Black Carbon Research Articles

Introduction/Background: The impact of exposure to air pollution (AP) in the home on cardiovascular health is limited because most data is based on outdoor exposure. This is an important data gap because in the United States people spend approximately 90% of their time indoors. This study quantifies home exposure to AP and examines its association with various indicators of cardiovascular health. Research Questions/Hypothesis: The hypothesis being tested is that increased exposure to AP in the home is associated with increased heart rate (HR), mean arterial pressure (MAP), and central and brachial blood pressure (BP) in older adults. Methods/Approach: The Household Air Pollution Study (HAPS) is an ongoing prospective cohort (n=100) of adults age ≥ 60 years in New Orleans, Louisiana, examining the association between exposure to particulate matter ≤ 2.5 mg/m-cubed (PM 2.5 ), black carbon (BC), and nitrogen dioxide (NO 2 ) in the home on various indicators of heart health. Pollutant concentrations are measured in the home at two time points, baseline and 6 months. Each sampling period is 7 consecutive days. Outcomes are measured every other day (n=4) during each sampling period. Central and brachial BP, HR, MAP are measured three times at each home visit using a SphygmoCor XCEL. Outcomes are averaged for each sampling period. Unadjusted generalized estimating equation models with a Gamma distribution and log link are used to account for the repeated measures and the non-normal distributions of the air pollutants. PM 2.5 , BC, and NO 2 are modelled separately, and treated as continuous variables. Results/Data (descriptive and inferential statistics): This preliminary analysis includes 93 participants. The median age of participants is 71.5 years; baseline median BC is 0.626 µg/m-cubed, PM 2.5 is 5.283 µg/m-cubed, and NO 2 is 6.79 ppb. Higher concentrations of PM 2.5 and BC is positively associated with HR: A 10-unit increase in PM 2.5 is associated with a 1.01 unit increase in mean HR (p-value=0.0003), and a 10-unit increase in BC results in a 1.05 unit increase in HR (p-value=0.0016). There were no associations between PM 2.5 , BC, or NO 2 and the other outcomes. Conclusion: These preliminary results suggest that exposure to low levels of indoor PM 2.5 and BC in the home may contribute to increased mean HR in older adults. Additional studies are needed to further explore these findings.

Abstract. Black carbon (BC) is a key atmospheric forcer due to its interaction with solar radiation and clouds. However, accurately quantifying and understanding the impact of atmospheric aging on BC properties and radiative forcing remains a major challenge. To address this, the AIDA (Atmospheric Interactions and Dynamics in the Atmosphere) aRCtic Transport Experiment (ARCTEx) project simulated BC aging under quasi-realistic Arctic conditions in the AIDA chamber. Four distinct scenarios were simulated based on reanalysis data, representing summer and winter conditions at both low and high altitudes, to capture the variability in BC aging processes in the presence of nitrate and organic matter precursors during Arctic transport. In the first part of the paper, we define the meteorological conditions characterizing northward transport under different scenarios and describe the technical solutions to simulate 5 d transport in the AIDA chamber. In the second part of the work, we assess the evolution of fundamental properties, including density, morphology, and mixing state, as observed during the aging process. The ARCTEx project demonstrates that large facilities such as AIDA can successfully reproduce environmental conditions, enabling a gradual aging process that closely follows the natural timescales observed in the atmosphere. Our experiments revealed that temperature strongly influences the aging timescale and the evolution of BC's diameter, effective density, and coating thickness. Low-altitude scenarios exhibited rapid aging, resulting in fully coated, compact BC particles within 39–98 h, corresponding to 50 and 80° N, respectively. In contrast, high-altitude transport was characterized by slow aging, with limited coating and compaction, even after 115 h of simulation. These findings provide valuable insights into the temporal evolution of BC properties during Arctic transport. In forthcoming work, we will report the implications of this evolution for climate-relevant properties such as light absorption and activation as cloud droplets and ice crystals. Together, these studies aim to enhance the representation of BC aging in climate models, reducing uncertainties in Arctic radiative-forcing estimates.

Heterogeneous ice nucleation is a key process for ice cloud formation, snowfall, and freezing of water bodies. Ice nucleating particle (INP) cloud feedbacks are one of the largest sources of uncertainties in Earth’s Energy Budget. Although INPs are essential in the development of mixed-phased and glaciated clouds, their composition, sources, and cloud feedbacks remain poorly constrained. Previous studies have shown mixed results on the potential of light-absorbing particles (LAP), such as black carbon (BC) and high latitude dust (HLD), serving as INPs. However, many of these studies use laboratory or model-generated particles that may not represent the complex morphology and behaviors of ambient light-absorbing particles sufficiently. Here, we use in situ surface snow samples, collected during Spring 2018 in Svínafellsjökull, Iceland. The samples were analyzed by an immersion freezing mechanism for their ice nucleation activity (INA). Portions of the filtered samples were concentrated by lyophilization to observe the potential enhancement of INA. We investigated environmental samples of deposited aerosols to better understand the role activity of HLD and BC in ice nucleating activity in mixed-phase clouds in Iceland. We found concentrations of 16 ± 27 ng g−1 and 33 ± 66 × 106 ng g−1 for BC and HLD, respectively. However, we found that isolated methanol-soluble organic aerosols have a more prominent role than BC and HLD in Iceland. We conclude that BC and HLD are insignificant INP but that they can inhibit INA from other INP.

