How do they impact your health?

There’s no question that wildfires are harmful to the environment. They can cause the destruction of thousands of acres of land and kill wildlife. In addition, they can damage property and result in death if people don’t get out of the way. However, this isn’t the only impact it can have on humans. What are the effects on your health from wildfires? How long do they last?

WildfiresSummer is a time for being outside, enjoying the weather and activities that you can’t do the rest of the year. Unfortunately, the heat of summer also brings an increased threat of wildfires. Wildfires are uncontrolled fires that occur in forests and vegetated areas. They’re able to spread rapidly and are difficult to control, which makes them incredibly destructive. Of California’s top 10 most destructive fires, nine have occurred in the 21st century with six of them in the past few years. In 2015, they consumed 10 million acres in the United States and an estimated $2 billion spent on federal firefighting suppression. The Valley fire in Lake County happened that year, and it burned 50,000 acres within 24 hours. In 2017, the Tubbs Fire consumed 36,000 acres, 2,800 homes (over 5,600 buildings total), and 22 human beings in Napa and Sonoma Counties, making it one of the most destructive fires on record. A year later, the Camp Fire displaced it, after lasting 17 days and killing 86 people in the town of Paradise. Last year, the Kincade Fire torched nearly 80,000 acres. The issue is that it isn’t just the destruction caused by the fire itself, but the smoke can cause significant problems as well. For instance, during the Camp Fire, residents of nearby Northern California communities breathed in enough smoke to equal half a pack of cigarettes. In 2016, wildfires in Alaska and Canada burned more than 9.8 million acres, according to the National Interagency Fire Center. However, the smoke threatened the lung health of Americans thousands of miles away. One fire in northern Canada had pollutants reached people in North Dakota, South Dakota, Minnesota, and Iowa. An estimated 20,000 people die sooner than expected every year in the US because of continuous exposure to wildfire smoke. Due to the frequency and intensity of the recent fires, scientists expect the number to double in the next 100 years. On a global scale, wildfire smoke is thought to cause over 339,000 premature deaths a year. These numbers are far more than those who lose their lives directly in these blazes.

There is a combination of factors that are causing wildfires to happen with the severity that they are. One is the influx of people moving into high fire risk areas. Currently, about 49 million people in the US live near forests and the number grows by 350,000 every year. Another issue is a century of poor forest management. This has allowed brush to pile up and provides plenty of ready fuel. Even when they do controlled fires to clear out underbrush, or prescribed burns, it can cause health effects. The good news is that the result isn’t as strong as wildfire smoke. An additional factor that contributes to the influx of wildfires is the rising heat and subsequent drying of plant matter due to climate change. The warming temperatures have resulted in droughts in many areas across the Western US and Alaska. The higher spring and summer temperatures also mean that there are earlier spring snow-melt, which cause soils to be drier for more extended periods. These hot, dry conditions increase the likelihood that fires are more intense and long-burning.

Wildfire smoke contains particulate matter, carbon monoxide, carbon dioxide, water vapor, hydrocarbons, nitrogen oxides, and various volatile organic compounds. The actual composition can vary depending on the fuel type, fire temperature, and wind conditions. Of these pollutants, particulate matter (PM) is the most concerning, given their tiny size and ability to be inhaled deeply into the lungs. They’re no larger than one third the diameter of a single piece of hair. A recent key finding is that particles released from burning vegetation become more toxic over time because they chemically react with trace radicals (molecules with unpaired electrons) in the air. This process is called oxidation and converts the smoke particle compounds into highly reactive compounds, or free radicals. When they are breathed in, they can damage cells and tissues in the body. Tests show that smoke samples taken from the air over five hours after they were released showed them to be twice as toxic as initially and, in the laboratory, the toxicity increased to four times the original levels as time went on. In addition to burning vegetation, wildfires burn homes and other structures, which adds to the health risks since building materials and household items made from petroleum-based plastics, which burn hotter and generate more poisonous smoke. All of the chemicals in a wildfire can significantly reduce air quality, both locally and in areas downwind of fires. Wildfire smoke can circulate the globe because it gets injected into the upper atmosphere where strong winds move it rapidly around, resulting in air pollution in areas far away from where the fire is. Historically, the US has treated smoke pollution as a local problem, but it’s becoming increasingly clear that this isn’t the reality. One of the challenges of estimating the level of air pollution released by a fire is that the amount of each substance can vary dramatically and requires predicting where that pollution will go using a calculation that relies on complex air-movement models and weather analyses.

As a result of wildfire frequency, the smoke now makes up almost half of people’s exposure to PM2.5 in the western part of the US, which is up from less than 20% a decade ago. Many cities in the West saw their highest-ever particulate levels in 2017 and 2018 when more than 10 million people were exposed to levels of PM2.5 above the air quality standards. The reactive compounds are thought to have several short and long-term health effects. The short-term effects are wheezing, coughing, shortness of breath, and sore eyes/throats. The long-term problems are making people more prone to infections; triggering asthma attacks, heart attacks, and strokes; and leading to premature death. Anyone with cardiovascular or respiratory issues, the elderly, and children are most vulnerable to wildfire smoke. For the elderly or those with existing cardiac or respiratory problems, the fine and ultrafine particles in smoke can aggravate chronic diseases. Children’s airways are still developing and they often spend more time outdoors than adults, so they’re more likely to inhale more smoke. A concerning factor is that emerging research suggests children and babies are particularly vulnerable to long-lasting health effects. Recent work shows that exposure to wildfire smoke may alter their immune systems for years, or even permanently. Stanford University researchers tested the blood of 36 children exposed to wildfire smoke in Fresno in 2015. They found changes in a gene helps with the development and function of T cells (an important component of the immune system). The alteration put the children at greater risk of developing allergies or infection. The long-term effects of these changes are not known yet. This is why researchers at the University of California, Davis are planning a longitudinal study of the long-term health impacts by following some of the recently exposed individuals.

