Quantifying impacts of exposure to air pollutants from wildfires

This document was produced under the terms and conditions of Grant Agreement No. 101037419 of the European Commission. It does not necessarily reflect the view of the European Union and in no way anticipates the Commission’s future policy in this area. D5.10 - Quantifying impacts of exposure to air pollutants from wildfires www.fire-res.eu [email protected] Project Acronym: FIRE-RES Project name: Quantifying impacts of exposure to air pollutants from wildfires Call ID: H2020-LC-GD-1-1-2020 (Preventing and fighting extreme wildfires with the integration and demonstration of innovative means) Work Package: WP5 Task Number: 5.3 Lead beneficiary: Institute of Environmental Assessment and Water Research (IDAEACSIC) Contributing beneficiary(ies): D5.10 – Quantifying impacts of exposure to air pollutants from wildfires Publication Publication date: 22/11/2024 Authors: Jordina Gili (CSIC), Aina Maín (CSIC); Mar Viana (CSIC) Abstract: Health effects of aerosols emitted by wildfires remain poorly quantified due to uncertainties on wildfire emissions assessment. Exposure to air pollutants from wildfires is linked to serious health effects such as respiratory and cardiovascular problems This issue is particularly pronounced for firefighters, who, while performing fire control and extinguishing operations, firefighters are exposed to smoke that contains substantial amounts of known harmful pollutants. A deeper understanding of the concentrations of air pollutants from wildfires is essential to developing effective mitigation strategies. This will help protect firefighters from the harmful effects of these pollutants and enhance public health and safety. Key words: Source apportionment, black carbon, particulate matter, wildland fire, aerosols. DOI: 10.5281/zenodo.14181594 Dissemination level [ ] PUPublic: must be available in the website [X] COConfidential: Only for members of the Consortium and the Commission Services [ ] CI – Classified: As referred in to Commission Decision 2001/844/EC Document history Edition Date Status Author Version 1 12/11/2024 Draft Jordina Gili (CSIC), Aina Maín (CSIC), Mar Viana (CSIC) Version 2 14/11/2024 Revision Miguel Mendes (TSYLVA) Version 3 19/11/2024 Revision Lluís Coll (CTFC) Version 4 22/11/2024 Revision Elena Rafailova (UF) Version 5 22/11/2024 Revised version Jordina Gili (CSIC), Aina Maín (CSIC), Mar Viana (CSIC) D5.10 – Quantifying impacts of exposure to air pollutants from wildfires Copyright © All rights reserved. This document or any part thereof may not be made public or disclosed, copied or otherwise reproduced or used in any form or by any means, without prior permission in writing from the FIRE-RES Consortium. 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The information and views set out in this publication does not necessarily reflect the official opinion of the European Commission. Neither the European Union institutions and bodies nor any person acting on their behalf, may be held responsible for the use which may be made of the information contained therein. D5.10 – Quantifying impacts of exposure to air pollutants from wildfires Table of contents 1. INTRODUCTION ........................................................................................................................ 1 2. METHODOLOGY ....................................................................................................................... 2 2.1 Personal exposure ........................................................................................................................................ 2 2.1.1 Study locations ................................................................................................................................... 2 2.1.2 PM2.5 and BC monitors ...................................................................................................................... 3 2.1.3 Source apportionment of BC ............................................................................................................ 4 2.2 Air quality ..................................................................................................................................................... 4 2.2.1 Study area ........................................................................................................................................... 4 2.2.2 Identification of NW Iberian Peninsula wildfires in summer 2022 .............................................. 6 3. RESULTS AND DISCUSSION ....................................................................................................... 8 3.1 BC and PM2.5 exposures during wildland fires and prescribed burns from portable monitors .................... 8 3.1.1 PM2.5 exposures .................................................................................................................................. 8 3.1.2 BC exposures ...................................................................................................................................... 9 3.2 Air pollution data series from static sensors .............................................................................................. 11 3.2.1 Evaluation of wildfires impacts in Galicia ..................................................................................... 11 4. TECHNOLOGY READINESS LEVEL (TRL) OF KEY FINDINGS.......................................................... 