Co-occurrence of and Infant Exposure to Multiple Common and Unusual Phenolic Antioxidants in Human Breast Milk

Abstract

In this study, eight common and two unusual synthetic phenolic antioxidants (SPAs), as well as four transformation products (TPs), were comprehensively analyzed in 80 human breast milk samples collected from lactating women in South China. All 10 SPAs and 4 TPs were detected in the breast milk samples. 2,4-Di-tert-butylphenol (DBP) was detected at high concentrations (mean of 16.9 ng/mL), followed by 2,6-di-tert-butyl-hydroxytoluene (BHT) (mean of 1.52 ng/mL). DBP and BHT collectively contributed to 91.9% of the mean ∑SPAs (sum concentrations of all 10 detected SPAs). The lipid content was identified as an important endogenous factor that influenced the levels of DBP and BHT in breast milk. The concentrations of BHT, DBP, and ∑TPs (sum concentrations of all four detected TPs) in the breast milk were significantly associated with maternal education level, eating habits, and personal care product use (p < 0.05). Furthermore, the concentrations of BHT and its TPs in the breast milk were also found to be significantly associated with newborn birth outcomes, including prematurity and birth length (p < 0.05). This is the first study to report significant associations of the concentrations of some SPAs in breast milk with some important demographic characteristics and lifestyle factors.

Synthetic Phenolic Antioxidants: A Review of Environmental Occurrence, Fate, Human Exposure, and Toxicity

“…A general conclusion that can be drawn from the studies reported above is that BHT and DBP tend to be the two dominant congeners in humans. Interestingly, while DBP was present at much lower concentrations than BHT in both indoor and outdoor environments, the reverse tends to be true in humans: DBP has been observed at higher concentrations than BHT in human serum, 24 urine, 83 and breast milk samples 81 (Table 2). This mismatch between high concentrations of DBP in humans and low concentrations in the environment suggests the existence of unknown human exposure pathways to DBP.…”

“…The transplacental transfer efficiencies of all SPAs and metabolites except AO2246 were below one. SPAs were also analyzed in breast milk from Chinese donors . Eight SPAs (BHT, DBP, AO246, DTBSBP, BHA, D t AP, 4- t OP, and AO2246) were detected in the human breast milk samples, with high concentrations of DBP (median: 14.2 ng/mL) and BHT (median: 1.13 ng/mL) making these the dominant congeners.…”

Rat Metabolism Study Suggests 3-(3,5-Di-tert-butyl-4-hydroxyphenyl)propionic Acid as a Potential Urinary Biomarker of Human Exposure to Representative 3-(3,5-Di-tert-butyl-4-hydroxyphenyl)propionate Antioxidants

“…Human exposure to these chemicals has also been reported . Low-molecular-weight SPAs such as BHT have been detected in human fingernail, serum, , breast milk, and urine , samples from donors in China and the United States. As SPAs are not persistent organic pollutants, they can be transformed into related metabolites in biota.…”

“…For example, AO1010, octadecyl-3-(3,5-di- tert -butyl-4-hydroxyphenyl)­propionate (AO1076), and octyl-3-(3,5-di- tert -butyl-4-hydroxyphenyl)­propionate (AO1135) were detected in indoor dust collected in Toronto, Canada, and Bloomington, USA, and in outdoor air particulate matter collected in Tarragona, Spain . Although 3-(3,5-di- tert -butyl-4-hydroxyphenyl)­propionate antioxidants are largely produced and used and the widespread detection of 3-(3,5-di- tert -butyl-4-hydroxyphenyl)­propionate antioxidants in indoor and outdoor environments suggests potential human exposure pathways to these novel contaminants via dust ingestion and inhalation, ,, very limited information is available on human internal exposure to these novel contaminants . Human urine is a simple matrix that is much easier to collect and analyze compared to other matrices such as human blood and feces.…”

“…2 Although 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate antioxidants are largely produced and used and the widespread detection of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate antioxidants in indoor and outdoor environments suggests potential human exposure pathways to these novel contaminants via dust ingestion and inhalation, 2,13,14 very limited information is available on human internal exposure to these novel contaminants. 34 Human urine is a simple matrix that is much easier to collect and analyze compared to other matrices such as human blood and feces. In the present study, we seek to provide this information by analyzing human urine samples from United States donors to investigate the presence of seven 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate antioxidants (AO1010, AO1024, AO1035, AO1076, AO1098, AO1135, and AO697; full names are listed in Table S1) that have previously been detected in the environment.…”