Behind the paper: climate change, hygiene, and health

We talk to Jessica Gerard, Lauren D’Mello-Guyett and colleagues, authors of the recent PLOS Climate publication “Climate change, hygiene, and health: A research roadmap for climate adaptation”

What led you to decide on this research question?

Water and sanitation dominate the current framing on the links between WASH (water, sanitation, and hygiene) and climate change, while hygiene – the actual behaviours and enabling conditions that interrupt disease transmission – was consistently underspecified. Hygiene is one of the most fundamental tools we have for preventing infectious disease, yet it barely featured in climate-health research agendas. At the same time, our team was seeing clear evidence that climate hazards, from floods to droughts, were actively undermining the infrastructure, water supply, and supply chains that people depend on to maintain basic hygiene.  In our engagement with research funders, including the Reckitt Global Hygiene Institute (RGHI) who supported this work, we learned that there is a clear interest in strengthening the evidence base on the links between climate, hygiene, and health but there was a lack of clear, articulated priorities that could inform targeted funding opportunities.

How did you go about designing your study?

We used a structured, consensus-driven method called the Child Health and Nutrition Research Initiative (CHNRI) method, which is designed specifically to identify and priorities health research questions in a transparent and replicable way [1]. We knew that to identify research questions across such a broad domain would require casting a wide net in the published literature and broad engagement with experts. In that regard, we decided on a three-stage approach. First, we conducted a rapid scoping review of the existing literature, and second a series of in-depth interviews with key informants working across climate adaptation, water, sanitation and hygiene, and public health. Together, these produced over 140 initial questions, which we then screened, refined, and consolidated down to 57 with input from a technical advisory group. We then built an online survey in five languages (Arabic, English, French, Portuguese, and Spanish) and asked global stakeholders to score each question against four criteria: relevancy, answerability, potential impact, and potential for translation into practice. The survey reached 141 respondents from 40 countries spanning academia, NGOs, multilateral agencies, and government, which gave us a genuinely diverse set of perspectives to draw from.

Did you encounter any challenges in collecting or interpreting your data?

Respondents, even experts in WASH, found it difficult to think about hygiene as a distinct domain, separate from the broader water and sanitation framing they were accustomed to. That conceptual blur may have influenced how some people interpreted and scored the questions. We were also conscious of selection bias: the people most likely to complete our survey were already working in hygiene, climate, or disaster risk reduction (DRR), which required a sustained effort on our part to ensure that the perspectives from adjacent sectors, private industry, government ministries, donors were engaged. Varying familiarity with climatological terminology across respondents was another challenge; what one person means by “water scarcity” may differ from an IPCC-defined “climate impact driver.” We tried to address this through careful question design and by offering the survey in multiple languages.

What struck you most about your results? What are the key messages and who do you hope might benefit from these new insights?

The strongest finding that surprised us the most, was the clear priority around basic descriptive research. Three-quarters of the top 20 questions were about improving our basic understanding the current relationships between climate, hygiene, and health; such as how much disease burden is attributable to climate-related hygiene disruption, how people adapt their hygiene practices under water scarcity, what happens to hygiene behaviours during floods. This tells us the field is still at a very early stage – we still lack the foundational evidence base needed to design in-depth research, deliver interventions and scale effective responses.

The prominence of equity concerns also stood out. Questions about people with disabilities, women managing menstrual health and hygiene during disasters, and communities facing overlapping climate pressures consistently ranked highly, a signal that the research community cares deeply about not leaving the most vulnerable behind.

Our key hope is that this agenda helps direct funding toward these descriptive priorities, while simultaneously pushing researchers, policymakers, and practitioners to treat hygiene as a core component of climate adaptation, not an afterthought. Hygiene a high-impact tool for adaptation, and deeply intertwined with health outcomes, yet it’s barely mentioned in national adaptation plans or major climate-health frameworks.

We were encouraged that the equity impacts of climate change on hygiene and health was an important priority – this builds directly on our new and upcoming publications in PLOS Climate what happens to personal hygiene for people with disabilities during cyclones and flooding in Bangladesh [2], and systematic review on climate and menstrual health and hygiene [3]. Together, these papers start to build the evidence base this agenda identified as so urgently needed.

What further research would you like to see in this area?

The most urgent need is for empirical, contextually grounded research that quantifies how climate hazards disrupt hygiene and its downstream health consequences are. We need longitudinal studies that follow document how floods, droughts, heatwaves, and other shocks effect hygiene practices and disease incidence. We also need more research on the slow-onset hazards. While acute events tend to dominate research and discussions, gradual changes like saltwater intrusion, land degradation, and rising average temperatures may be eroding hygiene capacity in ways that need more attention.

On the intervention side, there is very little evidence on how to adapt hygiene promotion for climate-stressed settings – how do we promote improved hygiene when water is scarce? What messages support disaster resilience and disaster response? These delivery-focused questions are practically urgent, and the evidence base is thin. We would also strongly advocate for more research that integrates disability, gender, and other equity lenses from the outset, rather than treating these as add-ons.

What made you choose PLOS Climate as a venue for your article?

PLOS Climate felt like a natural home for this work. The journal sits at the intersection of climate science and its real-world impacts, and our paper is precisely about bridging those domains, connecting climate hazards to something as concrete and everyday as hygiene. The open-access model was also important to us. We engaged respondents from 40 countries, many of them in low- and middle-income settings, and it matters enormously that the research agenda we produced with their input is freely accessible to them, and to the policymakers and practitioners who most need to act on it.

References

1.          Rudan I, Gibson JL, Ameratunga S, El Arifeen S, Bhutta ZA, Black M, et al. Setting priorities in global child health research investments: guidelines for implementation of CHNRI method. Croat Med J. 2008;49(6):720-33. Epub 2008/12/19. https://doi.org/10.3325/cmj.2008.49.720

2.          Nawaz S, Upoma TA, Goshami A, Podder B, Akter J, Hasan M, et al. Personal hygiene-related challenges faced by people with disabilities affected by cyclone and flooding in Bangladesh: A qualitative study. PLOS Climate. 2026;5(6):e0000922. https://doi.org/10.1371/journal.pclm.0000922

3.          D’Mello-Guyett L, Jaggarwal N, Wilbur J, Torondel B, Ranganathan M. Effects of climate change on menstrual health and hygiene: a global mixed-methods systematic review. Pre-Print. 2026. doi: https://doi.org/10.21203/rs.3.rs-8763541/v1.

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