Waste pollutes clean water, making it undrinkable. Even today in some African cities, there are inadequate water supplies because most of the water is lost in pipe leakages, according to the UN. Today, outdoor air pollution contributes to about two million deaths a year and a host of chronic health problems.
The normal, healthy heart has its own pacemaker that regulates the rate that the heart beats. However, some hearts don't beat regularly. A pacemaker can sometimes correct the problem. A pacemaker is a small device that sends electrical impulses to the heart muscle to maintain a suitable heart rate and rhythm. A pacemaker may also be used to treat fainting spells (syncope), congestive heart failure, and hypertrophic cardiomyopathy.
The role of VVI pacemaker is that in the event that a heart is slowing down, or stop, sends an electrical impulse to the right ventricle and activates the heart. Electrical impulses from the right ventricle passes to the left ventricle and thereby runs the blood flow.VI pacemaker is not sufficient when the ventricles are not able to beat together in the cases of congestive cardiac failure and then dual chamber pacemaker is required. Possible problems during implementation of VVI pacemakers are: 1  collapsed lung. 2  infection.