(Created 12/02)
UNL Environmental Health and Safety · (402) 472-4925 · http://ehs.unl.edu
• Aspirin, which inhibits cloning.
• Benzene, which decreases the number of platelets.
• Tetrachloroethane, which increases the number of platelets.
Leukocytes (white blood cells) are primarily responsible for defending the body against foreign
organisms or materials by engulfing and destroying the material or by producing antibodies.
Chemicals that increase the number of leukocytes include naphthalene, magnesium oxide, boron
hydrides, and tetrachloroethane. Agents that decrease the number of leukocytes include benzene
and phosphorous.
Erythrocytes (red blood cells) transport oxygen in the blood. Chemicals that destroy (hemolyze)
red blood cells include arsine (a gaseous arsenic compound and contaminant in acetylene),
naphthalene (used to make dyes), and warfarin (a rodenticide).
Oxygen Transport. Some compounds affect the oxygen carrying capabilities of red blood cells.
A notable example is carbon monoxide which combines with hemoglobin to form
carboxyhemoglobin. Hemoglobin has an affinity for carbon monoxide 200 times greater than
that for oxygen.
While carbon monoxide combines reversibly with hemoglobin, some chemicals cause the
hemoglobin to change such that it cannot combine reversibly with oxygen. This condition is
called methemoglobinemia. Some chemicals that can cause this are:
• Sodium nitrite, used in meat curing and photography.
• Aniline, used in manufacture of rubber accelerators and antioxidants, resins, and
varnishes.
• Nitrobenzene and dinitrobenzene, used in manufacture of dyestuffs and explosives.
• Trinitrotoluene (TNT), used in explosives.
• Mercaptans, used in manufacture of pesticides and as odorizers for hazardous odorless
gases.
• 2-nitropropane, used as a solvent.
