The Iodine Concentration of Market Milk in Tennessee, 1981-1986

Three hundred samples of processed milk from 10 milk processors in Tennessee were collected during the years 1981-1986, and analyzed for iodine concentration. Although some fluctuations occurred during the period, a downward trend was noted from the 287 μg/kg milk in 1981 to the 214 μg/kg milk in 1986. The overall average was 240 μg/kg. Seasonal differences were observed; spring samples had an average of 298 μg/kg; summer samples 200 μg/kg, and fall samples 234 μg/kg. Differences between plants were also found, with averages ranging from 153 to 344 μg/kg milk. Thirty-eight samples of raw tanker milk collected at one plant location during 1982-1986 had iodine concentrations ranging from 82 μg/kg to 1898 μg/kg, for an average of 240 μg/kg.