Tracking Source Variations of Inhalation Cancer Risks and Ozone Formation Potential in Hong Kong over Two Decades (2000-2020) Using Toxic Air Pollutant Monitoring Data.

Toxic air pollutants (TAPs) are a class of airborne chemicals known or suspected to cause serious health issues. This study, applying positive matrix factorization and inhalation unit risk estimates of TAPs, quantifies the changes in significant sources contributing to inhalation cancer risks (ICRs) from 2000 to 2020 in Hong Kong, China. Total ICR decreased from 1701 to 451 cases per million between 2000-2004 and 2016-2020, largely attributed to the reduction in diesel particulate matter (DPM), gasoline and solvent use-related volatile organic compounds (VOCs), and coal/biomass combustion-related polycyclic aromatic hydrocarbons and metal(loid)s.

Surgical Face Mask as an Air Sampling Device for Assessing Personal Exposure to Airborne Antimicrobial Resistance Gene-Bearing Bacteria.

In this study, we assessed the feasibility of using a surgical face mask as a sampling device to collect airborne antimicrobial resistance genes (ARGs). The method entails collection of ARG-bearing microbes on face masks, followed by their DNA extraction and quantification by qPCR analysis. Analysis of masks worn by volunteers showed an apparent mask wearing time-dependent accumulation of 16S rRNA gene and select ARGs trapped on masks, highlighting the applicability of the method in monitoring personal ARG exposure through inhalation.

New Analytical Paradigm to Determine Concentration of Brown Carbon and Its Sample-by-Sample Mass Absorption Efficiency.

Brown carbon (BrC) has a substantial direct radiative effect, but current estimates of its impact on radiative balance are highly uncertain due to a lack of measurements of its light-absorbing properties, such as mass absorption efficiency (MAE). Here, we present a new analytical paradigm based on a Bayesian inference (BI) model that takes multiwavelength aethalometer measurements and total carbon data to resolve the concentrations of black carbon and BrC, and MAEs of BrC on a sample-by-sample basis. Hourly MAEs, unattainable in previous studies, can now be calculated, enabling the first-time observation of the darkening-bleaching dynamics of BrC in response to photochemical transformation.

Urinary Thioproline and Thioprolinyl Glycine as Specific Biomarkers of Formaldehyde Exposure in Humans.

Assessment of personal formaldehyde (FA) exposure is most commonly carried out using formate as a biomarker, as it is the major product from FA metabolism. However, formate could also have originated from the metabolism of other endogenous and exogenous substances or from dietary intake, which may give rise to overestimated results with regard to FA exposure. We have developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) coupled with an isotope-dilution method for rigorous quantitation of two major urinary FA conjugation products: thioproline (SPro) and thioprolinyl glycine (SPro-Gly), formed in the reaction between FA and endogenous cysteine or cysteinyl glycine, respectively, as marker molecules to assess personal FA exposure.

Combustion-Derived Pollutants Linked with Kidney Disease in Low-Lying Flood-Affected Areas in the Balkans.

Tens of thousands of people in southern Europe suffer from Balkan endemic nephropathy (BEN), and four times as many are at risk. Incidental ingestion of aristolochic acids (AAs), stemming from the ubiquitous(birthwort) weed in the region, leads to DNA adduct-induced toxicity in kidney cells, the primary cause of BEN. Numerous cofactors, including toxic organics and metals, have been investigated, but all have shown small contributions to the overall BEN relative to non-BEN village distribution gradients.

Phosphocholine-induced energy source shift alleviates mitochondrial dysfunction in lung cells caused by geospecific PM components.

Fine particulate matter (PM) is globally recognized for its adverse implications on human health. Yet, remain limited the individual contribution of particular PM components to its toxicity, especially considering regional disparities. Moreover, prevention solutions for PM-associated health effects are scarce.

Unambiguous Analysis and Systematic Mapping of Oxygenated Aromatic Compounds in Atmospheric Aerosols Using Ultrahigh-Resolution Mass Spectrometry.

Compositional analysis of organic aerosols (OAs) at the molecular level has been a long-standing challenge in field and laboratory studies. In this work, we applied different extraction protocols to aerosol samples collected from the ambient atmosphere and biomass burning sources, followed by Orbitrap mass spectrometric analysis with a soft electrospray ionization source operating in both positive and negative ionization modes. To systematically map the distribution of mono- and dioxygenated aromatic compounds (referred to as aromatic CHO and CHO formulas) in OA, we developed a unique two-dimensional Kendrick mass defect (2D KMD) framework.

[Chemical Composition and Characterization of Nitroaromatic Compounds in Urban Areas of Shanghai].

