Editor's Note: This story was originally published on April 5, 2017 and has been updated.
In a suspected chemical weapon attack, like the one in Syria over the weekend, children are the most vulnerable targets. They are more likely than adults to die from chemical agents and to suffer injuries. If they survive, they also suffer from the physical and mental trauma of the attack for far more years than adults simply because they have more years left to live.
The alleged chlorine gas attack that was reported in Douma, in the eastern part of Ghouta, a suburb of Damascus, killed 43 people, according to the Syrian Civil Defense, a pro-opposition group also known as the White Helmets. The number of deaths is still being verified and the number of children killed remains unknown as of this report.
This is not the first time that chlorine gas has been used in the Syrian war. It was reportedly used in Idlib in February, according to the Associated Press. Ghouta was also the site of a sarin missile attack in August 2013, when at least 280 people were killed.
Dr. Sandro Galea, an emergency physician and epidemiologist at Boston University, noted that there is abundant evidence that the health consequences of ongoing trauma like the Syrian war are cumulative. "One fanciful mistake that we sometimes make is thinking, 'Well, multiple exposures, they inoculate us for the next one.' That's not right. The evidence is clear that more of a bad thing is worse," he says.
The effects are especially damaging for children. The exposures to traumas, be it chemical or physical attacks, will "result in children having reduced capacity for a full range of adult functioning, he says. "This is changing the developmental trajectory and the potential of a whole generation."
Chemical weapons are more devastating for kids for a number of reasons. "Because kids are smaller, there's a higher impact on a smaller body," says Dr. Steven Hinrichs, director of the Center for Biosecurity at the University of Nebraska Medical Center. A smaller dose of a chemical agent can do more damage to their organs. If the agent is sarin gas, a victim's lungs and airways can fill up with fluid, causing suffocation. Children would die faster than adults because a child has smaller airways and a smaller chest.
"Children have fewer defenses," says Galea, who has studied mass trauma and conflict globally. They can't run away as quickly from the site of a chemical attack. And once the chemicals enter their system, their immune systems are less mature and not as good at fighting them off. "It makes them more vulnerable, immunologically and physically," he says.
In early April 2017, 20 children were among the 72 civilian casualties from an air raid accompanied by the apparent chemical attack on the rebel-held city Khan Shaykhun in Idlib province in Syria, according to the Syrian Observatory for Human Rights.
Moreover, if children survive a chemical attack, they will live with the long-term effects far longer than, say, a 50-year-old. Survivors often have lifelong problems with fine motor skills like writing or cutting paper accurately with a pair of scissors. They often have gross motor disabilities as well, such as problems with their walking gait — trouble balancing or coordinating the movement of walking — and with the hand-eye coordination necessary to play sports or do many kinds of physical paid work.
The impact of chemical attacks can be mental as well as physical, although it's difficult to tease out the effects of nerve damage from post-traumatic stress disorder since symptoms sometimes overlap. Researchers believe that chemical attacks, like other violent attacks, can lead to PTSD and severe depression for survivors of all ages.
It's also difficult to separate the impact of a single attack, chemical or conventional, from the larger trauma of living through a war.
"Toxic stress affects brain development, learning and the social emotional ability to regulate one's own behavior," says Lindsay Stark of Columbia University, who studies childhood trauma in refugee and conflict settings.
But children are also incredibly resilient, Stark says. Child soldiers in war-ravaged African countries didn't turn out to be a lost generation as mental health professionals feared, she says. Many learned to cope with their traumatic pasts and went on to have productive lives.
She cautions against pessimistic outlooks for Syria's children. "We have to be careful in terms of how we talk about this generation," she says. "All hope is not lost."
But, she cautions, the longer children remain in conflict settings, the more challenging it can be to counteract the trauma they live through. Parents need to be able to buffer children from the chronic stress of war by creating a sense of normalcy with routines like going to school every day.
"It's the best thing parents can do," Stark says. But in war-torn countries like Syria, she adds, "it may be just not possible."
Rina Shaikh-Lesko is a science journalist who writes about medicine, global health and the life sciences. She can be reached @rinawrites