The massive wildfires that impacted the Los Angeles area destroyed over 10,000 structures and affected hundreds of thousands of individuals. Toxic smoke and ash acutely triggered many respiratory issues, the impact of which was felt across emergency rooms in the greater L.A. area. Data shows that wildfire smoke increases the incidence of cardiovascular conditions such as hypertension, heart failure, pulmonary embolism, and cardiac arrest. Of great interest to those within neurocritical care is that wildfire smoke is also associated with increased cerebrovascular risks, especially the risk of ischemic stroke in individuals aged 65 and older, and the risk of transient ischemic attack among adults 45 to 64 years of age.^(1,2)

Unlike other wildfire events in rural areas, this year’s Los Angeles fires and the 2024 Maui fire in Hawaii consumed thousands of structures. The massive numbers of homes and commercial structures that burned contained plastics, standard batteries, lithium batteries, paint, lighting fixtures, petroleum products, insulation, and many other toxic materials. These fires had effects that were very similar to the military’s experience when burning these types of materials in the burn pits of Iraq and Afghanistan.⁽³⁾ Burn pit exposure affected 3.5 million service members, with the Veterans Administration tracking the rise of associated lung diseases and cancers affecting the blood, brain, kidney, and other organs. The VA has also reported a rise in cerebrovascular and cardiovascular diseases in exposed individuals despite their young age.

Of course, the L.A. wildfires likely affected more individuals from a broader age group than those from the military’s burn pit experience. Adding to the common toxins reported in the past, these fires released many heavy metals into the environment. It is widely known that lithium—which is now common in the batteries of cars, tractors, electronics, and power tools—is highly toxic, and this has led to several national and state regulations for its safe disposal. Due to the increasingly widespread use of lithium, the incineration of such batteries may be the largest release of lithium into the environment ever recorded. As a result, there should be increased awareness of the neurological symptoms of lithium toxicity, which include tremors, ataxia, gait problems, myoclonus, hyperreflexia, dysarthria, seizures, and incontinence. Modern lighting fixtures also contain mercury and many other toxic substances that can cause tremors, insomnia, memory loss, headaches, loss of vision, and motor and cognitive dysfunction.

It is imperative that our public health officials develop a robust tracking system, both to educate exposed individuals and to provide close follow-up. We as experts in acute neurological disease should aim to help mitigate the effects of these exposures through research and early interventions—activities that will only increase in importance as climate change leads to wildfires becoming more and more widespread in urban areas around the world.