A closer look at the historical progress and various applications of medical geology in Italy

Introduction

On the surface, geology and medicine may seem like distinct fields of study. Today, however, it is estimated that the health of at least 5 billion people worldwide is directly related to geological factors and contexts. The importance of geological contexts for health is created by the ongoing interactions between living organisms and their environments. Medical geology, as an emerging scientific endeavor, studies the relationships between health, geological materials, and environmental and processes. The overall goal is to identify the factors that influence certain disease onsets and the related protective factors. This can only be achieved through careful integration of different disciplines including those of geology, biology, and medicine. Medical geology is, therefore, a frontier approach that is distinctly interdisciplinary and very new, hence lacks a broad foundation of prior studies. We expect this to change significantly as the number of databases related to the importance of the environment on health is increasing locally, nationally, and internationally.

In common perception, the natural environment is considered “healthy” while an anthropogenically altered environment, especially if industrial, is perceived as “unhealthy”. A completely “natural” water source, however, can intercept sulfide mineralization in its underground path and be rich in mercury, an element known to be neurotoxic (Aschner et al., 1990). Similarly, radioactive contamination can occur due to geomorphological and lithological processes if there is a concentration of radon gas due to rocks rich in thorium and uranium; in these contexts, thorium tends to concentrate in soils while uranium is leached by water. Air, water, and soil – all deeply impacted by geological contexts – are essential for life and their quality directly influence health conditions. Relatively few research projects have analyzed the characteristics of these elements and their influence on health. It is not easy to carry out such research due to disciplinary boundaries. Fortunately, these conceptual walls are becoming more porous and the number of inter- or multidisciplinary collaborations is increasing. Much remains to be done, however, and adequate resources, analytical tools, fieldwork skills, and evaluators capable of providing peer review for multidisciplinary projects of a distinctly nature will be indispensable. Additionally, a combination of political will and scientific willingness is required. 

Discussion

The International Medical Geology Association (IMGA) sponsors conferences every two years in a different country; the most recent of these, the 8th International Medical Geology (MEDGEO) Conference, was held in Guiyang, China, in August 2019. Due to the pandemic, the MEDGEO 2021 conference was entirely virtual. A special volume of the journal Ecotoxicology and Environmental Safety was dedicated to 2019 MEDGEO conference. Topics included the relationship between human health and environmental geochemistry, water, soil pollution and remediation, and air pollution. These studies embody medical geology through their combinations of analytical methodologies, toxicology, epidemiology, public health, and regulatory science with contextual geological data.

Another very active association in Italy, the Italian Association of Medical Geology (AGMItalia), aims to support and promote this new multidisciplinary approach through an informal group of over 250 researchers and specialists. Following suggestions and discussions over multiple meetings, AGMItalia was founded at the end of the 1st Advanced Course of Medical Geology held in Urbino in October 2009. Thematic meetings, short congresses, and scientific sessions were organized by AGMItalia in collaboration with the International Society of Doctors for the Environment (ISDE Italia, www.isde.it), the National Institute for Insurance against Accidents at Work (INAIL), and as part of the National Festival of Geosciences “Settimana del Pianeta Terrra” (www.settimanaterra.org). Publications and documents relating to these events are available on the AGMItalia website ( http://www.agmitalia.org).

In broad stroke, natural materials such as water, mud, gas, etc. are used to improve human health. The use of geo-materials for healing purposes is based on documented results and is also favored by the frequent public confidence in the natural world over industrial pharmacological solutions. The use of curative geo-materials can improve the patient’s compliance with the physician’s proposed therapy. As already mentioned, these geo-materials must be evaluated for both favorable effects and possible contraindications. Multivariate analyses can help analyze these.

