Environmental Science & Technology Letters Environ.最新文献

Urbansewer networks may be an underquantified source of environmentalantibiotic resistance genes (ARGs), as ARG-bearing biomass, extracellularDNA, mobile genetic elements, and particle-associated material accumulatein wastewater, biofilms, and deposits before wet-weather release.Climate-driven intensification of heavy rainfall may enhance overflow,surcharging, flooding, and hydraulic connectivity between sewers andsurface waters, increasing episodic ARG export. Here we synthesizecurrent evidence using a coupled source–storage, mobilization–routing,and fate–exposure framework. Rainfall can detach biofilms,erode deposits, redistribute intracellular and extracellular ARGsbetween freely suspended and particle-associated states, and increaseevent loads even when concentrations decline through dilution. However,field studies rarely quantify antecedent stocks, release thresholds,hydrograph-resolved fluxes, source contributions, decay, or exposuredose. We therefore identify the state variables, rate functions, andmeasurements needed to couple sewer hydraulics, particle transport,microbial ecology, molecular surveillance, and exposure assessment.Reframing storm-associated antimicrobial resistance as a compartmentalmass-balance and transport problem can move the field from occurrencemapping toward prediction of peak concentrations, event loads, depositionhotspots, persistence, and exposure likelihood in climate-stressedurban watersheds.

Primary emissions and secondary formation are potentialsourcesof free amino acids (FAAs) in atmospheric aerosols, but their relativeimportance and governing mechanisms remain unclear. Leveraging COVID-19lockdown as a natural experiment with reduced primary emissions andvariable atmospheric oxidation, we investigated FAA sources and evolutionin PM_2.5 in Beijing. Neutral glycine consistently dominated,forming primarily via secondary aqueous-phase processes driven byrelative humidity and aerosol liquid water content, especially inwinter. In spring, the level of hydrophilic FAAs increased but acid–basechemistry enriched basic amino acids with sharp aerosol pH shifts,unlike pure plant-derived enhancement. Hydrophobic alanine, secondto glycine, became dominant under enhanced primary dust/combustionevents, matching glycine-to-alanine (Gly/Ala) spatial ratio decreases:city-to-rural with primary anthropogenic emissions and backgroundwith primary productivity. Our findings demonstrate that FAA profilesprovide a useful indicator of both source shifts and aerosol physicochemicalprocessing, offering critical insights into the atmospheric nitrogencycle.

Benzothiazole (BTH) derivatives are used widely. In particular,2-methylthiobenzothiazole (2-MeS-BTH), used in rubber products andtextiles and formed in the degradation of other BTH compounds, isfound in air, particles, and water systems. In air, it reacts withOH radicals. We report here the first studies of the kinetics, products,and mechanisms of the gas-phase reaction of OH with 2-MeS-BTH. Relativerate studies carried out in air at 1 atm and 298 K give a rate constantfor 2-MeS-BTH reaction with OH of (5.4 ± 0.9) × 10^–12 cm³ molecule^–1 s^–1 (1σ), indicating a lifetime of ∼2 days in air at 1× 10⁶ cm^–3 OH. The reaction proceedsthrough (1) the abstraction of hydrogen atoms from the thiomethylgroup, (2) the addition of OH to the thiomethyl sulfur atom, and (3)the addition of OH to benzene ring as a minor path. Sulfuric acidand benzothiazole-2-sulfonic acid are major products, contributingto particle formation. This is consistent with contributions fromthe oxidation of SO₂ formed in the reaction as well asthe direct formation of SO₃ in the oxidation pathways.Thus, not only the parent compound but also its oxidation productsshould be included in assessments of 2-MeS-BTH environmental impacts.

A growing numberof cities dye waterways to celebrate significantcultural or social events. However, the ecological safety of thesepractices has not been evaluated in the open literature. The ChicagoRiver has been dyed annually since 1962, yet the identity, fate, andimpacts of the applied dye have not been independently verified. Fieldmeasurements combined with chemical analyses identified the dye asfluorescein. Surface water fluorescein concentrations reached 63±4μg/L within 2 h of application and declined to near-backgroundlevels within days with an apparent attenuation half-life of ∼15h, consistent with photochemical transformation. Measured concentrationswere well below predicted no-effect concentrations, indicating lowecological risk. These results provide an empirical evaluation ofwidely cited environmental claims regarding the safety of a well-knowncelebratory dyeing event.

Ultra-short-chain per- and polyfluoroalkyl substances(PFASs) arehighly mobile, persistent, and difficult to monitor using conventionalPFAS workflows, leaving their occurrence in bottled beverages andtap water poorly characterized. We screened five ultra-short-chainPFASs [trifluoroacetic acid (TFA), perfluoropropanoic acid (PFPrA),perfluoromethanesulfonic acid (PFMeS), perfluoroethanesulfonic acid(PFEtS), and perfluoropropanesulfonic acid (PFPrS)] in 113 samples:43 bottled beverages and 70 New Jersey tap water samples across 21counties. TFA was the dominant analyte, with a detection frequency(DF) of 86.7% across all samples analyzed. PFPrA (DF, 23.9%), PFEtS(DF, 11.5%), and PFPrS (DF, 9.73%) were detected less frequently,with concentrations ranging from 2.60 to 7640 ng L^–1. PFMeS was not detected. The concentration of TFA ranged from 74.0to 1360 ng L^–1 (DF, 91.4%) in tap water and from59.6 to 94 100 ng L^–1 (DF, 79.1%) in bottledbeverages. Among bottled beverages, formulated beverages (n = 12; 15 400 ng L^–1) containedsubstantially higher mean TFA concentrations than bottled water (n = 31; 295 ng L^–1), a 52.2-fold difference.As the first statewide monitoring study of ultra-short-chain PFASsin the United States, this work demonstrates widespread TFA occurrenceand supports the need for coordinated nationwide surveys.