15 5. CONCLUSIONS ........................................................................................................................ 15 REFERENCES .............................................................................................................................. 17 D5.10 – Quantifying impacts of exposure to air pollutants from wildfires 1 1. Introduction A comprehensive understanding of exposure concentrations and exposure scenarios is crucial for developing mitigation strategies aimed at enhancing occupational and public health and safety. The main objectives of the IA5.7 – Quantifying impacts of exposure to air pollutants from wildfires, are as follows: • Characterize personal exposures: Identify and quantify the specific exposure concentrations experienced by firefighters. • Validate the use of portable monitors: Assess the reliability and accuracy of portable monitoring devices for monitoring personal exposure during wildfires and prescribed burns. • Communicate the health impacts of firefighters’ exposure to smoke: Raise awareness of the potential health risks associated with repeated or prolonged exposure to fire smoke, emphasizing the importance of protective measures. • Quantify impacts on air quality: Study the impacts of wildfire smoke plumes on ambient air quality. To achieve these objectives, two complementary approaches are employed: (i) Personal exposure monitoring, by employing portable monitors that firefighters can carry throughout their shifts. The exposure data collected provides deeper insights into emissions and their impact on exposure profiles. This information becomes the foundation for developing occupational health and safety strategies, aiming to reduce the health risks associated with prolonged exposure to harmful pollutants. By implementing protective measures based on real-time exposure data, the firefighter community can proactively enhance worker safety, minimize health impacts, and provide novel information for developing protocols and decision support systems. (ii) Air quality monitoring, focused on assessing ambient air quality in areas impacted by fire smoke using static sensors strategically placed in locations vulnerable to smoke dispersion. These sensors provide data about the environmental concentrations of smoke-related pollutants in a fixed area, providing ambient air quality data over time. This data is essential for validating and refining smoke dispersion models, which predict how smoke will move and settle in different environmental conditions. Accurate smoke dispersion models allow for better understanding of the broader impact of fire events on air quality, offering valuable insights for public health advisories and environmental safety protocols. By improving predictive capabilities through model validation, authorities and researchers can more effectively manage air quality impacts, identify high-risk areas, and issue timely warnings to the public in affected regions. D5.10 – Quantifying impacts of exposure to air pollutants from wildfires 2 Together, these approaches provide a robust framework for reducing health risks, promoting safety and improving both occupational and public health responses to exposure scenarios. 2. Methodology Between 2022 and 2024, pollutant measurement campaigns have been conducted with portable monitors for (i) Personal exposure and with static sensors for (ii) Air quality. Below are the details of the campaigns for each of these approaches. 2.1 Personal exposure 2.1.1 Study locations Exposure monitoring was conducted between 2022 and 2024 during 15 prescribed burns across Catalonia, Spain. The sampling locations included various sites in the provinces of Barcelona, Girona, Tarragona, and Lleida, each with different vegetation types such as Mediterranean vegetation, shrubs, young trees, and grass. Burn areas varied in size from 0.3 to 4 hectares. Prescribed burns (PB), performed annually as a management tool, follow specific guidelines based on meteorological conditions, fuel types, and terrain. These burns aim to control vegetation, prevent wildfires, and support plant regeneration. They occur in two main periods: PB1 (summer-autumn) with temperatures between 24°C and 30°C, and PB2 (winter) with colder conditions below 15°C. Logistically, the monitoring for PB1 and PB2 varied; during PB1, researchers had no direct access to burn sites, whereas PB2 allowed for easier access and more data collection. For sampling, portable monitors were given to firefighters, and post-shift questionnaires were used to gather data on burn activities such as lighting, holding (also referred to as perimeter controlling), and mopping-up. Lighting involves the fire ignition process with a drip-torch fuelled by a mix of gasoil and diesel (torcher). Holding involves the management of fire within the perimeter and use of manual tools to prevent fire spread (line operator). Mopping-up entails the extinguishing of smouldering fire after the major burning phase, by stirring the top-soil layer, using handheld tools (e.g. spades). In prescribed burns, firefighters are assigned two primary roles: Torcher and Line operator. Monitoring was also conducted during eight wildfires in 2022 and 2023, with varying burn intensities and areas. Exposure records varied greatly based on the specific conditions of each burn and the firefighter's shift, ranging from 1 to 8 hours for prescribed burns and 1 to 13 hours for wildfires. D5.10 – Quantifying impacts of exposure