Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Regionally distinct threats from polycyclic aromatic hydrocarbons in global reservoirs

Abstract

Polycyclic aromatic hydrocarbons pose inconsistent yet increasing threats to freshwater reservoirs worldwide, with implications for ecosystem health and water security. Although local-scale contamination has been widely documented, a comprehensive global synthesis of polycyclic aromatic hydrocarbon occurrence and drivers in reservoirs remains lacking. Here we developed a framework of data compilation, arrangement and statistics to integrate existing data to determine the geographical distribution and potential sources of polycyclic aromatic hydrocarbon pollution in reservoirs globally. Statistical analyses revealed spatial heterogeneity in dominant components and pollution levels across continents. Almost 38% of water samples exceeded an ecologically relevant threshold (0.20 μg l−1), and 42% of sediment samples surpassed the threshold effect concentration, indicating widespread ecological risks. Cluster analysis and source apportionment of the reservoir-level data identified three distinct polycyclic aromatic hydrocarbon patterns, each shaped by region-specific land-use practices, combustion sources and climatic factors. These findings emphasize and inform the need for region-specific monitoring and management strategies, such as expanding monitoring in subtropical and temperate regions, with a focus on polycyclic aromatic hydrocarbon accumulation in aquatic organisms.

This is a preview of subscription content, access via your institution

Access options

Buy this article

USD 39.95

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Global occurrence and components of PAHs in reservoirs.
Fig. 2: Components’ similarity and source attribution of PAHs in reservoir sediments.
Fig. 3: Spatio-temporal patterns of PAH pollution in three clusters.
Fig. 4: CAS framework for assessing PAH pollution in freshwater reservoirs.

Similar content being viewed by others

Data availability

The datasets that support the findings of this study are available via figshare at https://doi.org/10.6084/m9.figshare.30626969 (ref. 51). Source data are provided with this paper.

References

  1. Boström, C. E. et al. Cancer risk assessment, indicators, and guidelines for polycyclic aromatic hydrocarbons in the ambient air. Environ. Health Perspect. 110, 451–488 (2002).

    Google Scholar 

  2. Kim, K. H., Jahan, S. A., Kabir, E. & Brown, R. J. A review of airborne polycyclic aromatic hydrocarbons (PAHs) and their human health effects. Environ. Int. 60, 71–80 (2013).

    Google Scholar 

  3. Shrivastavaa, M. et al. Global long-range transport and lung cancer risk from polycyclic aromatic hydrocarbons shielded by coatings of organic aerosol. Proc. Natl Acad. Sci. USA 114, 1246–1251 (2017).

    Google Scholar 

  4. Babek, O. et al. Reservoir deltas and their role in pollutant distribution in valley-type dam reservoirs: Les Kralovstvi dam, Elbe River, Czech Republic. Catena 184, 104251 (2020).

    Google Scholar 

  5. González-Gaya, B. et al. Biodegradation as an important sink of aromatic hydrocarbons in the oceans. Nat. Geosci. 12, 119–125 (2019).

    Google Scholar 

  6. Li, R. F., Hua, P., Zhang, J. & Krebs, P. Effect of anthropogenic activities on the occurrence of polycyclic aromatic hydrocarbons in aquatic suspended particulate matter: evidence from Rhine and Elbe rivers. Water Res. 179, 115901 (2020).

    Google Scholar 

  7. Lv, M. et al. Human impacts on polycyclic aromatic hydrocarbon distribution in Chinese intertidal zones. Nat. Sustain. 3, 878–884 (2020).

    Google Scholar 

  8. González-Gaya, B. et al. High atmosphere–ocean exchange of semivolatile aromatic hydrocarbons. Nat. Geosci. 9, 438–442 (2016).

    Google Scholar 

  9. Cooley, S. W., Ryan, J. C. & Smith, L. C. Human alteration of global surface water storage variability. Nature 591, 78–81 (2021).

    Google Scholar 

  10. Janssen, A. B. G. et al. Shifting states, shifting services: Linking regime shifts to changes in ecosystem services of shallow lakes. Freshwater Biol. 66, 1–12 (2020).

    Google Scholar 

  11. Janssen, A. B. G. et al. Characterizing 19 thousand Chinese lakes, ponds and reservoirs by morphometric, climate and sediment characteristics. Water Res. 202, 117427 (2021).

    Google Scholar 

  12. Li, D. F. et al. High Mountain Asia hydropower systems threatened by climate-driven landscape instability. Nat. Geosci. 15, 520–530 (2022).

    Google Scholar 

  13. Ryan, J. C., Smith, L. C., Cooley, S. W., Pitcher, L. H. & Pavelsky, T. M. Global characterization of inland water reservoirs using ICESat-2 altimetry and climate reanalysis. Geophys. Res. Lett. 47, e2020GL088543 (2020).

