The U.S. Environmental Protection Agency (EPA) defines environmental justice as a provision of “an environment where all people enjoy the same degree of protection from environmental and health hazards and equal access to the decision-making process to maintain a healthy environment in which to live, learn, and work.”

Our most prevalent environment is indoors, and our most extensive exposure is the air we breathe. When preventing health hazards becomes a benchmark for environmental justice, maintaining universally safe IAQ standards is an essential component. While we know occupied buildings close in proximity to outdoor pollution sources, such as roadways, may need additional systems to maintain proper IAQ, there are other scenarios that also require special attention.

Best practice guidelines for indoor environments must now move beyond occupant comfort and protecting the health of the hypothetical “average” occupant. The more stringent standards found in health care settings, where people are immunocompromised or more vulnerable because of age, need to be extended to other settings. Medical research has uncovered an inherited condition, not modifiable by lifestyle changes, that conveys greater sensitivity to harm from airborne pollutants.  

Sickle cell disease (SCD) is a genetically transmitted disorder that is found primarily in African Americans. People inheriting SCD have abnormal hemoglobin, the oxygen carrying molecule, in their red blood cells. The consequence is a shortened half-life of red blood cells that leads to anemia and fatigue. Furthermore, the altered hemoglobin can deform red blood cells, changing them from the normal disc shape to an abnormal sickle shape. When triggered, the sickle-shaped cells stick to blood vessel walls, causing clots that stop the flow of blood and oxygen to down-stream tissues. These vaso-occlusive crises occur without warning, are very painful, and repeated episodes lead to high blood pressure, restricted lung function, and damage to other key organs. Despite the widespread prevalence of SCD, the causes of disease flare-ups have not been well understood until recently. Medical research has now revealed that exposure to airborne pollutants can be a powerful trigger for the inflammatory cascade that results in a SCD crisis.

To better understand the role of air pollution in SCD flare-ups, nine years of data from the Study on Particles and Health in Atlanta was analyzed to correlate ambient pollution levels with SCD-related emergency department visits.

The analysis found that boys under 18 were significantly at risk for increased flare-ups, and that pollutants associated with traffic emissions, including carbon monoxide, nitrous dioxide, and fine particles containing elemental carbon were most strongly associated with SCD.  

Overall, these findings reveal that individuals with SCD have increased susceptibility to environmental exposures that trigger inflammatory pathways that contribute to increased disease and a shortened life span. Furthermore, these harmful effects occurred at levels below air quality standards previously considered to be safe. The benefit of understanding the role of air pollution in disease is that we can create best-practice standards that are protective for all people. This is the precise goal of environmental justice that we are striving for.