An environmental approach to water quality will save lives
With poor water quality increasingly becoming a health and economic issue, looks at the type of interventions which could of benefit.
WITH climate change accelerating and its effects exacerbating other geopolitical and development crises, the role of environmental protection in preserving and improving human wellbeing has become starkly apparent.
This recognition lies at the heart of the concept of “planetary health,” which focuses on the health of human civilisation and the condition of the natural systems on which it depends.
The concept’s logic is simple: if we try to deliver better health to a growing population, without regard for the health and security of our natural resources, we will not just struggle to make new strides; we will reverse the progress already made. Where things get complicated is in applying the concept, particularly when addressing the nexus of water services, health, and ecosystem integrity.
Since at least 1854, when John Snow discovered that cholera was spread through contaminated water supplies in central London, humans have understood that polluted water is bad for our health. The degradation of freshwater ecosystems often brings disease, just as the protection or strengthening of such ecosystems improves health outcomes.
But, while it is now well understood that progress in one area improves outcomes in another, such co-beneficial dynamics often are insufficient to spur investment in both areas.
For example, investing to protect a watershed can also protect biodiversity and improve water quality in associated rivers, thereby benefiting human health. But if the goal is explicitly to improve human health, it might be more cost-effective simply to invest in a water-treatment plant.
A more compelling dynamic is complementarity: when investment in one area increases the returns on investment in other areas.
A well-functioning water sector attempts to balance complementary interventions. Indeed, such a system amounts to a multidisciplinary triumph – involving engineering, hydrology, governance, and urban planning — with far-reaching complementary impacts on human health and economic development.
In 1933, through the Tennessee Valley Authority Act, the United States established an agency whose purpose was to build hydroelectric dams on the Tennessee River. That effort benefited industry, agriculture, flood control, and conservation throughout the Tennessee Valley watershed, until then one of the country’s most disadvantaged regions.
Since then, governments worldwide have recognised the potential of water infrastructure to complement other economic and social policies.
But the question is whether there is an optimal mix of environmental protection and direct health interventions on which policymakers can rely to maximise investment returns for both.
An analysis suggests that, in rural areas, a 30% increase in upstream tree cover produces a 4% reduction in the probability of diarrhoeal disease in children — a result comparable to investing in a sanitation facility.
But, if that is true, we have yet to determine at what point reforestation becomes a better investment than improving sanitation, let alone increases the returns of other health interventions.
Another study found an estimated 42% of the global malaria burden, including a half-million deaths annually, could be eliminated through focused on land use, deforestation, water resource management, and settlement siting.
But the study didn’t cover the potential benefits of employing insecticide-treated nets as a tool for fighting malaria.
Worldwide, around 40% of cities’ source watersheds show high to moderate levels of degradation. Sediment from agricultural and other sources increases the cost of water treatment, while loss of natural vegetation can change water-flow patterns.
All of this can adversely affect supply, increasing the need to store water in containers that serve as mosquito larval habitats. Can we show that ecological restoration of the watershed could do more than just insecticides or mosquito nets to support efforts to reduce malaria (and dengue) in cities?
In all of these cases, finding the best option requires knowing not just the relative contribution of interventions, but understanding their complementarity. In a world of limited resources, policymakers must prioritise their investments, including by differentiating the necessary from the desirable.
Some 2.1 billion people worldwide lack access to safe, readily available water at home, and more than twice as many — a whopping 4.5 billion — lack safely managed sanitation, severely undermining health outcomes and fuelling river pollution.
With a growing share of the world’s population — including many of the same people — feeling the effects of environmental degradation and climate change firsthand, finding solutions that simultaneously advance environmental protection, water provision, and health could not be more important.
Global health and conservation professionals must cooperate more closely to find those solutions — and convince policymakers to pursue them.
- Giulio Boccaletti is Chief Strategy Officer and Global Managing Director for Water at The Nature Conservancy.
- www.project-syndicate.org