    Google Scholar 

  14. Cooley, S. W. Global loss of lake water storage. Science 380, 693 (2023).

    Google Scholar 

  15. Seopela, M. P., McCrindle, R. I., Combrinck, S. & Augustyn, W. Occurrence, distribution, spatio-temporal variability and source identification of n-alkanes and polycyclic aromatic hydrocarbons in water and sediment from Loskop dam, South Africa. Water Res. 186, 116350 (2020).

    Google Scholar 

  16. Wilcke, W. Global patterns of polycyclic aromatic hydrocarbons (PAHs) in soil. Geoderma 141, 157–166 (2007).

    Google Scholar 

  17. Chamberlain, K. J., Lehnert, K. A., McIntosh, I. M., Morgan, D. J. & Wörner, G. Time to change the data culture in geochemistry. Nat. Rev. Earth Environ. 2, 737–739 (2021).

    Google Scholar 

  18. Janssen, A. B. G. et al. Exploring, exploiting and evolving diversity of aquatic ecosystem models: a community perspective. Aquat. Ecol. 49, 513–548 (2015).

    Google Scholar 

  19. Spake, R. et al. Implications of scale dependence for cross-study syntheses of biodiversity differences. Ecol. Lett. 24, 374–390 (2021).

    Google Scholar 

  20. Laubmeier, A. N. et al. Ecological dynamics: integrating empirical, statistical, and analytical methods. Trends Ecol. Evol. 35, 1090–1099 (2020).

    Google Scholar 

  21. Gurevitch, J., Koricheva, J., Nakagawa, S. & Stewart, G. Meta-analysis and the science of research synthesis. Nature 555, 175–182 (2018).

    Google Scholar 

  22. Nakagawa, S., Yang, Y. F., Macartney, E. L., Spake, R. & Lagisz, M. Quantitative evidence synthesis: a practical guide on meta-analysis, meta-regression, and publication bias tests for environmental sciences. Environ. Evidence 12, 8 (2023).

    Google Scholar 

  23. Pizzini, S. et al. PAHs, PCBs, PBDEs, and OCPs trapped and remobilized in the Lake of Cavazzo (NE Italy) sediments: temporal trends, quality, and sources in an area prone to anthropogenic and natural stressors. Environ. Res. 213, 113573 (2022).

    Google Scholar 

  24. Yoon, S. J. et al. Large-scale monitoring and ecological risk assessment of persistent toxic substances in riverine, estuarine, and coastal sediments of the Yellow and Bohai seas. Environ. Int. 137, 105517 (2020).

    Google Scholar 

  25. Baskaran, D. & Byun, H. Current trend of polycyclic aromatic hydrocarbon bioremediation: mechanism, artificial mixed microbial strategy, machine learning, ground application, cost and policy implications. Chem. Eng. J. 498, 155334 (2024).

    Google Scholar 

  26. Yunker, M. B. et al. PAHs in the Fraser River basin: a critical appraisal of PAH ratios as indicators of PAH source and composition. Org. Geochem. 34, 489–515 (2002).

    Google Scholar 

  27. Liu, D. et al. Data-driven insights into the contamination of polycyclic aromatic hydrocarbons in marine bays. Environ. Sci. Technol. 58, 15202–15213 (2024).

    Google Scholar 

  28. Li, W. W. et al. Spatiotemporal occurrence, sources and risk assessment of polycyclic aromatic hydrocarbons in a typical mariculture ecosystem. Water Res. 204, 117632 (2021).

    Google Scholar 

  29. Vilanova, R. M., Fernández, P., Martı́nez, C. & Grimalt, J. O. Polycyclic aromatic hydrocarbons in remote mountain lake waters. Water Res. 35, 3916–3926 (2001).

    Google Scholar 

  30. Hadibarata, T., Syafiuddin, A. & Ghfar, A. A. Abundance and distribution of polycyclic aromatic hydrocarbons (PAHs) in sediments of the Mahakam River. Mar. Pollut. Bull. 149, 110650 (2019).

    Google Scholar 

  31. Bigus, P., Tobiszewski, M. & Namieśnik, J. Historical records of organic pollutants in sediment cores. Mar. Pollut. Bull. 78, 26–42 (2014).

    Google Scholar 

  32. Hites, R. A., Laflamme, R. E. & Farrington, J. W. Sedimentary polycyclic aromatic hydrocarbons: the historical record. Science 198, 829–831 (1977).

    Google Scholar 

  33. Guo, J. Y., Chen, J. G. & Wang, J. F. Sedimentary records of polycyclic aromatic hydrocarbons in China: a comparison to the worldwide. Crit. Rev. Environ. Sci. Technol. 47, 1612–1667 (2017).

