Role of Health Professionals Regarding the Impact of Climate Change on Health—An Exploratory Review

Health professionals are increasingly urged to act to protect individuals and populations against the negative effects of climate and environment change on health. However, the amount of evidence supporting initiatives to that end is unknown. We explored the literature examining the awareness, preparedness, and role of healthcare professionals to inform about the impact of climate change on health on the one hand, and literature about the effectiveness of interventions mediated by health professionals aiming at reducing the environmental impact of human activities on the other hand. We included 137 articles published between 2000 and 2020, mostly in general medical and nursing journals. The typical article was a perspective, commentary, or other special article aimed at alerting readers about the impact of climate and environment change on health. We identified 22 studies, of which only two reported interventions. Despite increasing efforts of health professionals to address climate and environment change and related health risks, health literature supporting such efforts remains scarce, and studies assessing the effectiveness of interventions are lacking. We need appropriate evidence to indicate which interventions should be prioritized, considering that the association of health issues with climate and environment change could constitute an effective lever for change.


Introduction
The negative effects of climate and environment change on human health have been reported for several decades [1]. Climate change already produces negative effects on human health, worldwide, and will have additional harmful effects in the future. The World Health Organization emphasizes the risks for human health due to climate changes in a "health topic" [2]. The "Commission on Health and Climate Change" established in 2015 by The Lancet reports every year on the situation, presenting various data and indicators on the effects of climate change on the health of populations and on the political and health policy decisions aimed at mitigating the harmful effects of climate change on health. The most recent updated report was published in December 2020 [3]. More frequent extreme temperatures (e.g., heat waves) may endanger human life and increase morbidity (e.g., through dehydration, cardiovascular events, infectious conditions), leading to higher health services use and losses in working hours. The expansion of vector-and water-borne infections is occurring in many regions. In addition, because of the effects of climate change on soil, agriculture yield is decreasing, contributing thus to limit access to appropriate food, especially in already deprived areas. Moreover, healthcare is contributing to carbon dioxide emissions, corresponding to an average close to 5% worldwide [3] and higher in several developed countries. For several years, different initiatives have been targeting healthcare and public health professionals, inciting them to contribute actively to protect individuals and populations against the negative effects of climate change on health. For example, the World Organization of Family Doctors (WONCA) produced a "Declaration calling for family doctors of the world to act on planetary health" [4], and the Canadian Association of Physicians for the Environment published in 2019 a toolkit for physicians to fulfil this goal [5]. These initiatives are welcomed; however, their recommendations do not appear to be supported by much evidence. Healthcare professionals are usually trusted by the public [6], it is therefore crucial that the recommendations and actions proposed by healthcare professionals, collectively or individually, are based on robust and direct evidence.
Therefore, we need to know which information and evidence is available in the literature to better design possible interventions involving healthcare professionals, including research and development programs, to contribute to tackle the harmful effects of climate and environment change on the health of individuals and populations. Thus, the aim of this exploratory review was to provide an overview of existing scientific articles about the awareness, preparedness, and role of healthcare professionals to inform individuals, communities, and populations concerning the relationships among the environment, climate change, and health. To fulfill our ultimate objective, we searched for the existence and effectiveness of interventions mediated by healthcare professionals to motivate individuals and communities to adapt lifestyles reducing the impact of human activities on climate and environment change.

