Degradation of Chlorinated Hydrocarbon Pesticides in Milk and Butteroil by Ultraviolet Energy

tIigh-intensity ultraviolet energy produced by a carbon arc lamp will degrade organochlorine insecticides contaminating fluid whole milk or butteroil. Rate of degradation was a function of the film thickness and depth of penetration of the rays when operating conditions were held constant. Degradation of methoxychlor in butteroil was 96% after one exposure; smaller percentages of other insecticides were degraded. The degradation products for methoxychlor were identified and are structurally similar to those reported for DDT. Removal of pesticides from milk and butteroil by ultraviolet light is still unsatisfactory. Apparently, the most satisfactory control measures involve monitoring the contaminants in the rations fed to lactating animals. Continued demands on farudand for increased production currently necessitate the use of pesticides. As a result, inadvertent contamination of crops, misuse, and occasionally mislabeling lead to pesticides in our food supplies. With the exception of the chlorinated hydrocarbons, the dairy cow detoxifies almost all insecticides during normal metabolism. However, the organoehlorine pesticides are stored in the body fat of the cow. Because of an equilibrium between the blood lipids and depot fat, pesticides are circulated through the animal, and some quantities are transported into the milk.