Population, health, and the environment (PHE) is an integrated approach to human development that links family planning and health with conservation to achieve better outcomes for both people and ecosystems than single‑sector efforts. There is a deep relationship among population, health, and the environment, and they are interconnected with other factors that help maintain those links.

More than one billion people live in ecological hotspots—many in remote areas of critical biodiversity under intense human pressure. Conservation work is often focused in these places, while local communities frequently face poor health due to limited access to health services and family planning, inadequate nutrition, and insufficient water and sanitation. Economic hardship and livelihoods dependent on natural resources and small‑scale agriculture can force people to use resources unsustainably, especially under pressures such as rapid population growth and health problems. That unsustainable use damages ecosystems and biodiversity, and human health in turn depends on healthy environments. The surrounding ecosystem provides goods and services—water, food, medicine, fuelwood, building materials, and other resources. Damage or disruption of these services can have severe consequences for human health. Population, Health, and Environment (PHE) projects work to create healthier communities and ecosystems by expanding health services in remote areas, increasing participation in conservation, and promoting family planning to slow population growth that strains natural resources. PHE simultaneously improves access to health care and helps communities manage natural resources to bolster health and livelihoods while protecting the environment. It also pursues synergies between human and ecosystem health through sustainable resource management, livelihood support, food security and nutrition programs, and habitat and ecosystem restoration. By aligning community well‑being with environmental conservation, PHE conserves biodiversity and improves local environmental health, demonstrating positive results across multiple sectors. History of PHE

In the late 1980s, conservation organizations and practitioners began to see the benefits of improving people's quality of life by managing biodiversity and natural resources. These efforts were initially called integrated conservation and development projects (ICDPs) and addressed a wide range of community development needs. By the late 1990s it became clear that many ICDPs were not achieving conservation or development goals as successfully as expected, often because their scope was too broad. A key lesson was that projects succeed when they focus on a few targeted interventions and avoid excessive complexity.

Drawing on these lessons, the conservation sector developed the PHE approach and a new generation of integrated projects. Program designers found that biodiversity conservation in developing countries produced the best long-term results when local people perceived the efforts as serving their economic and cultural interests. To be successful, ICDPs must consider the linkages between conservation and development objectives in each unique location; the first step is identifying where these goals intersect. Development interventions should be introduced where these intersections occur. One of the most important lessons from ICDPs over the past 20 years is that failing to involve project beneficiaries equitably as partners in all phases of implementation—from design through evaluation—has led to consistently disappointing results. Local participants are not a homogeneous group but differ widely in access to and dependence on resources, economic status, and vulnerability to environmental change. Lessons from past ICDPs led to the development of stakeholder analysis tools that identify individuals and groups with a stake in the project and incorporate them into every stage of design and implementation. Drawing on those experiences, the conservation sector piloted the PHE approach in the 1990s with the first generation of integrated projects. Since then, USAID, the David and Lucile Packard Foundation, Johnson & Johnson, and the Summit Foundation have worked to strengthen the approach. The PHE approach has advanced with the United Nations Millennium Development Goals (MDGs) in mind and has demonstrated the kinds of synergies needed to help achieve those goals. Past PHE Project Profiles

Successful Communities from Ridge to Reef, Kenya
This project was implemented in an area designated a UNESCO reserve, the Kiunga National Marine Reserve. The reserve has outstanding marine biodiversity of over 11,000 species, 60–70% of which are endemic to the Indo‑Pacific Ocean. The World Wildlife Fund (WWF), with funding from USAID, provided communities that depend on the reserve’s resources with access to family planning through a mobile clinic. Members of the community began to actively participate in conservation activities once they knew WWF was willing to help them meet basic health needs.

Healthy Families, Healthy Forests, Cambodia
When refugees from the Cambodia–Vietnam war in the 1970s returned home, they found their land had been destroyed by logging and agriculture. With USAID support, Conservation International helped the Khmer Daeum refugees replenish their land and provided them with their first access to family planning. Healthy families were able to develop long-term plans for sustainable land use, and local women created associations that mobilized the community to increase income-earning opportunities and strengthen participation in conservation activities.