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Targino AC, Krecl P, Oukawa GY, Mollinedo EM. A short climatology of black and brown carbon and their sources at a suburban site impacted by smoke in Brazil. J Environ Sci (China) 2024; 136:498-511. [PMID: 37923459 DOI: 10.1016/j.jes.2022.12.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 12/20/2022] [Accepted: 12/20/2022] [Indexed: 11/07/2023]
Abstract
Emissions from biomass burning challenge efforts to curb air pollution in cities downwind of fire-prone regions, as they contribute large amounts of brown carbon (BrC) and black carbon (BC) particles. We investigated the patterns of BrC and BC concentrations using Aethalometer data (at λ = 370 and 880 nm, respectively) spanning four years at a site impacted by the outflow of smoke. The data required to be post processed for the shadowing effect since, without correction, concentrations would be between 29% and 35% underestimated. The BrC concentrations were consistently higher than the BC concentrations, indicating the prevalence of aerosols from biomass burning. The results were supported by the Ångström coefficient (Å370/880), with values predominantly larger than 1 (mean ± standard deviation: 1.25 ± 0.31). Å370/880 values below 1 were more prevalent during the wet season, which suggests a contribution from fossil fuel combustion. We observed sharp BrC and BC seasonal signals, with mean minimum concentrations of 0.40 µg/m3 and 0.36 µg/m3, respectively, in the wet season, and mean maximum concentrations of 2.05 µg/m3 and 1.53 µg/m3 in the dry season. The largest concentrations were observed when northerly air masses moved over regions with a high density of fire spots. Local burning of residential solid waste and industrial combustion caused extreme BrC and BC concentrations under favourable wind directions. Although neither pollutant is included in any ambient air quality standards, our results suggest that transboundary smoke may hamper efforts to meet the World Health Organization guidelines for fine particles.
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Affiliation(s)
- Admir Créso Targino
- Graduate Program in Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, Londrina, PR 86036-370, Brazil.
| | - Patricia Krecl
- Graduate Program in Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, Londrina, PR 86036-370, Brazil
| | - Gabriel Yoshikazu Oukawa
- Department of Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, Londrina, PR 86036-370, Brazil
| | - Eva Maria Mollinedo
- Graduate Program in Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, Londrina, PR 86036-370, Brazil
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Krecl P, Oukawa GY, Charres I, Targino AC, Grauer AF, Silva DCE. Compilation of a city-scale black carbon emission inventory: Challenges in developing countries based on a case study in Brazil. Sci Total Environ 2022; 839:156332. [PMID: 35640756 DOI: 10.1016/j.scitotenv.2022.156332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 05/03/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
Black carbon (BC) inventories for cities are scarce, especially in developing countries, despite their importance to tackle climate change and local air pollution. Here, we draw on results from a case study in a Brazilian city to discuss the challenges of compiling a BC inventory for different activity sectors. We included traditionally inventoried sectors, such as industries and on-road transportation, other less reported sectors (food establishments and aviation), and open burning of household solid waste (HSW), typically found in developing countries. We present a machine-learning technique (Random Forest) as a novel approach to obtain HSW burning activity using a set of spatial predictors. The BC inventory was based on PM2.5 emissions weighted by the fraction of PM2.5 emitted as BC and developed for the year 2018. We also reported the disaggregated spatial PM2.5 emissions for the same combustion sources, and documented the databases used for activity data and emission factors (EF). The total estimated BC and PM2.5 emissions amounted to 57.88 and 234.75 tons, respectively, with on-road vehicle exhaust emissions and industrial combustion as the main BC sources (63 and 22%, respectively). For PM2.5 emissions, on-road transportation (exhaust and non-exhaust) contributed 48%, followed by industrial combustion (21%) and food establishments (20%). Population density, number of vacant lots, and property tax values were identified as the most important features to predict the HSW fire activity. A comparison with other inventories revealed that the BC emission profile of Londrina is similar to the profile reported for Greater Mexico City, another Latin American city. Thus, the methodology used in this study could be extended to other cities with similar local BC sources. Finally, we highlight that the lack of local activity data, representative EF, and even methodology may undermine the development of reliable BC inventories, and intensive research should be conducted to characterize the emission sources.
