2,4,6-Trinitrotoluene (TNT) Air Concentrations, Hemoglobin Changes, and Anemia Cases in Respirator Protected TNT Munitions Demilitarization Workers

Background: 2,4,6-Trinitrotoluene (TNT) is an explosive used in munitions production that is known to cause both aplastic and hemolytic anemia in exposed workers. Anemia in a TNT worker is considered a SHE(O). Deaths have been reported secondary to aplastic anemia. Studies have shown that TNT systemic absorption is significant by both the respiratory and dermal routes. No studies encountered looked at hemoglobin change or anemia cases in respiratory protected workers.

Hypothesis: Respiratory protection is insufficient to protect TNT workers from the risk of anemia development and hemoglobin concentration drop.

Methods: A records review of eight groups of respiratory protected TNT workers' pre-exposure hemoglobin levels were compared with their during-exposure hemoglobin levels for statistically significant (alpha level 0.05) hemoglobin level changes; and anemia cases were recorded. Mean hemoglobin changes within each of the 8 groups of workers were then regressed on mean TNT air concentrations using air sampling that was performed closest in time to during-exposure hemoglobin follow-ups.

Results: Statistically significant hemoglobin level drops and anemia cases were apparent at TNT air concentrations about the REL and PEL in respiratory protected workers. There were no anemia cases or statistically significant hemoglobin level drops at concentrations about the TLV, however. For TNT air concentrations from 0.12mg/m^3 to 0.31mg/m^3 there was a strong positive linear association with regard to magnitude of hemoglobin change (r=0.996). Conclusion: Respiratory protection may be inadequate to prevent workers who are at risk for TNT skin absorption from developing anemia.