As a tool to reveal potential trends and associations between chemical exposures, a correlation matrix is shown in Supplementary Table . Most notably, a strikingly strong correlation between methylparaben and propylparaben levels is revealed, as well as correlation between, among some others, ethylparaben and methylparaben/n-butylbenzenesulfonamide, and glycitein and daidzein. This is in line with expected routes of exposure, as the respective compounds likely stem from identical or related sources. To the best of our knowledge, the detection of the pyrrolizidine alkaloids jacobine-and riddelliin-Noxide, the tropane alkaloids anisodamine and scopolamine, and the heterocyclic aromatic amine PhIP have never been previously reported in breast milk. The latter was detected at trace levels on two consecutive days of sampling and suggests consumption of a heavily-contaminated food product, e.g., typically well-done, roasted, or grilled meat. Phytotoxin contamination was apparent throughout the sampling period as the individual was known to regularly consume herbal tea mixtures that are intended to promote milk production. For the first time, this study demonstrated that infants can be exposed to these plant alkaloids of emerging interest via breast milk if the mother regularly consumes certain foodstuffs or drinks.