Christovam Barcellos is a geographer, researcher at the Oswaldo Cruz Foundation (Fiocruz), and professor at the National School of Public Health. He is a specialist in public health, with a PhD in geosciences from the Fluminense Federal University. He has worked as a public health specialist in government agencies such as the Rio de Janeiro State Health Secretariat and the Brazilian Ministry of Health. He is one of the coordinators of the Climate and Health Observatory.
Raphael Saldanha is a geographer and researcher at the Oswaldo Cruz Foundation (Fiocruz). He is a climate and health data scientist and holds a PhD in Health Information and Communication. He has participated in several projects as a developer, data visualization specialist, and team leader. He works at the Climate and Health Observatory and at the Data Science Platform Applied to Health (PCDaS).
The Observatory is also part of a project coordinated by the Pasteur Network; the Climate and Health Accelerator Program which brings together all Pasteur Network Members from LMICs. Fiocruz serves as an exemplar for the entire Network, particularly in the Americas region, demonstrating how integrated climate–health information systems can underpin preparedness, monitoring, and decision‑making across diverse settings.
1/ Why is data such a key issue when talking about the interconnection between climate, the environment and health? How can they inform the development of public policies?
The health sector inherited the practice of recording births and deaths, which were originally used solely for civil registration purposes but have clear epidemiological relevance. John Snow’s famous mapping of cholera in London in 1850s was based on mortality data obtained from the General Register Office. Over the course of the twentieth century, health services also began to record hospital and outpatient care. So, there is a permanent effort to expand the volume, coverage, and to improve quality of existing health data, which should include demographic information, geolocation, details on the health care provision, and, of course, accurate diagnoses regarding symptoms and causes of health problems.
By the end of the Twenty Century, however, it had become clear that health data alone were not sufficient to guide prevention strategies. A healthcare professional treating a patient in a clinic is unlikely to be able to relate individual cases to what is happening in the climate and the environment. We should not expect a doctor to become a data scientist or a climate specialist. Doctors need technical support to understand what is happening outside the healthcare system, both during disasters (floods, heat waves, droughts) and in a contexts in which climate change may alter disease profiles, for example, aggravating chronic noncommunicable diseases (diabetes, hypertension, mental health issues) or the introduction of a new pathogen in the region where patients come from (dengue and diarrheal diseases are some examples of expanding diseases). To this end, mechanisms have been established and refined within public health sectors that go beyond epidemiological surveillance and encompass environmental health, One Health, vector control, as well as weather climate and monitoring.
What happens in the environment can have direct repercussions on health conditions, like air pollution, disease vector infestation, temperature extremes, water contamination, and other environmental factors, all of them plays a role. What had initially been purely administrative records gradually became powerful sources of information for detecting outbreaks, analysing trends, and identifying the most vulnerable population groups, and relate it with their environmental determinants.
2/ What are the current challenges in integrating environmental and health data that you are trying to address with the Observatory of Climate and Health?
Health and environmental data are two completely different types of information. Health data is collected during events that occur throughout people’s lives. A person who goes to a hospital seeking a diagnosis and treatment, a lab test that confirms an infection, someone’s death from any cause. Transforming these records into health indicators is already part of the routine for epidemiologists and health managers, who calculate incidence rates, mortality rates, etc. But this figure alone may not be sufficient for decision-making. What would an outbreak be, if not a set of days or weeks with high incidence rates of a particular disease in a region?
Climate data, on the other hand, is collected at weather stations and by satellites in the earth orbit, each source with specific characteristics of spatial coverage and precision. Geoprocessing techniques are needed to generalize this data over the territory. These data must also be processed to detect trends. A long historical series of temperature or precipitation data can be statistically analysed to detect “anomalies” in the dataset.
A third task for analysts is to harmonize the data, seeking common spatial (a city district, a state…) and temporal (epidemiological weeks, months, years…) aggregations. This phase must be consistent with the conceptual model and the objectives of the job.
This data harmonization process is highly complex, involving large volumes of information with different types, scales, and characteristics. Conducting it requires an interdisciplinary team capable of integrating diverse datasets and producing meaningful outputs that support decision‑making and planning. It is within this context that the Climate and Health Observatory in Fiocruz plays a strategic role.
These analyses, which are generally beyond the capacity of health services, have been undertaken by the Climate and Health Observatory and its interdisciplinary team. We offer web-based services tailored to a variety of users. Behind these services lie extensive databases, predictive models, and tools for visualizing indicators, all designed to facilitate an understanding of ongoing processes and support decision-making. To this end, the Observatory employs data scientists, epidemiologists, geographers, public health professionals, computer programmers, and cartographers. And this entire process – from developing dashboards to selecting indicators and presenting data – is carried out with the active participation of health officials and civil society representatives, because they are the ones best positioned to identify the problems and have the greatest stake in finding solutions.
3/ In a few weeks, France will host a One Health summit, bringing together the scientific community, decision-makers, private entities and civil society to address issues ranging from vector-borne diseases to exposure to pollution. In your opinion, what can we expect from this international summit that would advance the issue of data integration and overcome some of the challenges?
In order to understand local relationships between climate and health, it is necessary to recognise their intrinsic complexity and the various cultural, economic, biological and physical factors that mediate these relationships and may exacerbate social inequalities.
Based on the Observatory’s 16 years of experience, we can synthetise the conditions that are essential to monitor and address the critical conditions of this crisis:
- data in large quantity and diversity, which portrays meteorological and environmental conditions at a fine spatial and time resolution;
- information on the health and socio-economic situation of vulnerable population groups;
- the intensive use of spatio-temporal statistical analysis and data mining techniques to detect trends, disease outbreaks and climate anomalies;
- a network of local researchers, with the support of international groups, from various disciplines who can draw up studies, produce technical documents and alerts, and finally;
- the engagement of local groups who formulate problems, interpret the results of research in conjunction with researchers and government, and establish priorities for adaptation strategies.
We need to bring together new and established theories, community-based experiences, multidisciplinary teams, and laboratory support to understand the link between climate events, their impact on health, and appropriate solutions. The One Health Summit is an excellent opportunity to gather all these elements.
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