Assessment of cat exposure to phthalates through phthalate metabolites analysis in the hair samples.

Phthalates are substances used in industry which are harmful to humans and animals. Cats and dogs, living in close proximity to humans, are particularly exposed to the effects of phthalates. Although hair samples seem to be the best matrix for studies on long-term exposure to phthalates, no such studies have been conducted in cats to date. This study aimed to establish concentration levels of selected phthalate metabolites (i.e. monomethyl phthalate-MMP, monoethyl phthalate-MEP, mono-isobutyl phthalate-MiBP, monobutyl phthalate-MBP, monobenzyl phthalate-MBzP, mono-cyclohexyl phthalate-MCHP and mono(2-ethylhexyl) phthalate-MEHP) in cat hair samples using liquid chromatography with mass spectrometry (LC-MS/MS) analysis. MiBP and MEHP were found in 100% of samples with median 66.6 pg/mg and 35.9 pg/mg, respectively, MBP in 97.1% with median 55.7 pg/mg, MEP in 94.3% with median 152.0 pg/mg, MMP in 85.7% with median < limit of quantification (LOQ) and MBzP in 32.9% with median < limit of detection (LOD). MCHP has not been found in cat hair samples during this study. The study has shown that cats are exposed to phthalates. This exposure is higher in indoor cats and depends on the body condition. On the other hand, statistically significant gender- and age-dependent differences in phthalate metabolites levels have not been found during this study. The results have also shown that hair samples may be used as a matrix during studies on levels of phthalate metabolites in cats.