Environmental Science & Technology Letters Environ.最新文献

Mineral dust particles are omnipresent in the atmosphere all over the globe. Nitrogen dioxide (NO₂) can be adsorbed on the dust surface and converted to nitrous acid (HONO), which in turn represents one of the most important sources of hydroxyl radicals (OH) driving the oxidation capacity of the atmosphere. Here, we evaluate the conversion of NO₂ to HONO on mineral dust samples from different regions of the world. We reveal that the synergistic effects of relative humidity (RH), UV-light, titanium dioxide (TiO₂), and microbes present on the mineral dust surface are responsible for the observed high HONO yields. The light-induced uptake coefficients of NO₂ on mineral dust surface are 1 order of magnitude higher than the uptakes measured in the dark. Intriguingly, the uptakes of NO₂ are higher in the absence of water vapor; however, the HONO yields increase with the increase of RH (0–90%), the NO₂ concentration (10–50 ppb), and the light intensity (19–50.4 W m^–2). Our findings demonstrate that mineral dust contributes to atmospheric HONO through light- and RH-dependent processes with high HONO yields (up to 80.3%) under realistic conditions. Global models must account for both uptake coefficients and HONO yields to accurately quantify this source, particularly in dust-prone regions.

Fine particulate matter (PM) poses a major threat to public health, with organic aerosol (OA) being a key component. Major OA sources, hydrocarbon-like OA (HOA), biomass burning OA (BBOA), and oxygenated OA (OOA), have distinct health and environmental impacts. However, OA source apportionment via positive matrix factorization (PMF) applied to aerosol mass spectrometry (AMS) or aerosol chemical speciation monitoring (ACSM) data is costly and limited to a few supersites, leaving over 80% of OA data uncategorized in global monitoring networks. To address this gap, we trained machine learning models to predict HOA, BBOA, and OOA using limited OA source apportionment data and widely available organic carbon (OC) measurements across Europe (2010–2019). Our best performing model expanded the OA source data set 4-fold, yielding 85 000 daily apportionment values across 180 sites. Results show that HOA and BBOA peak in winter, particularly in urban areas, while OOA, consistently the dominant fraction, is more regionally distributed with less seasonal variability. This study provides a significantly expanded OA source data set, enabling better identification of pollution hotspots and supporting high-resolution exposure assessments.

Valley fever is a lung infection caused by the inhalation of infectious spores from the fungus Coccidioides spp. Coccidioides is a genus of soil dwelling fungi endemic to the arid regions of the southwestern United States, Mexico, and Central and South America. Few Valley fever studies have focused on detecting Coccidioides spores in airborne respirable particles, which is the primary infection vector. This study looks at the presence of Coccidioides in air at a highly soil positive site in Mesa, Arizona. Aerosol samples were collected for 24 h every 6 days, following the Environmental Protection Agency sampling schedule. Meteorological data were collected from a nearby weather station. Coccidioides were detected in ∼68% of the aerosol samples. Bulk PM₁₀ did not have a statistically significant relationship with presence of Coccidioides; however, there was a significant relationship between the amount of crustal material in the aerosols and presence of Coccidioides. Previous studies link the presence of Coccidioides in air with bulk PM₁₀ concentrations; however, we found that bulk PM₁₀ concentrations give an incomplete story. Additionally, there were statistically significant relationships with the presence of Coccidioides and meteorological parameters, including relative humidity, temperature, and wind speed. This study emphasizes the importance of dust entrainment in the transmission of Coccidioides.

Although the widespread release of microfibers (MFs) from textile production and consumption is well-recognized, regional disparities and MF flows embodied in trade remain poorly understood. This study performed an environmental extended multiregional input–output model to trace the MFs footprint of China’s textile trade. Results showed that 224, 182, and 208 trillion textile MFs were emitted in 2012, 2015, and 2017. Zhejiang, Jiangsu, and Fujian Provinces were the largest contributors, linked to cotton, chemical fibers, and blended fabrics. Significant industry agglomeration was confirmed by the Lorenz curve and Gini coefficient, with the top five provinces accounting for 93.5% to 96.4% of emissions. Microfibers embodied in trade declined from 151 billion in 2012 to 121 billion in 2017, with 61.3% of provinces engaged in bilateral trade among which 52.6% were net importers. Spillover effects were evident as flows shifted from the Southeast Coast toward North China. Structural decomposition analysis identified demand structure (−46.7%), input–output structure (−41.0%), and emission intensity (−20.1%) as major inhibitory drivers, while demand scale (7.8%) facilitated emissions. The study highlights the potential environmental risks of MFs pollution in aquatic and terrestrial ecosystems and provides actionable insights for policy makers to design regionally differentiated mitigation strategies that support sustainable textile production.

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.