Enumerated powers. The enumerated powers are a list of items found in Article I, Section 8 of the U.S. Constitution that set forth the authority of Congress. In summary, Congress may exercise the powers that the Constitution grants it, subject to the individual rights listed in the Bill of Rights.
The average adult has 10-12 pints of blood. Someone needs blood every two seconds in the U.S. 40,000 pints: Amount of donated blood used each day in the U.S. and Canada. Through a process of separating blood into its individual parts, a single unit of blood can help extend the lives of as many as three people.
Regular blood donation can be done every 8 weeks. A person with severe iron overload may need to give blood as much as 8 times in a single month! The goal is to bring blood ferritin levels to an ideal range of 50-150ng/mL. Depending on the amount of iron overload at the time of diagnosis, reaching normal levels can require several phlebotomies. Serum ferritin drops about 30ng/mL with each full unit (500cc) of blood removed.