Radioactivity in Milk and Dairy Products of Camaguey, Cuba

Milky Industry plays an important economic role in our region, being Camaguey the main producer of milk and dairy products in Cuba. In this paper the concentrations of some radionuclides in milk and dairy products are given. Surveillance is based on a monthly sampling of milk and dairy products from a milk processing plant during a year. Radioactivity is measured using gamma spectrometry, alpha radiometry and radiochemical determination. Mean annual concentrations of natural and artificial radionuclides in milk and dairy products are lower than their reference activity concentrations. Previous works have shown that Camaguey region can be characterized as a region with a low radiological background, and it is been only exposed to global radioactive contamination. Of all radioactivity in milk, 99,6 % is due to the presence of natural radionuclides. The main contributor is 40K Variations in monthly concentrations of radionuclides in milk are linked with the grazing habits and climate conditions (rainy and dry seasons). Also the soil-to-milk transfer of radionuclides is studied, being 9,5.10-5 for Ra-226; 0,228 for K-40 and 0,016 for Cs-137. Based upon measured concentrations the age-dependent associated effective dose due to the ingestion of milk has been calculated. The highest value of effective dose was achieved for the age interval < 1 year, being 1,37 mSv.y1. Considering that radionuclide content in milk and dairy products of the region is far lower than the indicative levels for this kind of products, we conclude that consumption of these products is safe form the point of view of their radio toxicity. (Author)