Health burden and inequities of urban environmental stressors in Sofia, Bulgaria

Sasha Khomenko; Angel Burov; Angel M. Dzhambov; Kees de Hoogh; Marco Helbich; Bas Mijling; Ivaylo Hlebarov; Ivaylo Popov; Donka Dimitrova; Reneta Dimitrova; Iana Markevych; Nevena Germanova; Danail Brezov; Tamara Iungman; Federica Montana; Xuan Chen; Ulrike Gehring; Haneen Khreis; Natalie Mueller; Belen Zapata-Diomedi; Jiawei Zhang; Mark Nieuwenhuijsen

doi:10.1016/j.envres.2025.121782

Health burden and inequities of urban environmental stressors in Sofia, Bulgaria

Sasha Khomenko
, Angel Burov
, Angel M. Dzhambov
, Kees de Hoogh
, Marco Helbich
, Bas Mijling
, Ivaylo Hlebarov
, Ivaylo Popov
, Donka Dimitrova
, Reneta Dimitrova
, Iana Markevych
, Nevena Germanova
, Danail Brezov
, Tamara Iungman
, Federica Montana
, Xuan Chen
, Ulrike Gehring
, Haneen Khreis
, Natalie Mueller
, Belen Zapata-Diomedi

Jiawei Zhang, Mark Nieuwenhuijsen^*

^*Corresponding author for this work

Research output: Contribution to journal › Article › Academic › peer-review

Abstract

Background: The number of studies on the health impacts of urban environmental stressors has been growing. However, research for South-Eastern Europe remains limited. We conducted a baseline Health Impact Assessment for Sofia, Bulgaria, focusing on air pollution, green space, road-traffic noise, and urban heat island (UHI) exposure aiming to promote discussions on sustainable, health-centric urban and transport planning policies. Methods: The analysis was conducted at the neighbourhood level (n = 4969). The study population included 1,168,382 inhabitants, considering adults and children. Data were retrieved from Europe-wide and local exposure models, local censuses and surveys. We used comparative risk assessment methodology, comparing baseline with optimal scenarios for health, such as meeting World Health Organization (WHO) air quality and road-traffic noise guidelines, green space recommendations, and no UHI effect. We also examined exposure and health impact distributions by area-level socioeconomic status (SES). We approximated differences in baseline disease rates by SES using data from local surveys. The results were stratified by SES quartiles and analysed spatially using global and local bivariate Moran's I statistics, the latter to identify priority areas for intervention based on SES, environmental exposures, and health outcomes. Results: All Sofia residents lived in neighbourhoods where particulate matter with diameter ≤2.5 μm (PM_2.5) and nitrogen dioxide (NO₂) levels exceeded the WHO air quality guidelines, with mean noise levels of 62.2 dB(A) L_day, 77 % lacking sufficient availability of green space, and an average summer UHI of 2.5 °C. The largest mortality burden was from PM_2.5 exposure (1939 annual deaths (95 % CI: 1349–2571)), followed by NO₂ (1172 annual deaths (444-2027)), road-traffic noise (902 annual deaths (556-1311)), insufficient green space (217 annual deaths (169–262)), and UHI (95 summer deaths (58–130)). PM_2.5 contributed to 17–21 % of cardiovascular disease cases, while noise accounted for 5 % of Ischaemic Heart Disease and stroke cases. NO₂, noise, and UHI exposures tended to be higher in higher SES areas, while PM_2.5 tended to be lower. Spatial analysis revealed that central areas, with high-SES populations, and northern, north-eastern, and north-western areas, with lower-SES populations, all experience high exposure and health impacts. Conclusions: The analysis showed a significant health burden from urban environmental stressors in Sofia, with an uneven distribution across SES groups. Health-promoting policy interventions should consider both environmental and socioeconomic factors to prioritize areas for action.

Original language	English
Article number	121782
Number of pages	15
Journal	Environmental Research
Volume	279
Issue number	Pt 1
Early online date	8 May 2025
DOIs	https://doi.org/10.1016/j.envres.2025.121782
Publication status	Published - 15 Aug 2025

Bibliographical note

Publisher Copyright:
© 2025 Elsevier Inc.

