The environmental damage we cause by continuing to burn fossil fuels affects children most, including yours. While the studies on climate change are still emerging, there has been enough research to result in a broad scientific agreement that climate change is negatively affecting children’s health. In fact, one study estimated that about 88 percent of the disease from climate change afflicts children.

As an emergency medicine physician in Boston seeing these consequences, I have had a growing realization that my responsibility to protect my patients, especially vulnerable groups such as children, has to also include speaking up about the forces that impact them outside of the hospital.

Frederica P. Perera, a professor of environmental health sciences and director of the Columbia Center for Children’s Environmental Health, recently released a review article showing yet again how air pollution and climate change interact to multiply the negative health effects children face.

The truth is gravely startling. Ever since the industrial revolution, we've been dependent on fossil fuels to make energy. In 2011, 82 percent of our energy came from fossil fuels. Fossil fuels are largely coal and natural gas but also include diesel fuel, gasoline, and oil. A broad range of air pollutants are created when these are burned to produce electricity or heat or used in transportation and industry.

These pollutants include a laundry list reminiscent of chemistry class, including fine particulate matter, black carbon, polycyclic aromatic hydrocarbons, mercury, nitrogen dioxide, sulfur dioxide, carbon monoxide, sulfate, nitrates, and ozone. Combustion of fossil fuels also produces carbon dioxide, or CO2, which is the biggest driver of climate change.

A multiplier effect

The combination of air pollutants and warmer temperatures creates a perfect storm where they interact to multiply the effects that each would have alone. For example, Perera writes, the warmer environmental temperatures created by climate change causes the chemical reaction that forms ozone, an air pollutant with many negative health effects, to happen faster and more frequently. This increases ozone, which increases the negative health effects. Another example is that the concentration of small particles of pollutants increases as climate change alters temperature and precipitation cycles (i.e. floods and droughts) and creates stagnant air.

People of all ages are exposed to this myriad of air pollutants in the changing climate, but children are more at risk of a wide spectrum of negative health effects because their developing bodies can suffer permanent damage from interference with their growth.

When children begin growing in the womb, they are especially susceptible to any factors that may alter the formation of their body. For example, a fetus develops nearly all of its 86 billion brain cells there. And cell development is very sensitive to exposures that may damage genes.

Once a child is born, the brain, lungs, and immune system aren’t fully formed until the age of six. Even their air and food exposure in proportion to their size is much higher than adults – the amount they eat in relation to their body weight is three to four times greater than that of adults. Young children also have no control over what they get exposed to – they must rely on their adult caretakers to keep them safe.

We all instinctually seem to recognize this vulnerability; there is a nearly universal core response to protect children from suffering. This is often the starting foundation that allows me to immediately bond with parents while on a shift in the emergency department. Any shift could provide examples, but there are always some encounters which remain with you.

One memorable couple was Megan and Rashad*. After entering the exam room, I found Megan resting her hand softly on her growing belly as her other hand tightly gripped that of her husband. Before she discussed the urination issue the triage note described, she sheepishly confessed that this was her first pregnancy and apologized if she was being overly cautious. After I provided reassurance, Rashad began to tell me how worried he was about her going out in these hot summer days.

“I know that we can’t protect our son from everything in this world, but we want to try to make it as perfect as possible while he is still in there,” he said as he gestured to his wife’s belly. He gave Megan’s hand a squeeze as they looked tenderly at one another.

He's not wrong to worry. When a fetus is exposed to air pollution, they are at increased risk of having a low and unhealthy birth weight, being smaller in size, or dying. Certain air pollutants have been found to affect the development of the brain and nervous system. Children also have an increased risk for being developmentally delayed, having lower intelligence scores, and less of a certain part of the brain called white matter, the stuff that helps you walk and talk. Their mental health is also at risk as children exposed to air pollution have higher rates of anxiety, depression, and difficulty paying attention.

