Endocrine Disruption Is Reduced but Still Widespread in Wild Roach (Rutilus rutilus) Living in English Rivers

Abstract

Endocrine disruption of wild fish, primarily resulting in the feminization of males, has been reported in English river sites for several decades. Estrogenic activity emanating from wastewater treatment works (WwTW) has been conclusively demonstrated to be the main driver of these feminized phenotypes. Here, we revisit 10 English river sites previously surveyed in the late 1990s and early 2000s to assess how the frequency and severity of feminization now compare with the historical surveys. In the contemporary assessment, 60% of the sites revisited still showed endocrine disruption at the tissue organization level (oocytes present in otherwise male gonads; intersex) and 90% of sites had average male plasma vitellogenin concentrations (female-specific yolk protein; a sensitive biomarker of estrogen exposure) above natural baseline levels. In contrast to the historic surveys, none of the males sampled in the contemporary survey had ovarian cavities. At one of the larger WwTW, improvements to treatment technology may have driven a significant reduction in intersex induction, whereas at several of the smaller WwTW sites, the frequencies of feminization did not differ from those observed in the late 1990s. In conclusion, we show that although the severity of feminization is now reduced at many of the revisited sites, endocrine-disrupting chemicals are still impacting wild fish living downstream of WwTW in England.

Assessing Environmental Risks during the Drug Development Process for Parasitic Vector-Borne Diseases: A Critical Reflection

“…While the contamination of the aquatic ecosystem occurs through drug excretion and improper disposal, the terrestrial environment is also exposed to APIs through the application of sewage sludge, leaching from landfills, the application of treated or untreated wastewater to irrigate arable land, and directly from excretion of veterinary medicines by animals . As a noteworthy illustration of aquatic pollution, the upregulation of vitellogenin, a protein predominantly associated with females, in male fish exposed to estrogenic APIs in the environment resulted in the feminization of freshwater species. , A striking case in the terrestrial environment is that of unforeseen secondary poisoning effects following off-label use of the nonsteroidal anti-inflammatory drug diclofenac, which had a devastating impact on vultures and caused a >99% population decline among Gyps vulture species in India and Pakistan due to renal failure after the consumption of diclofenac-contaminated cattle carcasses. , Additionally, the ramifications of improper disposal are evident in cases like ivermectin, which has been detected in soil and water, potentially serving as a source of single- or multidrug resistance …”