    Google Scholar 

  34. Wang, W. W., Xu, J. L., Qu, X. L., Lin, D. H. & Yang, K. Current and future trends of low and high molecular weight polycyclic aromatic hydrocarbons in surface water and sediments of China: insights from their long-term relationships between concentrations and emissions. Environ. Sci. Technol. 56, 3397–3406 (2022).

    Google Scholar 

  35. Martins, C. C. et al. Polycyclic aromatic hydrocarbons (PAHs) in a large South American industrial coastal area (Santos Estuary, southeastern Brazil): sources and depositional history. Mar. Pollut. Bull. 63, 452–458 (2011).

    Google Scholar 

  36. Jones, K., Sanders, G., Wild, S. R., Burnett, V. & Johnston, A. E. Evidence for a decline of PCBs and PAHs in rural vegetation and air in the United Kingdom. Nature 356, 137–140 (1992).

    Google Scholar 

  37. Kuempel, C. D. Sedimentation sifted out of pollution priorities. Science 379, 1098–1099 (2023).

    Google Scholar 

  38. Shen, H. Z. et al. Global atmospheric emissions of polycyclic aromatic hydrocarbons from 1960 to 2008 and future predictions. Environ. Sci. Technol. 47, 6415–6424 (2013).

    Google Scholar 

  39. McDonough, C. A., Khairy, M. A., Muir, D. C. G. & Lohmann, R. Significance of population centers as sources of gaseous and dissolved PAHs in the lower great lakes. Environ. Sci. Technol. 48, 7789–7797 (2014).

    Google Scholar 

  40. Abbott, B. W. et al. Human domination of the global water cycle absent from depictions and perceptions. Nat. Geosci. 12, 533–540 (2019).

    Google Scholar 

  41. Ramirez-Castaneda, V. et al. A set of principles and practical suggestions for equitable fieldwork in biology. Proc. Natl Acad. Sci. USA 119, e2122667119 (2022).

    Google Scholar 

  42. Spake, R. et al. Improving quantitative synthesis to achieve generality in ecology. Nat. Ecol. Evol. 6, 1818–1828 (2022).

    Google Scholar 

  43. González-Gaya, B., Zuniga-Rival, J., Ojeda, M. J., Jimenez, B. & Dachs, J. Field measurements of the atmospheric dry deposition fluxes and velocities of polycyclic aromatic hydrocarbons to the global oceans. Environ. Sci. Technol. 48, 5583–5592 (2014).

    Google Scholar 

  44. Guo, Z. F. et al. Global meta-analysis of microplastic contamination in reservoirs with a novel framework. Water Res. 207, 117828 (2021).

    Google Scholar 

  45. Hoel, E. P., Albantakis, L. & Tononi, G. Quantifying causal emergence shows that macro can beat micro. Proc. Natl Acad. Sci. USA 10, 19790–19795 (2013).

    Google Scholar 

  46. Khelifa, R. & Mahdjoub, H. An intersectionality lens is needed to establish a global view of equity, diversity and inclusion. Ecol. Lett. 25, 1049–1054 (2022).

    Google Scholar 

  47. Zipkin, E. F. et al. Addressing data integration challenges to link ecological processes across scales. Front. Ecol. Environ. 19, 30–38 (2021).

    Google Scholar 

  48. Husic, B. E. & Pande, V. S. Ward clustering improves cross-validated Markov state models of protein folding. J. Chem. Theory Comput. 13, 963–967 (2017).

    Google Scholar 

  49. Ward, J. H. Hierarchical grouping to optimize an objective function. J. Am. Stat. Assoc. 58, 236–244 (1963).

    Google Scholar 

  50. Wang, J. F. et al. Geographical detectors-based health risk assessment and its application in the neural tube defects study of the Heshun region, China. Int. J. Geogr. Inf. Sci. 24, 107–127 (2010).

    Google Scholar 

  51. Guo, Z. F. et al. Regionally distinct threats from polycyclic aromatic hydrocarbons in global reservoirs. figshare https://doi.org/10.6084/m9.figshare.30626969 (2025).

Download references

Acknowledgements

This work was financially supported by the Young Scientists Program of the National Natural Science Foundation of China (grant number 42307066 to Z.-F.G.), the National Key Research and Development Program of China (grant number 2025YFE0111301 to Y.-Y.X. and Z.-F.G.) administered by the Ministry of Science and Technology, the Open Competition Mechanism to Select the Best Candidates Program (grant number IUE-JBGS-202203 to Y.-Y.X.) from the Institute of Urban Environment, Chinese Academy of Sciences (IUE, CAS) and the Ningbo S&T project (2021-DST-004 to Y.-Y.X.) at the Ningbo Science and Technology Bureau.

