11.1: Introduction
Environmental health includes both the human impact on the earth, as well as the health effects of different environmental exposures (chemicals, gasses, radiation, etc.) on humans. According to the World Health Organization (WHO):
Healthier environments could prevent almost one quarter of the global burden of disease….Clean air, stable climate, adequate water, sanitation and hygiene, safe use of chemicals, protection from radiation, healthy and safe workplaces, sound agricultural practices, health-supportive cities and built environments, and a preserved nature are all prerequisites for good health (WHO, 2020).
Environmental factors contribute to leading causes of morbidity and mortality around the world, causing nearly 1 in 4 human deaths globally in 2016 (WHO, n.d.). Recognizing that human health is interconnected to the health of animals as well as the entire ecosystem in which we live, the One Health framework has been developed to promote an interdisciplinary approach to environmental health. Taking this holistic approach can help to reduce zoonotic disease transmission, improve access to food and clean water, and mitigate and adapt to the effects of climate change (WHO, 2022).
Any ecosystem has a maximum capacity, called the “carrying capacity” for sustaining the life of a particular organism. If this capacity is reached and exceeded, there will not be enough resources to sustain the further growth of that species, and the population will decline to below the carrying capacity (Frumkin, 2016). On planet Earth this includes both the potential “using up” of Earth’s natural resources, as well as our contributions to climate change which have an effect on ecosystems themselves. Climate change may cause some areas of the planet to become uninhabitable by humans in the (near) future. Many regions are already experiencing the cascading effects to human health caused by climate change. In this chapter, we will explore the health effects of climate change, as well as some common environmental toxins and pollutants, environmental regulations, and public health responses to environmental health concerns.