Environmental Science & Technology Letters Environ.最新文献

Microplastics (MPs) are increasingly detected in human blood, particularly in individuals with cardiovascular diseases. However, understanding their direct interactions with blood cells remains challenging due to the lack of reliable detection methods. Available fluorescent probes suffer from spectral overlap with red blood cell (RBCs) autofluorescence, masking MP-induced effects. To overcome this, we proposed activatable near-infrared (NIR) probes that specifically target indicators in the RBCs. The NIR probes operate within a spectral range distinct from RBCs autofluorescence, exhibiting minimal background and a high turn-on response. Coupled with NIR imaging, this platform enabled the quantification of key redox indicators in zebrafish RBCs following exposure to pristine/aged biodegradable MPs poly(lactic acid) (PLA). Dose–response analyses revealed that PLA disrupted redox homeostasis in a dose-dependent manner. PLA showed greater toxicity than polystyrene, and aging further amplified their toxicity. Notably, the toxicity threshold of PLA and aged PLA was lower than the MP concentrations found in certain healthy human blood, and all MPs toxicity thresholds were below the levels detected in cardiovascular patients. This study provides a highly sensitive detection platform and underscores the urgent need to monitor the adverse effects of MPs on RBCs, particularly for PLA, for which monitoring data and toxicological evaluation remain critically lacking.

On-site nonpotable water systems (ONWS) must be designed to reduce pathogen risks to protect human health. However, variation among quantitative microbial risk assessment (QMRA) models used in this process has led to a range of treatment goals or pathogen log reduction targets (LRTs). When evaluating a range of potential treatment levels, designers and regulators should be aware of the cost and environmental implications of alternative system designs and how these metrics balance against public health objectives. In this study, we quantified and compared the life cycle costs and environmental impacts of several on-site nonpotable reuse systems designed to meet different LRTs within the range of available QMRA model variability. Though treatment system disinfection processes vary considerably in their dosages, the net effect on overall system cost and environmental impacts is generally on the order of ±5% or less. We find that other factors such as geographic location, dual-pipe plumbing requirements, and energy needed for the removal of organics are considerably more important and discuss ways in which total system cost and environmental impacts could be reduced while maintaining high levels of human health protection.

Plastic particles (PPs; ≤5 mm diameter) are ubiquitous environmental contaminants, and concerns exist about their potential to impact human health negatively. Public perceptions about seafood contamination by PPs have been shaped by media communications rather than scientific evidence, and these perceptions can inform behavior and public policy inappropriately. Our objective is to challenge perceptions with evidence and to discuss the extent to which concerns of PP contamination of seafoods are justified. Evidence indicates that levels of PPs in seafoods are consistent with those of other foods and beverages and that human exposure to PPs is higher via indoor air and dust than by ingestion of foods and beverages. While uncertainties remain, there is currently minimal evidence of dietary toxicity of PPs and no consumption advisories for PPs. The levels of substances (e.g., toxic contaminants) associated with PPs that may be released upon PP ingestion are often orders of magnitude below levels of toxicological concern. Overattention on PP contamination of seafoods (>70% compared to all other foods combined) in scientific media communications is unjustified and must be rebalanced to avoid misconceptions and loss of beneficial health effects of seafood consumption.

Microplastics (MPs) are widespread emerging environmental pollutants that present significant health risks to humans. While the presence of MPs has been documented in various human tissues, the detection of MP residues in the human retina remains uncertain. Herein, we characterized the types and concentrations of MPs in 12 post-mortem human retinal samples via pyrolysis gas chromatography–mass spectrometry. The size, shape, and morphologies of MP particles in another two post-mortem human retinal samples were further characterized using laser direct infrared spectroscopy and scanning electron microscopy. MPs were detected in all 12 human retinal samples at concentrations ranging from 8.93 to 91.05 μg/g with an average concentration of 49.21 μg/g. Various MPs such as polystyrene (PS), polyethylene (PE), polypropylene (PP), poly(methyl methacrylate), and polyvinyl chloride (PVC) were identified, with PS, PE, PP, and PVC detected in all analyzed samples. The diameters of the MPs detected in the human retinal samples predominantly ranged from 20 to 50 μm, with most particles exhibiting fragmented or fibrous morphologies. This study presents the first detailed qualitative and quantitative analyses of MPs in the human retina, which provides a crucial foundation for future research assessing their potential risks and detrimental impacts on retinal health.

Incomplete burning of solid fuels in residential stoves emits various hazardous air pollutants, including some volatile toxic organic compounds, to ambient and indoor air. Due to high spatiotemporal variations in combustion emissions and household characteristics, indoor pollution of volatile organic compounds (VOCs) is poorly characterized, especially due to a lack of a nationwide assessment. Here, a field campaign was conducted to evaluate indoor emissions of 37 VOCs, including chlorinated hydrocarbons, aromatics, and chlorinated aromatics, for representative fuel-stove combinations in use for China, and real-world emission rates were used to assess indoor VOC pollution using a single-zone model. VOCs from the solid fuel burning in vented stoves leaked into indoor space substantially, with more leakages for high-molecular-weight VOCs (p < 0.01). In rural China, on the national scale, the simulated 24 h average indoor concentration attributed to residential solid fuel burning was 11.6, 1.76, and 0.28 μg/m³ for benzene, naphthalene, and trichloroethylene, respectively. Approximately 85% of households had indoor benzene concentrations exceeding the WHO guideline of 1.7 μg/m³, while the exceedance of naphthalene and trichloroethylene attributed to indoor fuel combustion emissions was much more limited. Higher indoor VOC contamination was in northern and northeastern China, where large amounts of coal were burned inefficiently for daily energy demands.

Transport of fragmentary nano- and microplastics in environmental porous media is an emerging research concern driven by their prevalence in environmental porous media. This brief critical review highlights opportunities for researchers to explore the relevance of accumulated knowledge from transport experiments and simulations involving commercial spherical nano- and microplastics and other colloids. Several recent publications concerning nano- and microplastic transport in porous media are examined to highlight how interpretations and conclusions could potentially change with incorporation of accumulated knowledge from their commercial spherical counterparts.

Candida is the largest genus of medically significant yeasts, causing diseases ranging from mucosal to life-threatening invasive infections. Airborne transmission of Candida has gained attention following its genotypic detection in ambient air and isolation in occupational air. However, more comprehensive phenotypic evidence, including viability, antifungal resistance, and phylogenetic relatedness to clinical strains, is needed in ambient air, with implications for community-level exposure, colonization, and infection. To address this gap, we sampled air at an urban and a coastal site using six-stage Andersen impactors. Viable isolates of C. parapsilosis, C. albicans, and C. tropicalis─all World Health Organization priority fungal pathogens─were recovered from ambient urban air, primarily associated with respirable particle sizes (2.1–7 μm) across seasons. Antifungal susceptibility testing identified C. parapsilosis as the predominant multidrug-resistant species. Whole-genome sequencing revealed airborne C. parapsilosis shared 99.53% genetic similarity with nearby clinical strains, differing by only 94 out of 20,206 single-nucleotide polymorphisms. This suggests the plausibility of community-acquired infection via airborne routes. These findings highlight the need to investigate airborne transmission from environmental reservoirs to human colonization and infection. This is particularly critical under urban megatrends and climate change, emphasizing an emerging microbial hazard beyond antibiotic-resistant bacteria within the One Health framework.