The concentrations of selective endocrine disruptors in milk from different lactation periods of cows

Abstract

Milk can be contaminated with organochlorine pesticides, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers, and polycyclic aromatic hydrocarbons (PAHs), which are known as endocrine disruptors (EDCs). However, the relationship between the lactation period of cows and the residues of EDCs is unknown. Milk collected from cows during each lactation period was analyzed in terms of fat content and EDC residues. One or more contaminants were detected in almost all (98%) of the milk taken in three lactation periods. For example, 3 PCBs and 11 PAHs were found together in the first lactation period, and one more PAH was added to them in other periods. Also, it was seen that the most risky period was the first lactation period, followed by the third and second periods. The same ranking is valid for the fat content in milk. Thus, it was concluded that the excretion of lipophilic EDCs in milk is related to the fat content in milk, and the higher the fat content in milk, the more lipophilic EDCs are excreted in milk. However, regardless of the lactation period, when EDC residues are found in milk above the reference levels, it can be considered to disrupt the endocrine system in both adults and children.