Climate Change Effects on Skin: A Q&A With Dr. Markus Boos

Dr. Markus Boos, a pediatric dermatologist at Seattle Children’s, with one of his sons.

Climate change, a result of elevated carbon dioxide levels, leads to environmental changes that affect everyone, says Dr. Markus Boos, a pediatric dermatologist at Seattle Children’s. The 20 warmest years on record globally all occurred in the last 22 years, with the past 5 years being the warmest. While natural disasters such as wildfires, hurricanes and other forms of extreme weather can cause lasting physical, mental and emotional harm to all people, specific populations are more adversely affected. This includes the elderly, individuals with disabilities and children.

These major environmental changes put children’s health and safety at risk, according to the American Academy of Pediatrics. Recent reports have estimated children under age 5 bear 88% of the burden of disease due to climate change. On the Pulse talked to Boos about how climate change impacts skin conditions in children, and how parents can protect their kids from ultraviolet (UV) radiation.

Q: How are children affected by climate change?

A: Children are uniquely vulnerable to changes in the environment, specifically to extreme changes such as heat waves and air pollution that are worsened by climate change. Since their bodies and metabolism are still developing, children are unable to regulate their temperature well. Compared to adults, children are exposed to more pollutants in air, food and water. At the same time, they have a greater challenge in clearing inhaled or ingested pollutants. Kids just being kids, such as spending more time outdoors, and dependence on adult caregivers also place them at much higher risk of climate-related health burdens than adults.

Specifically, children may suffer from impaired lung development, increased asthma symptoms, worsening allergies and malnourishment as a result of climate change. Post-traumatic stress, physical injury, disruptions in education and loss of a stable home environment are additional ways that children can be negatively affected by natural disasters.

Q: What skin conditions are made worse by climate change?

A: A variety of skin diseases appear to be worsened by climate change. This includes inflammatory disorders such as eczema (atopic dermatitis) and pemphigus, an autoimmune blistering disorder. While the effects of UV exposure, humidity and temperature on eczema are not clear, air pollution is known to cause eczema flares. Anecdotally, I have seen in my own clinics that the warmer spring in Seattle, and presumably elevated pollen levels, causes an increased number of patients with eczema flares. We also know that emotional stress causes conditions such as eczema, vitiligo and psoriasis to flare. This would be expected in communities that have been affected by natural disasters.

Infectious diseases that affect the skin are also on the rise because of global warming. Specifically, an increase in Lyme disease is thought to be related to warmer environments that are more favorable to tick survival, as well as a greater availability of hosts like deer and mice. In our warming world, a group of temperature-sensitive Vibrio bacteria has now been identified in Alaskan waters, causing skin injury and in some cases death via exposure to shellfish and other marine organisms.

As a result of warmer temperatures, mosquito-borne viral illnesses such as dengue, Zika and Chikungunya have been identified in parts of the south and southwest United States and are expected to increase with time. Increased temperature and humidity also result in more cases of hand, foot and mouth disease from enteroviruses. Valley fever (coccidioidomycosis) is a fungal infection contracted via inhalation that can cause disfiguring skin lesions and sometimes death if the fungus spreads throughout the body. Historically, Coccidioides species were regularly found in the southwestern United States, but there are now reported cases in southeast Washington, which has been attributed to climate change.

Finally, elevated temperature and UV light exposure, as well as damage to the ozone layer, are thought to put people at increased risk for various skin cancers.

Q: Is it true that some sunscreens are better for the environment than others?

A: There are many perspectives on how to best protect ourselves and our children from the harmful effects of UV radiation. As a dermatologist, my recommendation is to wear sun-protective clothing and seek shade or avoid the sun at peak hours (10 a.m. to 4 p.m.) to limit the need for sunscreen. Still, if you plan on being in the sun, use sunblock.

Although chemical sunscreens (containing oxybenzone, octinoxate, octocrylene, avobenzone and other similar active ingredients) remain safe and effective for use, some have raised concerns about their environmental impacts. Specifically, water that has been treated for reuse often still contains these compounds, as wastewater treatment plants are unable to filter them. As a result, these chemical UV filters have been found in water sources as far away as in the Arctic and in chlorinated pools, as well as in marine organisms. Although these chemicals do not have widely recognized adverse effects, their continued use has unclear implications for environmental and human health, as these products become increasingly concentrated at higher levels in the food chain. There is also some evidence that certain chemical blockers may increase the speed of coral reef bleaching, though these studies are not definitive.

Sunscreens containing zinc oxide or titanium dioxide, also known as “mineral sunscreens” or physical blockers, are an alternative to chemical blockers and are also  approved as safe and effective by the Food and Drug Administration. However, concerns about physical blockers are that they are known to cause lung irritation and can produce damaging free radicals upon exposure to UV light. However, they are not thought to penetrate deep enough into the skin to cause damaging effects, though people using them are advised not to place these sunscreens on open or badly inflamed skin, as this may result in absorption.

Bottom line: Seeking shade and covering up are the most effective ways to prevent skin damage from the sun. However, if these are not reasonable options and you plan on being in the sun, the American Academy of Dermatology recommends regular sunscreen use. While both chemical and physical blockers are considered safe for use in humans, physical blockers appear to have less detrimental effects on the environment.