Estrogens and xenoestrogen residues in manure-based fertilizers and their potential ecological risks

Optimal manure treatment aimed at usage as agricultural soil fertilizers is a prerequisite ecological pollution control strategy. In this work, livestock manure-based fertilizers were collected from 71 animal farms across 14 provinces in China. The contamination levels and potential ecotoxicological risks of residual steroid estrogens (SEs): estrone (E1), estriol (E3), 17 & alpha;-estradiol (17 & alpha;-E2), 1713-estradiol (1713-E2) and xenoestrogen (XE) bisphenol A (BPA), were investigated. The results showed that the occurrence frequencies for SEs and XE ranged from 66.67% to 100%, and the mean concentration varied considerably across the study locations. The total content of SEs and XE in Hebei province was the highest, and swine manure-based fertilizers concentrations were higher than the levels reported in other animal fertilizers. Compared with farm level manure, manure-based fertilizers are processed by composting, and the micropollutants quantities are significantly reduced (mean: 87.65 - 534.02 & mu;g/kg). The total estradiol equivalent quantity (EEQ) that might migrate to the soil was estimated to be 1.23 & mu;g/kg. Based on the estimated application rate of manure, 38% of the fertilizers risk quotients exceeded 0.1, indicating medium to high risks pressure on terrestrial organisms. Nonetheless, the estrogenic risk was lower in manure-based fertilizers than in manure. This study highlights the significance of proper treatment of livestock manure and designing an optimal manure fertilization strategy to mitigate the risks posed by SEs and XEs to the agroecosystems.

Automated summary

This study investigated the contamination levels and potential ecotoxicological risks of hormone substances and xenoestrogens in livestock manure-based fertilizers collected from 71 animal farms in China. The results showed varying frequencies and concentrations of these substances across different study locations. Compared with farm level manure, manure-based fertilizers had significantly reduced quantities of micropollutants. However, 38% of the fertilizers had risk quotients that exceeded 0.1, indicating medium to high risks to terrestrial organisms. Nonetheless, manure-based fertilizers had lower estrogenic risks compared to manure. This study emphasizes the importance of proper treatment of livestock manure and designing optimal fertilization strategies to mitigate the risks posed by hormone substances and xenoestrogens to agroecosystems.