Investigators reported that "Jet Lag" is caused from air travel through changing time zones, and hence leading to disturbance of melatonin rhythms ²⁶. The main but not only cause of jet lag is crossing time zones. Usually going east is worse than going west ^27,28. Finally, the obtained negative relationship between mortality data and elevation is clear in the sense that reduced temperature occur higher elevation where there is less water vapor to trap and hold heat.

The resulted regression model must be analyzed carefully. We believe that all the environmental factors are related together in such way that they represent an optimal integrated model. That is, we can not treat their influence on the mortality rate separately.

Spatial variation in the distribution of breast cancer rates has been well documented, both internationally and within the United States ^5,29. We proposed a medical-based Geographic Information System (mGIS) application for monitoring and reducing the risk factors associated with the spatial environmental factors.