Here, we review present understanding of sources and trends in human exposure to poly- and perfluoroalkyl substances (PFASs) and epidemiologic evidence for impacts on cancer, immune function, metabolic outcomes, and neurodevelopment. More than 4000 PFASs have been manufactured by humans and hundreds have been detected in environmental samples. Direct exposures due to use in products can be quickly phased out by shifts in chemical production but exposures driven by PFAS accumulation in the ocean and marine food chains and contamination of groundwater persist over long timescales. Serum concentrations of legacy PFASs in humans are declining globally but total exposures to newer PFASs and precursor compounds have not been well characterized. Human exposures to legacy PFASs from seafood and drinking water are stable or increasing in many regions, suggesting observed declines reflect phase-outs in legacy PFAS use in consumer products. Many regions globally are continuing to discover PFAS contaminated sites from aqueous film forming foam (AFFF) use, particularly next to airports and military bases. Exposures from food packaging and indoor environments are uncertain due to a rapidly changing chemical landscape where legacy PFASs have been replaced by diverse precursors and custom molecules that are difficult to detect. Multiple studies find significant associations between PFAS exposure and adverse immune outcomes in children. Dyslipidemia is the strongest metabolic outcome associated with PFAS exposure. Evidence for cancer is limited to manufacturing locations with extremely high exposures and insufficient data are available to characterize impacts of PFAS exposures on neurodevelopment. Preliminary evidence suggests significant health effects associated with exposures to emerging PFASs. Lessons learned from legacy PFASs indicate that limited data should not be used as a justification to delay risk mitigation actions for replacement PFASs.

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A review of the pathways of human exposure to poly- and perfluoroalkyl substances (PFASs) and present understanding of health effects

Fungi possess the biochemical and ecological capacity to degrade environmental organic chemicals and to decrease the risk associated with metals, metalloids and radionuclides, either by chemical modification or by influencing chemical bioavailability. Furthermore, the ability of these fungi to form extended mycelial networks, the low specificity of their catabolic enzymes and their independence from using pollutants as a growth substrate make these fungi well suited for bioremediation processes. However, despite dominating the living biomass in soil and being abundant in aqueous systems, fungi have not been exploited for the bioremediation of such environments. In this Review, we describe the metabolic and ecological features that make fungi suited for use in bioremediation and waste treatment processes, and discuss their potential for applications on the basis of these strengths.

Untapped potential: exploiting fungi in bioremediation of hazardous chemicals

https://hal.archives-ouvertes.fr/hal-01577861/document

A comparison of technologies for remediation of heavy metal contaminated soils

Polycyclic aromatic hydrocarbons (PAHs) include a group of organic priority pollutants of critical environmental and public health concern due to their toxic, genotoxic, mutagenic and/or carcinogenic properties and their ubiquitous occurrence as well as recalcitrance. The increased awareness of their various adverse effects on ecosystem and human health has led to a dramatic increase in research aimed towards removing PAHs from the environment. PAHs may undergo adsorption, volatilization, photolysis, and chemical oxidation, although transformation by microorganisms is the major neutralization process of PAH-contaminated sites in an ecologically accepted manner. Microbial degradation of PAHs depends on various environmental conditions, such as nutrients, number and kind of the microorganisms, nature as well as chemical property of the PAH being degraded. A wide variety of bacterial, fungal and algal species have the potential to degrade/transform PAHs, among which bacteria and fungi mediated degradation has been studied most extensively. In last few decades microbial community analysis, biochemical pathway for PAHs degradation, gene organization, enzyme system, genetic regulation for PAH degradation have been explored in great detail. Although, xenobiotic-degrading microorganisms have incredible potential to restore contaminated environments inexpensively yet effectively, but new advancements are required to make such microbes effective and more powerful in removing those compounds, which were once thought to be recalcitrant. Recent analytical chemistry and genetic engineering tools might help to improve the efficiency of degradation of PAHs by microorganisms, and minimize uncertainties of successful bioremediation. However, appropriate implementation of the potential of naturally occurring microorganisms for field bioremediation could be considerably enhanced by optimizing certain factors such as bioavailability, adsorption and mass transfer of PAHs. The main purpose of this review is to provide an overview of current knowledge of bacteria, halophilic archaea, fungi and algae mediated degradation/transformation of PAHs. In addition, factors affecting PAHs degradation in the environment, recent advancement in genetic, genomic, proteomic and metabolomic techniques are also highlighted with an aim to facilitate the development of a new insight into the bioremediation of PAH in the environment.

/pdf/current-state-of-knowledge-in-microbial-degradation-of-480ex77r3r.pdf

Current State of Knowledge in Microbial Degradation of Polycyclic Aromatic Hydrocarbons (PAHs): A Review

Mercury (Hg) is ubiquitary, naturally enriched in volcanic regions, and has wide applications in science, industry, and agriculture Recently, the increasing awareness of Hg toxicity has led to the replacement of Hg in many areas; however, anthropogenic activities such as coal burning and smelting of metal ores continue to release large amounts of Hg into the environment In particular, the atmospheric distribution of the highly volatile Hg around the globe can result in the pollution of pristine regions without local emission sources The chemical speciation of Hg determines its mobility and toxicity; in flooded soils and sediments, microbial methylation can occur Bioaccumulative (mono)methylmercury (MeHg; CH3Hg+) can affect human health particularly via the consumption of contaminated fish and rice since methylmercury is a potent neurotoxin Also, elemental Hg vapor is harmful for the central nervous system, while inorganic Hg compounds primarily affect the kidney This review summarizes recent

https://www.tandfonline.com/doi/pdf/10.1080/10643389.2017.1326277

Cycling of mercury in the environment: Sources, fate, and human health implications: A review

Deca-bromodiphenyl ether (BDE-209) is the major component of the commercial deca-BDE flame retardant. There is increasing concern over BDE-209 due to its increasing occurrence in the environment and in humans. In this study the behavior of BDE-209 in the soil−plant system was investigated. Accumulation of BDE-209 was observed in the roots and shoots of all the six plant species examined, namely ryegrass, alfalfa, pumpkin, summer squash, maize, and radish. Root uptake of BDE-209 was positively correlated with root lipid content (P < 0.001, R2 = 0.81). The translocation factor (TF, Cshoot/Croot) of BDE-209 was inversely related to its concentration in roots. Nineteen lower brominated (di- to nona-) PBDEs were detected in the soil and plant samples and five hydroxylated congeners were detected in the plant samples, indicating debromination and hydroxylation of BDE-209 in the soil−plant system. Evidence of a relatively higher proportion of penta- through di-BDE congeners in plant tissues than in the soil indi...

/pdf/behavior-of-decabromodiphenyl-ether-bde-209-in-the-soil-2uaw4xa30p.pdf

Behavior of Decabromodiphenyl Ether (BDE-209) in the Soil−Plant System: Uptake, Translocation, and Metabolism in Plants and Dissipation in Soil

Plant uptake and dissipation of PBDEs in the soils of electronic waste recycling sites

The roles of protein and lipid in the accumulation and distribution of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in plants grown in biosolids-amended soils

Honglin Huang

Papers

Behavior of Decabromodiphenyl Ether (BDE-209) in the Soil−Plant System: Uptake, Translocation, and Metabolism in Plants and Dissipation in Soil

Plant uptake and dissipation of PBDEs in the soils of electronic waste recycling sites

The roles of protein and lipid in the accumulation and distribution of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in plants grown in biosolids-amended soils

Relationships between aging of PAHs and soil properties

Occurrence and distribution of organophosphorus esters in soils and wheat plants in a plastic waste treatment area in China