Materials and Methods
We scoped a large range of article types and made simple descriptive analyses to illustrate our findings, which we reported narratively. According to our exploratory intent, we used one database only, and one reviewer performed data extraction. We included articles addressing the awareness, preparedness, and possible roles of healthcare professionals regarding climate and environment change, as well as interventions of healthcare professionals intended to contribute to mitigate these changes. We included articles published between 2000 and 2020 in the health literature, reporting explorations, surveys, and interventions targeting the aforementioned aims. We included original studies, quantitative and qualitative, or mixed, reviews, and various types of reports. We thus purposefully searched a large range of published articles. We excluded articles written in a language not mastered by the authors and articles for which we could not obtain a full-text version.
An initial pilot search was conducted on the PubMed, Embase, and Epistemonikos databases that indicated that searching on PubMed only was sufficient to fill our exploration purpose. The most recent search update was conducted on 23 October 2020. The search strategy included the following components: target population (healthcare professionals), context (climate and environment, and health issues), information (knowledge implementation, guidance, training, intervention). The actual search strategies were constructed and tested with the support of a senior librarian (Supplementary 1 presents the search strategy). The initial selection was based on titles with the aim of excluding articles that were obviously out of scope. In case of uncertainty, the abstract was examined. This step was achieved by one reviewer (J.D. or B.B.). The initial selection was examined by the second reviewer and the final list of articles to be considered for full-text analysis and potential inclusion was obtained by consensus. Similarly, the list of included articles was confirmed by consensus.
We extracted the following descriptive information from the included articles: publication year, author number, journal type (general, specialized), country of realization, page and reference count, type of article (editorial, letter, special article (e.g., perspective, commentary, debate, report), position paper, narrative review (no method indicated), study (formal review, intervention, survey, qualitative method)). We also intended to record the aim of the article (explicit or implicit) and the propositions or recommendations made. One reviewer performed the extraction (J.D. or B.B.); a double extraction was performed on a series of 10 articles, which indicated an excellent agreement (close to full agreement), with the exception of the recommendations and propositions of articles' authors that we did not consider reliable enough to perform a quantitative analysis. We performed a simple descriptive analysis of the information retrieved from all included articles, which we reported in a table form. We undertook a more detailed analysis of the subgroup of studies. Within the analysis, we described the studies' aim, method, and target participants and participation proportion, to which we added a narrative comment. We did not intend to perform a qualitative analysis of a very heterogeneous and large group of editorials, commentaries, and perspective or opinion articles in this initial approach. In addition, we did not formally assess the quality of the included studies given our exploratory purpose, the various designs used, and the large diversity in the reported methods and results.

Global Analysis
The literature search allowed us to include 137 articles published in 84 journals (full list is available in Supplementary 2). Twenty-three journals published more than one article (up to seven in our selection). The article selection flowchart is presented in Figure 1. The characteristics of the included articles are presented in Table 1. Most articles were published in general medical and nursing journals. About half of the retrieved articles were published between 2016 and 2020 and were written by authors based in the USA, whereas much fewer articles were published by European authors. These articles were often relatively short with a median of four pages and 16 references. Forty-two percent of these articles were single authored, and the median number of authors was two. The typical article was a perspective, commentary, or other special article aimed at informing and alerting readers about the links between climate and environment change and human health. to include climate change and environmental sustainability topics in their programs [15][16][17][18][19]. One, limited, survey among patients visiting a general practice in Israel [20] and a larger U.S. population survey [21] indicated that, although aware that global warming may harm health, patients and population need, and may expect, more complete and specific information about health in relation with climate and environmental changes. Three surveys had important limitations either due to a small size or the methods used, and three other surveys had response rates below 20%.

Qualitative and Mixed Methods Studies
The qualitative and mixed methods studies also indicated needs for specific professional training on climate and environment change and health and the necessity to support messages and actions targeting patients and the public [22][23][24][25]. A case study of Australian health agencies indicated that available competencies and frameworks were transferable to action on climate change, such as health promotion practices oriented toward active and sustainable transport and healthy and sustainable food supply, for instance [26].

Intervention Studies
One training and education intervention targeted hospital workers (housekeeping and food departments) and indicated improvements in the use of cleaning chemicals and waste disposal [27]. A pilot study indicated the feasibility and high adherence to an adult education program about energy use and sustainability, combined with mindfulness meditation [28].   Most articles (98, 72%) did not explicitly present their objective. However, proposals and recommendations for the possible roles of healthcare professionals were frequently made. Most often, they concerned information and advocacy targeting the public and decision-makers, proposals of actions within healthcare organizations or practices, and enhanced education and training of healthcare professionals. Less often, direct information and advocacy targeting patients and changes in personal actions (role model) were indicated.

