Black Carbon Research Articles

Prevalence of pulmonary anthracosis in household dogs in southwest states in Nigeria: a sentinel for environmental pollution.

Nigeria, stemming from vehicular traffic, generator sets, industrial sources, residential combustion, and road dust. Pulmonary anthracosis, the accumulation of carbon particles in the lungs, is a known risk factor for cancer. While this condition has been observed in stray dogs, data on its prevalence in household dogs is limited. This study aimed to determine the prevalence of pulmonary anthracosis in household dogs within three southwestern states of Nigeria over a decade (2011-2020) and to analyze the histopathological features of pulmonary anthracosis observed in canine lung tissue samples submitted for post-mortem examination. Lung tissue samples from 472 dog carcasses submitted to the Federal University of Agriculture, Abeokuta, and the University of Ibadan for post-mortem examination were analyzed in this study. Lesions suggestive of pulmonary anthracosis were identified through gross examination and further analyzed histologically to confirm their characteristics. The findings were presented using tables, charts, and chi-square to determine association between breed, age, and sex considering p < 0.05 as significant. Out of total lungs sampled, 150 (31.8%) were positive for pulmonary anthracosis. No significant association was found between breed (p = 0.95) or sex (p = 0.98) and anthracosis, but age was statistically significant (p = 0.01). Histopathological findings included bronchiolar smooth muscle hypertrophy (90%), severe fibrosis (80%), and bronchiolar epithelial hyperplasia (50%). The study concluded that pulmonary anthracosis is prevalent among household dogs in the region. The pathological changes highlighted the adverse effects associated with the condition in affected organs and that black carbon as a major air pollutant that poses health risks to humans and animals.

Effect of Long Term Nutrient Management on Carbon Pools and Indices in Rice-Rice Cropping System in Lateritic Soils of Humid Tropics

ABSTRACT Soil organic carbon (SOC) serves a vital role in sustaining environmental quality and supporting agroecosystems. The study evaluated the effects of long-term manuring and fertilization on SOC pools in rice-rice cropping system in the lateritic soils of Central Plain, Kerala, India. Soil samples from the long term fertilizer plots were used to determine the SOC pools. Treatments were: 50% recommended dose of nitrogen (N), phosphorus (P), potassium (K) (50% NPK), 100% NPK, 150% NPK, 100% NPK + lime, 100% NP, 100% N, 100% NPK + farm yard manure (FYM) (100% NPK + FYM), 50% NPK + FYM, 100% NPK + Sesbania aculeata (SA), 50% NPK + SA and no fertilizers or manures (control). Integrated nutrient management (INM) treatments improved the Walkley and Black carbon (WBC) content. Water-soluble carbon (WSC) ranged from 0.009 to 0.012%, with the highest value found in INM. KMnO4-oxidizable carbon ranged from 0.092 to 0.158%. The management practices were found to greatly influence microbial biomass carbon (MBC) in the soil with values 195.55 to 298.19 µg g−1 soils. The treatments had a significant effect on fractions of SOC that are strongly connected to aggregate stability namely, total polysaccharides, and glomalin. Application of NPK from 50% to 150% improved WBC, WSC and MBC by 7.69%, 22.22% and 27.90%, respectively. The INM practices also improved the SOC stocks. The carbon management index (CMI) found to be superior in one receiving INM practices than one receiving prescribed levels of nutrition using only mineral fertilizers.

Exploring the Holiday Effect on Elevated Traffic-Related Air Pollution with Hyperlocal Measurements in Chengdu, China

Traffic-related air pollutants (TRAPs) pose significant health risks in megacities, yet fixed monitoring sites often fail to capture their complexity. To characterize the TRAP concentrations which fixed sites cannot address, we employed a mobile platform to effectively capture real-time hyperlocal-scale TRAP variations in Chengdu, China. A 17-day sampling campaign was conducted covering the National Holiday of China and collected ~1.2 × 105 1 Hz paired data. We measured particle number concentration (PNC), black carbon (BC), and nitrogen oxides (NOx) across urban and rural freeway environments to assess the impact of reduced heavy-duty diesel vehicles (HDDVs) during the holiday (i.e., holiday effect). No clear impact of wind direction on TRAP concentrations was found in this study. However, substantial differences (two times) were observed when comparing non-holiday to holiday campaigns. Spearman correlations (0.21–0.56) between TRAPs persistently exceeded Pearson correlations (0.14–0.41), indicating non-linear relationships and suggesting the necessity for data transformations (e.g., logarithms) in TRAP analysis. The comparison of the background subtracted TRAPs concentrations between non-holiday and holidays, revealing approximately a 50% reduction in TRAPs across microenvironments. Among the TRAPs, NOx emerged as a reliable indicator of HDDV emissions. The study provides insights into vehicle fleet composition impacts, paving the way for enhanced exposure assessment strategies.

