DANGER IN THE WORKPLACE

Occupational associations of skin cancer

Feature

By Emily Margosian, Assistant Editor, March 1, 2023

In 1775, English physician Sir Percivall Pott made history, publishing the first report of cancer caused by occupational exposure. Pott had noted an unusually high incidence of skin sores on men working as chimney sweeps in 18th century London, which he attributed to the accumulation of carcinogenic coal soot in their clothes. 

Nearly 250 years later, medicine's understanding of occupational cancer risk continues to expand, as studies draw connections between elevated on-the-job UV and chemical exposures and increased rates of melanoma and non-melanoma skin cancers. "Occupational cancer is probably more widespread than we think," said Massachusetts dermatologist Christine Kannler, MD, FAAD. "Most physicians will ask patients about family history, sexual history, and travel history, but few ask about occupation. Many occupations, such as firefighters, petrochemical workers, asphalters, or roofers, likely have on-the-job exposures that are playing into some of their health concerns." 

This month, dermatologists discuss what we know about occupational skin cancer risk, and their recommendations for mitigation and prevention measures for high-risk professions. 

Firefighters

While firefighters face a host of dangers on the job, data reveal cancer as a potentially hidden hazard. A 2014 National Institute for Occupational Safety and Health (NIOSH) study of 30,000 firefighters across the U.S. found that firefighters have a 9% higher incidence of cancer and a 14% higher mortality rate compared with non-firefighter cohorts (doi: 10.1136/oemed-2013-101662). Other studies examining melanoma risk among firefighters have found a higher rate of melanoma compared to non-firefighters, particularly between the ages of 30 and 49 years of age (doi: 10.1136/oemed-2013-101803). "That is alarming, because in America, the typical person who gets melanoma is usually a 65-year-old Caucasian male," said Dr. Kannler. 

In 2017, Dr. Kannler began researching occupational cancer risk among firefighters and hosting skin cancer screenings for fire departments within the Boston area. "For me, it's a very personal topic. My brother was a firefighter in Massachusetts and was diagnosed with esophageal cancer at age 36. He passed away a year later at age 37. I had suspected there was a tie between firefighters and occupational cancer, but it wasn't until I started looking through tons of literature that it became evident there was a statistically significant connection." 

According to Dr. Kannler, common risk factors include chemical exposures and carcinogens from soot. The former is of increasing concern to cancer researchers as building materials have shifted over time from natural elements such as wood and metal to more synthetic materials. "A kitchen fire started in a teflon frying pan might not seem that scary compared to an airplane exploding on a runway, but the PFAS (Per- and polyfluoroalkyl substances) that are aerosolized in that kitchen pan are extremely dangerous known carcinogens," she explained. 

Skin absorption levels during fires may also play a role, Dr. Kannler suggests. "When you think about the skin, as soon as that alarm bell rings, their endorphins are going, they start sweating, and are running to get to the engine. Once they're at the fire, they're lifting heavy objects and physiologically, their blood vessels are dilating, and the blood to the muscles and their pores are dilated as well. Studies have found that when a firefighter is performing, the skin around the jawline has 100 times more absorption compared to when they're not fighting a fire." 

In response to emerging research on cancer risk and incidence among firefighters, in 2022 the International Agency for Research on Cancer reclassified the occupation of being a firefighter to the highest hazard category as a group one carcinogen. "That's important for a few reasons," said Dr. Kannler. "When they look at occupational exposure, there are five different mechanisms that can be found in causing cancer, and the occupation of firefighting has all five of them." 

For the past several years, Dr. Kannler has organized local skin cancer screening events for firefighters and has been involved with efforts to broaden outreach to other parts of the United States. "My goal was to take the AAD's Spot Skin Cancer™ screening program to the firehouse," she said. "I'll screen at fire departments and educational conventions with other dermatologists. We also educate firefighters about melanoma and their risk. There are certain things they can do at the scene, like using wipes to get the soot off their face, washing their gear as soon as they get back, and taking a shower. After the full screen, if they need follow-up care we will connect them with a list of local dermatologists."

