Dr. Mark Boos

Mark Boos

How are children affected by climate change?

Dr. Mark Boos, pediatric dermatologist, Seattle Children’s: We are all affected by the changes in our natural environment that have been precipitated by the climate emergency our world is experiencing secondary to elevated atmospheric carbon dioxide levels. But 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 children, the elderly and individuals with disabilities. Currently, it is estimated that 88% of the existing global burden of disease secondary to climate change affects children less than 5 years old.

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. Children have an immature physiology and metabolism that prevent them from optimally regulating their temperature. Additionally, children have a greater challenge in clearing inhaled or ingested pollutants, while simultaneously having an increased exposure to these agents (per unit body weight) in air, food and water. Furthermore, their distinctive behavior patterns (i.e., spending more time outdoors) and dependence on adult caregivers place children at much higher risk of climate-related health burdens than adults. Specifically, children may suffer from impaired lung development, asthma exacerbations, 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.

How do we know that global warming and climate change are occurring?

Dr. Boos: Atmospheric carbon dioxide has increased from 280 ppm before the Industrial Revolution to 415 ppm today, the highest it has been in the past 3 million years. The 20 warmest years on record globally all occurred in the last 22 years, with the past 5 years being the warmest. Carbon dioxide is known to be a potent greenhouse gas, and its increased presence in the atmosphere is secondary to human consumption of fossil fuels (i.e., it is an anthropogenic phenomenon). Currently, climate scientists can say with 99.9999% accuracy that human activity is the cause of global warming.

I think it is also important for us to recognize that 10% of U.S. greenhouse gas emissions come from the healthcare sector. We are literally the problem, and if we seek to abide by the Hippocratic Oath, then we must demand changes to the way we power our hospitals and clinics and provide quality care. We can also be the solution to this crisis.

What conditions involving the skin are exacerbated by climate change?

Dr. Boos: A variety of skin diseases appear to be worsened by climate change. This includes inflammatory disorders such as atopic dermatitis (eczema) and pemphigus (an autoimmune blistering disorder), as well as infectious diseases that benefit from warmer climes and an expanded vector habitat. While the effects of UV exposure, humidity and temperature on atopic dermatitis are not clear, air pollution is known to cause flares of atopic dermatitis. 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 presenting with flares of their eczema. We also know that emotional stress causes conditions such as atopic dermatitis, vitiligo and psoriasis to flare; this would be expected in populations that have been affected by natural disasters.

Infectious diseases that affect the skin are also on the rise because of environmental 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 (deer and mice). Non-cholera Vibrio spp. of gram-negative bacteria live in brackish waters and are temperature sensitive. In our warming world, Vibrio has now been identified in Alaskan waters, causing skin bullae, ecchymoses and necrosis via direct inoculation or ingestion of shellfish and other marine organisms. As a result of more favorable temperatures, the incidence of mosquito-borne viral illnesses such as dengue, Zika and Chikungunya are increasing in parts of the south and southwest United States, while increased temperature and humidity also result in more cases of hand, foot and mouth disease from enteroviruses. Coccidioidomycosis (“Valley fever”) is a fungal infection that is contracted via inhalation and, while often asymptomatic, can cause disfiguring skin lesions and sometimes death if the fungus disseminates throughout the body. Historically, Coccidioides species were endemic to the southwestern United States, but there are now reported cases in southeast Washington, which is attributable 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.

I have heard that some sunscreens are better for the environment than others. Is that true?

Dr. Boos: 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. That being said, some use of sunblock is unavoidable. Although chemical sunscreens (containing oxybenzone, octinoxate, octocrylene, avobenzone and other similar active ingredients) remain safe for use, concerns have been raised 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. This has potential implications for the environment, as well as human health, as these products become “biomagnified” up the food chain; nevertheless, no obvious adverse health effects have been reported in humans. There is also some evidence that certain chemical blockers may hasten coral reef bleaching.

Physical sunscreens containing zinc oxide or titanium dioxide (“mineral sunscreens”) are an alternative to chemical blockers and are also FDA-approved as safe and effective. Concerns have been raised about these physical blockers, however, as they are known to cause pulmonary irritation and can produce damaging free radicals upon exposure to UV light. Nevertheless, they are not thought to penetrate deep enough into the skin to cause damaging local or systemic effects, though patients are advised not to place it on open or badly inflamed skin, as this may result in absorption.

Bottom line: Avoid any sunscreens if you can by seeking shade and covering up, but if you plan on being in the sun, the American Academy of Dermatology recommends regular sunscreen use. While both chemical and physical blockers appear safe for use in humans, physical blockers appear to have less detrimental effects on the environment.