Street-scale black carbon modelling over the West Midlands, United Kingdom: Sensitivity test of traffic emission factor adjustments.

Black carbon is harmful for climate, environment, and human health. Road traffic is one of the major sources for black carbon in urban areas. This study develops a street scale air quality model configuration for the dispersion of black carbon concentrations across the West Midlands, UK, incorporating updated road traffic emission factors. A range of modelling cases accounting for traffic emission factor adjustments was conducted and evaluated against measurements at three monitoring sites within the region. The model overall has good performance. With unadjusted traffic emission factors, the model can capture black carbon annual concentrations at urban background sites. However, an adjustment (factor of 3) for the traffic emission factors is needed to better represent the roadside site (although with a slight overestimation of 3% in annual concentration). There are near-linear relationships between black carbon concentrations and the adjustment ratio for the traffic emission factor. Black carbon concentration maps have been generated at 10m×10m resolution, which were then aggregated into health-related electoral ward and local authority levels.

Exposure to Black Carbon (BC) and the Secondary Aerosol (p-SO42– and p-NO3‒) Components of Fine Particulate Matter (PM2.5), and Cardiopulmonary Morbidity in Jeddah, Saudi Arabia

Abstract: This study assessed the morbidity risk for respiratory (RDs) and cardiovascular diseases (CVDs) from the exposure to black carbon (BC), p-SO42–, and p-NO3‒ measured in PM2.5 collected from Jeddah. The 24 h PM2.5 sampling was done at three sites for 6 weeks quarterly from 8 April 2013 to 18 February 2014, with concurrent hospital data collection. Though the data were collected more than a decade ago, the results are still applicable to the current middle east region and beyond. The relative risk (RR) for CVDs and RDs was computed in a single pollutant GLM time-series model using moving averages (MAs) and presented with 95% confidence intervals (CI). Overall, the morbidity risk was highest in outpatients. The risk of RDs was highest in younger age groups with age group 0–14 years being the most vulnerable, while the risk of CVDs was highest in age groups above 30 years. BC: The risk of RDs was highest in outpatient females of 0–14 years at all MAs; 1.483 (1.035, 2.123) to 2.501 (1.522, 4.112), and males of 31–45 years; 1.758 (1.134, 2.725) to 1.895 (1.142, 3.145) at MAs 5–7. The risk of CVDs was highest in age group 61–75 years but with a marginal statistical significance. p-SO42–: The risk of RDs was highest in males of 31–45 years; 1.173 (1.066, 1.291) to 1.256 (1.126, 1.400) at MAs_3–7. The risk of CVDs was also highest in age group 31–45 years; 1.078 (1.004, 1.157) to 1.090 (1.010, 1.177), with higher risk estimates in males; 1.084 (0.986, 1.191) to 1.120 (1.013, 1.239) at MAs 4–7. p-NO3‒: No significant risk was observed for RD morbidity. The overall risk of CVDs was significant in outpatients with an age group of 61–75 years at all MAs; 1.204 (1.014, 1.429) to 1.316 (1.096, 1.579); females, 1.221 (0.987, 1.511) to 1.428 (1.123, 1.816); and males, 1.205 (1.022, 1.421) to 1.258 (1.052, 1.505). This is the first study to assess the cardiopulmonary risk from BC, p-SO42–, and p-NO3‒ exposure in Jeddah. A high morbidity risk was observed in all age groups, accentuating the effects of elevated air pollution in Saudi Arabia and beyond. Females of 0–14 years were more at risk for RDs morbidity while the CVDs morbidity risk was relatively higher in males in age groups above 30 years.

The black carbon record of mid- to late-holocene environmental changes and its links to climate change and anthropogenic activity on the northwest Qinghai-Tibetan plateau.