According to Dr. Kannler, taking screening efforts directly to firehouses and educational conferences has yielded several success stories over the years. "I've found a lot of stage one melanomas, and a stage three melanoma at a union meeting on a firefighter who wasn't going to do the screening originally and was convinced by her colleague because it was free at the conference," she recalled. "This further illustrates that bringing the screenings to them is where you're going to get the most buy-in because of their personalities. These are people who run into burning buildings, so they're used to taking care of other people versus taking care of themselves. In many ways, it's a similar outlook that we have sometimes as physicians." 

Dr. Kannler recommends regular skin cancer screenings as a primary prevention measure for firefighters. "I would say they should do it annually, unless something's found. Since studies have indicated that melanomas can occur in the ages of 30 to 49 in firefighters, they might want to start at age 30 or even a little bit before that. It would be great if we could have more dermatologists screen their local firefighters and develop a long-term relationship, because these folks are at high risk." 

Dermatologists from any state who are interested in volunteering can contact Dr. Kannler at MassFFDerm@gmail.com or visit the Massachusetts Occupational Cancer in the Fire Service page. For more information about screening opportunities, visit the National Firefighter Cancer Support Network or contact Russell Osgood at rosgood@fcsn.net. 

Military members

Like firefighters, while veterans and active-duty military members regularly face dangerous conditions in the line of duty, they also experience greater occupational risk in the form of increased incidence of cancer. A JAAD systematic review found that active-duty military members and veterans in the United States are at an elevated risk for melanoma and non-melanoma skin cancers, with the trend present across nine decades dating back to World War II (https://doi.org/10.1016/j.jaad.2017.11.062). 

Wisconsin dermatologist Jerry Miller, MD, FAAD, who served in the first Gulf War, says he has also observed this trend among his own patient population. "Currently, I don't see a lot of active duty, but I do have patients who are veterans, and yes, there is a general trend of increased incidence of skin cancer among that population."

According to Dr. Miller, increased UV exposure during deployment is likely the biggest risk factor faced by members of the military. "When you conduct operations close to the equator, you're going to get increased levels of ultraviolet exposure. There was a study done on military members coming back from Iraq and Afghanistan which found 64% of personnel spent about 75% of the day in bright sunlight, and only about 30% had routine access to sunscreen." 

"I certainly think occupational sun exposure is probably the number one risk factor for people in the military," agreed Jonathan Bingham, MD, FAAD, who has 32 years of military experience and currently serves as a flight surgeon in the Montana Air National Guard. "There are areas in the world — what we would call theaters of operation — where UV exposure can be very significant, for example, in places like the Middle East and Africa. Additionally, there are some restrictions or inability to practice good sun protection, whether it be just not having access to things like sunscreen or sun protective clothing, or the servicemember not prioritizing sun protection as something that's important in an operational setting."

Within the military, data suggest that skin cancer risk is even more elevated among members of the Air Force. A 2021 study found that Air Force pilots and their crews were 24% more likely to be diagnosed with melanoma compared to their non-aviator peers (doi: 10.1097/JOM.0000000000002353). This increased risk is likely due to prolonged exposure to cosmic ionizing radiation, according to Dr. Miller. "In aviation, when you go up in altitude, you're exposed to more radiation. If you take a domestic commercial flight from coast to coast in the United States, you get the equivalent of about one chest X-ray. If you're spending more time at altitude as a fighter pilot, you're netting more exposure." 

With the passage of the Promise to Address Comprehensive Toxics (PACT) Act in 2022, increased attention is also being paid to toxic exposures during military service and their potential impact on cancer rates among veterans. "I was deployed as the division surgeon with the 2nd Armored Division during the first Gulf War. We were the first American unit in Iraq prior to the actual ground war, so we experienced lots of things — oil well fires, the threat of chemical weapons, depleted uranium intracorporal exposure, and other toxicities such as exposure to chemical agent resistant coating paint," said Dr. Miller. "Any time you put the military in the field, especially in remote places, there is no public sanitation. Humans generate waste. Liquid waste is somewhat easy to take care of. It's the solid waste that's the issue." 