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Affiliation(s)
- Patricia Krecl
- Graduate Program in Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370 Londrina, PR, Brazil.
| | - Gabriel Yoshikazu Oukawa
- Department of Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370 Londrina, PR, Brazil
| | - Isabella Charres
- Graduate Program in Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370 Londrina, PR, Brazil
| | - Admir Créso Targino
- Graduate Program in Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370 Londrina, PR, Brazil
| | - Andreas Friedrich Grauer
- Graduate Program in Urban and Industrial Environment, Federal University of Paraná, Av. XV de Novembro, 1299, 80060-000 Curitiba, PR, Brazil
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Oukawa GY, Krecl P, Targino AC. Fine-scale modeling of the urban heat island: A comparison of multiple linear regression and random forest approaches. Sci Total Environ 2022; 815:152836. [PMID: 34990665 DOI: 10.1016/j.scitotenv.2021.152836] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 12/08/2021] [Accepted: 12/28/2021] [Indexed: 05/17/2023]
Abstract
Characterizing the spatiotemporal variability of the Urban Heat Island (UHI) and its drivers is a key step in leveraging thermal comfort to create not only healthier cities, but also to enhance urban resilience to climate change. In this study, we developed specific daytime and nighttime multiple linear regression (MLR) and random forest (RF) models to analyze and predict the spatiotemporal evolution of the Urban Heat Island intensity (UHII), using the air temperature (Tair) as the response variable. We profited from the wealth of in situ Tair data and a comprehensive pool of predictors variables - including land cover, population, traffic, urban geometry, weather data and atmospheric vertical indices. Cluster analysis divided the study period into three main groups, each dominated by a combination of weather systems that, in turn, influenced the onset and strength of the UHII. Anticyclonic circulations favored the emergence of the largest UHII (hourly mean of 5.06 °C), while cyclonic circulations dampened its development. The MLR models were only able to explain a modest percentage of variance (64 and 34% for daytime and nighttime, respectively), which we interpret as part of their inability to capture key factors controlling Tair. The RF models, on the other hand, performed considerably better, with explanatory power over 96% of the variance for daytime and nighttime conditions, capturing and mapping the fine-scale Tair spatiotemporal variability in both periods and under each cluster condition. The feature importance analysis showed that the meteorological variables and the land cover were the main predictors of the Tair. Urban planners could benefit from these results, using the high-performing RF models as a robust framework for forecasting and mitigating the effects of the UHI.
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Affiliation(s)
- Gabriel Yoshikazu Oukawa
- Department of Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370 Londrina, PR, Brazil
| | - Patricia Krecl
- Graduate Program in Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370 Londrina, PR, Brazil.
| | - Admir Créso Targino
- Graduate Program in Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370 Londrina, PR, Brazil
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Krecl P, de Lima CH, Dal Bosco TC, Targino AC, Hashimoto EM, Oukawa GY. Open waste burning causes fast and sharp changes in particulate concentrations in peripheral neighborhoods. Sci Total Environ 2021; 765:142736. [PMID: 33268251 DOI: 10.1016/j.scitotenv.2020.142736] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/09/2020] [Accepted: 09/23/2020] [Indexed: 05/20/2023]
Abstract
The open burning of municipal solid waste (MSW) -frequently observed in developing countries- emits harmful pollutants, including fine particulate matter (PM2.5) and black carbon (BC), and deteriorates the air quality in urban areas. This work reports on PM2.5 and BC measurements (fixed and mobile) conducted in a residential neighborhood on the outskirts of a Brazilian city (Londrina), complemented by a public opinion survey to understand the open burning in the context of waste management. Mean (± standard deviation) BC concentration (1.48 ± 1.40 μg m-3) at the fixed sites of the neighborhood was lower than downtown, while PM2.5 (9.68 ± 8.40 μg m-3) concentration was higher. The mobile monitoring showed higher mean PM2.5 concentrations but lower BC/PM2.5 ratios than downtown, with sharp and fast spikes (up to 317.87 and 565.21 μg m-3 for BC and PM2.5, respectively). The large spatial heterogeneity of particulate concentrations was associated with the occurrence of MSW burning events. Our observations were verified by the survey respondents who identified poor waste management practices: garbage in streets, waste burning, and illegal dump sites. Even though the area has a municipal waste collection service, the majority of the respondents (87%) had seen waste burning close to their homes on a weekly basis, and think that people burn waste out of habit (54%) and because they are not patient to wait for the collection services (67%). To combat this illegal practice, we suggest raising the public awareness through campaigns at local level, adopting education initiatives and economic incentives for correct waste segregation, and enforcing regular inspection of burning events by the authorities. Our research method proved to be a time- and cost-effective approach for mapping particulate concentrations and for identifying undesirable waste practices, and could be effectively applied to other global cities.