Reconstructing long-term black carbon (BC) variations is crucial to improve our understanding of climatic and anthropogenic impacts on the Qinghai-Tibetan Plateau (QTP), due to its particular geographical location and its vulnerable ecosystem. Based on a fine resolution BC record from Sumxi Co combined with various other paleoenvironmental proxies, this study reconstructs regional environmental change and reveals its link to climate change and anthropogenic activities on the QTP and its surrounding areas over the past five millennia. The results show that the BC fluxes were about 875.1mgm-2yr-1 during 4.9-4.2calka BP, remained at a relatively low level from 4.1 to 0.1calka BP, and then increased rapidly to the present 3408.6mgm-2yr-1. The decrease in pre-industrial fire activities was caused by reduced biofuel availability during cold and dry periods, which is consistent with many other high altitude fire records from the Arid Central Asia. However, this pattern is different from that of the monsoon-influenced QTP, where more fires occurred during the late Holocene as a result of climatic aridification and early anthropogenic activities. With rapid population growth and socioeconomic development, there has been an overall increase in BC flux across the QTP and its surrounding areas, suggesting that enhanced anthropogenic activities have gradually superseded natural processes and profoundly impacted the regional environment since the beginning of Industrial Revolution. These findings are significant in terms of understanding the climatic and anthropogenic impacts on regional environmental change.

More biomass burning aerosol is being advected westward over the southern tropical Atlantic since 2003.

Each year, agricultural fires in southern continental Africa emit approximately one third of the world's biomass burning aerosol. This is advected westward by the prevailing circulation winds over a subtropical stratocumulus cloud deck. The radiative effects from the aerosol and aerosol-cloud interactions impact regional circulations and hydrology. Here we examine how concurrent changes in the burning season and regional climate in southern Africa over the past 18years (2003-2020) impact the southeast Atlantic. We combine satellite-derived burned area datasets (GFEDv5 primarily) with ECMWF-reanalysis carbon monoxide (CO), black carbon, and meteorology from the biomass burning season (May-October) in southern Africa. The burning season begins in May in woody savannas in the northwest and shifts to open savanna and grassland fires in the southeast, with small fires (<1km2) contributing significantly to total burned area. In the most recent decade, more small fires are occurring in the middle of the biomass burning season and the overall season is shorter, corroborated by reanalysis carbon monoxide fields. Free tropospheric winds, also known as the Southern African easterly jet, increase significantly and shift southward, transporting smoke aerosol further southwest over the southeast Atlantic. The advection increases middle-tropospheric CO by 5% of the total column per decade, and is coupled with a southern shift in the south Atlantic subtropical high and an increase in the low cloud fraction on the southern edge of the stratocumulus cloud deck. While smoke emissions sources have not changed significantly, changes in the smoke transport pathway, attributed to increasing surface temperatures in southern Africa and tropical expansion, combined with an altered low cloud distribution, explain how the all-sky shortwave top-of-atmosphere direct aerosol radiative effect has become more positive - a climate warming - in recent decades.

Stable isotopes of black carbon and their implications to paleoclimate in the eastern Tethys during the PETM

Stable isotopes of black carbon and their implications to paleoclimate in the eastern Tethys during the PETM

Response of soil phosphorus components to black carbon in seasonally frozen areas: Insight into ecoenzymatic stoichiometry

Response of soil phosphorus components to black carbon in seasonally frozen areas: Insight into ecoenzymatic stoichiometry

Assessment of pollution sources and health risks of black carbon aerosols in industrial cities of Northwestern China using light absorption observations

Assessment of pollution sources and health risks of black carbon aerosols in industrial cities of Northwestern China using light absorption observations

Black Carbon Reflects Extremely Efficient Aerosol Wet Removal in Monsoonal Convective Transport

Black Carbon Reflects Extremely Efficient Aerosol Wet Removal in Monsoonal Convective Transport

Observations of Saharan Dust Intrusions over Potenza, Southern Italy, During 13 Years of Lidar Measurements: Seasonal Variability of Optical Properties and Radiative Impact