Funding

We acknowledge support from the grant CEX2023-0001290-S funded by MCIN/AEI/10.13039/501100011033, support from the Generalitat de Catalunya through the Centres de Recerca de Catalunya (CERCA) Program, and support from Centro de Investigacion Biomedica en red Epidemiologia y Salud Publica (CIBERESP) . This project has received funding from the European Union's, Horizon Europe Framework Programme (HORIZON) under GA No 101094639 -THE URBAN BURDEN OF DISEASE ESTIMATION FOR POLICY MAKING (UBDPolicy) . We also acknowledge support from the "Strategic Research and Innovation Program for the Development of Medical University - Plovdiv", Contract No. BG-RRP-2.004-0007-C01, Establishment of a network of research higher schools, National Plan for Recovery and Resilience, financed by the European Union - NextGenerationEU, which funded the collection of SRIPD-MUP data and the time spent on this publication by Angel M. Dzhambov, Angel Burov, Marco Helbich, Donka Dimitrova, and Iana Markevych, and the Bulgarian National Science Fund (BNSF) , under the project "Development of a methodology for assessing air quality and its impact on human health in an urban environment", grant number: K & Pcy;-06- & Ncy;54/2-15.11.2021 which funded the BNSF-SU data collection and the time spent on this publication by Reneta Dimitrova, Nevena Germanova, and Danail Brezov. The funders have not been involved in any aspect of the study design or reporting.

Funders	Funder number
MCIN/AEI
Generalitat de Catalunya through the Centres de Recerca de Catalunya (CERCA) Program
Centro de Investigacion Biomedica en red Epidemiologia y Salud Publica (CIBERESP)
European Union's, Horizon Europe Framework Programme (HORIZON)	101094639
Strategic research and innovation program for the development of Medical University - Plovdiv	BG-RRP-2.004-0007-C01
Establishment of a network of research higher schools, National Plan for Recovery and Resilience
European Union - NextGenerationEU
Bulgarian National Science Fund (BNSF)	K Pcy;-06- Ncy;54/2-15.11.2021
???publication-publication-funding-organisation-not-added???	CEX2023-0001290-S

Keywords

Air pollution
Cities
Environmental justice
Green space
Health impact assessment
Noise
Temperature

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1016/j.envres.2025.121782

1-s2.0-S0013935125010333-mainFinal published version, 11.8 MBLicence: Taverne

Cite this

Khomenko, S., Burov, A., Dzhambov, A. M., de Hoogh, K., Helbich, M., Mijling, B., Hlebarov, I., Popov, I., Dimitrova, D., Dimitrova, R., Markevych, I., Germanova, N., Brezov, D., Iungman, T., Montana, F., Chen, X., Gehring, U., Khreis, H., Mueller, N., ... Nieuwenhuijsen, M. (2025). Health burden and inequities of urban environmental stressors in Sofia, Bulgaria. Environmental Research, 279(Pt 1), Article 121782. https://doi.org/10.1016/j.envres.2025.121782

@article{0ec953c7f2544d7086cf1edb6248a39e,

title = "Health burden and inequities of urban environmental stressors in Sofia, Bulgaria",

abstract = "Background: The number of studies on the health impacts of urban environmental stressors has been growing. However, research for South-Eastern Europe remains limited. We conducted a baseline Health Impact Assessment for Sofia, Bulgaria, focusing on air pollution, green space, road-traffic noise, and urban heat island (UHI) exposure aiming to promote discussions on sustainable, health-centric urban and transport planning policies. Methods: The analysis was conducted at the neighbourhood level (n = 4969). The study population included 1,168,382 inhabitants, considering adults and children. Data were retrieved from Europe-wide and local exposure models, local censuses and surveys. We used comparative risk assessment methodology, comparing baseline with optimal scenarios for health, such as meeting World Health Organization (WHO) air quality and road-traffic noise guidelines, green space recommendations, and no UHI effect. We also examined exposure and health impact distributions by area-level socioeconomic status (SES). We approximated differences in baseline disease rates by SES using data from local surveys. The results were stratified by SES quartiles and analysed spatially using global and local bivariate Moran's I statistics, the latter to identify priority areas for intervention based on SES, environmental exposures, and health outcomes. Results: All Sofia residents lived in neighbourhoods where particulate matter with diameter ≤2.5 μm (PM2.5) and nitrogen dioxide (NO2) levels exceeded the WHO air quality guidelines, with mean noise levels of 62.2 dB(A) Lday, 77 \% lacking sufficient availability of green space, and an average summer UHI of 2.5 °C. The largest mortality burden was from PM2.5 exposure (1939 annual deaths (95 \% CI: 1349–2571)), followed by NO2 (1172 annual deaths (444-2027)), road-traffic noise (902 annual deaths (556-1311)), insufficient green space (217 annual deaths (169–262)), and UHI (95 summer deaths (58–130)). PM2.5 contributed to 17–21 \% of cardiovascular disease cases, while noise accounted for 5 \% of Ischaemic Heart Disease and stroke cases. NO2, noise, and UHI exposures tended to be higher in higher SES areas, while PM2.5 tended to be lower. Spatial analysis revealed that central areas, with high-SES populations, and northern, north-eastern, and north-western areas, with lower-SES populations, all experience high exposure and health impacts. Conclusions: The analysis showed a significant health burden from urban environmental stressors in Sofia, with an uneven distribution across SES groups. Health-promoting policy interventions should consider both environmental and socioeconomic factors to prioritize areas for action.",

