Dichlorodiphenyldichloroethylene (DDE) residue limit exceeded in pig tissues after feed-borne exposure to maximum allowed concentration

Monitoring of undesirable substances by the European Union indicates a presence of natural and anthropogenic pollutants in animal feed that may be of concern for the producers, as well as the veterinary services. Although the literature concerning toxicity of DDT (an insecticide widely used in the past) is extensive, less attention has been focused on the biological properties of DDE and its interactions with other contaminants. This study reports on the concentration profile of p,p’-DDE and two other ogranochlorines (p,p’-DDT, p,p’-DDD) in different tissues of immature gilts after 14, 28, and 42 days of oral exposure to p,p’-DDE alone (0.5mg·kg-1feed·day-1) and in mixture with naturally occurring mycotoxin zearalenone, ZEN (0.5+0.1mg·kg-1feed·day-1). The treatment resulted in a time© UNIVERSITY OF WARMIA AND MAZURY IN OLSZTYN INTRODUCTION Dichlorodiphenyltrichloroethane (DDT) is an organochlorine pesticide, used worldwide in the past to control insect vectors of infectious diseases (Rogan and Chen 2005). DDTwas also used as an insecticide to protect crops, including Poland, before it was banned in most countries in the 1970’s for its negative effects on humans, wildlife, and the environment. Despite the ban, this insecticide is still used as a cost-effective method to prevent malaria in some tropical regions (Bettinetti et al. 2011). DDT is a highly persistent pollutant. In the environment, it may last for many years, as it is slowly biodegraded to DDE (dichlorodiphenyltrichloroethylene) and DDD (dichlorodiphenyldichloroethane) in processes generally driven by the action of microorganisms in the soil (ATSDR 2002). Common and intensive use of DDT has resulted in worldwide pollution with this compound. It has been found in organisms living in deserts as well as in the depths of oceans (Turusov et al. 2002). Since the times of DDT extensive use, its residual levels in the environment have greatly declined. 2 ENVIRONMENTAL BIOTECHNOLOGY 11 (1) 2015 However, due to its persistence, the pesticide will be present at low concentrations for decades (Glynn et al. 2009; NTP 2011). Current human exposure to DDT and its metabolites is known to occur mainly through dietary intake, particularly consumption of contaminated fish or meat (ATSDR 2002; NTP 2011). Technical grade DDT is a mixture of different isomers: approximately 85% of the p,p-DDT isomer with o,p’-DDT and o,o’-DDT present in lesser amounts (ATSDR 2002). In mammals, the p,p’-DDT isomer is metabolized mainly to p,p’-DDE and p,p’-DDD by the microsomal cytochrome P450 system (Kitamura et al. 2002). Due to their high lipophilic properties (p,p’-DDD