We present a multi-year study of Saharan dust intrusions on a mountainous site located in the central Mediterranean Basin regarding their aerosol optical and geometrical properties. The observations were carried out at the Consiglio Nazionale delle Ricerche-Istituto di Metodologie per l’Analisi Ambientale (CNR-IMAA) located in Potenza (40,360N, 15,440E), Italy, from March 2010 to October 2022, using ACTRIS (Aerosol Clouds and Trace Gases Research InfraStructure). A total of 101 night-time lidar measurements of dust intrusions were identified. The following properties were calculated for the periods December, January, February (DJF), March, April, May (MAM), June, July, August (JJA) and September, October, November (SON): aerosol layer center of mass altitude, particle lidar ratio at 355 and 532 nm, particle depolarization ratio at 532 nm and backscattering Ångström exponent at 532–1064 nm. Both geometrical and optical aerosol properties vary considerably with the seasons. During SON and DJF, air masses transporting dust travel at lower altitudes, and become contaminated with local continental particles. In MAM and JJA, dust is also likely to travel at higher altitudes and rarely mix with other aerosol types. As a result, aerosols are larger in size and irregular in shape during the warm months. The ratio of the lidar ratios at 355 and 532 nm is 1.11 ± 0.15 in DJF, 1.12 ± 0.07 in SON, 0.94 ± 0.12 in MAM, and 0.92 ± 0.08 in JJA. The seasonal radiative effect estimated using the Fu–Liou–Gu (FLG) radiative transfer model indicates the most significant impact during the JJA period. A negative dust radiative effect is observed both at the surface (SRF) and at the top of the atmosphere (TOA) in all the seasons, and this could be related to a minimal contribution from black carbon. Specifically, the SRF radiative effect estimation is −14.48 ± 1.32 W/m2 in DJF, −18.00 ± 0.89 W/m2 in MAM, −22.08 ± 1.36 W/m2 in JJA, and −13.47 ± 1.12 W/m2 in SON. Instead, radiative effect estimation at the TOA is −22.23 ± 2.06 W/m2 in DJF, −38.23 ± 2.16 W/m2 in MAM, −51.36 ± 3.53 W/m2 in JJA, and −22.57 ± 2.11 W/m2 in SON. The results highlight how the radiative effects of the particles depend on the complex relationship between the dust load, their altitude in the troposphere, and their optical properties. Accordingly, the knowledge of aerosols optical property profiles is of primary importance to understand the radiative impact of dust.

The high-resolution global shipping emission inventory by the Shipping Emission Inventory Model (SEIM)

Abstract. The high-resolution ship emission inventory serves as a crucial dataset for various disciplines including atmospheric science, marine science, and environmental management. Here, we present a global high-spatiotemporal-resolution ship emission inventory at a resolution of 0.1° × 0.1° for the years 2013 and 2016–2021, generated by the state-of-the-art Shipping Emission Inventory Model (SEIMv2.2). Initially, the annual 30 billion Automatic Identification System (AIS) data underwent extensive cleaning to ensure data validity and accuracy in temporal and spatial distribution. Subsequently, integrating real-time vessel positions and speeds from AIS data with static technical parameters, emission factors, and other computational parameters, SEIM simulated ship emissions on a ship-by-ship, signal-by-signal basis. Finally, the results were aggregated and analyzed. In 2021, the ship activity dataset established based on AIS data covered 109 300 vessels globally (101 400 vessels reported by the United Nations Conference on Trade and Development). Concerning the major air pollutants and greenhouse gases, global ships emitted 847.2×106 t of CO2, 2.3×106 t of SO2, 16.1×106 t of NOx, 791.2 kt of CO, 737.3 kt of HC (hydrocarbon), 415.5 kt of primary PM2.5, 61.6 kt of BC (black carbon), 210.3 kt of CH4, and 45.1 kt of N2O in 2021, accounting for 3.2 % of SO2, 14.2 % of NOx, and 2.3 % of CO2 emissions from all global anthropogenic sources, based on the Community Emissions Data System (CEDS). Due to the implementation of fuel-switching policies, global ship emissions of SO2 and primary PM2.5 saw a significant reduction of 81.3 % and 76.5 % in 2021 compared to 2019, respectively. According to the inventory results, the composition of vessel types contributing to global ship emissions remained relatively stable through the years, with container ships consistently contributing ∼ 30 % of global ship emissions. Regarding vessel age distribution, the emission contribution of vessels built before 2000 (without Tier standards) has been declining, dropping to 10.2 % in 2021, suggesting that even a complete phase-out of these vessels would have limited potential for reducing NOx emissions in the short term. On the other hand, the emission contribution of vessels built after 2016 (meeting Tier III standard) kept increasing, reaching 13.3 % in 2021. Temporally, global ship emissions exhibited minimal daily fluctuations. Spatially, high-resolution emission characteristics of different vessel types were delineated. Patterns of ship emission contributions by different types of vessels vary among maritime regions, with container ships predominant in the North and South Pacific, bulk carriers predominant in the South Atlantic, and oil tankers prevalent in the Arabian Sea. The distribution characteristics of ship emissions and intensity also vary significantly across different maritime regions. Our dataset, which is accessible at https://doi.org/10.5281/zenodo.10869014 (Wen et al., 2024), provides a daily breakdown by vessel type and age; it is available for broad research purposes, and it will provide a solid data foundation for fine-scale scientific research and shipping emission mitigation.