Author information

Authors and Affiliations

Authors

Contributions

Z.-F.G. and Y.-Y.X. conceptualized the research. Z.-F.G., Y.-Y.X. and D.L. collected and analysed the data. Z.-F.G., W.J.B., Y.-Y.X., E.B., O.A.A.-M., D.L. and X.-R.Y. contributed to the interpretation of the results and paper writing. Z.-F.G. and Y.-Y.X. acquired funding. All authors contributed to the final manuscript and approved its submission.

Corresponding author

Correspondence to Yao-Yang Xu.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Geoscience thanks Yonghong Bi, Belén González-Gaya and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Primary Handling Editor: Alison Hunt, in collaboration with the Nature Geoscience team.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 Relationship between ∑16PAH concentration and distance from the dam.

Correlations were evaluated using two-sided Pearson’s tests (df = n-2). For each fitted relationship, coefficient of determination (R²) and p-values are reported in the corresponding panels. Linear regressions were fitted only when |Pearson’s r | ≥ 0.3 and  ≥ 0.15. Shaded areas denoted 95% confidence intervals. All statistical analyses were performed using two-sided tests without adjustment for multiple comparisons.

Source Data

Extended Data Fig. 2 ∑PAH concentrations at different sampling depths within an individual reservoir.

Different colors represent different sampling sites of sediments: Vossoroca (VS, Cluster α), Osaka Castle (OC, Cluster β), Echo (EC, Cluster γ), Fosdic (FS, Cluster γ), Como (CO, Cluster γ).

Source Data

Extended Data Fig. 3 Heterogeneity of PAH composition in different environmental media.

Analysis of similarities (ANOSIM) was used to test the null hypothesis that PAH compositions do not differ signidicantly among environmental media. Correlations were evaluated using a two-sided, permutation-based test (999 permutations). The r statistic (effect size) and p-values are shown in the corresponding panels. y-axis indicates the degree of dissimilarity between and within groups. Boxplots display the distribution of rank dissimilarities: centre line = median, box = 25th–75th percentiles, whiskers = min/max within 1.5 times interquartile range (IQR), points beyond whiskers = outliers. Statistical significance is denoted as “*” for p < 0.05 and “**” for p < 0.01. For Loskop Reservoir, sediment (n = 18, N = 9) and water (n = 16, N = 9) samples were collected from nine sites during flood and storage seasons; for Blachownia, sediment (n = 5, N = 4) and water (n = 20, N = 4), and for Cedara, sediment (n = 4, N = 4) and water (n = 4, N = 4) samples were collected across seasons. Each n denotes an independent field sample (biological replicate). PAH concentrations were meansured in triplicate (technical replicates), and mean values were used for analyses.

Source Data

Extended Data Fig. 4 Interannual and seasonal variation in PAH concentrations from reservoir water and sediment.

The blue represents water and the green is sediment. Seasonal comparisons were evaluated using two-sided Mann–Whitney U tests, and interannual variations using two-sided Kruskal–Wallis tests with Dunn’s post-hoc tests (Bonferroni adjustment). Statistical significance is denoted as “*” for p < 0.05. Boxplots show the distribution of PAH concentrations: centre line = median, box = 25th–75th percentiles, whiskers = min/max within 1.5 times interquartile range (IQR), points beyond whiskers = outliers. Sampling sites included the Three Gorges (water N = 59; sediment N = 13), Shuikou (N = 10), and Loskop (water N = 24; sediment N = 14) reservoirs across multiple years and hydrological seasons (see Supplementary Data 1). Each n denotes an independent field sample (biological replicate).

Source Data

Extended Data Table 1 Median concentrations of PAHs in different environmental media and corresponding sample sizes across continents

Supplementary information

Supplementary Information (download PDF )

Supplementary Fig. 1 and Texts 1 and 2.

Supplementary Data 1 (download XLSX )

Source data for supplementary figures.

Source data

Source Data Fig. 1 (download XLSX )

Source data for Figs. 1–4, Extended Data Figs. 1–4 and Extended Data Table 1.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Guo, ZF., Boeing, W.J., Xu, YY. et al. Regionally distinct threats from polycyclic aromatic hydrocarbons in global reservoirs. Nat. Geosci. 19, 68–74 (2026). https://doi.org/10.1038/s41561-025-01872-4

Download citation

  • Received:

  • Accepted:

  • Published:

  • Version of record:

  • Issue date:

  • DOI: https://doi.org/10.1038/s41561-025-01872-4

Search

Quick links

Nature Briefing Anthropocene

Sign up for the Nature Briefing: Anthropocene newsletter — what matters in anthropocene research, free to your inbox weekly.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing: Anthropocene