Analysis of Actual Studies
Twenty-two articles presented a study (three literature reviews, 12 surveys, five qualitative and mixed methods studies, and two interventions studies). They are described in Table 2, classified by study type. Most felt that climate change poses a serious threat to public health and that they lack resources or information to cope with that threat. Nonetheless, implementation of mitigation programs was ongoing

Reviews
The first review indicated the increased vulnerability of elderly individuals to extreme heat and the role of general practitioners in identifying them and to implement strategies to minimize their risks [7]. The second review was conducted to support the recommendations of the American College of Physicians to call physicians to act to "improve human health and avert dire environmental outcomes" [8]. The third review identified the climate change and sustainability topics to be included in nursing education [9].

Surveys
Most identified surveys targeted healthcare professionals. Three surveys targeted public health departments' officers [10][11][12] indicating that many of them acknowledged that climate change is a relevant threat for public health, but very often they lacked information, expertise, or resources to address that threat. In two related surveys, a majority of national and international American Thoracic Society respondent members indicated that climate change is happening, already affecting patients' health [13,14]. Five surveys targeted nursing and medical education curricula, which indicated perceived needs to include climate change and environmental sustainability topics in their programs [15][16][17][18][19]. One, limited, survey among patients visiting a general practice in Israel [20] and a larger U.S. population survey [21] indicated that, although aware that global warming may harm health, patients and population need, and may expect, more complete and specific information about health in relation with climate and environmental changes. Three surveys had important limitations either due to a small size or the methods used, and three other surveys had response rates below 20%.

Qualitative and Mixed Methods Studies
The qualitative and mixed methods studies also indicated needs for specific professional training on climate and environment change and health and the necessity to support messages and actions targeting patients and the public [22][23][24][25]. A case study of Australian health agencies indicated that available competencies and frameworks were transferable to action on climate change, such as health promotion practices oriented toward active and sustainable transport and healthy and sustainable food supply, for instance [26].

Intervention Studies
One training and education intervention targeted hospital workers (housekeeping and food departments) and indicated improvements in the use of cleaning chemicals and waste disposal [27]. A pilot study indicated the feasibility and high adherence to an adult education program about energy use and sustainability, combined with mindfulness meditation [28].