Evaluation of aerosol loading and its relationship with geopotential height in Nigeria’s Guinea Coast

Climate variability and atmospheric changes significantly affect weather patterns and human activities. Aerosols impact the Earth's climate by influencing cloud formation, scattering radiation, and cooling the planet. However, aerosols, like black carbon, absorb and reemit radiation, contributing to global warming. This study aims to assess aerosol optical depth (AOD) over Nigeria's Guinea Coast, compare aerosol loading across the region, examine the relationship between aerosol loading and geopotential height, and explore the impact of meteorological variables on aerosol levels. AOD data were sourced from MODIS, while geopotential height and meteorological data was obtained from MERRA-2. The study found significant aerosol loading during the dry season, particularly along the coastal region (Lagos, Warri, and Port Harcourt), and lower AOD during the wet season. Geopotential height values were higher during the wet season, especially at 1000-hPa and 850-hPa. A positive correlation was found between AOD and geopotential height. Wind speeds were higher in the north and along the coast, with specific humidity at 1000-hPa directly correlating with geopotential height and inversely with wind speed. The study also showed that the annual AOD distribution mirrors geopotential height patterns at 1000-hPa, with higher values in southern Nigeria. In conclusion, aerosol loading is higher during the dry season, particularly in coastal regions and at lower atmospheric levels. The study highlights how seasonal changes and geographical factors influence aerosol distribution. It also shows that geopotential height strongly affects aerosol concentration, with higher heights linked to increased AOD. This underscores the importance of surface-level aerosols for human health, agriculture, and visibility, and suggests that geopotential height influences where aerosol loading is highest.

Comparative analysis of ambient, in-home, and personal exposures reveals associations between breathing zone pollutant levels and asthma exacerbations in high-risk children

BackgroundAir pollution is associated with poor asthma outcomes in children. However, most studies focus on ambient or indoor monitor pollution levels. Few studies evaluate breathing zone exposures, which may be more consequential for asthma outcomes.MethodsWe measured personal exposures to NO2, O3, PM10 and PM10 constituents, including black carbon (BC), brown carbon (BrC), environmental tobacco smoke (ETS), endotoxins, and \U0001d6fd-glucan, in a cohort of children with exacerbation-prone asthma for 72 h using wearable monitors. Personal exposures were compared to concentrations from in-home monitors in the child’s bedroom and ambient EPA air quality monitoring using correlation analyses. Personal exposures were tested for association with lung function and compared between participants with and without well-controlled asthma and signs of exacerbation in the prior 60 days using censored regression with robust standard errors.Results81 children completed 219 monitoring sessions. Personal NO2, O3, and PM10 exposures ranged from < 2 to 99.1 parts per billion (ppb), < 1.5 to 23.3 ppb, and < 1 to 141.9 \U0001d707g/m3, respectively. Personal endotoxin ranged from 0.04 to 101.3 EU/m3, \U0001d6fd-glucan from 18.5 to 1,162 pg/m3, BC from < 0.3 to 46.9 \U0001d707g/m3, BrC from < 0.3 to 6.1 \U0001d707g/m3, and ETS from < 0.3 to 56.6 \U0001d707g/m3. Correlations between personal and ambient PM10, NO2, and O3 concentrations were poor, whereas personal PM10 and NO2 correlated with in-home concentrations. In-home monitoring less frequently detected BrC (Personal:79% > lower limit of detection, Home:36.8%) and ETS (Personal:83.7%, Home:4.1%) than personal exposures, and detected BC in participants without personal exposure (Personal: 26.5%, Home: 96%). Personal exposures were not significantly associated with lung function or daily asthma control. Children requiring corticosteroid treatment for asthma exacerbation within 60 days of exposure monitoring had 1.98, 2.21 and 2.04 times higher personal exposures to BrC (p < 0.001; 95% CI: 1.43–2.37), ETS (p = 0.007; 95% CI: 1.25–3.91), and endotoxin (p = 0.012; 95% CI: 1.14–3.68), respectively.ConclusionsAlthough in-home monitoring was correlated with personal exposure to PM10 and NO2, in-home detection of ETS and BrC was not associated with personal exposures. Personal PM10 exposures in general, as well as BrC, ETS, and endotoxin levels were associated with recent childhood asthma exacerbations.Clinical trial numberNot applicable.

