Californians have always known wildfires to be a part of their lives, but in recent years things have changed for the worse. Due to the deleterious impact of climate change, and compounded by the fact that more and more fire-prone land is being developed, fires are becoming deadlier, more destructive, and more frequent throughout the western United States. The horrible devastation caused by the Tubbs Fire in 2017 and the Camp Fire in 2018, only 150 miles from the Buck Institute, prompted us to ask, “how do wildfires affect aging in survivors and those impacted by poor air quality?”
Smoke from wildfires is composed of some nasty stuff, including but not limited to gases like carbon monoxide and nitrogen oxides, plus tiny particles that can get inhaled into the lungs and enter the bloodstream. Needless to say, the body doesn’t take too kindly to these foreign contaminants; they can interact with vital parts of our biology, usually not for the better.
One hallmark of aging is telomere shortening. Telomeres are the last bit of DNA at the end of a chromosome. Every time our DNA replicates, a little bit of the end is cut off, so our telomeres act as protection for the rest of our coding DNA. As we age, our telomeres become shorter and shorter, and once the telomere is too short to sufficiently protect the DNA during replication, then replication of that chromosome stops. When telomeres were discovered, it was such an eye-opening and important discovery that three scientists – Elizabeth Blackburn, Carol Grieder, and Jack Szostak – were awarded the 2009 Nobel Prize in Physiology and Medicine. Telomere shortening leads to permanent growth arrest of the cell, known as replicative senescence. At the Buck Institute, we study many of hallmarks of aging, including replicative senescence in Dr. Judy Campisi’s laboratory, and how these senescent cells affect our lifespan and healthspan.
Vast amounts of research, including a meta-analysis of over 12,000 people, support the hypothesis that air pollution from smoke can affect telomere shortening. This tracks with other research that urban firefighters have an increased risk of lung cancer. In 2000 the World Health Organization (WHO) completed a comparative risk assessment to determine the burden of disease worldwide due to outdoor air pollution. A 2018 study found that air pollution reduces global life expectancy by almost two years. Through the 2000 assessment, the WHO determined that outdoor air pollution causes approximately 1.2% of all premature deaths globally (800,000 people), which equates to a total of 6.4 million lost years of life. This analysis may be hard for somebody to wrap their mind around, so to put it in perspective it is estimated that unsafe water causes 1.7 million premature deaths, outdoor air pollution causes 800,000, and lead causes 234,000 annually. It is undeniable that outdoor air pollution caused by wildfires and other sources is detrimental to our global lifespan, so what can people do to protect themselves?
When there is smoke in the air, the people most affected are older adults, the young, and those with lung and heart conditions (https://www.cdc.gov/features/wildfires/index.html). This is because pollution from smoke adds a stressor to the body, and those with systems less prepared to deal with stressors will feel the impacts the most. The best way to protect yourself is to limit exposure. It is always a good idea to check the local air condition, found at airnow.gov, where an “Air Quality Index” (AQI) is listed and ranked for safety. In the event of poor air conditions, it is a good idea to reduce time spent outdoors, especially for strenuous activities. People can also choose to wear N95 or P100 masks designed to protect lungs from inhaling dangerous pollutants that become airborne with fire.
Regular exposure to smoke pollution is certainly associated with adverse health effects. Exposure that takes place over a single wildfire season might exacerbate pre-existing conditions, but is unlikely to accelerate aging over the long term, However, as fires become more widespread and the fire season extends year-round, taking smoke pollution as a serious health concern that needs to be managed will help protect your cells from toxic pollutants and support healthy aging in the long term.
Anja Holtz went to the University of Minnesota and graduated in 2017 with a BS in Genetics, Cell Biology and Development as well as Ecology, Evolution and Behavior. Since then she worked at the Masonic Cancer Center doing breast cancer research for a year until she joined the Buck Institute in the summer of 2018. Anja has been extremely interested in genetics ever since the Human Genome Project was first publicized.