Chris Carlsten advocates for the study of complex, real-world exposures in CHEST

Imagine if your allergy or asthma management plan took into account not only the nature of your allergic condition, but also the level of traffic pollution in your neighbourhood, the proximity of your house to an allergen-intensive green space, and the effect of wildfire season on local air quality. Such a plan would be far more likely to benefit you than one that did not take these additional factors into account, according to AllerGen investigator Dr. Chris Carlsten (The University of British Columbia [UBC]).

In a new article published in CHEST, Dr. Carlsten asserts such a comprehensive approach to addressing respiratory and other diseases—and managing an individual’s health in general—is needed. Physicians, patients, policymakers, and drug companies must take into account the interactive effects of multiple environmental exposures. To enable this, he argues, health researchers must do better at studying health and disease within their complex, real-world contexts.

Traditionally, health researchers have studied the effects of individual environmental exposures in isolation, observes Dr. Carlsten. In the real world, however, we are exposed to many things in our environments simultaneously, and a growing body of research exploring the multi-dimensional interactions among these exposures has revealed processes and relationships underlying disease that were previously hidden.

Dr. Carlsten cites various studies, including his own AllerGen-supported studies of allergen-diesel co-exposure, that have shown that the effects of exposures in combination can differ radically from the effects of exposures individually. As an example, he mentions how combined exposure to allergens and common respiratory viruses greatly heightens the risk for being admitted to hospital for asthma, compared to the risk associated with either exposure alone. As another, he mentions the “staggering potency of cigarette smoking combined with inhalation of asbestos in terms of risk for lung cancer.”

Approaches to disease treatment, management and prevention that overlook these differences, Dr. Carlsten notes, will often miss the mark, depending on a patient’s environmental context (and genetic make-up). His paper outlines some of the potential clinical and public health implications of better acknowledging real-world complexity, including the possibility of eventually being able “to robustly develop individual risk scores that help care providers better customize exposure avoidance.”

Finally, the realities of climate change and air pollution underline the increasing need for research that better incorporates real-world environmental complexity, adds Dr. Carlsten. By advancing our awareness of the co-exposure effects related to these phenomena, he argues, researchers might empower patients to push for better treatments and for actions to mitigate environmental degradation.

Read the article, “Synergistic environmental exposures and the airways: capturing complexity in humans.”


Dr. Carlsten is Professor and Head of the Respiratory Medicine Division at UBC; Astra-Zeneca Chair and Canada Research Chair in Occupational and Environmental Lung Disease; and Director of the Air Pollution Exposure Laboratory. He also holds adjunct positions with Peter Wall Institute for Advanced Studies, UBC School of Population and Public Health and the Centre for Heart Lung Innovation.