Determining Sources of Air Pollution Exposure Inequity in New York City Through Land-Use Regression Modeling of PM2.5 Constituents

Differences in exposures and resources to manage personal health contribute to persistent inequities in air pollution burden despite vast air quality improvements over the past 2–3 decades in the United States. These factors are, partly, linked to historic racist practices, such as redlining, a discriminatory housing policy that was practiced legally between 1935 and 1968. Using 100 m × 100 m resolution land-use regression predicted surfaces of PM2.5 constituents (black carbon, nickel, vanadium, and copper) as pollution source indicators, we fit Bayesian generalized linear mixed-effects models to examine differences in source exposures over two study periods, 2008–2015 and 2016–2019, comparing (1) redlined to not redlined and (2) high-asthma to low-asthma neighborhoods. We examine redlining as an indicator of historical, and structural racism and asthma rates as an indicator of present-day community burden. Redlined areas saw near elimination of disparities in exposure to residual oil boilers and marine residual oil but persistent disparities in traffic. High-asthma neighborhoods continue to have disproportionately high exposures to both residual oil boilers and traffic, with no discernable disparities related to marine residual oil emissions. Overall exposure disparities are small, with PM2.5 disparities by both asthma morbidity and redlining amounting to less than 1 µg/m3 and NO2 disparities by asthma and redlining amounting to less than 2 ppb in the post-2016 period. For context, 2019 NYC average PM2.5 and NO2 were 8.5 µg/m3 and 20 ppb, respectively. Our findings suggest that local pollution policy should focus on reducing traffic and building boiler emissions in high-asthma neighborhoods to reduce exacerbations.

Primary Particulate Matter and Aerosol Emissions from Biodiesel Engines During Idling in Plateau Environments of China

Diesel vehicles are recognized as significant mobile sources of particulate matter emissions. As a renewable and environmentally friendly alternative to conventional fossil diesel, biodiesel offers the benefit of reducing greenhouse gas emissions. However, existing research on biodiesel emissions primarily focuses on primary emissions, with a limited understanding of their impact on secondary organic aerosol (SOA) formation. In this study, a diesel engine test bench was employed under idle conditions using three commonly used biodiesel blends. Exhaust emissions were directly introduced into the HAP-SWFU chamber, a quartz glass smog chamber designed to characterize both primary emissions and SOA formation during the photochemical oxidation process. The black carbon and primary organic aerosol (POA) emission factors for the three biodiesel blends under idle conditions ranged from 0.31 to 0.58 g kg−1 fuel and 0.99 to 1.06 g kg−1 fuel, respectively. The particle size of exhaust particulates peaked between 20 and 30 nm, and nucleation-idle conditions were found to be the dominating mode. The SOA production factor was between 0.92 and 1.15 g kg−1 fuel, and the SOA/POA ratio ranged from 1.35 to 2.37, with an average of 1.86. This study concludes that the POA emission factor for biodiesel under idle conditions is comparable to values reported in previous studies on pure diesel exhaust, with the maximum SOA production factor reduced by 38%.

Light Absorbing Particles Deposited to Snow Cover Across the Upper Colorado River Basin, Colorado, 2013–2016: Interannual Variations From Multiple Natural and Anthropogenic Sources