Discussion
In this exploratory review, we identified more than 100 published articles addressing the awareness, preparedness, and role of healthcare professionals in the context of climate and environment change. We included a large and heterogeneous group of articles. The majority of them were commentaries, editorials, and opinion or perspective texts. We found 22 actual studies presenting quantitative or qualitative results. Our ultimate goal was to find evaluations of interventions aimed at modifying the decisions, behaviors, or habits of patients, healthcare professionals, or other stakeholders to mitigate climate change consequences. We found only two such studies. Almost all articles intended to alert on the increasing risks of climate and environment change on humans, human health, and the planet, contributing thus to increase the awareness of healthcare professionals. However, this number of 137 publications must be weighed against the very large number of existing health-related journals. The number of readers who eventually read these articles may be limited. However, various entities as well as international and national associations of healthcare professionals provide information, position statements, recommendations, or toolboxes on websites. Table 3 presents several examples of those, as we did not aim to provide a systematic description and analysis of their contents. In order to compare our results with those of similar reviews, we found the protocol of a scoping review with a comparable aim ("mapping the range and nature of existing evidence regarding health professionals' knowledge, attitudes, perceptions, and practices regarding climate change and health impacts and the challenges they face") [29]. Two other published protocols of scoping reviews focused on hospital climate actions and assessment tools [30], on the one hand, and on teaching the relationship between health and climate change [31], on the other hand. However, we did not find the corresponding reviews in the literature. Another review had a related but different purpose, which focused on the environmental competencies required and pedagogic approaches used to include sustainability in curricula in nursing education [9]. In addition, a review focused on nurse preparedness to face the growing number of natural disasters, which concluded that although increasing, nurse preparedness should be further improved [32]. The 2016 recommendations developed by the American College of Physicians in a position paper on climate change and health [8] were based on a literature review of studies and reports about the association of climate change and human health.
Various initiatives and propositions about the possible roles of healthcare professionals were presented in the retrieved articles. Several proposed actions and changes aimed at increasing the pre-, postgraduate, and continuing education of healthcare professionals about climate and environment change, their effects, and their already-occurring and future consequences on human health. These actions are supposed to improve the awareness and preparedness of healthcare professionals. However, we found only two reports of studies aimed at assessing the effectiveness of interventions to motivate individuals, patients, and communities to intentionally reduce the impact of human activities on climate and environment change through lifestyle changes. The co-benefits of lifestyle changes on both human health and the climate should be better supported. Eating less meat products and, when distance permits, walking or biking instead of using transportation that contributes to global warming and environmental pollution; these constitute two examples of individual and collective actions that should be more intensively promoted by healthcare professionals. Nevertheless, we need appropriate evidence of the effectiveness of such interventions and corresponding indicators to allow their development, support, and improvement. Indeed, the various recommendations retrieved in this review were chiefly based on logical reasoning, given the lack of evidence of effective interventions.
Collective awareness of the association of climate and environment change with human health has been relatively limited until recently. Indeed, a new indicator introduced in the 2019 report of The Lancet Countdown on health and climate change indicated little connectivity between the clusters "health" and "climate change" in searches conducted on Wikipedia [33]. However, the 2020 report indicated a 24% increase in information seeking about health and climate change from 2018 to 2019, which was mainly driven by the initial interest of individuals in health [3]. The 2020 report also emphasized a "growing response from health professionals" (e.g., decarbonization efforts, linkage with meteorological services for health services planning). In addition, the coverage of health and climate change in the media, worldwide, almost doubled from 2018 to 2019.
Most included articles present narrative descriptions of the relations among climate and environment change and health, opinions, position statements (e.g., for healthcare sector decarbonization), mitigation strategies (e.g., to reduce the impact of heatwaves on elderly individuals), or recommendations to reach global or specific sustainability targets supposed to limit the negative effects of climate and environment change on health and the planet. Actually, the content of many of these special articles or editorials is not very different from the perspective paper published by McCally and Kassel in 1990 [34].
Our exploratory review has several limitations, already indicated in the methods section. The literature search was not exhaustive, despite the tested search equation. We conducted our literature search in one database only. We excluded several publications not written in English, but they did not report studies. In addition, although it fitted our purpose, the search scope might have been too broad. Indeed, it could have been more fruitful to focus on more specific questions or interventions. Moreover, we provided a limited description and analysis of the publications and studies. The 12 published surveys indicate that a majority of healthcare professionals believe that climate and environmental changes are real and constitute a threat for human health, and that healthcare professionals have the duty to alert and act. However, given the relatively limited response rates to these surveys, these results may be biased. Finally, despite the limitations of this exploratory review, we believe that the provided depiction of the literature offers a rather reliable image.

Conclusions
Our exploratory review indicated that the role of healthcare professionals, individually or collectively, through professional organizations, could include informing and alerting patients, individuals, communities, and decision-makers about the association of climate and environment change with health and the need to act to limit and mitigate these risks to protect health. Various channels have been used such as websites of healthcare organizations, interventions targeting decisions-makers, and highly visible reports such as The Lancet Countdown on health and climate change edited anew each year. However, there are relatively few publications in the health literature, and we lack studies assessing the effectiveness of various interventions to be implemented by healthcare professionals, directly (e.g., promoting lifestyle changes at the individual or community level) or indirectly (e.g., promoting structural changes through laws and regulations, as well as organizational changes in hospitals and health systems). Nevertheless, we believe that healthcare professionals have a professional public health duty to foster the assessment and implementation of effective interventions, to improve the education of their peers, and to keep informing and alerting various audiences through potentially appropriate communication interventions [35,36]. Indeed, the association of health issues with climate and environment change could constitute an effective lever for change.