Phytotoxic Hazard of Air Pollution Associated with Munition Production.

Abstract : The phytotoxicity of nitrotoluenes (NT), tetranitromethane (TNM), nitromethane (NM), methyl nitrate (MN), acetic acid and SO2 were tested on seven species of plants: wheat, alfalfa, soybean, tobacco, corn, white oak and scotch pine. These species were fumigated for 120 min after which effects were observed for several hours or days. The plant species were grown in large pots in air conditioned greenhouses prior to and after fumigation. Low concern concentrations were specified by the Government as criteria for the intensity of testing. Based on low concern concentrations, wheat, alfalfa, tobacco, soybean and corn were injured sufficiently with TNM or HAC to warrant further studies. White oak and scotch pine did not exhibit severe enough injury to warrant further study. Moreover, minimal or no injury was observed on any of the plant species tested with NM, NT, or MN. An index of toxicity, EC50 was devised which represented the dosage of phytotoxicant which caused injury to 50% of all the leaves on an exposed plant population. EC50's of TNM were as follows: wheat 0.68, alfalfa 0.93, tobacco 6.1, soybean 0.69 and corn 2.1 mg/cu m; SO2 on wheat 3.35, alfalfa 6.8 tobacco 18.6, soybean 6.8 and corn 21.4 mg/cu m; HAc on wheat 23.3, alfalfa 7.8, tobacco 41.2, soybean 20.1 and corn 50.1 mg/cu m. TNM is, in fact, one of the most phytotoxic compounds which has been tested on plants.