AbstractAtmospheric particulate matter (PM) as light‐absorbing particles (LAPs) deposited to snow cover can result in early onset and rapid snow melting, challenging management of downstream water resources. We identified LAPs in 38 snow samples (water years 2013–2016) from the mountainous Upper Colorado River basin by comparing among laboratory‐measured spectral reflectance, chemical, physical, and magnetic properties. Dust sample reflectance, averaged over the wavelength range of 0.35–2.50 μm, varied by a factor of 1.9 (range, 0.2300–0.4444) and was suppressed mainly by three components: (a) carbonaceous matter measured as total organic carbon (1.6–22.5 wt. %) including inferred black carbon, natural organic matter, and carbon‐based synthetic, black road‐tire‐wear particles, (b) dark rock and mineral particles, indicated by amounts of magnetite (0.11–0.37 wt. %) as their proxy, and (c) ferric oxide minerals identified by reflectance spectroscopy and magnetic properties. Fundamental compositional differences were associated with different iron oxide groups defined by dominant hematite, goethite, or magnetite. These differences in iron oxide mineralogy are attributed to temporally varying source‐area contributions implying strong interannual changes in regional source behavior, dust‐storm frequency, and (or) transport tracks. Observations of dust‐storm activity in the western U.S. and particle‐size averages for all samples (median, 25 μm) indicated that regional dust from deserts dominated mineral‐dust masses. Fugitive contaminants, nevertheless, contributed important amounts of LAPs from many types of anthropogenic sources.

Treatment of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in stormwater using polishing columns with biochar and granular activated carbon.

Polycyclic Aromatic Hydrocarbons (PAHs) and Polychlorinated Biphenyls (PCBs) are recalcitrant organic pollutants often detected in stormwater. Various stormwater control measures (SCMs) can remove PAHs and PCBs by filtration, adsorption, and biodegradation. However, dissolved PAHs and PCBs remain present in the treated outflow of SCMs. To provide further treatment, two types of biochar (biochar A and biochar B), a granular activated carbon (GAC), and a regenerated GAC (RAC) were tested in a column study with synthetic stormwater containing PAHs and PCBs in low concentrations. Results showed that PAH concentrations were reduced by 98.2-99.8% (range: <limit of quantification (LOQ) - 1.89μg/L), while PCB concentrations were reduced by 86.0-97.9% (range: <LOQ - 0.7μg/L). The extraction of PCBs from the media showed that >62% of the PCBs accumulated at the first third of the column due to adsorption onto the black carbon material thus providing information for management. The difference in treatment performances of different PAHs and PCBs may be caused by the molecular structure of the contaminants. Lifetime calculations indicated that biochar had lifetimes >36-51 years, while GAC and RAC showed lifetimes longer than 147 and 206 years, respectively, based on predicted precipitation for scaled up designs. The results showed that biochar and activated carbons can be efficient adsorbents for stormwater polishing treatment. With consideration of efficiency, sustainability and cost, RAC is recommended for polishing treatment of dissolved PAHs and PCBs.

Long-term exposure to air pollution and greenness in association with respiratory emergency room visits and hospitalizations: The Life-GAP project.

Air pollution has been linked to respiratory diseases, while the effects of greenness remain inconclusive. We investigated the associations between exposure to particulate matter (PM2.5 and PM10), black carbon (BC), nitrogen dioxide (NO2), ozone (O3), and greenness (normalized difference vegetation index, NDVI) with respiratory emergency room visits and hospitalizations across seven Northern European centers in the European Community Respiratory Health Survey (ECRHS) study. We used modified mixed-effects Poisson regression to analyze associations of exposure in 1990, 2000 and mean exposure 1990-2000 with respiratory outcomes recorded duing ECRHS phases II and III. We assessed interactions of air pollution and greenness, and of atopic status (defined by nasal allergies and hay fever status) and greenness, on these outcomes. The analysis included 1,675 participants, resulting in 119 emergency visits and 48 hospitalizations. Increased PM2.5 by 5 μg/m³ was associated with higher relative risk (RR) of emergency visits (1990: RR 1.16, 95% CI: 1.00-1.35; 2000: RR 1.24, 95% CI: 0.98-1.57; 1990-2000: RR 1.17, 95% CI: 0.97-1.41) and hospitalizations (1990: RR 1.42, 95% CI: 1.00-2.01; 2000: RR 2.20, 95% CI: 1.43-3.38; 1990-2000: RR 1.44, 95% CI: 1.04-2.00). Similar trends were observed for PM10, BC, and NO2, with only PM10 showing significant associations with hospitalizations across all periods. No associations were found for O3. Greenness exposure was linked to more emergency visits in 2000 but to fewer hospitalizations in 1990. Significant interactions were observed between greenness and atopic status for emergency visits, and between NDVI with O3 and BC for some time windows. Long-term exposure to particulate matter was associated with increased emergency room visits and hospitalizations. Significant associations were observed for BC and NO2 with hospitalizations. No link was found with O3. Greenness indicated a lower risk of hospitalizations, but increased risks for emergency visits for those with atopic status.