A spirometer is a medical device often used to assess respiratory function and diagnose respiratory diseases, including asthma, chronic obstructive pulmonary disease, and asbestosis.1 To use the device, you inhale and exhale as deeply as possible into a breathing tube attached to the spirometer itself, which measures your forced vital capacity (the maximum amount of air you can breathe in) and forced expiratory volume (how much you can breathe out in 1 second).1
Figure 1: This shows the basic set-up of a modern spirometer test. The patient wears a nose clip and breathes into a mouthpiece, and a monitor displays a graph of their inhaled and exhaled volume. (Source Wikipedia)
For each patient who is tested using a spirometer, the operator must enter information about the patient, including their age, sex, height, and race.2 Unbeknownst to many operators, selecting a patient’s race enables a “race correction” setting programmed directly into the spirometer software – typically a 10-15% lower baseline lung capacity for patients identified as Black, and 4-6% lower for patients identified as Asian.3 Despite conflicting studies contesting the validity of using racial correction factors,4 it continues to be taught in modern science. This idea that non-whites have intrinsically lower lung capacity began as a justification for slavery, and the ramifications of this notion have continued to manifest in modern-day medical devices.
In Thomas Jefferson’s “Notes on the State of Virginia,” the former president and slaveholder described deficiencies in “the pulmonary apparatus” of Black slaves.5 Plantation physician Samuel Cartwright further elaborated on Jefferson’s sentiments with his own spirometer studies, reporting a 20% “deficiency in the negro” in regards to lung capacity.6 Cartwright promoted slavery on the grounds that forced labor was necessary for Black people’s health due to their innately lower lung capacity. He stated that “it is the red vital blood sent to the brain that liberates their mind when under the white man’s control.” 6
After the Civil War, Benjamin Apthorp Gould further expanded on Cartwright’s work by comparing the lung capacity of Black and White soldiers. Although Gould did not account for height, age, or the living conditions of recently emancipated slaves, Gould’s conclusions mirrored those who came before him: “full blacks” had lower lung capacity than “whites.” 2,5,7 Gould’s study is still cited in scientific articles today.2
Over the course of the 20th century, researchers continued to fuel the idea of innate racial differences in lung function, repeatedly failing to account for the influence of socioeconomic conditions. In a review of articles published between 1922-2008 comparing lung function between races, 94% of articles did not examine race in the context of socioeconomic status.8 Although it is often ignored in research articles, lower lung capacity has been associated with poverty in past studies, as well as other social determinants including environmental toxin exposure and healthcare inaccessibility.2,5
In 1984, J.E. Myers published an article that questioned the body of data supporting innate racial differences in lung function. Myers conducted his own spirometer studies of Black workers in South Africa, and his calculations showed that the published South African standards considerably underestimated the lung volume of Black people.4 Myers also challenged the assumptions made in previous studies, pointing out that they neglected to account for socioeconomic factors including environmental pollutants, housing quality and nutrition quality.4
Several years after Myers’ article, in 1999, asbestos manufacturer Owens Corning used the argument that Black people have an intrinsically lower lung capacity to evade lawsuits from Black workers with lung damage. The company tried to argue that Black workers should be held to a different standard when assessing asbestos-induced lung damage because Black people consistently score lower on pulmonary function tests.9 The motion was overruled, but the case highlighted how historic assumptions on race have infiltrated modern lung research. As in the case of Owens Corning, modified lung function standards based on race have the potential to reduce diagnosis rates for respiratory illnesses and lung damage.
Current spirometers implement “race correction” automatically, defining race as a purely genetic difference, rather than exploring the environmental and socioeconomic factors that have been shown to influence lung function. Lundy Brahn, a Brown University professor of Africana studies and medical science, addresses these issues in her article “Race, ethnicity and lung function: A brief history,” where she provides insights on how to address lung function research in the future.
“Research and clinical practice needs to devote more careful attention to the social nature of racial and ethnic categories and draw on more complex explanatory frameworks that incorporate disproportionate exposures to toxic environments, differential access to high-quality care and the daily insults of racism in every sphere of life that manifest biologically.” 2
– Lundy Braun, PhD
1Spirometry: Mayo Clinic
2Race, ethnicity and lung function: A brief history, by Lundy Brahn
3 Breathing race into the machine: The surprising career of the spirometer from plantation to genetics, by Lundy Braun
4Different ethnic standards for lung functions, or one standard for all?, by J.E. Myers
5Science reflects history as society influences science: brief history of “race,” “race correction,” and the spirometer, by Heidi L. Lujan and Stephen E. DiCarlo
6 The Science and Politics of Racial Research, by William H. Tucker
7Investigations in the Military and Anthropological Statistics of American Soldiers, by Benjamin Apthorp Gould
8Defining race/ethnicity and explaining difference in research studies on lung function, by Lundy Braun
9Racial basis for asbestos lawsuits?; Owens Corning seeks more stringent standards for blacks, by Erin Texeira