The compositional characteristics, concentration of nitroaromatic compounds(NACs) in PM in urban Shanghai, and their correlation with gaseous precursors were investigated. A total of 39 winter and 46 summer PM samples from 2020 to 2021 were collected using a high-flow sampler and analyzed via ultra-performance liquid chromatography coupled with ESI-Orbitrap high-resolution mass spectrometry(UPLC-Orbitrap-HRMS). Quantitative analysis was performed on 12 NACs compounds, combined with backward trajectory meteorological elements, molecular composition, and classification analysis of CHON substances.

Dissecting the contributions of organic nitrogen aerosols to global atmospheric nitrogen deposition and implications for ecosystems.

Atmospheric deposition of particulate organic nitrogen (ON) is a significant process in the global nitrogen cycle and may be pivotally important for N-limited ecosystems. However, past models largely overlooked the spatial and chemical inhomogeneity of atmospheric ON and were thus deficient in assessing global ON impacts. We constructed a comprehensive global model of atmospheric gaseous and particulate organic nitrogen (ON), including the latest knowledge on emissions and secondary formations.

High spatial resolution estimates of major PM components and their associated health risks in Hong Kong using a coupled land use regression and health risk assessment approach.

Few studies have focused on the spatial distribution of the typical components and source tracers of PM and their associated health risks, despite the fact that the chemical components of PM pose potentially significant and independent risks to human health. The main objective of this study was to evaluate the spatial distribution of major PM components and their associated health risks in Hong Kong using a coupled land use regression and health risk assessment modeling approach. The established land use regression models of the major PM components and source tracers achieved a relatively high statistical performance, with training and leave-one-out cross-validation R values of 0.

Field observations of C and C organosulfates and insights into their formation mechanisms at a suburban site in Hong Kong.

Organosulfates (OSs) are formed from volatile organic compounds (VOCs) and their oxidation products in the presence of sulfate particles. While OSs represent an important component in secondary organic aerosol, the knowledge of their formation driving force, mechanisms, and environmental impact remain inadequately understood. In this study, we report ambient observations of C oxygenated VOCs derived OSs (C OSs) at a suburban location of Hong Kong during autumn 2016.

Abundance and sources of organic nitrogen in fine (PM) and coarse (PM) particulate matter in urban Hong Kong.

Organic nitrogen (ON) in atmospheric particles is much less monitored compared to inorganic nitrogen (IN), despite its significant contribution to atmospheric N deposition budget. In this study, we expanded a newly developed instrumental method for IN and ON in PM samples to PM samples. We determined the quantities of ON and IN for paired PM and PM samples collected at an urban coastal site in Hong Kong, southern China over a year.

Concurrent measurements of nitrate at urban and suburban sites identify local nitrate formation as a driver for urban episodic PM pollution.

Nitrate (NO) is often among the leading components of urban particulate matter (PM) during PM pollution episodes. However, the factors controlling its prevalence remain inadequately understood. In this work, we analyzed concurrent hourly monitoring data of NO in PM at a pair of urban and suburban locations (28 km apart) in Hong Kong for a period of two months.

Face Mask as a Versatile Sampling Device for the Assessment of Personal Exposure to 54 Toxic Compounds in Environmental Tobacco Smoke.

Exposure to environmental tobacco smoke (ETS), which contains hundreds of toxic compounds, significantly increases the risk of developing many human diseases, including lung cancer. The most common method of assessing personal exposure to ETS-borne toxicants is by sampling sidestream smoke generated by a smoking machine through a sorbent tube or filter, followed by solvent extraction and instrumental analysis. However, the ETS sampled may not truly represent the ETS in the ambient environment, due to complicating factors from the smoke released by the burning end of the cigarette and from the absorption of the chemicals in the respiratory tract of the smoker.

Development of an enhanced method for atmospheric carbonyls and characterizing their roles in photochemistry in subtropical Hong Kong.

Carbonyl compounds are ubiquitous and play vital roles in tropospheric photochemistry and oxidation capacity, particularly affecting radical cycling and ozone formation. An enhanced method based on ultra-high-performance liquid chromatography and electrospray ionization tandem mass spectrometry was developed to simultaneously quantify 47 carbonyl compounds with carbon (C) numbers from 1 to 13. Applying this new method to samples collected at ground and ship-borne field campaigns, we investigated the abundance, characteristic distribution, and photochemical activity of carbonyl species in the coastal atmosphere of Hong Kong.

Important Roles and Formation of Atmospheric Organosulfates in Marine Organic Aerosols: Influence of Phytoplankton Emissions and Anthropogenic Pollutants.