Ship emissions contribute significantly to climate changeand toair pollution at both global and regional scales. Considering thechanges in physical and chemical properties as well as long-rangespatial distribution of primary emissions during atmospheric aging,the implications for climate and public health remain poorly constrained.Real-world investigations of ship plume characteristics and theirevolution remain very limited and often lack flexibility and/or transferability.We developed a new framework, applying an oxidation flow reactor aboarda mobile research vessel with aerosol analytical equipment. This pilotstudy in the Baltic Sea demonstrates the targeted analysis of individualocean-going vessels. Specifically, gas phase and (potential) aerosolmass emission factors of real-world fresh ship plumes probed at distancesof 0.6–1.6 km and of the research vessels’ own plumewere determined. After photochemical aging, a notable increase inparticle mass concentration was observed for all ships. Ships withhigher emissions of SO₂, and hence higher fuel sulfur content,showed larger aerosol formation potential which aligns with the well-establishedconcept of sulfate as a driver of particle formation. Our study introducesthe proof-of-concept for a scalable experimental framework joiningand extending laboratory stack emission aging and stationary ambientmonitoring.

Advancements in observationalcapabilities have led to exponentialincreases in the number of compounds measured in air with unknowninhalation exposure guidelines or community health risks. Exposureframeworks try to capture a variety of exposure contexts with a rangeof guidelines; however, they are largely focused on occupational settings,and the relationship between guidelines is not always clear. Consequently,assessing measured compounds within these guidelines is not straightforward,and the question of whether air is safe is not easily answered. Here,the recommendations and aims of exposure frameworks are reviewed,which inherently drive guidelines and risk tolerance. U.S. and selectinternational ambient air quality and inhalation exposure guidelinesare compared, illustrating differences between the exposure frameworksand guidelines. For compounds with available exposure guidelines,this comparison provides order-of-magnitude estimates for protectionof public health. To improve on these estimates, exposure frameworksare needed that build on ambient observations, target the most vulnerablecommunity members, and consider real-world exposure durations fromdays to years.

The aging process reduces the photochemical reactivityof urbangrime. Here, we show that two-month accumulated urban grime from Guangzhousustains highly efficient photochemical conversion of NO₂ to nitrous acid (HONO) in the presence of trace methylamine (MA).Under UV-A irradiation and 80% relative humidity, MA addition increasedHONO yields up to (91.25 ± 2.35)% at 40 ppb MA, while 50 ppbMA generated a maximum measured surface flux of 2.5 × 10¹⁰ molecules cm^–2 s^–1, of the same order of magnitude as values reportedfor NH₃-promoted urban grime under different experimentalconditions. Using density functional theory, we reveal that MA actsas a hydrogen carrier, lowering the activation barrier for HONO formationfrom 1.12 to 1.01 eV under photoexcitation and, critically,reduces the barrier for regenerating photoactive pyrene-like sitesfrom 2.97 eV without MA to only 0.17 eV in the presenceof MA. While MA substantially promotes HONO formation under laboratoryconditions, its specific ambient contribution remains unquantified.Aged urban grime stays photochemically active with MA, marking ita persistent daytime HONO source. This MA-promoted pathway shouldbe included in urban air quality models to quantitatively assess itscontributions to urban HONO and OH radical budgets.

The recent outbreakof Andes virus, a rodentborne orthohantavirus,on the cruise ship MV Hondius has received significantmedia attention, with suggested gaps in response giving rise to concernsabout preparedness for the spread of rare zoonotic disease. Earlywarning of infection spread, such as that obtained through wastewatersurveillance (WS), could greatly benefit public health managementand interventions for orthohantavirus infections, particularly inregions with limited clinical surveillance. Given the similaritiesbetween orthohantaviruses and other enveloped RNA viruses successfullymonitored through WS, many of the principles developed by the globalWS community over the past several years may be transferable and rapidlyimplementable for orthohantavirus surveillance. With a specific focuson Andes virus, Sin Nombre virus, Hantaan virus, and Puumala virus,we present key features of orthohantaviruses relevant to advancingquantification efforts and interpreting wastewater data. We summarizethe current state of knowledge related to orthohantavirus sheddingin excretions relevant to wastewater, highlight case studies documentingorthohantaviruses in wastewater, and discuss promising approachesfor implementing WS. Because orthohantaviruses are shed in rodentexcretions and the habitats of these rodents are often associatedwith sanitation systems, the interpretation of orthohantavirus geneticmarkers in wastewater samples requires careful consideration. Furthermore,based on findings from previous WS studies and current knowledge regardingthe environmental persistence of enveloped viruses similar to ANDV,the risk of transmission through wastewater is likely low but notnegligible. Key gaps in our understanding include orthohantavirussurvival in environmental matrices (particularly wastewater and aerosols)as well as the development and validation of quantitative assays inenvironmental contexts, which are required for robust WS programs.Further, deployment of assays targeting orthohantaviruses in WS atsentinel sites, such as airports, hospitals, or cruise ships, wouldbe helpful to understand outbreak boundaries. Thoughtful applicationof orthohantavirus WS, in coordination with public health agenciesand existing surveillance and containment efforts, could not onlyhelp prevent disease spread but also serve as an important case studyfor the rapid translation of WS in response to an emerging diseaseoutbreak.