Environmental Threats in Rheumatic Disease

The effects of pollution (such as that shown here in Beijing, China) do not appear until later in the RA disease process.
Image Credit: designbydx/shutterstock.com

Rheumatic diseases are intrinsically linked to environmental conditions. With a constantly changing environment, how can rheumatologists adapt to the challenges of global climate change, pollution and other environmental threats?

The Environment + Genetics

Tamiko Katsumoto, MD, a clinical associate professor in the Division of Immunology and Rheumatology at Stanford University, Palo Alto, Calif.,  emphasizes the role of environment in addition to genetics as risk factors for the development of autoimmunity. She notes that there has been an increase in positive ANA titers, along with many rheumatic diseases and speculates on how environment plays a role in this.

Overall, the environment is estimated to play a role in about 80% of diseases. With Thomas Bush, MD, Dr. Katsumoto  compiled data from 87 studies linking rheumatic diseases to air pollution, among which 74 showed associations with increased disease activity or disease incidence.¹ She also notes that the range of arthritogenic infections has been expanding with climate change, such as dengue, chikungunya, Lyme disease and coccidiomycosis.

In addition to climate change, greater exposure to pollutants may be impacting disease activity. Persistent organic pollutants, from such sources as pesticides, industrial chemicals and chemical byproducts, tend to be lipid soluble, leading to bioaccumulation. Many of these POPs are endocrine disrupting chemicals. These endocrine disruptor chemicals have been associated to various degrees with autoimmune disease.

Dr. Katsumoto emphasizes the role of food in fueling autoimmunity and as an intervention to confront environmental threats. Prior research has shown that a higher cumulative ingestion of ultraprocessed food is associated with lupus. The Plants for Joints study showed a plant-based diet may help reduce symptoms in rheumatoid arthritis and osteoarthritis. To expand upon this, preliminary results from the Stanford PLANT study (Providers Learning About Nutrition Together) demonstrate that education for providers may help to educate patients on these benefits. Additionally, due to the energy expenditures in raising meat and dairy, a plant-based diet may be a practical way to address environmental threats.

Air Pollution

Sasha Bernatsky, MD, PhD, a rheumatologist with a PhD in epidemiology, and a James McGill professor of medicine at the Research Institute of the McGill University Health Centre, Montréal, further expands on the effects of air pollution on autoimmune disease. Air pollution is a major issue, with greater than 90% of the global population breathing air that exceeds WHO guideline limits, and over 85 million Americans living in areas where air pollution exceeds air quality standards, she said. Pollutants are heterogeneous, including gases and particulate matter that can penetrate airways and be absorbed into the body, leading to oxidative stress, inflammation, and immune system activation.

Because air pollution is a complex phenomenon, data linking air pollution and rheumatic diseases remain scarce and difficult to interpret. Using ground-level monitoring stations and satellite data, an increasing amount of data to better define and characterize air pollution has been collected. Fine particulate matter and nitrogen dioxide in air pollution have been associated with lupus flares, RA disease activity and RA risk.

Climate Change

Lastly, Paul Dellaripa, MD, Brigham and Women’s Hospital, Boston, discussed the implications of global climate change on patient health.² Because physicians are trusted sources on climate change, rheumatologists can play important roles in mitigation, adaptation and advocacy. In particular, clinicians can discuss with patients health co-benefits, such as increasing the intake of plant-based food.

In addition, as environmental exposures become more frequent, Dr. Dellaripa contends that clinicians will need to learn how to proactively warn those whose health may be at risk. Potential means to address this challenge include heat alert systems, air quality alert systems, natural disaster contingency plans and mental health services. He concludes by observing that 8% of global greenhouse gas emissions are from the U.S. healthcare system so there is a lot of scope for rheumatologists to help improve our ability to confront these threats.

Bharat Kumar, MD, MME, FACP, FAAAAI, RhMSUS, is the director of the rheumatology fellowship training program at the University of Iowa, Iowa City, and the physician editor of The Rheumatologist. Follow him on X (formerly Twitter) @BharatKumarMD.

References

1. Katsumoto TR, Stolyar L, Dandeniya CL, et al. Impact of climate change on rheumatic diseases: A scoping review. J Clim Chang Health. 2024 Sep–Oct;19:100338.
2. Dellaripa PF, Sung LH, Bain PA, et al.; American College of Rheumatology Committee on Research. American College of Rheumatology white paper: The effects of climate change on rheumatic conditions—An evolving landscape and a path forward. Arthritis Rheumatol. 2024 Oct;76(10):1459-1466. doi: 10.1002/art.42919. Epub 2024 Jun 4. PMID: 38751102; PMCID: PMC11498941.