Identifying and defining priority of obnoxious odor sources in ambient air in settlements using systematic hybrid analysis and fuzzy logic

Introduction. Obnoxious odors in ambient air in industrial centers are a significant medical and social issue.

The aim of this study is to develop and test methodical approaches to identifying potential obnoxious odor sources in residential areas of regions with developed industries using fuzzy logic and systematic hybrid data analysis.

Materials and methods. We have developed and tested a complex eight-stage methodology for identifying priority obnoxious odor sources in the urban environment. The suggested approaches have been tested using actual data collected in a large industrial center. Fuzzy logic is used as a method for identifying areas where odor sources are likely to be located. Within the method, an odor is given as a linguistic variable that considers people’s complaints and meteorological conditions. We have analyzed one thousand nine hundred twenty seven people’s complaints about obnoxious odors and meteorological parameters (2022–2024), ambient air monitoring data (automated pollution control stations, readings taken at representative points (GC-MS)) and have accomplished computational simulation of 23 olfactory-active substances together with calculating source contributions, sensor estimates, GIS-modeling, and graphic spatial analysis.

Results. Testing of the developed universal algorithms has established 249 chemicals to be olfactory active out of total 375 ones emitted into ambient air. We have found a spatial-temporal correlation between complaints, meteorological conditions and time: 67% complaints are made when the wind speed is 0–1 m/sec; the peaks are reached in the evening (59.3%) and morning (22.4%). Chemical levels systematically higher than single maximum MPC have been confirmed by field observations: hydrogen sulfide (up to 17.5 MPC), formaldehyde (up to 3.2 MPC), and ammonia (up to 1.5 MPC). We have identified three zones where obnoxious odor sources are likely to be located in the analyzed area (15.85–31.8 km²); these zones correspond to industrial clusters. Ranking of 21 enterprises as potential pollutant sources has established 6 priority ones creating >80% of the total contribution to concentrations of odor chemicals in places where people’s complaints are usually made.

Limitations. The results are based on routine operation of obnoxious odor sources; emergency situations have not been analyzed.

Conclusion. The developed universal approach to identifying obnoxious odor pollution sources under uncertainty has been found to be effective in variable meteorological conditions and to be ready for testing in other areas with similar problems.

Compliance with ethical standards. The study does not require approval by an ethical committee or any other documents.

Contributions:
Zaitseva N.V. – study concept and design;
Patyashina М.А., Prokofyeva М.V. – data collection, editing the text;
Kleyn S.V. – study concept and design, data collection, writing the text;
May I.V., Kiryanov D.А. – study concept and design, editing the text;
Klyachin А.А. – data collection and analysis, writing the text;
Chigvintsev V.М. – data collection and analysis.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Conflict of interest. The authors declare no conflict of interest.

Funding. The study had no sponsorship.

Received: July 23, 2025 / Revised: November 19, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

1. Goshin M.E., Budarina O.V., Ingel F.I. The odours in the ambient air: analysis of the relationship with the state of health and quality of life in adults residing in the town with food industries. Gigiena i Sanitaria (Hygiene and Sanitation, Russian journal). 2020; 99(12): 1339–45. https://doi.org/10.47470/0016-9900-2020-99-12-1339-1345 https://elibrary.ru/hntnez (in Russian)

2. Budarina O.A., Skovronskaya S.A., Ivanova S.V. International experience of air pollution assessment in areas where enterprises with odorous emissions are located (literature review). Gigiena i Sanitaria (Hygiene and Sanitation, Russian journal). 2022; 101(11): 1299–306. https://doi.org/10.47470/0016-9900-2022-101-11-1299-1306 https://elibrary.ru/ydrjqk (in Russian)

3. Cournoyer M., Maldera A., Gauthier A.C., Dal Maso F., Mathieu M.E. Effect of odor stimulations on physical activity: A systematic review. Physiol. Behav. 2024; 273: 114408. https://doi.org/10.1016/j.physbeh.2023

4. Goshin M.E., Budarina O.V., Demina N.N. Analysis of the health status of the population living in conditions of air pollution with odorous substances (literature review). Gigiena i Sanitaria (Hygiene and Sanitation, Russian journal). 2020; 99(9): 930–8. https://doi.org/10.47470/0016-9900-2020-99-9-930-938 https://elibrary.ru/sehytj (in Russian)

5. Syrchina N.V., Pilip L.V., Ashikhmina T.Ya. Control of odor pollution of atmospheric air (review). Teoreticheskaya i prikladnaya ekologiya. 2022; (2): 26–34. https://doi.org/10.25750/1995-4301-2022-2-026-034 https://elibrary.ru/qxkoxr (in Russian)

6. Kuzmin S.V., Budarina O.V., Rakhmanin Yu.A., Pinigin M.A., Dodina N.S., Skovronskaya S.A. Prospects of the development and harmonization of hygienic standardization taking into account the risk of odour in the ambient air. Gigiena i Sanitaria (Hygiene and Sanitation, Russian journal). 2024; 103(2): 96–103. https://doi.org/10.47470/0016-9900-2024-103-2-96-103 https://elibrary.ru/bvtxvx (in Russian)

7. Chepegin I.V., Andriyashina T.V. Emissions of odorous substances into the atmosphere. Problems and solutions. Vestnik Kazanskogo tekhnologicheskogo universiteta. 2013; 16(10): 80–3. https://elibrary.ru/qilftp (in Russian)

