Occurrence and Origin of Estrogenic Isoflavones in Swiss River Waters

Abstract

We report results from a systematic one-and-a-half year survey of the estrogenic isoflavones formononetin (FOR), biochanin A (BIO), daidzein (DAI), genistein (GEN), and equol in Swiss midland rivers. FOR was detected in about 90%, the other compounds in 13-56% of the weekly and fortnightly integrated flow proportional samples. Concentrations were mostly in the lower ng/L-range, with a maximum of 524 ng/L and 217 ng/L for equol and FOR, respectively. Due to dilution, concentrations were river discharge dependent with higher numbers in smaller rivers. Total isoflavone loads were in the order of a few kg/y, and occurred mainly during summertime. A complementary river water monitoring campaign throughout the country confirmed the above findings. Circumstantial evidence points to grassland as a major emission source of FOR and BIO (the main compounds in red clover) in surface waters, e.g., their absence in wastewater treatment effluents, better correlations of their loads with grassland areas than with population equivalents, similar isoflavone ratios in river water and grassland runoff. Source apportionment was less clear for DAI, GEN, and equol. The contribution of isoflavones to the total estrogenicity of surface waters is probably small, except maybe in local rural catchments without major anthropogenic activities.

Determination of seventeen endocrine disruptor compounds and their spatial and seasonal distribution in Ria Formosa Lagoon (Portugal)

“…Despite the high water turnover at each tide, several studies reported eutrophication and hypoxia, mainly in summer at some spots of the lagoon (Newton and Mudge 2005;Newton et al 2010); however, no information exists about the presence of either phytoestrogens or the annual fluctuation patterns of sitosterol. These compounds in spite of being of natural/vegetal sources, in high amounts phytoestrogens and sitosterol, are known to act as endocrine disrupter compounds (EDCs; Hoerger et al 2009;Clotfelter et al 2010). Thus, beyond the last compounds, the present study aimed to provide the first data for the Ria Formosa Lagoon about the levels of several of the most concerning worldwide anthropogenic/industrial EDCs such as estradiol, estrone, ethynylestradiol, 4-n-octylphenol, 4-toctylphenol, nonylphenol, several polyethoxylates (4-octylphenol monoethoxylate, 4-octylphenol diethoxylate, 4-nonylphenol monoethoxylate, 4-nonylphenol diethoxylate), and bisphenol A.…”

Fresh and ensiled forages as a source of estrogenic equol in bovine milk: a review

“…Formononetin was the most frequent compound. Concentrations were usually in the lower ng/l range with the maximum of 524 and 217 ng/l for equol and formononetin, respectively (Hoerger et al, 2009). Among isoflavone cumulative loads in the catchments, annual values of 105-220, 0.5-1, and 0.1-5.1 kg/ha were determined for red clover, manure, and soil.…”

Personal Care Products Are Only One of Many Exposure Routes of Natural Toxic Substances to Humans and the Environment

“…It is also used in foods and medicine, mainly in Asia, and is a known contaminant in milk produced by cows, sheep, and goats browsing on bracken [38]. There is ample As a consequence of their regular consumption via food and healthcare products, they are excreted and emitted via WWTP to the aqueous environment [27,28]. An alternative, and potentially even more important, source of isoflavones to the environment are agricultural areas cultivated with forage and grain legumes, as such plants can produce up to 220 kg of isoflavones per hectare and year [29].…”

“…An alternative, and potentially even more important, source of isoflavones to the environment are agricultural areas cultivated with forage and grain legumes, as such plants can produce up to 220 kg of isoflavones per hectare and year [29]. Indeed, formononetin, the dominating isoflavone compound in red clover, was detected most frequently in Swiss [28] and U.S. surface waters [30].…”