Medical geology is an emerging discipline on the ecosystem–human health interface. It explores the broader relationships between the geoenvironmental elements and the health or occurrence of disease in humans, animals, and plants living in the environment, reveals the impact of geological materials and geological processes on public health, and provides scientific support for the prevention and treatment of endemic diseases. In addition to the geographical distribution characteristics of geochemical elements and diseases, medical geology also pays special attention to the internal relationship of specific diseases with the physical and social environments. It is an interdisciplinary field involving disciplines such as hydrogeology, geochemistry, geography, biomedicine, and public health. The most vital objective of it is to recognize, solve, and improve health and disease problems related to the geological environment using multidisciplinary knowledge and tools. Medical geochemistry is a sub-branch of medical geology, which focuses on the relationship of geochemical processes of elements with human and animal health.

To report the latest outputs of medical geology and medical geochemistry, this special issue focuses on the current state of knowledge on the links between geological/geochemical processes and human health over the world, presented in 18 research or review papers.

The topics of the 18 papers can be roughly clustered into three clusters: groundwater and public health, exposure pathways and public health, and other related topics. A word cloud map was generated using titles and abstracts of the published papers to show the commonly used terms in these special issue papers (Fig. 1). As indicated by Fig. 1, the most commonly used terms in the papers are risk, groundwater, health, study, water, concentration, area, and metal. These terms suggested that water, especially groundwater, is the main media or exposure pathway causing health risk to the public, indicating waterborne diseases may be prevalent in the countries reported in these special issue papers. In addition, metals are probably the main index among all elements in water that have significant impacts on human health, and concentration of the elements is critical in determining the degree of health risk.

Fig. 1
figure 1

Word cloud generated using titles and abstracts of the special issue papers

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Though great achievements have been obtained in recent year, there still is much work remained for this emerging discipline. The following research directions should be enhanced:

  • The existence of harmful substances in the earth’s crust and their migration laws in the living environment, and the pathological changes caused by harmful substances entering the human body.

  • The geochemical processes responsible for species and human origin, and the patterns of major geological events related to the survival of humans and species.

  • The effects of various trace elements and toxic metal(loid)s originating from nature and human activities on the environment, ecology, and human health, and their pathological and toxicological mechanisms.

  • The cooperation of researchers from environmental toxicology, epidemiology, medical geology, and related disciplines to jointly provide scientific basis for the prevention of diseases and the improvement of human health.

  • The mutual interactions among different elements and substances and their effects on the toxicity of newly formed species by the interactions.

With the development of society, especially the impact of COVID-19 on current public health systems, many countries will increase investment in this research field. It is encouraged that researchers from different departments and different professions work together to tackle key problems in this research discipline, solve various health and disease problems that plague people, and raise our ability to solve practical health problems to a new level.