Planetary health and environmental justice at the forefront of an NHLBI workshop
Some 55 years ago the poet and environmentalist Wendell Berry pondered the distressing harm to the planet that had resulted from the very modernization that seemed to be improving lives. “We have lived by the assumption that what was good for us would be good for the world,” he wrote. “We have been wrong.”
Today researchers are alarmed, because they say they now better understand that the health of humankind is inseparably linked to the air, land, and water ecosystems. They call it planetary health. NHLBI recently brought researchers together with the specific goal of improving planetary health with the hope that cardiovascular health would also improve. For two days last December, experts on climate change, engineering, environmental justice, and cardiology discussed their best ideas in a workshop, Exploring The Research Opportunities From The Intersection Of Advancing Planetary Health And Cardiovascular Disease.
“The call for action of the workshop was to promote health, instead of being diseased focused,” said Larry Fine, M.D., Dr.PH, senior advisor in the Clinical Application and Prevention Branch in the Division of Cardiovascular Sciences and chair of the workshop planning committee. “Our aim is to someday get to that desirable future where we’re in a sustainable place for both human health and planetary health.”
The air we breathe
Jonathan Newman, M.D., M.P.H., assistant professor of cardiology and clinical research director for the Center for the Prevention of Cardiovascular Disease at NYU Langone Health and one of the workshop’s speakers, said this recognition of the impact of the environment on human health has been growing, but the new, focused research attention, while “overdue,” is much welcomed.
Newman’s work looks specifically at how the air we breathe can impact our hearts. Fine particulate matter, otherwise known as PM2.5, is a mixture of carbon and heavy metals that live as tiny particles in the air. PM2.5 is generated through the burning of fossil fuels, traffic, and agricultural dust and accounts for 8.9 million deaths each year globally, with the largest proportion of those due to cardiovascular diseases. Research by Newman and others has found that even short-term air pollution exposure can increase blood pressure by 2-10 mmHg, while longer-term exposure promotes the onset of full-blown hypertension.
“We’re trying to better understand if we can view air pollution and, in particular, indoor air quality as a modifiable risk factor for cardiovascular diseases,” said Newman.
His lab is testing the use of personal air cleaners (PACs) with HEPA filters to remove the PM2.5 that’s made its way indoors. He is currently running an NHLBI-funded clinical trial to test whether using PACs continuously in people’s bedrooms while they sleep can improve blood pressure. A pilot study specifically focused on public housing residents found that adults with hypertension experienced a decrease in blood pressure after 14 days using the PACs, though the result was not significant.
“We need to do follow up studies on this,” said Newman. “Blood pressure is one of the most common risk factors for heart disease and remains a difficult-to-control target.”
The water and land we use
And then there’s water. In certain parts of the country, manufacturing has led compounds known as per- and polyfluoroalkyl substances (PFAS) to be released into the environment, mostly into drinking water sources. PFAS make up a large, complex group of synthetic chemicals that are used in a variety of consumer products, such as non-stick cookware. PFAS molecules have a chain of linked carbon and fluorine atoms – one of the strongest ever designed. Because of this bond, these chemicals do not breakdown easily in the environment – or our bodies. Research is now uncovering a multitude of health effects that PFAS can have.
Newman and his colleagues have shown that some of the PFAS can have direct effects on vascular function. They measured vascular function and blood concentration of 14 different PFAS in adults with no known cardiovascular disease. They found that 10 out the 14 PFAS compounds measured were detectable in the blood in more than half the study participants, and those patients with high levels of PFAS had impaired vascular function.
This issue is bigger than just man-made compounds making their way into our drinking water. Natural sources, like inorganic arsenic which naturally occurs in soil and can leach into drinking water, is also problematic. Newman said that land use can impact the way humans are exposed to arsenic in water. Industrial farming and waste products, and development of aquifers can lead to increased exposure.
The NHLBI-funded Strong Heart Study is investigating how arsenic exposure can harm our hearts. Using data from a cohort of 3,600 American Indians living in in Arizona, Oklahoma, and North and South Dakota, researchers found that arsenic exposure, as measured in serum levels in urine samples, was associated with all-cause, cardiovascular, and cancer mortality even at low to moderate levels of exposure. The study highlighted the need to design public health measures to protect populations, especially the most vulnerable, from arsenic exposure unknowingly.
The centerpiece challenge: environmental justice
Previous research has shown that social determinates of health, including access to safe neighborhoods, nutritious food, and clean air and water, influence who will be most affected by adverse changes in planetary health and who may benefit the least from efforts to improve planetary – and by extension, cardiovascular health.
Take, for example, the arsenic contamination in groundwater supplies that disproportionately affects rural populations using private wells. In American Indian communities especially, arsenic removal programs are limited. Building on the Strong Heart study, the Strong Heart Water Study aimed to counteract this by examining the effectiveness of using arsenic filters and a mobile health program to reduce household exposure to arsenic in private well water – the first randomized controlled trial of an arsenic intervention in the U.S. Results have suggested a significant increase in reported use of arsenic-safe drinking water in these at-risk communities.
The workshop encouraged researchers to consider, as does the Strong Heart Study, how health inequity is worsened without focused attention on the distribution of resources to those who need it most.
“Cardiovascular diseases are preventable, and treatable. If equity is prioritized as a driving principle for preventive strategies, disproportionate risks of cardiovascular diseases in underrepresented groups would be reduced,” said Patrice Desvigne-Nickens, M.D., medical officer at NHLBI and one of the workshop organizers. “We are able to preserve the planet and if we do that equitably we save each other. It’s not a competing priority, but a necessity.”