Within the circulatory system blood is either blue or green. This means blood turns red when the hemoglobin on the erythrocytes (red blood cells) become covered with oxygen in the atmosphere.
The problem is everything in the air gets sucked into it to.

Like the Oreck filtration system commercials show there’s alot of contaminants (Black stuff) in the air. These contaminants include the diseases accumlated in hospitals (when drawn in hospitals). It is a well known fact that more people get sick in the hopital than anywhere else. There is currently no way to avoid the contamination of blood.

Also Blood like anything else foreign to the body, has the risk of rejection, or atleast causes the body more difficulty in healing itself due to having to adapt to the foreign material. [During the beginning of the AIDS pandemic in the 1980’s over 30,000 hemophiliacs aquired the disease from tainted Plasma which is a component of blood. Plasma screening was the most thorough blood screening system at that time]

Blood conservation techniques have the same mortality rate as using blood in surgery. The major difference is the lack of knowledge in these techniques and the fact that healing time is much shorter in blood conservation.

Another difference would be the use of electrocauterization (Electrcally closing cuts or surgical openings in the body). This almost imediately seals the openings without waiting for stitches to heal.

The truth is the bible used terms such as clean and unclean or holy and unholy to describe thngs that we now are beginning to understand as aseptic/septic (sannitary, unsanitary) or other definitions according to their context. This also applies to the food that we eat according the biblical laws, but those laws are no longer practiced with the admittance of gentiles.

Wether the interpretation of the scriptures are argued one way or another the scientific facts would still exist even with out the Jehovah’s witnesses.