Novel nanocomposites based on carbon black or multi-walled carbon nanotubes functionalized with carboxylic groups and Neutral red electropolymerized from reline were obtained in a one-step protocol and used for DNA biosensor development. The synthesis was carried out in potentiodynamic mode in a deep eutectic solvent reline consisting of a mixture of choline chloride and urea. The nanocomposite based on carbon black and poly(Neutral red) was applied for a voltammetric DNA biosensor developed to discriminate DNA damage. The sensor developed allowed the native, thermally denatured, and chemically oxidized DNA discrimination with either current changes or peak potential shifts. The nature of the DNA used had affected the sensor’s analytical response value. The DNA biosensor suggested was tested for the assessment of antioxidant capacity in such beverages as tea, coffee, white wine, and fruit-based drink purchased from local market. Simple, fast, and inexpensive approach of sensor modifying layer assembly would be demanded in control of food products and beverages quality, as well as for medical purposes.

Photocatalytic CO2 reduction holds great potential for sustainable solar fuel production, yet its practical application is often limited by inefficient charge separation and poor product selectivity. The photothermal effect presents a viable strategy to address these challenges by reducing activation energies and accelerating reaction kinetics. In this work, we report a rationally designed CN-B/Ti3C2 heterojunction that effectively leverages photothermal promotion for enhanced CO2 reduction. The black carbon nitride (CN-B) framework, synthesized via a one-step calcination of urea and Phloxine B, exhibits outstanding photothermal conversion, reaching 131.4 °C under 300 mW cm−2 illumination, which facilitates CO2 adsorption and charge separation. Coupled with Ti3C2 MXene, the optimized composite (3:1) achieves remarkable CO and CH4 production rates of 80.21 and 35.13 μmol g−1 h−1, respectively, without any cocatalyst—representing a 2.9-fold and 8.8-fold enhancement over CN-B and g-C3N4 in CO yield. Mechanistic studies reveal that the improved performance stems from synergistic effects: a built-in electric field prolongs charge carrier lifetime (3.15 ns) and reduces interfacial resistance, while localized heating under full-spectrum light further promotes CO2 activation. In situ Fourier transform infrared (FTIR) spectroscopy confirms the accelerated formation of key intermediates (*COOH and *CO). The catalyst also maintains excellent stability over 24 h. This study demonstrates the promise of combining photothermal effects with heterojunction engineering for efficient and durable CO2 photoreduction.

Distribution characteristics of black carbon in Taihu Lake sediments and their effects on microorganisms.

Gestational fine particulate matter exposures and spontaneous preterm birth: Elucidating mechanisms using placental transcriptome and metabolome signatures.

Association of ambient fine particulate matter (PM2.5) and its constituents with risk of pulmonary nodules in a lung cancer screening project.

Cumulative effect of PM2.5 chemical components surpasses PM2.5 mass on hypertension in older adults: A China-based national analysis.

Short-term exposure to particulate matter and apparent temperature is associated with schizophrenia severity in Italy.

The impact of China's Clean Air Action and future strategies: Actions targeting regionally dominant sources.

Release of organochlorine pollutants from forest fires: 2. possible long-term migration from ash and burnt soil.

Residential greenness modifies the association between long-term exposure to PM2.5 components and allergic diseases in schoolchildren: A large-scale study in Southern China.

This study, based on global AERONET observation data from 2023, employs a synergistic inversion algorithm that integrates aerosol optical, microphysical, and chemical properties to retrieve the global distribution of aerosol parameters. We find that the global annual mean aerosol optical depth (AOD), fine-mode AOD (AODf), coarse-mode AOD (AODc), absorbing aerosol optical depth (AAOD), single scattering albedo (SSA) are 0.20, 0.15, 0.04, 0.024, and 0.87, respectively. From the perspective of spatial distribution, in densely populated urban areas, AOD is mainly determined by AODf, while in the areas dominated by natural sources, AODc contributes more. Combined with the optical and microphysical properties, fine-mode aerosols dominate optical contributions, whereas coarse-mode aerosols dominate volume contributions. In terms of chemical components, fine-mode aerosols at most global sites are primarily carbonaceous. The mass concentrations of black carbon (BC) exceed 10 mg m−2 in parts of South Asia, Southeast Asia, and the Arabian Peninsula, while the mass fraction of brown carbon (BrC) accounts for more than 16% in regions such as the Sahara, Western Africa, and the North Atlantic Ocean reference areas. The dust (DU) dominates in coarse mode, with the annual mean DU fraction reaching 86.07% in the Sahara. In coastal and humid regions, the sea salt (SS) and water content (AWc) contribute significantly to the aerosol mass, with fractions reaching 13.13% and 34.39%. The comparison of aerosol properties in the hemispheres reveals that the aerosol loading in the Northern Hemisphere caused by human activities is higher than in the Southern Hemisphere, and the absorption properties are also stronger. We also find that the uneven distribution of global observation sites leads to a significant underestimation of aerosol absorption and coarse-mode features in global mean values, highlighting the adverse impact of observational imbalance on the assessment of global aerosol properties. By combining analyses of aerosol optical, microphysical, and chemical properties, our study offers a quantitative foundation for understanding the spatiotemporal distribution of global aerosols and their emission contributions, providing valuable insights for climate change assessment and air quality research.

Spatio-temporal characteristics and determining factors of traffic-related particulate matter in urban versus suburban areas.

Comparison of MERRA-2 black carbon aerosols and ground observation at a high-altitude mountainous site in southern China

Regulation of black carbon emissions from arctic Shipping: Overcoming challenges and shaping future governance

Influence of boundary layer-cloud coupling on cloud microphysics based on aircraft observations in the North China plain.

Investigating sources of black carbon in Beijing with receptor model and continuous hourly measurements from 2016 to 2019

Decadal analysis of black carbon aerosols over the central Indo-Gangetic Plain: trends, source regions, and policy impact