to air pollutants from wildfires 3 2.1.2 PM2.5 and BC monitors At each site, the goal was to monitor the personal exposure of 4 to 8 firefighters to Black Carbon (BC) and Particulate Matter (PM2.5). Lightweight, non-invasive portable monitors were used to track their exposure. Firefighters wore the monitors on their bodies (Figure 1), with the sampling inlet positioned near their breathing zone without disrupting their tasks. BC aerosols were measured using two types of portable Aethalometers: the AE51 (single-wavelength) and the MA200 (multi-wavelength). These monitors collected data on BC concentrations at 880 nm, with the MA200 estimating the BC contributions from both fossil fuel and biomass burning emissions. A total of four MA200 and five AE51 units were used, with data recorded at 1-minute intervals and a flow rate of 100 mL/min. Figure 1: Firefighter carrying the monitoring instruments during a prescribed burn. For PM2.5, ten portable AirBeam2 sensors were deployed. These devices, which use Plantower PMS7003 particle sensing units, operate independently with their own battery and can transmit data via Bluetooth or WiFi to a mobile phone. The sensors also include a GPS to map the recorded PM2.5 concentrations, with data averaged over 1-minute intervals. Before each sampling campaign, the devices were calibrated and compared for consistency. They were also compared to high-end instruments at an EU-reference air quality monitoring station in Barcelona. BC concentrations from the Aethalometers were compared to those from a stationary Multi-Angle Absorption Photometer (MAAP), while PM2.5 concentrations were cross-checked with an environmental dust monitor (GRIMM180). The PM2.5 sensor data were adjusted based on these reference measurements. The authors note that the sensors were calibrated using urban aerosols, which may differ from the wildfire smoke aerosols targeted in this study. D5.10 – Quantifying impacts of exposure to air pollutants from wildfires 4 2.1.3 Source apportionment of BC Source apportionment was conducted on the multi-wavelength BC datasets to separate the contributions of fossil fuel and biomass burning contributions. Equations from the Aethalometer model were employed to calculate the contribution of fossil fuel combustion (BCff) and biomass burning (BCbb)to BC (Sandradewi et al., 2008b). 2.2 Air quality Three wildfire campaigns were conducted during the summers of 2022, 2023 and 2024. Here, the impacts of the wildfires from the 2022 campaign will be specifically analyzed, which took place in Galicia. Analyses of the subsequent campaigns can be found in the annual reports. 2.2.1 Study area The study area covered the Galicia region (lat. 42° 45’N, long. 7° 41’W) (Figure 2), located in the northwest of the Iberian Peninsula. It is one of the regions in Europe with the highest activity of forest fires and, consequently, the most affected by the emissions from this source (Alonso-Betanzos et al., 2003). D5.10 – Quantifying impacts of exposure to air pollutants from wildfires 5 Figure 2. Map of the geographical distribution of PurpleAir (PA) monitors deployed in Galicia (NW Spain), major cities and wildfires during summer 2022. The seven largest wildfires considered in this study are labelled on the map (modified from Gili et al., 2024). Historically, a number of extreme wildfires have affected Northern Portugal and Northwestern Spain. The 2017 Iberian wildfires were some of the most severe wildfires and had a significant impact on the region, resulting in human deaths and major economic damage (Chas-Amil et al., 2020). According to the European Forest Fire Information System (EFFIS), these wildfires burned an area of about 700,000 hectares in total. Another exceptional wildfire season was in summer 2022 in Spain, where the number of observed fires and the extent of burned area were higher than the average of 2006-2021. Specifically, in Galicia, 50,000 hectares were burnt during this period. There are three key factors that make Galicia a fire-prone region. First, the regional climate promotes the accumulation of shrub biomass and consequently, the buildup of flammable forest fuels D5.10 – Quantifying impacts of exposure to air pollutants from wildfires 12 do Conso (WF_3) (Figures 6a, 6b, 6c). On July 19, a notable shift in wind direction allowed for atmospheric cleansing, temporarily reducing pollution levels. However, by July 21, the reappearance of south-southeastern winds likely reintroduced smoke-laden air masses from these fires, resulting in potential PM2.5 concentrations of up to 75 μg/m³. These wildfire events collectively raised mean PM2.5 concentrations by 36 μg/m³ above the baseline level of 24 μg/m³. Figure 6. Time series plot of contributions associated with the PM2.5 measured at PA14 (top) alongside the corresponding back-trajectory analysis (a, b, c) (bottom). On July 13, elevated PM concentrations monitored at PA4, PA5, PA6, PA15, PA17, and PA22 were likely influenced by emissions from the Melón (WF_20) and Ribadavia (WF_22) wildfires, as air masses originating from the southwest carried smoke from these events (Figure 7a). Additionally, northeast back trajectories pointed to smoke transport from the Folgoso do Courel wildfire (WF_1) to these monitoring sites (Figure 7c). The impact of wildfires is marked by a mean PM2.5 increase of 63 μg/m³ over a baseline of 34 μg/m³, with peak concentrations reaching 435 μg/m³. D5.10 – Quantifying impacts of exposure to air pollutants