Climate change and air pollution: Twin threats of burning fossil fuels with implications for the practice of dermatology

Climate change associated with widespread planetary warming has resulted in myriad detrimental impacts on human health and has been described as the most significant crisis facing the global healthcare system.1 As the primary (dynamic) barrier between individuals and their environment, skin is visibly sensitive to the health risks posed by a warming world, including heat-related illnesses, cutaneous and systemic infections, malignancy, photoaging and pigmentary disorders, as well as nutritional deficiencies secondary to food insecurity.1 Importantly, skin is also sensitive to air pollution. Exacerbations of allergic, autoimmune and inflammatory disorders, including atopic dermatitis, systemic lupus erythematosus, psoriasis and pemphigus, have all been associated with exposure to small particulate matter and the poor air quality that occurs secondary to the combustion of carbon sources.2 As such, it is important to recognize that air pollution is not a separate health issue distinct from climate change, but rather the opposite side of the same proverbial coin that occurs as a result of burning fossil fuels. With this in mind, Fadadu and colleagues' systematic review of air pollution and healthcare utilization for atopic dermatitis in this issue of The Journal is an important addition to a growing body of literature that clearly demonstrates the detrimental impact of fossil fuel combustion, air pollution and climate change on allergic disease.3 Building on their work showing an association between air pollution from the 2018 California Camp Fire and increased health care utilization for atopic dermatitis and itch,4 the authors reviewed 18 available global studies to more rigorously assess this association. Specifically, they found that across a majority of studies, increases in the concentration of small particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2) and sulphur dioxide (SO2) were associated with increased healthcare utilization for atopic dermatitis. Moreover, these effects may be modulated by other climatic variables including temperature, humidity and ultraviolet light exposure.3 What do we, as dermatologists, do with this important information? Practically speaking, it is unclear how to best minimize the effects of air pollution on atopic dermatitis, as this question has not been thoroughly studied. Common sense interventions include remaining indoors when air quality indexes are poor, use of indoor air filtration systems (if available and affordable) and daily bathing to remove as much particulate matter from the skin as possible. Nevertheless, important questions remain regarding these practices, including if frequent bathing disrupts protection afforded by the epidermis, exacerbating atopic symptoms upon continued exposure to air pollution. The authors themselves posit an interesting query: does the use of an emollient serve as a protective barrier against air pollution or might it serve as a depot for substances that in turn flare atopic dermatitis following prolonged exposure?3 As the nascent field of climate change dermatology continues to grow, these are the types of clinical questions that must be addressed in order to best prepare our patients and ourselves for the cutaneous impacts of air quality and temperature changes that will occur in an ever-warming world. Make no mistake—climate change is an existential threat that will not affect individual and public health in a distant future; it is a crisis that is affecting our well-being today. In recent years, wildfires across Australia and Europe, and now raging through much of Canada, have resulted in ever-worsening measures of air quality in cities as disparate as Sydney, Madrid, Chicago and Washington DC, with implications for dermatologic and overall health in locales that are unaccustomed to such conditions. We, therefore, must be prepared to help our patients navigate a new climate reality. Beyond providing skin care recommendations, dermatologists can leverage their expertise and longitudinal relationships with patients to help make connections between global warming, air pollution and dermatologic disease. Though this may feel like a daunting task due to rampant disinformation and political denial regarding the effects of climate change, different tactics including targeted risk communication, motivational interviewing and storytelling may make communicating these associations less fraught for providers, while increasing patient receptiveness to these facts.5 This in turn may help empower patients and mitigate climate change-related anxiety. Ultimately it is our ethical imperative as healthcare providers to clearly and effectively educate our communities about the indisputable facts of human-induced global warming and to advocate for measures (reductions in fossil fuel use, higher air quality standards, healthcare system preparedness and resiliency, etc.) that will reduce the negative impacts of climate change and air pollution on dermatologic health.1, 6 There's no time like the present. None. None. Data sharing is not applicable to this article as no datasets were generated or analysed during the current study.