: -3 to 36%) compared to baseline values suggesting a rebound effect. Stratified analyses showed an exposure effect on melatonin excretion in poor sleepers (26% increase; 95% CI: 8-47%) but not in good sleepers. Change in sleep quality and melatonin excretion was related to the extent of magnetic field reduction after the transmitter's shut down in poor but not good sleepers. However, blinding of exposure was not possible in this observational study and this may have affected the outcome measurements in a direct or indirect (psychological) way.