Effects of environmental change on health and the critical need for sex- and gender-disaggregated data

Environmental change represents one of the most pressing global challenges of our time, with devastating effects on ecosystems, economies and human health¹. Environmental change differs from climate change in the sense that it covers a broader range of alterations in the environment than changes in climate patterns only, encompassing both natural processes and human activities such as emission of greenhouse gasses, deforestation, urbanisation, pollution of air, water, and soil, overexploitation of resources and introduction of invasive species. Environmental change manifests through changes in ecosystems, landscapes, biodiversity, and natural resources, as well as climate change-related effects such as rising temperatures, altered precipitation patterns and increased frequency of extreme weather events.

The consequences of environmental change on human health are multifaceted, spanning physical, mental, and social health and well-being both directly and indirectly¹. For example, changes in temperature and precipitation patterns influence the distribution and transmission of infectious diseases, leading to rises in vector- and waterborne diseases. Heatwaves lead to heat-related illnesses such as heatstroke, dehydration, and heat exhaustion. Air pollution exacerbates the negative health impacts of heatwaves and also leads to various non-communicable diseases, including respiratory, cardiovascular, and malignant diseases². More frequent hurricanes, floods, and wildfires can result in injuries, infectious disease outbreaks, and mental health issues, and cause major strains on healthcare infrastructures. Environmental change also affects agricultural productivity, with direct health effects through changes in food availability and nutritional quality, and indirect health effects through social and political tensions, population displacement and migration.

While environmental change affects everyone, the magnitude of the impact is not equally distributed. The most vulnerable populations, including children, the elderly, those with pre-existing health conditions, and those in low-income communities, are often disproportionately affected. In addition, emerging evidence shows that the negative effects of environmental change on health are influenced by sex and gender^3,4,5. Although often used interchangeably, sex and gender are fundamentally different (Box 1). While sex is mainly related to biological variation between males and females, gender is a social and cultural construct and related to norms, behaviours, and roles considered to be appropriate for men and women. The effects of environmental change on sex and gender may be direct effects, for example, in female-specific conditions, such as adverse pregnancy outcomes^6,7,8, or with shifts in the distribution for outcomes in conditions affecting both women and men, such as excess deaths of older women during extreme heat events⁹. Examples of indirect effects include nutritional deficiencies and food insecurity during droughts, gender-based violence following natural disasters, and climate migration. While both women and men are exposed to these challenges, women, girls, and gender-diverse people are particularly affected since they, in many contexts, have less access to and control over environmental resources, and are disadvantaged due to social, political, and economic inequalities³. Indeed, climate-induced displacement and migration have shown to increase the risks of sexual violence, sex trafficking, and child marriage. Gender-based violence may be used as a means to limit or control women’s access to land and natural resources, their employment in conservation and natural resource sectors, and their participation in climate justice movements^3,10. Boys and men, on the other hand, also experience challenges in the fulfilment of roles and responsibilities traditionally prescribed to men, which is often overlooked. For example, male farmers in less affluent areas may experience higher rates of suicide during periods of drought¹¹.

Despite these differences by sex and gender, studies on the effects of environmental change and health have predominantly employed a gender-neutral lens, with little attention to the specific vulnerabilities and responses that individuals of different sexes and genders may exhibit¹². When effects on women are considered, it is often in the context of maternal and child health. While clearly relevant, this is a narrow view of the health of women and excludes both men and conditions that are responsible for the greatest disease burden in both women and men¹³. A clear understanding of the role of sex and gender in health outcomes influenced by environmental exposures throughout the life course is essential for developing targeted and effective mitigation and adaptation strategies.

A sex and gender lens in health research and policy is increasingly promoted. In 2024, the World Health Organisation adopted the Sex and Gender Equity in Research (SAGER) Guidelines to address the sex and gender gaps in evidence and to inform effective and equitable policies and interventions for better health outcomes^14,15. At COP28, the United Nations Climate Change Conference in 2023, a Call to Action was launched ‘Counting on a Sustainable future for all through gender and environment data’¹⁶. Led by high-level multilateral stakeholders, including the COP23 Presidency, UN Women and WEDO (Women’s Environment & Development Organization), the first action was to urgently promote and prioritise the production of gender and environment data, in an ethical and transparent way. Within this action, the need to develop tools and methodological guidance, through international cooperation and dialogue, to better measure the nexus between gender and the environment, and generate comparable, quality statistics was explicitly highlighted. Yet, the Global Health 50/50 report on gender justice for planetary health demonstrated the current gaps in the integration of gender in planetary health efforts. While some global health organisations recognise the importance of gender inequalities in planetary health, gender-transformative action remains remarkably absent from most planetary health efforts¹². There also is inadequate inclusion of women, especially those in marginalised communities, in the environmental change discourse and decision-making processes^3,12.