keywords = "Air pollution, Cities, Environmental justice, Green space, Health impact assessment, Noise, Temperature",

author = "Sasha Khomenko and Angel Burov and Dzhambov, \{Angel M.\} and \{de Hoogh\}, Kees and Marco Helbich and Bas Mijling and Ivaylo Hlebarov and Ivaylo Popov and Donka Dimitrova and Reneta Dimitrova and Iana Markevych and Nevena Germanova and Danail Brezov and Tamara Iungman and Federica Montana and Xuan Chen and Ulrike Gehring and Haneen Khreis and Natalie Mueller and Belen Zapata-Diomedi and Jiawei Zhang and Mark Nieuwenhuijsen",

note = "Publisher Copyright: {\textcopyright} 2025 Elsevier Inc.",

year = "2025",

month = aug,

day = "15",

doi = "10.1016/j.envres.2025.121782",

language = "English",

volume = "279",

journal = "Environmental Research",

issn = "0013-9351",

publisher = "Academic Press Inc.",

number = "Pt 1",

}

Khomenko, S, Burov, A, Dzhambov, AM, de Hoogh, K , Helbich, M, Mijling, B, Hlebarov, I, Popov, I, Dimitrova, D, Dimitrova, R, Markevych, I, Germanova, N, Brezov, D, Iungman, T, Montana, F, Chen, X , Gehring, U, Khreis, H, Mueller, N, Zapata-Diomedi, B, Zhang, J & Nieuwenhuijsen, M 2025, 'Health burden and inequities of urban environmental stressors in Sofia, Bulgaria', Environmental Research, vol. 279, no. Pt 1, 121782. https://doi.org/10.1016/j.envres.2025.121782

TY - JOUR

T1 - Health burden and inequities of urban environmental stressors in Sofia, Bulgaria

AU - Khomenko, Sasha

AU - Burov, Angel

AU - Dzhambov, Angel M.

