Phthalate metabolite concentrations in urine samples from Swedish pet dogs

Sammanfattning: Phthalates are chemicals used as plasticizers and can be found in a number of different consumer products. Phthalates may leak from these products into the environment, and hereby humans and animals may be exposed to phthalates through oral intake, dermal exposure and inhalation. Experimental studies on primarily rodents have shown that phthalate exposure causes toxic effects on the reproductive system, such as effects on the levels of testosterone, progesterone and estradiol, the weight and descent of testes, the onset of puberty and maintenance of pregnancy. The purpose of this study was to quantify the concentrations of phthalate metabolites in urine samples from healthy pet dogs and to investigate relationships between the concentrations and the home environment of the dogs using a questionnaire filled out by the dogs’ owners. Sixteen dogs were included in the study, with matched groups of which eight dogs lived in homes with plastic flooring and eight dogs lived in homes without plastic flooring. Urine samples were collected and analysed for ten different phthalate metabolites originating from the phthalates diethyl phthalate (DEP), dibutyl phthalate (DBP), butylbenzyl phthalate (BBzP), di(2-ethylhexyl) phthalate (DEHP) and diisononyl phthalate (DiNP). The results showed that all dogs participating in the study had identifiable levels of each of the different metabolites in their urine. The dogs living in homes with plastic flooring had higher levels of phthalate metabolites in their urine compared to the dogs living in homes without plastic flooring. This difference was statistically significant for MBzP, the metabolite of BBzP, and for MEHP, MHEHP, MOEHP and MCEPP, metabolites of DEHP. Plastic toys were also identified as a possible risk factor for higher phthalate metabolite concentrations in urine. The results of this study show that dogs are exposed to and absorb phthalates from the environment, and that dogs living in homes with plastic flooring appear to be exposed to and absorb a greater amount of phthalates than dogs living in homes with non-plastic flooring.