Exploring Environmental Health Inequalities: A Scientometric Analysis of Global Research Trends (1970-2020)

Abstract

Environmental health inequalities (EHI), understood as differences in environmental health factors and in health outcomes caused by environmental conditions, are studied by a wide range of disciplines. This results in challenges to both synthesizing key knowledge domains of the field. This study aims to uncover the global research status and trends in EHI research, and to derive a conceptual framework for the underlying mechanisms of EHI. In total, 12,320 EHI publications were compiled from the Web of Science core collection from 1970 to 2020. Scientometric analysis was adopted to characterize the research activity, distribution, focus, and trends. Content analysis was conducted for the highlight work identified from network analysis. Keyword co-occurrence and cluster analysis were applied to identify the knowledge domain and develop the EHI framework. The results show that there has been a steady increase in numbers of EHI publications, active journals, and involved disciplines, countries, and institutions since the 2000s, with marked differences between countries in the number of published articles and active institutions. In the recent decade, environment-related disciplines have gained importance in addition to social and health sciences. This study proposes a framework to conceptualize the multi-facetted issues in EHI research referring to existing key concepts.

Keywords: environmental health inequalities; environmental justice; framework; health determinants; health disparities; indicators; research trends; scientometric analysis.

Figure 1

Analysis Framework (white = methods applied, blue shading = results of the analysis).

Figure 2

The number of EHI scientific publications, active journals, and categories by year.

Figure 3

Top 10 WoS Categories of the EHI studies over the three time periods. The percentage of publications that have been associated with each category is proportional to the size of the rectangular.

Figure 4

Geographic distribution of EHI publications.

Figure 5

Development of key clusters of EHI publications over time [41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61].

Figure 6

The keyword cluster (green, environmental hazards and benefits; blue, social vulnerability; and red, health disparities).

Figure 7

A framework of EHI based on scientometric findings, incorporating concepts from Bolte et al. [2], European Environment Agency [7], Briggs [66], and WHO [67].