Organosulfates (OSs) could be potentially important compounds in marine organic aerosols, while their formation in marine atmospheres is far from clear due to a lack of cruise observations. In this work, shipboard atmospheric observations were conducted over the Yellow Sea and Bohai Sea to investigate the abundance and formation of biogenic isoprene/monoterpene-OSs in marine aerosols. The quantified OSs and NOSs accounted for 0.

Bayesian Inference Approach to Quantify Primary and Secondary Organic Carbon in Fine Particulate Matter Using Major Species Measurements.

The determination of primary organic carbon (POC) and secondary organic carbon (SOC) in fine particulate matter using ambient measurements is essential in atmospheric chemistry. A novel Bayesian inference (BI) approach is proposed to achieve such quantification using only major component measurement data and tested in two case studies. One case study composes of filter-based daily compositional data made in the Pearl River Delta region, China, during 2012, while the other uses online measurement data recorded at the Dianshan Lake monitoring site in Shanghai in wintertime 2019.

Field Evidence for Asian Outflow and Fast Depletion of Total Gaseous Mercury in the Polluted Coastal Atmosphere.

Atmospheric mercury (Hg) cycling in polluted coastal atmosphere is complicated and not fully understood. Here, we present measurements of total gaseous mercury (TGM) monitored at a coastal mountaintop in Hong Kong downwind of mainland China. Sharp TGM peaks during cold front passages were frequently observed due to Asian pollution outflow with typical TGM/CO slopes of 6.

Ambient particle characteristics by single particle aerosol mass spectrometry at a coastal site in Hong Kong: a case study affected by the sea-land breeze.

The sea-land breeze (SLB) circulation plays a vital role in the transport of atmospheric pollutants in coastal cities. In this study, a single particle aerosol mass spectrometer (SPAMS) and combined bulk aerosol instruments were deployed to investigate the ambient particle characteristic at a suburban coastal site in Hong Kong from February 22 to March 10, 2013. Significant SLB circulations were captured from March 6-10, 2013, during the campaign.

Highly time-resolved measurements of elements in PM in Changzhou, China: Temporal variation, source identification and health risks.

The temporal variation, sources, and health risks of elemental composition in fine particles (PM) were explored using online measurements of 19 elements with a time resolution of 1 h at an urban location in Changzhou, China, from December 10, 2020 to March 31, 2021. The mass concentration of PM was 50.1 ± 32.

The interplays among meteorology, source, and chemistry in high particulate matter pollution episodes in urban Shanghai, China.

High particulate matter (PM) pollution episodes still occur occasionally in urban China, despite of improvements in recent years. Investigating the influencing factors of high-PM episodes is beneficial in the formulation of effective control measures. We herein present the effects of weather condition, emission source, and chemical conversion on the occurrence of high-PM episodes in urban Shanghai using multiple online measurements.

Polyurethane Foam Face Masks as a Dosimeter for Quantifying Personal Exposure to Airborne Volatile and Semi-Volatile Organic Compounds.

Airborne volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) are commonly quantitated by collecting the analytes on solid sorbent tubes or passive air samplers, followed by solvent extraction and instrumental analysis, or by grab bag/canister measurements. We report herein a user-friendly sampling method by breathing through polyurethane foam (PUF) face masks to collect airborne VOCs and SVOCs for chemical analysis. Specifically, dibasic esters, phthalate esters, polycyclic aromatic hydrocarbons, linalool, and nicotine trapped on PUF masks were quantitated by gas chromatography-mass spectrometry analysis as model VOCs and SVOCs.

Hourly organic tracers-based source apportionment of PM before and during the Covid-19 lockdown in suburban Shanghai, China: Insights into regional transport influences and response to urban emission reductions.

During the Covid-19 outbreak, strict lockdown measures led to notable reductions in transportation-related emissions and significantly altered atmospheric pollution characteristics in urban and suburban areas. In this work, we compare comprehensive online measurements of PM major components and organic molecular markers in a suburban location in Shanghai, China before lockdown (Dec. 28, 2019 to Jan.

[Characteristics of Nitroaromatic Compounds in PM in Urban Area of Shanghai].

Nitroaromatic compounds (NACs) are an important class of nitrogen-containing compounds in fine particles. The investigation of characteristics and seasonal variation of NACs in PM increases our knowledge about nitrogen-containing compounds and contributes to the scientific basis in formulating reduction policies of NO in urban areas. In this study, we analyzed the chemical composition of PM samples collected from March 2018 to February 2019 in an urban location in Shanghai.