8. Capelli L., Sironi S., Del Rosso R. Odor sampling: techniques and strategies for the estimation of odor emission rates from different source types. Sensors (Basel). 2013; 13(1): 938–55. https://doi.org/10.3390/s130100938

9. Budarina O.V., Sabirova Z.F., Goshin M.E. A complex hygienic assessment of atmospheric air pollution, taking into account the risk of smell. In: Health Risk – 2024: Materials of the XIV All-Russian Scientific and Practical Conference with International Participation [Analiz riska zdorov’yu – 2024: Materialy XIV Vserossiiskoi nauchno-prakticheskoi konferentsii s mezhdunarodnym uchastiem]. Perm’; 2024: 9–16. https://elibrary.ru/byrtkk (in Russian)

10. Karelin A.O., Lomtev A.Yu., Friedman K.B., Yeremin G.B., Pankin A.V. Identification of emission sources of pollutants causing complaints of unpleasant odours. Gigiena i Sanitaria (Hygiene and Sanitation, Russian journal). 2019; 98(6): 601–7. https://elibrary.ru/cebqhl (in Russian)

11. Brattoli M., de Gennaro G., de Pinto V., Loiotile A.D., Lovascio S., Penza M. Odour detection methods: olfactometry and chemical sensors. Sensors (Basel). 2011; 11(5): 5290–322. https://doi.org/10.3390/s110505290

12. Makovetskaya A.K., Khripach L.V., Goshin M.E., Budarina O.V., Karmanov A.V. The role of sociological methods in implementation of environmental hygienic health monitoring for territories. Gigiena i Sanitaria (Hygiene and Sanitation, Russian journal). 2023; 102(9): 902–8. https://doi.org/10.47470/0016-9900-2023-102-9-902-908 https://elibrary.ru/qplnzf (in Russian)

13. Nicell J.A. Assessment and regulation of odour impacts. Atmos. Environ. 2009; 43(1): 196–206. https://doi.org/10.1016/J.ATMOSENV.2008.09.033

14. Brancher M., Griffiths K.D., Franco D., de Melo Lisboa H. A review of odour impact criteria in selected countries around the world. Chemosphere. 2017; 168: 1531–70. https://doi.org/10.1016/j.chemosphere.2016.11.160

15. Capelli L. Measuring odours in the environment vs. dispersion modelling: A review. Atmos. Environ. 2013; 79: 731–43. https://doi.org/10.1016/j.atmosenv.2013.07.029

16. Dolgushina N.A., Kuvshinova I.A. Air pollution and non-cancenogenic risk assessment in industrial cities of Chelyabinsk region. Ekologiya cheloveka. 2019; (6): 17–22. https://doi.org/10.33396/1728-0869-2019-6-17-22 https://elibrary.ru/ahpzti (in Russian)

17. Baktybaeva Z.B., Suleymanov R.A., Valeev T.K., Rahmatullin N.R., Stepanov E.G., Davletnurov N.Kh. Environmental and hygienic assessment of ambient air pollution in oil-producing and oil-refining areas of the republic of Bashkortostan and population health status. Zdorov’e naseleniya i sreda obitaniya – ZNiSO. 2020; (2): 26–32. https://doi.org/10.35627/2219-5238/2020-323-2-26-32 https://elibrary.ru/xdsvzr (in Russian)

18. Zaitseva N.V., May I.V. Ambient air quality and health risks as objective indicators to estimate effectiveness of air protection in cities included into the ‘clean air’ federal project. Analiz riska zdorov’yu. 2023; (1): 4–12. https://doi.org/10.21668/health.risk/2023.1.01 https://elibrary.ru/omvwle (in Russian)

19. Svitskov S.V. Passive degassing of landfills. The experience of the Salaryevo training ground. Tverdye bytovye otkhody. 2021; (9): 54–7. https://elibrary.ru/wqlqxb (in Russian)

20. Karypkin L.M., Suetinov V.P., Rakhmanov Yu.A. Polygon “Red Bor”: ways and methods of solution. Firm household waste. Tverdye bytovye otkhody. 2017; (6): 26–7. https://elibrary.ru/zagqmz (in Russian)

21. Tsibulskii V.V., Yatsenko-Khmelevskaya M.A., Khitrina N.G., Korolenko L.I. Approaches to rationing the smell in the atmospheric air of Russia based on olipactometric measurements of smell in industrial emissions. Ekologicheskaya khimiya. 2011; 20(1): 1–10. https://elibrary.ru/sodgqh (in Russian)

22. Kostyleva N.V., Oputina I.P., Gileva T.E., Nigmatzyanova K.R. On the question of standardizing odor pollution in the Russian Federation. Astrakhanskii vestnik ekologicheskogo obrazovaniya. 2024; (4): 12–22. https://doi.org/10.36698/2304-5957-2024-4-12-22 https://elibrary.ru/budvnc (in Russian)

23. Zaitseva N.V., May I.V., Kiryanov D.А., Kleyn S.V., Chigvintsev V.М., Klyachin А.А. Methodical approaches to spatial identification of probable sources of obnoxious odors in ambient air based on fuzzy logic. Health Risk Analysis. 2024; (4): 14–26. https://doi.org/10.21668/health.risk/2024.4.02.eng