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Affiliation(s)
- Patricia Krecl
- Graduate Program in Environmental Engineering, Federal University of Technology, Londrina, Brazil.
| | - Caroline Hatada de Lima
- Graduate Program in Environmental Engineering, Federal University of Technology, Londrina, Brazil
| | | | - Admir Créso Targino
- Graduate Program in Environmental Engineering, Federal University of Technology, Londrina, Brazil
| | - Elizabeth Mie Hashimoto
- Graduate Program in Environmental Engineering, Federal University of Technology, Londrina, Brazil
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Krecl P, Targino AC, Oukawa GY, Cassino Junior RP. Drop in urban air pollution from COVID-19 pandemic: Policy implications for the megacity of São Paulo. Environ Pollut 2020; 265:114883. [PMID: 32504979 PMCID: PMC7259904 DOI: 10.1016/j.envpol.2020.114883] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/11/2020] [Accepted: 05/25/2020] [Indexed: 05/19/2023]
Affiliation(s)
- Patricia Krecl
- Federal University of Technology, Graduate Program in Environmental Engineering, Londrina, Brazil; Federal University of Technology, Department of Environmental Engineering, Londrina, Brazil.
| | - Admir Créso Targino
- Federal University of Technology, Graduate Program in Environmental Engineering, Londrina, Brazil
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Targino AC, Krecl P, Cipoli YA, Oukawa GY, Monroy DA. Bus commuter exposure and the impact of switching from diesel to biodiesel for routes of complex urban geometry. Environ Pollut 2020; 263:114601. [PMID: 33618461 DOI: 10.1016/j.envpol.2020.114601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 04/05/2020] [Accepted: 04/13/2020] [Indexed: 06/12/2023]
Abstract
We report on commuters' exposure to black carbon (BC), PM2.5 and particle number (PN, with aerodynamic diameter, da, in the range 0.01 <da< 1.0 μm) collected on-board diesel- and biodiesel-fuelled buses of the Bus Rapid Transit (BRT) system of the city of Curitiba, Brazil. Particulate concentrations measured at high sampling rates allowed the capture of fine gradients along the route and the comparison of in-cabin air pollution on buses of different technologies. Of all metrics, BC showed the largest discrepancies, with mean concentrations of 20.1 ± 20.0 μg m-3 and 3.9 ± 26.0 μg m-3 on diesel- and biodiesel-fuelled buses, respectively. Mean PM2.5 concentrations were similar (31.6 ± 28.5 μg m-3 and 29.0 ± 17.8 μg m-3), whilst mean PN concentrations were larger on the biodiesel buses (56,697 ± 26,800 # cm-3vs. 43,322 ± 32,243 # cm-3). The results are in line with studies on biodiesel emission factors that reported lower BC mass but more particles with smaller diameters. Our hypothesis is that different emission factors of diesel and biodiesel engines reflected in differences of in-cabin particulate concentrations. We found that the passenger exposure during the bus commutes was affected not only by the fuel used but also by the street geometry along the route, with segments with canyon configurations resulting in peak exposure to particulates. The results suggest that i) switching from diesel to biodiesel may help abate commuters' exposure to BC particles on-board buses of the BRT system, whilst it would need to be complemented with after-treatment technologies to reduce emissions; ii) further reductions in exposure (to peaks in particular) could be achieved by changing bus routes to ones that avoid passing through narrow urban street canyons.
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Affiliation(s)
- Admir Créso Targino
- Graduate Program in Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370, Londrina, PR, Brazil.
| | - Patricia Krecl
- Graduate Program in Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370, Londrina, PR, Brazil
| | - Yago Alonso Cipoli
- Department of Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370, Londrina, PR, Brazil
| | - Gabriel Yoshikazu Oukawa
- Department of Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370, Londrina, PR, Brazil
| | - David Andrés Monroy
- Graduate Program in Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370, Londrina, PR, Brazil
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