Another unforgettable encounter was with Devon, a four-year-old boy with asthma who came to the ER with difficulty breathing. Devon’s mother was perched nervously at the end of her seat next to the oversized stretcher that seemed to dwarf her little boy. I made a funny face at him, and he smiled playfully despite having such labored breathing. The oxygen and medication in his face mask filled the room with a hissing noise as they tried to re-open his air tracts. I handed his mother a tissue as tears began to form in the corner of her eyes.

“He has so many of these breathing attacks now," she whispered. "This is his third this week. Something is changing. I am afraid to even let him go outside anymore."

Young lungs are also at risk for wheezing as the increased CO2 in the air causes plants to produce more pollen. Air pollution can also cause serious issues; it has been found to reduce lung function even in children without a diagnosed lung disease like asthma. Researchers have found that children exposed to higher levels of air pollution earlier in life have reduced function at the age of 18, when the lungs are nearly mature, without an ability to recover; these children have reduced lung function for the rest of their life. Some research suggests that exposure to air pollution in the womb or early in life can actually cause asthma.

Climate change can also cause children to suffer from malnutrition and from infections. A 2014 study by environmental health scientist Samuel Myers at Harvard found that increased CO2 in the air causes crops to have less nutrition. This can have serious implications if food is already scarce. And children are more at risk for infectious disease due to factors such as immature immune systems. Since climate change is worsening malaria and diarrheal illnesses, children's' risk of contracting them keep growing.

As though these examples of the biological repercussions of air pollution and warming weren't enough, they are also causing more extreme weather, which can lead to children dying from physical trauma, like drowning. Globally each year between the years of 1990 and 2000, 66.5 million children were affected by extreme weather, and 600,000 died.

Society's toxic environment

It's impossible to research these effects using the standard experiment setup that includes groups experiencing different conditions, because that would require an unethical design, such as exposing one group of children to a known air pollutant and not another group and then measuring the incidence of the health outcome. Thus, in public health these association studies are enough for action, especially when one considers the precautionary principle. This states that when harm to other humans is plausible, actions should be taken to reduce it.

An example of one of these research studies cited in Perera’s paper was completed by C. Arden Pope III, an economist at Brigham Young University, in the late 1980s. Data on the health of the residents of the Utah Valley was collected from the time period before, during, and after a nearly three-year closure of a local steel mill. Since the steel mill was the primary source of pollution in that region, the amount of air pollution the citizens were exposed to was much lower during its closure. The findings showed very clear associations: more people suffered from the effects of air pollution when it was open.

Meanwhile, back on shift, I check in on Devon to see if his breathing is improving with treatment. His mother smiles warmly as I enter, prying her eyes away from the TV screen. “Have you seen the news about these forest fires out west? I have never seen fires so bad,” she exclaims. Their frequency and intensity are worsening with the warmer temperatures of climate change and droughts that decrease soil moisture. The air pollution caused by these fires can travel far distances and affects everyone’s lungs. I shake my head as I imagine the havoc the fire pollution would cause on Devon’s lungs, which are still filled with high-pitched wheezes.

As I say goodbye to Rashad and Megan, Megan informs me that she had given up smoking a year ago in preparation for her pregnancy. I excitedly reinforce her decision as she reaches her right hand above her head to give me a high five. As I watch them walk towards the double doors, I sigh as I think of the all of the fossil fuel pollutants in the air that may in fact be worse than the cigarette smoke she so excitedly discarded for the sake of her unborn child. While they rightly want to do everything they can to create a perfect environment for their child, we as a society are creating a toxic one.

At the end of my shift, I myself pass through those double doors and into the muggy city air. I know that as long as the burning of fossil fuels spews forth more air pollution and climate change, I will continue to see exponentially more children suffering lung problems as parents' goal of creating a perfect environment for their child to develop in becomes more impossible to achieve. Instead, I will see more and more child illnesses from fossil fuel. It is the children in my life, as well as my patients, that spur me to action. Unless we make drastic changes now, this harm is unavoidable.

*Identifying details have been changed to protect patient privacy.