AU - de Hoogh, Kees

AU - Helbich, Marco

AU - Mijling, Bas

AU - Hlebarov, Ivaylo

AU - Popov, Ivaylo

AU - Dimitrova, Donka

AU - Dimitrova, Reneta

AU - Markevych, Iana

AU - Germanova, Nevena

AU - Brezov, Danail

AU - Iungman, Tamara

AU - Montana, Federica

AU - Chen, Xuan

AU - Gehring, Ulrike

AU - Khreis, Haneen

AU - Mueller, Natalie

AU - Zapata-Diomedi, Belen

AU - Zhang, Jiawei

AU - Nieuwenhuijsen, Mark

PY - 2025/8/15

Y1 - 2025/8/15

N2 - Background: The number of studies on the health impacts of urban environmental stressors has been growing. However, research for South-Eastern Europe remains limited. We conducted a baseline Health Impact Assessment for Sofia, Bulgaria, focusing on air pollution, green space, road-traffic noise, and urban heat island (UHI) exposure aiming to promote discussions on sustainable, health-centric urban and transport planning policies. Methods: The analysis was conducted at the neighbourhood level (n = 4969). The study population included 1,168,382 inhabitants, considering adults and children. Data were retrieved from Europe-wide and local exposure models, local censuses and surveys. We used comparative risk assessment methodology, comparing baseline with optimal scenarios for health, such as meeting World Health Organization (WHO) air quality and road-traffic noise guidelines, green space recommendations, and no UHI effect. We also examined exposure and health impact distributions by area-level socioeconomic status (SES). We approximated differences in baseline disease rates by SES using data from local surveys. The results were stratified by SES quartiles and analysed spatially using global and local bivariate Moran's I statistics, the latter to identify priority areas for intervention based on SES, environmental exposures, and health outcomes. Results: All Sofia residents lived in neighbourhoods where particulate matter with diameter ≤2.5 μm (PM2.5) and nitrogen dioxide (NO2) levels exceeded the WHO air quality guidelines, with mean noise levels of 62.2 dB(A) Lday, 77 % lacking sufficient availability of green space, and an average summer UHI of 2.5 °C. The largest mortality burden was from PM2.5 exposure (1939 annual deaths (95 % CI: 1349–2571)), followed by NO2 (1172 annual deaths (444-2027)), road-traffic noise (902 annual deaths (556-1311)), insufficient green space (217 annual deaths (169–262)), and UHI (95 summer deaths (58–130)). PM2.5 contributed to 17–21 % of cardiovascular disease cases, while noise accounted for 5 % of Ischaemic Heart Disease and stroke cases. NO2, noise, and UHI exposures tended to be higher in higher SES areas, while PM2.5 tended to be lower. Spatial analysis revealed that central areas, with high-SES populations, and northern, north-eastern, and north-western areas, with lower-SES populations, all experience high exposure and health impacts. Conclusions: The analysis showed a significant health burden from urban environmental stressors in Sofia, with an uneven distribution across SES groups. Health-promoting policy interventions should consider both environmental and socioeconomic factors to prioritize areas for action.

AB - Background: The number of studies on the health impacts of urban environmental stressors has been growing. However, research for South-Eastern Europe remains limited. We conducted a baseline Health Impact Assessment for Sofia, Bulgaria, focusing on air pollution, green space, road-traffic noise, and urban heat island (UHI) exposure aiming to promote discussions on sustainable, health-centric urban and transport planning policies. Methods: The analysis was conducted at the neighbourhood level (n = 4969). The study population included 1,168,382 inhabitants, considering adults and children. Data were retrieved from Europe-wide and local exposure models, local censuses and surveys. We used comparative risk assessment methodology, comparing baseline with optimal scenarios for health, such as meeting World Health Organization (WHO) air quality and road-traffic noise guidelines, green space recommendations, and no UHI effect. We also examined exposure and health impact distributions by area-level socioeconomic status (SES). We approximated differences in baseline disease rates by SES using data from local surveys. The results were stratified by SES quartiles and analysed spatially using global and local bivariate Moran's I statistics, the latter to identify priority areas for intervention based on SES, environmental exposures, and health outcomes. Results: All Sofia residents lived in neighbourhoods where particulate matter with diameter ≤2.5 μm (PM2.5) and nitrogen dioxide (NO2) levels exceeded the WHO air quality guidelines, with mean noise levels of 62.2 dB(A) Lday, 77 % lacking sufficient availability of green space, and an average summer UHI of 2.5 °C. The largest mortality burden was from PM2.5 exposure (1939 annual deaths (95 % CI: 1349–2571)), followed by NO2 (1172 annual deaths (444-2027)), road-traffic noise (902 annual deaths (556-1311)), insufficient green space (217 annual deaths (169–262)), and UHI (95 summer deaths (58–130)). PM2.5 contributed to 17–21 % of cardiovascular disease cases, while noise accounted for 5 % of Ischaemic Heart Disease and stroke cases. NO2, noise, and UHI exposures tended to be higher in higher SES areas, while PM2.5 tended to be lower. Spatial analysis revealed that central areas, with high-SES populations, and northern, north-eastern, and north-western areas, with lower-SES populations, all experience high exposure and health impacts. Conclusions: The analysis showed a significant health burden from urban environmental stressors in Sofia, with an uneven distribution across SES groups. Health-promoting policy interventions should consider both environmental and socioeconomic factors to prioritize areas for action.

KW - Air pollution

KW - Cities

KW - Environmental justice

KW - Green space

KW - Health impact assessment

KW - Noise

KW - Temperature

UR - https://www.scopus.com/pages/publications/105004418893

U2 - 10.1016/j.envres.2025.121782

DO - 10.1016/j.envres.2025.121782

M3 - Article

C2 - 40345423

AN - SCOPUS:105004418893

SN - 0013-9351

VL - 279

JO - Environmental Research

JF - Environmental Research

IS - Pt 1

M1 - 121782

ER -

Health burden and inequities of urban environmental stressors in Sofia, Bulgaria

Abstract

Bibliographical note

Funding

Keywords

UN SDGs

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