Often, waste disposal in deployment settings involves the use of burn pits. "They're used to burn massive amounts of waste in an open-air fashion without an incinerator," explained Dr. Bingham. "Usually, jet fuel is used as the ignition source for burn pits. Sometimes they'll be referred to as garbage fires as well. There is just a myriad of items that will go into these burn pits. You name it; it's probably been put into a burn pit. As a result, we are learning now that there are multiple potential toxins and carcinogens that are released as part of these burn pits, which are being associated with an increased risk of cancer." 

Dr. Bingham recommends that if a dermatologist has concerns about a veteran patient's skin cancer and whether it might be related to military service, they should refer to the VA for an assessment to determine if the condition is service connected. "This is an ever-changing point of concern for the Veterans Administration," he said. "Whether it be Agent Orange exposure or burn pits, the VA is constantly reassessing scientific data as to whether or not it could be related to service." 

Despite some practical limitations, military members do have some options for mitigating their UV exposure. "When you're in a deployed setting the issued uniforms generally do a good job at giving UV protection, provided that they're being worn in the correct fashion with the sleeves down," said Dr. Bingham. "There are also what are called boonie covers, which are a type of a wide-brimmed hat. Provided that their command allows it, members can wear that boonie style to offer some sun protection."

Dr. Miller also recommends regular screening for active-duty military members and veterans. "Ideally, one should be surveilled at least once a year, but if they have a history of anything precancerous or cancerous, that should be moved up," he said. "I think the biggest thing in terms of mitigation is making individuals aware of their risk. Only 30% of veterans self-report that they have sought a screening, so word needs to get out that they have an increased risk of skin cancer. The data compel people to get screened initially and then on a regular basis. I think it's important for us to encourage our military veterans to be screened by a physician, especially a board-certified dermatologist, because the sooner we can detect a malignancy, the easier it is to treat, and the better the overall outcome." 

Pilots and flight crew members

Data have also suggested that prolonged time spent among the clouds may carry unique risks regarding skin cancer. In a 2018 study, flight attendants were found to have higher incidences of cancer than members of the general population, including melanoma and non-melanoma skin cancer. The study also found that among female flight attendants in particular, elevated incidence of breast and skin cancer was especially pronounced. 

Among pilots, a JAMA meta-analysis found that pilots have approximately twice the incidence of melanoma compared with the general population (doi:10.1001/jamadermatol.2014.1077). According to Dallas dermatologist Jerald Sklar, MD, FAAD, these findings reflect what he has observed in his own practice. "I live in the Dallas-Fort Worth Metroplex which is the headquarters for both Southwest and American Airlines, and over my 30-plus years as a dermatologist, I've treated quite a few pilots. I definitely see them as a high-risk group compared to my regular patient population." 

Like military pilots, commercial airline workers are exposed to increased levels of UV exposure and cosmic radiation. "Airplane windows block UVB but not UVA rays, and then there's also the ionic or cosmic radiation that flight crews are exposed to at higher altitudes," said Dr. Sklar. Studies have also speculated that disruptions in circadian rhythm due to chronic jet lag and extended time spent sunbathing in tropical climates on days off may also be contributing factors to increased incidence of skin cancer among flight crew workers. However, "these are all just theories that might play a role beyond the basic premise of increased UV radiation," according to Dr. Sklar.

While some planes are outfitted with window shade screens to help filter sunlight, Dr. Sklar recommends that pilots try to mitigate their risk further with sunscreen application and sun protective clothing. "It's similar advice to what we'd give to outdoor workers and other professions who spend a lot of time outside," he said. "I'd also recommend more frequent skin screening, like other high-risk patients. If they're a pilot, they probably should come in to get checked yearly, and if they've ever had skin cancer, they should be seen more often." Dr. Bingham agrees that pilots and flight crew should focus on practicing good sun protection inside and outside the cockpit. "Pilots generally don't think about sun protection being important at their current stage of career, but being mindful that they have an increased risk is important," he advised. "One thing pilots love to do is fly, and they don't want anything to jeopardize that. I'd recommend that if they have any concern about a potential skin cancer, that they should reach out and get assessed."

Sent from my iPhone

Benjamin Hidalgo-Matlock
Skin Care Physicians of Costa Rica

Clinica Victoria en San Pedro: 4000-1054
Momentum Escazu: 2101-9574

Please excuse the shortness of this message, as it has been sent from
a mobile device.