In this perspective, we describe the current state of knowledge regarding sex and gender dimensions of the health impacts of environmental change. We provide a critical reflection on improving the quality of sex- and gender-disaggregated data on the health effects of environmental change. In doing so, we seek to encourage a more inclusive and informed discourse on environmental change and health, ultimately paving the way for evidence-based policies and interventions that account for the diverse experiences of individuals across the sex and gender spectrum. Definitions of sex- and gender-disaggregated data are provided in Box 2.

Sex and gender play an important role in virtually all major causes of death and disability, not only because of inherent biological differences between males and females, but also because of differences in gender roles and norms resulting in inequalities in autonomy, power, and access to resources¹⁷. In the context of environmental change and health, data on the unique impacts of sex and gender are still limited. However, differences could arise from differences in biology, behaviour, and exposure patterns. Using the examples of water, heat, and air pollution, we demonstrate the relevance of sex and gender both in conditions that affect both women and men, as well as sex-specific factors. Key recommendations are provided in Box 3.

Water

Environmental change is intrinsically linked to worsening of floods, rising sea levels, shrinking ice fields, wildfires and droughts. About two billion people worldwide do not have access to safe drinking water¹⁸, and about half of the world’s population is experiencing severe water scarcity for at least part of the year¹⁹. As sea levels rise, groundwater is projected to salinize further, leading to a decreased availability of freshwater in coastal areas. Water carrying, especially by head loading, is a major contributing factor in musculoskeletal disorders and pain in low-income countries²⁰. As water collection is mainly done by women and girls, the health risks associated with water fetching disproportionally affect women. Moreover, because of increasing water insecurity, women increasingly struggle to safely obtain enough water for their households, which increases their risk of gender-based violence, including physical and sexual attacks and transactional sex¹⁰. Menstrual hygiene management can also be impacted by disruption of access to clean water, leaving women and girls open to a range of genitourinary infections. Extreme weather events and natural disasters such as floods cause widespread disruptions in access to health services, including antenatal care, which drastically increases the risks of morbidity and mortality for both women and their unborn children.

Heat

Between 1998 and 2017, more than 166,000 people died due to heatwaves, including over 70,000 deaths during the 2003 heatwave in Europe²¹. As extreme temperature events are increasing in frequency, duration, and magnitude as a result of climate change, the number of people exposed to heatwaves increased by around 125 million between 2000 and 2016, and this number is expected to grow further with the current temperature projections²¹. The primary contributors to heat-related mortality are heatstroke, dehydration, and cardiovascular strain. Vulnerable populations, particularly the elderly, face an elevated risk due to lower thermoregulatory capabilities. Individuals with chronic health conditions, particularly those affecting the cardiovascular and respiratory systems, are also more susceptible. Because of sex differences in life expectancy, there are more elderly women than elderly men in most regions. Moreover, elderly women often experience more comorbidities compared to their male counterparts, which could explain the excess burden of heat-related mortality in elderly women compared to elderly men⁹. However, even when comparing women and men of the same age, mortality rates in elderly women can be up to 1.5 times higher than in elderly males. In April 2024, The European Court ruled in favour of a group of, mainly older, Swiss women who claimed their age and gender made them particularly vulnerable to the effects of heat, and the inadequacy of Switzerland’s efforts to meet its reduction targets was a violation of their human rights^22,23. Heat also has negative impacts on maternal health. Previous studies have shown about a 15% rise in the risk of premature birth and stillbirth during heatwaves⁷, with higher rates reported from vulnerable populations in low-and middle-income countries²⁴.