Measurements and analyses can be complex, as is the case of the exposure to solar radiation of an entire territory and its significant effects on health risks and benefits. These include the risk of developing melanoma compared to the benefits of UBV rays for reducing of the spread of the Sars-Cov19 pandemic (De Natale et al. 2020), the production of vitamin D, or the protective effect for multiple sclerosis. In this context, Sardinia appears to be an ideal territory for the study of correlation models between environmental factors and some diseases for their high incidence in the regional territory due to the genetic characteristics of the population and unique environmental context. This is the case of autoimmune diseases such as Type 1 Diabetes and Multiple Sclerosis, which are increasingly frequent in the Sardinian territory (Pugliatti et al. 2006, Bruno et al 2013) and for which geo-environmental factors seem to influence their onset (Valera et., 2014, 2015; Monti et al., 2016; Sanna et al., 2018). In another example, a soil sampling campaign was recently launched throughout the Italian territory with the aim of assessing the concentration of compounds harmful to human health such as polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and organochlorine pesticides (OCPs).

Another important aspect on human health is the evaluation of atmospheric dispersion of hydrogen sulfide (H₂S) from 32 geothermal power plants (out of 35 active ones) belonging to the geothermal districts of Larderello, Travale-Radicondoli and Monte Amiata, in Tuscany (Italy). An updated geographic database, was built, to be used in a GIS, to process the input data required by the code and to manage the outputs. The results suggest that H₂S plumes emitted by geothermal power plants are concentrated mainly around the emission stacks (H₂S concentration up to 1100 μg/m3) and dilute rapidly along the dominant direction of the local wind. Although the estimated values of airborne H2S concentrations are orders of magnitude higher than those of non-polluted areas, they do not indicate an immediate health risk for neighboring communities in the most frequent local atmospheric conditions. Starting from the estimated values, validated by field measurements, it is possible to formulate some considerations on the environmental impact of H₂S emission in all geothermal areas in the Tuscany region (Somma et al., 2017). The production of thematic maps at different scales, such as the Atlante Geochimico d’Italia, responds to the need for a large-scale geochemical mapping based on FOREGS procedures. The aim of the Atlante Geochimico d’Italia is to define the base values of chemical elements on a national scale and to help governmental decision-makers to define the activation and action limits on a local scale, bearing in mind the complex spatial variability of Italian geology (De Vivo et al., 2009; Cannas et al., 2020; Zuzolo et al., 2020).

Numerous studies carried out on marine sediments in coastal areas and in ports affected by former industrial sites are of national interest. Disused industrial activities are responsible for persistent environmental degradation, mainly due to the long-term accumulation of xenobiotic contaminants in the environment. This chronic form of pollution poses a great threat to human health, biodiversity, and the functioning of ecosystems.. Environmental remediation practices should be associated with restoration plans that aim to reverse the trend of degradation and return areas to environmental health so that they can provide valuable ecosystem goods and services. A striking case is offered by the industrial site of Bagnoli-Coroglio and by the characterization of the contamination of marine sediments by arsenic and other potentially toxic elements or PAHs (Giglioli et al., 2020). Pioneering research suggests that CoDA represents a powerful tool for answering long-term questions about the geochemistry of sediments in polluted areas. This work suggests that anomalous arsenic concentrations are mainly due to pyroclastic deposits in the Phlegraean Fields and seepages with hydrothermal component, supported by a low contribution of variables in a robust PCA of distal zone sediments (Buccino et al., 2021; Somma et al., 2021).

Recent medical geology studies have the great merit of identifying the complex factors that may be involved and thus the way to appropriately address subsequent investigations. The potential for the identification predisposing factors and of protective factors and treatments related to multifactorial diseases with important social and economic implications is truly remarkable. Considering the large number of geo-environmental topics potentially related to health, it is not surprising that several issues are still underdeveloped: for example, contributions of geophysics on natural electromagnetic fields and their variations are very rare. However, what really seems to be systematically lacking is the significant “descent into the field” of medical sciences. Epidemiological data, at least in Italy, are often inaccessible. At the moment, however, the greatest difficulties seem to be represented disciplinary barriers and by the scarce attention of public administrations towards the important role that medical geology can play in the health field.

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