46 Question 8 - Already, the Mississippi River dumps about 800,000 curies of tritium every . day into the Gulf of Mexico. About 4% of that tritium is produced by . eosmic rays, but the other 96% is man-made tritiuh. Do you have any ideas about how that amount of tritium might affect marine life in the Gulf of Mexico? Answer The Mississippi River discharges nowhere near 800,000 curies of tritium per day into the Gulf of Mexico. 100,000 curies per year. The present value is on the order of This is lower than in 1963 and 1964 when the concentration of tritium in atmospheric precipitation, as well as inthe river, was higher. During the 6-month periods April-September 1963 and 1964, it averaged 64,300 and 82,100 curies per month, respectively. It is the concentration of tritium in water, not the total amount discharged, that would determine its possible effect on marine life. The average concentration of tritium in the Mississippi River at New Orleans during January through June 1969, as reported ty the U. S. Public Health Service, was 0.2 nanocuries per liter (noa/1).° Assuming that the specific activity in an organism is the same as in the water, this average coneentration corresponds to an estimated whole-body dose of 0,034 nrem/year in man, less than 0.024 of the FRC's Radiation Protection Guide for a suitable sample to the population (170 mrem/year). l. Stewart, G. L. 1965. Experiences using tritium in scientific hydrology pp. 643-658. In Radiocarbon and Tritium Dating, Proceedings of 6th International Conference held at Washington State University, Pullman, Washington. 2, USAEC Report CONF - 650652. Radiological Health Data and Reports, Vol. 10, No. 11 (Nov., 1969)