Air pollution

Exposure to air pollution is associated with 6.7 million premature deaths annually, of these, an estimated 3.2 million premature death are because of household air pollution². Most of these deaths are from non-communicable diseases including chronic obstructive pulmonary disease (COPD), lung cancer and cardiovascular diseases. Cheap and accessible fuels, such as wood and coal, are widely used for cooking and are a major contributor to household air pollution. Typical gendered divisions of labour mean that women tend to be responsible for cooking for their families in large parts of the world. This disproportionally exposes women to harmful household air pollutants. On the other hand, since men predominate the industrial workforce, for example, in construction and road works, they may be more exposed to ambient occupational air pollution, for example, through exposure to heavy metals and asbestos. Air pollution has been shown to have shown to have effects on reproductive function as well, as it has been associated with reduced sperm quality²⁵ and may negatively affect men’s fertility. Maternal exposure to air pollution has been linked to reduced foetal growth²⁶.

Despite emerging evidence, research on the sex- and gender-associated health impacts of environmental change is limited by the often unmeasured or inadequately measured exposure to environmental factors. This holds true for both external exposures, such as air quality or heat exposure, as well as for internal exposures, i.e. internal biological effects.

For external exposures, most environmental data is not collected at the individual level, but at the aggregate level, such as the household level. This means that intra-household exposure differences related to gender are not captured. For example, land use regression (LUR) models of ambient air quality typically predict exposures to specific points, with household-level exposures often being considered a proxy for personal exposures. However, differences between men and women in the amount of time spent at home and place of work limit the accuracy of these predictions. An approach to addressing this can be to deploy personal environmental monitors in a study population to provide individualised measurements²⁷. However, this can be costly and difficult to achieve at scale. Therefore, incorporating components such as occupational histories (including place of work) and relative time spent at home into field surveys are relatively simple ways to address this limitation and yield more representative data²⁸. It is also possible to employ exposure ratios to differentiate by sex or gender. For example, the WHO’s Household Multiple Emission Sources (HOMES) model, intended to estimate exposure to household air pollution due to cooking and heating with biomass (an activity primarily performed by women), considers time spent in the kitchen to estimate male, female, and child levels of exposure^29,30.

After external exposures are experienced (i.e. air breathed in or food consumed), biological and metabolic processes determine intermediate and disease endpoints. Sex- and gender-specific factors, such as hormonal variations, pregnancy state, body fat deposition and medication usage, can alter the absorption, distribution, metabolism and excretion of environmental contaminants. This can be especially relevant where in -omics analysis where both known and unknown compounds are evaluated, as sex-related biological features can potentially alter metabolic profiles³¹. Disaggregating data by sex and gender will, therefore, assist in distinguishing these effects. A final component of internal exposures is that of lab-based studies utilising animal or cell models, where, even at a cellular level, sex-related mechanisms has the potential to influence the exposure-response pathway^32,33.

There is increasing recognition of sex and gender influences in the impact of environmental change on health. It is important to recognise that neither sex nor gender are causal mechanisms by itself³⁴. Instead, sex and gender can be seen as proxies of underlying mechanisms that are classified under different sex and gender categories. There is a need to study the causal mechanisms as well, as this gives a more accurate interpretation of the data and allows policies and interventions, where possible, to be tailored to the causal mechanism rather than the sex or gender category. In the space of the sex and gender-related effects of environmental change on health, however, research mostly only characterises differences in exposure levels, often with suboptimal (i.e. household level) exposure data. Substantially less is known about potential sex and gender heterogeneity in disease mechanisms and adaptation strategies. High-quality research is needed to better characterise the sex- and gender-specific impacts of environmental change on health across the life course and to reveal the underlying mechanisms. For such research to be conducted, environmental data should be collected or modelled at the individual level, so to account for heterogeneity between women and men in environmental exposures, including intra-household heterogeneity. An intersectional approach should also be incorporated, as the sex and gender-related impact of environmental change on health vary across contexts and can interact with other socio-demographic factors such as age or socioeconomic position. The role of sex and gender in the effects of environmental change and health should be routinely considered in policy and environmental change adaptation strategies, which is currently largely absent¹². Adequate representation of women and gender-diverse people in the environmental change and health discourse is also essential.

An emerging body of evidence demonstrates that the direct and indirect impacts of environmental change on health are affected by sex and gender. However, the evidence is sparse and there is an urgent need for high-quality research to better characterise the nexus between sex and gender, environmental change, and health, to identify mechanisms, and to inform policy action in order to protect and promote health and wellbeing in the face of the growing threat of environmental change on population health.