from wildfires 13 Figure 7. Time series plot of contributions associated with the PM2.5 measured at PA4 (top) alongside the corresponding back-trajectory analysis (a, b, c) (bottom). On August 3, the highest concentration recorded at monitor PA8 was likely linked to a local source, as the back trajectories showed significant divergence (Figure 8). Additionally, PA8 was probably affected by emissions from the Lobeira wildfire on August 24, 2022. The overall impact of wildfires resulted in a 24 μg/m³ increase in mean PM2.5 concentrations over the baseline level of 19 μg/m³. D5.10 – Quantifying impacts of exposure to air pollutants from wildfires 14 Figure 8. Time series plot of contributions associated with the PM2.5 measured at PA8. Between July 16 and 18, 2022, south-southeasterly back trajectories passing through the Vilariño do Conso wildfire (WF_3) region likely contributed to PM2.5 concentrations reaching up to 150 μg/m³ monitored at PA3 (Figures 9a, 9b). On July 20, emissions from WF_1 may have influenced PA3, as air masses from the northeast of the sensor site brought higher concentrations, resulting in the highest values recorded by PA3 (Figure 9c). The overall impact of wildfires led to a 25 μg/m³ increase in mean PM2.5 concentrations compared to the baseline level of 19 μg/m³. Figure 9. Time series plot of contributions associated with the PM2.5 measured at PA3 (top) alongside the corresponding back-trajectory analysis (a, b, c) (bottom). D5.10 – Quantifying impacts of exposure to air pollutants from wildfires 15 4. Technology Readiness Level (TRL) of Key Findings The IA5.7, which focuses on quantifying firefighter exposure to wildfire smoke and assessing its impacts on air quality, has advanced from TRL 6 to TRL 7 by demonstrating its readiness in operational environments. This progress has been solidified through extensive testing in real-world scenarios, including active wildfires between 2022 and 2024. Portable monitors reliably captured exposure data for firefighters under diverse and challenging conditions, while static monitors deployed in Galicia, provided robust ambient air quality data during wildfire events. These systems demonstrated high accuracy and reliability, validated through calibration with EU-reference instruments and adjustments tailored to wildfire-specific aerosols. Furthermore, the collected data have been integrated into practical applications, enabling the development of decisionsupport systems for firefighting operations and air quality management. 5. Conclusions The increasing frequency and intensity of wildfires, driven by changes in climate and landuse, pose significant risks to both human health and the environment. This study aimed to deepen our understanding of the types and sources of aerosols, particularly Particulate Matter (PM2.5) and Black Carbon (BC), generated during wildfires and prescribed burns, which is crucial for exposure management and mitigation. Key findings indicate that human exposure to combustion aerosols (PM2.5 and BC) was notable and comparable in both prescribed burns and wildfires. For instance, mean PM2.5 concentrations were 152 µg/m³ during wildfires and ranged between 110-149 µg/m³ during prescribed burns. This similarity suggests that prescribed burns can serve as useful proxies for wildfires in exposure studies, simplifying aerosol monitoring in experimental settings. Wildfires, however, resulted in higher overall PM2.5 doses compared to prescribed burns, due to longer exposure durations. Although peak PM2.5 concentrations were higher during prescribed burns, the duration of wildfires led to greater total exposure. For BC, prescribed burns showed higher peak concentrations, while mop-up tasks, involving soil disturbance during firefighting activities, were identified as an unexpected contributor to increased PM2.5 exposure, particularly among line operators. These tasks stirred up mineral aerosols, with BC accounting for 62 % of PM2.5 exposure for torch operators and only 22 % for line operators, highlighting the role of soil re-suspension in specific firefighting activities. Additionally, source apportionment analysis revealed distinct exposure patterns between firefighter roles, with drip torch operators exposed predominantly to BC from fire-fronts (77 %) while line operators had more balanced exposure between BC from fire- D5.10 – Quantifying impacts of exposure to air pollutants from wildfires 16 fronts and background sources. These findings emphasize the need to assess specific firefighting tasks in terms of aerosol exposure risk. Source apportionment of wildfire emissions contributing to PM2.5 concentrations was performed using Positive Matrix Factorization (PMF) combined with back-trajectory analysis. Wildfires were found to increase background PM2.5 levels by an average of 21-39 µg/m³ over 5-10 days, reaching up to 63 µg/m³ and maximum hourly peak concentrations of 435 µg/m³. These results emphasize the extensive reach of wildfire emissions and their variability depending on the fire's size and location. The study also confirmed the effectiveness of portable monitors and multi-wavelength aethalometers in assessing wildfire emissions and human exposure in real-time. These tools enabled source apportionment and provided high-quality data for spatial and temporal analysis, such as identifying pollution sources during major wildfires and smaller fires that impacted nearby areas. 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