Primary phthalate metabolite concentrations in the hair of dairy cows in Kyrgyzstan.

Phthalates are commonly used in industry, contaminating the environment and harming living organisms. However, there is very limited information regarding farm animal exposure to these chemicals. Therefore, this study aimed to assess the levels of primary phthalate metabolites (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 dairy cows' hair. Hair samples were collected from dairy cows bred in three regions of Kyrgyzstan. Phthalate metabolite levels were analysed using the liquid chromatography with mass spectrometry (LC-MS) method. Phthalate metabolites were detected in dairy cow hair. MEHP was the most frequently observed (in 70.8% of samples), with a mean concentration (±standard deviation) of 27.3 ± 27.8 pg/mg. MiBP and MBP were found less frequently (in 60.4% of samples), with mean concentrations of 50.7 ± 103.9 pg/mg and 18.8 ± 31.7 pg/mg, respectively. MMP and MBzP were noted in 15% and 2.1% of the samples, respectively, and their mean concentrations were below the limit of detection (LOD). MEP and MCHP were not observed in hair samples in this study. Statistically significant differences in MEHP levels were noted between the regions included in the study. The study has demonstrated that hair analysis is a suitable method for biomonitoring phthalates in cow's hair. Moreover, it has been shown that dairy cows in Kyrgyzstan are primarily exposed to di-2-ethylhexyl phthalate, di-isobutyl phthalate, and dibutyl phthalate, which are the parent substances of MEHP, MiBP, and MBP, respectively.