On the linkage between urban heat island and urban pollution island: Three-decade literature review towards a conceptual framework

With the doubling of urban population within the next two decades and the disproportionate growth of megacities, it is critical to explore the synergism between urban heat and pollution. In this paper, a systematic review is conducted on the existing knowledge, collected since 1990, on the link between urban heat island (UHI) and urban pollution island (UPI). Results from 16 countries and 11 Koppen-Geiger climatic zones are perused and compared to delineate methodological and experimental trends, geographical dependencies and research gaps. Detailed content analysis is conducted according to five prominent topics: i) the role of UHI on temperature-dependent chemistry, ii) the daytime/nighttime variability in the UHI-UPI interaction, iii) the role of urban geomorphic types, forms and growth schemes, iv) future trends and v) primary and secondary effects of UHI mitigation on urban air quality. Different approaches and observations are eventually harmonized to outline opportunities and challenges towards the disentanglement and/or the two-way mitigation of both phenomena. This will help governments and urban planners to deliver coping strategies and precautions towards a more salutogenic urban design. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

This paper conducts a systematic review of the existing knowledge on the link between urban heat island (UHI) and urban pollution island (UPI) since 1990, analyzing results from 16 countries and 11 climatic zones. By examining methodological and experimental trends, geographical dependencies, and research gaps, the paper outlines opportunities and challenges towards disentangling and mitigating these phenomena. Detailed content analysis according to five prominent topics provides a blueprint for coping strategies and precautions in urban design.