Another area that is being examined is the impacts that wildfires are having on animals because scientists feel that those who survived previous blazes can help us better understand long-term effects on humans. For example, a new study done at the University of California, Davis found that cats who survived the Tubbs Fire in 2017 and Paradise Fire in 2018 wound up with heart problems. From the two fires, there were 51 cats rescued and over 50% developed heart muscle thickening, which could lead to an enlarged heart or congestive heart failure. Another 30% either had blood clots or were at higher risk of developing blood clots, which could result in a stroke or sudden death. A different study at the University of California, Davis is focused on rhesus macaques that live in an outdoor enclosure at the California National Primate Research Center who were exposed to smoke in June and July of 2008. The monkeys were exposed to 10 days of PM2.5 levels that exceeded the 24-hour air quality standard set up the Environmental Protection Agency. Since rhesus monkeys give birth in the spring, this means that the babies breathed in the polluted air. By three years of age (adolescents, by monkey standards), researchers found that those exposed to wildfire smoke produced less of an immune-related protein when compared to monkeys not exposed to smoke as babies. That protein triggers inflammation to fight pathogens. A closer look at the genes of a subset of these adolescent monkeys revealed immune-related genetic changes that stay with that cell for its entire life. Some of the female monkeys have even passed on the genetic changes to their offspring. However, the researchers did find that these changes were not seen in monkeys exposed to smoke as adults.

Another area that isn’t often addressed following a wildfire is mental health. This is worrisome since psychological recovery is one of the most challenging problems. Even for those who have been spared the imminent danger and acute fear of death from the fire, experience trauma. The loss of homes, livestock, and pets have a significant consequence. Per the National Center for Post-Traumatic Stress Disorder, 10-30% of wildfire survivors develop diagnosable mental-health conditions, such as PTSD and depression. An additional 50% can suffer from serious subclinical effects that fade with time. An added factor is that research has shown that substance abuse and domestic violence increase after natural disasters. Many wildfire survivors say they feel fragile and less capable of managing stress for years after. Studies have shown that the ongoing personal, logistical, and financial difficulties that accompany the aftermath lead to depression. These problems also make it more challenging for individuals to put the trauma behind them. When a whole neighborhood or town feels these effects at the same time, the result is community-wide trauma. While most survivors make a full recovery, many require formal treatment. The obstacle is that it’s becoming harder for people to recover because the areas that are prone to wildfires now have them in quick succession, so one trauma is building upon the previous without enough time for healing to occur.

A study done by researchers at the University of Washington and the Nature Conservancy in 2018 shows that wildfires disproportionately impact low-income communities. In a 2017 report, the Substance Abuse and Mental Health Services Administration found that less wealthy, less educated survivors are more likely to suffer from depression or PTSD in the aftermath of disasters. These communities lack resources, which means that their recovery is not equal to that of wealthier ones. For example, Lake County is one of the poorest in California, with a median household income of just over $40,000 a year and a poverty rate just below 20%. It’s ranked as one of the top counties in the state for annual opioid deaths, almost 14% of residents have a disability (over twice the state average), and it has limited internet and computer accessibility. According to a 2015 survey from the Medical Board of California, the county doesn’t have a single psychiatrist who provides patient care for at least 20 hours a week. The physical and psychological impacts of a wildfire in this area has been far more devastating than other areas that have more resources. After the 2017 Wine Country Fires, the Legal Aid of Sonoma County asked prospective clients to fill out a mental-health intake survey. If a person scored 15 or higher, it indicated that they needed mental health support. The office analyzed the 50 assessments it had collected in the year and a half after the fire and just one person scored below a 15.

With COVID-19, there’s a strong potential for interaction between it and wildfires because both the smoke and the virus take a toll on the body’s respiratory and cardiovascular systems. There are several ways that smoke exposure could make the pandemic worse. One primary concern is when your immune system is overwhelmed by particles from smoke, it’s not going to do a good job fighting infections, like the coronavirus. Also, the particles stick to the hair-like cilia that cleans your lungs, making it harder for them to clear out pathogens. There’s some proof that the immune system effects can linger for months because a recent study done in Montana discovered that smoky summers led to more severe flu seasons the following winter. Another problem is that wildfires often necessitate massive evacuations of people to shelters. This type of interaction among people could increase the number of people who contract the virus.

Preparation is vital, especially for vulnerable individuals. With community clean air shelters being risky as the result of the pandemic, public health officials are advising that people stay home with windows and doors closed as much as possible. If your house has forced air, the Centers for Disease Control and Prevention recommends installing a filter that will scrub out harmful particles. The filter should have a MERV rating of 13 or higher. You should also set your system to recirculate. If you can’t do this, select one room of your home, ideally the coolest, and use a portable air cleaner. If you’re out, cloth face coverings can help prevent the spread of coronavirus, but they don’t protect you from the smoke. The only mask that does is a properly fitted N95 respirator. Unfortunately, they’re in short supply in many places.

With wildfires becoming more frequent due to climate change, it’s essential to have a better understanding of the harm they can cause. This is why studies looking at identifying the health effects of smoke and mental health impacts are vital. In the meantime, all of us need to do our part to mitigate the risk of wildfires developing. One important aspect is to encourage state and federal agencies to practice better forest management techniques. Another element is to do what we can to slow the progression of climate change. It’s also vital to take individual steps to protect yourself and your loved ones. Wildfires are extremely dangerous, not only to those in their direct path but to everyone, which is why we all should be concerned.