Distribution of Endocrine Disruptor Chemicals and Bacteria in Saline Pétrola Lake (Albacete, SE Spain) Protected Area is Strongly Linked to Land Use

Bioremediation of Endocrine Disrupting Chemicals- Advancements and Challenges

Endocrine Disrupting Chemicals (EDCs), major group of recalcitrant compounds, poses a serious threat to the health and future of millions of human beings, and other flora and fauna for years to come. A close analysis of various xenobiotics undermines the fact that EDC is structurally diverse chemical compounds generated as a part of anthropogenic advancements as well as part of their degradation. Regardless of such structural diversity, EDC is common in their ultimate drastic effect of impeding the proper functioning of the endocrinal system, basic physiologic systems, resulting in deregulated growth, malformations, and cancerous outcomes in animals as well as humans. The current review outlines an overview of various EDCs, their toxic effects on the ecosystem and its inhabitants. Conventional remediation methods such as physico-chemical methods and enzymatic approaches have been put into action as some form of mitigation measures. However, the last decade has seen the hunt for newer technologies and methodologies at an accelerated pace. Genetically engineered microbial degradation, gene editing strategies, metabolic and protein engineering, and in-silico predictive approaches - modern day's additions to our armamentarium in combating the EDCs are addressed. These additions have greater acceptance socially with lesser dissonance owing to reduced toxic by-products, lower health trepidations, better degradation, and ultimately the prevention of bioaccumulation. The positive impact of such new approaches on controlling the menace of EDCs has been outlaid. This review will shed light on sources of EDCs, their impact, significance, and the different remediation and bioremediation approaches, with a special emphasis on the recent trends and perspectives in using sustainable approaches for bioremediation of EDCs. Strict regulations to prevent the release of estrogenic chemicals to the ecosystem, adoption of combinatorial methods to remove EDC and prevalent use of bioremediation techniques should be followed in all future endeavors to combat EDC pollution. Moreover, the proper development, growth and functioning of future living forms relies on their non-exposure to EDCs, thus remediation of such chemicals present even in nano-concentrations should be addressed gravely.

Heavy Metals in Sediments and Greater Flamingo Tissues from a Protected Saline Wetland in Central Spain

Aquatic ecosystems often act as sinks for agricultural, industrial, and urban wastes. Among potential pollutants, heavy metals can modify major biogeochemical cycles by affecting microorganisms and other biota. This study assessed the distribution and concentration of heavy metals (Cd, Hg, Cu, Pb, and Zn) in Pétrola Lake, a heavily impacted area in central Spain where the greater flamingo Phoenicopterus roseus breeds. This study was designed to determine the concentration and identify the potential sources of heavy metals in Pétrola Lake protected area, including sediments, agricultural soils, and tissues of the greater flamingo. A six-step sequential extraction was performed to fractionate Cu, Pb, and Zn from lake sediments and agricultural soil samples to gain insight into different levels of their bioavailability. Our results showed that Pb and Cd accumulated in lake sediments and agricultural soils, respectively, most likely derived from anthropogenic sources. Multivariate analysis revealed differences between these (Pb and Cd) and the remaining studied elements (Cu, Hg, and Zn), whose concentrations were all below the pollution threshold. Lead pollution in sediments was apparently dominated by organic matter binding, with fractions up to 34.6% in lake sediments. Cadmium slightly accumulated in agricultural soils, possibly associated with the use of fertilizers, but still below the pollution thresholds. In the flamingo samples, low bioaccumulation was observed for all the studied elements. Our study suggests that human activities have an impact on heavy metal accumulation in sediments and soils, despite being below the pollution levels.

Sedimentary spectrum and potential ecological risks of residual pharmaceuticals in relation to sediment-water partitioning and land uses in a watershed

Pharmaceutical residues in river surficial sediment are prone to anthropogenic impacts and environmental factors in watershed, but the mechanisms remain unclear. This study attempted to reveal surficial sediment-water pseudo-partitioning and anthropogenic (land use) patterns of pharmaceutical residues in surficial sediment among 23 subwatersheds of Jiulong River, southeast China with a gradient of urban land use percentile in dry and wet seasons. Thirty-eight out of target 86 compounds from six-category pharmaceuticals were quantified and ranged from below the quantification limits (0.001 mg kg^-1 dry mass) up to 8.19 mg kg^-1 dry mass (chlortetracycline) using a developed SPE-HPLC-MS/MS protocol. Antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs) collectively dominated sedimentary pharmaceutical residues for 34.5-99.8% of the total quantified compounds (median at 92%). Land uses in subwatersheds showed high consistency with sedimentary pharmaceutical residues in the dry season rather than the wet season, especially for human use only and veterinary use only compounds. Surficial sediment-water partitioning of pharmaceutical compounds influenced their sedimentary residues regardless of season, which were determined by properties of compound and surficial sediment interactively. All tetracycline compounds, trimethoprim (sulfonamides synergist), caffeine (central nervous system drug), and oxfendazole (antiparasitic drug) were quantified to pose high potential ecological risks to aquatics. Findings of this study suggest that pseudo-persistent legacy of human and veterinary pharmaceuticals requires a wider coverage of pharmaceutical compounds for a comprehensive ecological assessment in the environment and more involvement of anthropogenic impacts and socioeconomic factors in the future studies.