The number of calls to poison control centres for nicotine poisoning from e-cigarettes has risen dramatically in recent years, according to US health officials.
Calls related to poisoning from the liquid nicotine used in these devices were running at a rate of roughly one a month in 2010, but jumped to 215 in February of this year, according to the US Centres for Disease Control and Prevention.
Even more troubling, more than half (51%) of the poison calls involved children aged 5 and younger, while 42% involved people aged 20 and older.
"The time has come to start thinking about what we can do to keep this from turning into an even worse public health problem," said Dr Tim McAfee, director of the CDC's Office on Smoking and Health.
He added that many people are not aware that liquid nicotine is toxic. "We need to make sure we can avert the possibility of an unintended death from nicotine poisoning," he added.
"We have not had an unintentional poisoning death from e-cigarettes yet in the United States that we know of, but the potential is there given the amount of concentrated nicotine in these solutions – it would not take a lot for a child death to occur," McAfee noted.
Dr Vincenzo Maniaci, an emergency medicine specialist at Miami Children's Hospital, agreed that the danger to children is real.
"The concentration of nicotine in these solutions is significant and they need to be made childproof and regulated," Maniaci said. "Especially for kids under the age of 5, this amount of nicotine can be fatal."
McAfee noted that the US Food and Drug Administration is planning to propose regulations for e-cigarettes. He added that he hopes these regulations will include how the product is packaged, including childproof caps and warning labels.
"These things can be hardwired into these products, rather than being left to the whim of the manufacturer," he said.
More toxic than bleach
In the meantime, McAfee advised keeping these devices, and their refills, out of the reach of children.
"These should be treated with the same caution one would use for bleach. In some ways, this is more toxic than bleach," he said.
Poisoning from the liquid nicotine in e-cigarettes can happen in one of three ways: by swallowing it, inhaling it, or absorbing it through the skin or membranes in the mouth and lips or eyes, McAfee said. Once it is in a person's system, nicotine can cause nausea, vomiting or seizures.
The problem may be even bigger than the report indicates, McAfee noted.
"All we are reporting is calls to poison control centres. There are many people who had an episode, but didn't call a poison control centre. This report also doesn't include people who had such severe symptoms that they called 911 or went to an emergency room," he said.
The report is published in the CDC's Morbidity and Mortality Weekly Report.
Calls about children
As part of the study, the researchers compared the monthly volume of calls to poison centres involving e-cigarettes and regular cigarettes. They found the proportion of e-cigarette-related calls jumped from 0.3% in September 2010 to 41.7% in February 2014.
"The remarkable thing about this is that e-cigarettes account for less than 2 percent of tobacco product sales," McAfee said.
The number of calls per month about regular cigarettes did not increase during the same period. The most common way regular cigarettes cause a problem is when a child eats one, the researchers said.
That more than half the calls were about children is very concerning, said Dr Robert Glatter, an emergency medicine physician at Lenox Hill Hospital in New York City.
"That's a warning for parents who use these products. They need to keep them locked in a secure place, and it argues for tamperproof caps on these liquid nicotine products to prevent kids from getting into them," he said. "These can be deadly – the risks are real."
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