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-dependent accumulation of p,p’-DDE in fat-rich tissues. Although the pesticide’s concentration found in the adipose tissue exceeded the FAO/WHO maximum residue limit (5mg·kg-1 of fat), human dietary risk is little, as it requires a substantial consumption of such contaminated pork fat. Importantly, the high concentration of p,p’-DDE found in the adrenal glands suggests a threat to the animals’ health. Finally, a difference in the accumulation of p,p’-DDE was observed between the groups treated with this compound alone or in mixture with ZEN. This is most likely related to growth performance of the animals, altered by the endocrine disrupting activity of both compounds. Further research should evaluate the effects of p,p-DDE at the observed concentrations on the pigs’ health status and enable the studies of possible interactions with other environmental pollutants.