NHLBI Workshop: Frontiers of Planetary Health and Environmental Justice
Some 55 years ago, poet and environmentalist Wendell Berry reflected on the dire harm that the modernization that seemed to improve our lives had wrought on the planet. “We had lived under the assumption that what was good for us would be good for the world,” he wrote. “We were wrong.”
Today, researchers feel a sense of urgency because they increasingly understand that human health is inextricably linked to the ecosystems of our air, land, and water. They call this “planetary health.” NHLBI recently brought researchers together with the specific goal of improving planetary health and hoping that cardiovascular health will improve as well. Last December, experts in climate change, engineering, environmental justice, and heart disease discussed their best ideas over two days at a workshop called “Exploring Research Opportunities from the Intersection of Advancing Planetary Health and Cardiovascular Disease.”
“The call of the workshop was to promote health rather than focus on disease,” said Larry Fine, MD, senior advisor in the Division of Clinical Applications and Prevention in the Department of Cardiovascular Sciences and chair of the workshop planning committee. “Our goal is to one day get to a desirable future that is a sustainable place for both human health and the health of the planet.”
The air we breathe
Jonathan Newman, MD, MPH, assistant professor of cardiology at NYU Langone Health and director of clinical research at the Center for Cardiovascular Disease Prevention and one of the workshop speakers, said that while there is growing awareness of the environment's impact on human health, the new focused research attention is “overdue” but very welcome.
Newman's research specifically examines how the air we breathe affects our hearts. Fine particulate matter (aka PM2.5) is a mixture of carbon and heavy metals that exists as tiny particles in the air. PM2.5 is produced by fossil fuel burning, traffic, and agricultural dust, and is responsible for 8.9 million deaths worldwide each year, the majority of which are due to cardiovascular disease. Newman and his colleagues found that while short-term exposure to air pollution can increase blood pressure by 2-10 mmHg, long-term exposure promotes the development of full-blown hypertension.
“We're trying to better understand whether air pollution, particularly indoor air quality, can be viewed as a modifiable risk factor for cardiovascular disease,” Newman said.
His lab is testing the use of personal air purifiers (PACs) with HEPA filters to remove PM2.5 that has made its way indoors. He is currently conducting an NHLBI-funded clinical trial to test whether continuous use of a PAC in the bedroom while sleeping improves blood pressure. A pilot study focusing specifically on public housing residents found that adults with high blood pressure experienced a reduction in blood pressure after using a PAC for 14 days, although the results were not significant.
“This is something that needs to be followed up on,” Newman said. “Blood pressure is one of the most common risk factors for heart disease and remains a difficult target to control.”
The water and land we use
And then there's the water issue. In some parts of the country, manufacturing has released per- and polyfluoroalkyl substances (PFAS) into the environment, most of which ends up in drinking water sources. PFAS make up a large and complex group of synthetic chemicals used in a variety of consumer products, including nonstick cookware. PFAS molecules are chains of carbon and fluorine atoms bonded together, making them some of the strongest molecules ever designed. This bond makes these chemicals difficult to break down in the environment or in our bodies. Research is now uncovering a range of possible health effects that PFAS may have.
Newman and his colleagues showed that some PFASs may directly affect vascular function. They measured vascular function and blood levels of 14 PFASs in adults with no history of cardiovascular disease. They found that 10 of the 14 PFAS compounds they measured were detected in the blood of more than half of the study participants, and that patients with higher PFAS levels had impaired vascular function.
The issue isn't just about man-made compounds getting into drinking water. Natural sources such as inorganic arsenic, which is naturally found in soil and can leach into drinking water, are also an issue. Newman said land use can affect human exposure to arsenic in water. Industrial agriculture, waste and aquifer development can lead to increased exposure.
The NHLBI-funded Strong Heart study is investigating how arsenic exposure harms the heart. Using data from a cohort of 3,600 American Indians living in Arizona, Oklahoma, North Dakota, and South Dakota, researchers found that arsenic exposure, measured by serum levels in urine samples, was associated with all-cause mortality, cardiovascular disease mortality, and cancer mortality, even at low-to-moderate exposure levels. The study highlighted the need to develop public health measures to protect people, especially those most vulnerable, from unknowing arsenic exposure.
Central Issue: Environmental Justice
Previous research has shown that social determinants of health, including access to safe neighborhoods, nutritious food, and clean air and water, affect both those most affected by adverse impacts on planetary health and those who benefit least from efforts to improve planetary health, and therefore cardiovascular health.
For example, arsenic contamination of groundwater supplies disproportionately impacts rural residents who use private wells. Arsenic removal programs are limited, especially in American Indian communities. Building on the Strong Heart study, the Strong Heart Water study aimed to combat this issue by examining the effectiveness of using arsenic filters and a mobile health program to reduce arsenic exposure in households to private well water. This is the first randomized controlled trial of an arsenic intervention in the United States. Results suggest that these at-risk communities have a significant increase in reported use of arsenic-safe drinking water.
The workshop encouraged researchers to consider how health disparities could be exacerbated if we do not focus on allocating resources to those who need them most, as the Strong Heart Study has done.
“Cardiovascular disease is preventable and treatable, and the disproportionate risk of cardiovascular disease among underrepresented groups will be reduced if equity is prioritized as a driver of prevention strategies,” said Patrice Devin-Nickens, M.D., medical director at NHLBI and one of the workshop's organizers. “We can save the planet, and we can save each other if we do it equitably. This is not a competing priority, it's a necessity.”
