Electronic cigarettes are igniting fear within the medical establishment, despite a shortage of scientific research on their medical effects.

It’s not totally unfounded. E-cigarettes do contain nicotine, which leads to tobacco addiction. That has made smoking the number one cause of preventable death.

However, some experts concede vapor from e-cigarettes is safer than smoke from regular cigarettes, while others argue that they are breeding a new generation of addicts.

“E-cigarettes are at least 90 percent less harmful, and maybe much less harmful than that,” said Jonathan Foulds, who studies tobacco addiction at Penn State Milton S. Hershey Medical Center.

Jonathan Foulds studies tobacco addiction at Penn State Milton S. Hershey Medical Center, and thinks e-cigarettes may be a safer alternative to tobacco cigarettes.

Foulds said he believes e-cigarettes might be a long-sought public health savior: A device that can supply nicotine to those unable to overcome their craving, while sparing them from most cancer-causing agents contained in tobacco smoke.

Burning tobacco produces thousands of chemicals, including dozens that cause cancer. It produces carbon monoxide, which is a poisonous gas, and tar, which clogs the lungs.

“It’s really the smoke that does the harm,” Foulds said.

E-cigarettes, on the other hand, involve not smoke but vapor resulting from heated nicotine. The vapor contains few of the toxins contained in cigarette smoke. It doesn’t contain carbon monoxide or tar, according to Foulds and other medical experts.

It does contain nicotine, although nicotine isn’t the main cancer-causing ingredient in cigarette smoke, Foulds said.

Still, nicotine can contribute to heart disease, although it’s not the main contributor to heart disease that results from smoking.

And nicotine is especially dangerous to an unborn fetus, so e-cigarettes don’t offer an acceptable option for pregnant women, Foulds said.

But for most smokers, “any cigarette replaced by vaping is probably a step in the right direction,” he said.

Still, organizations including the Pennsylvania Medical Society are sounding alarms over the growing use of e-cigarettes.

The biggest concern is that the devices will appeal to nonsmokers, especially young people, and lead to an addiction that will end in full-blown tobacco use and smoking of regular cigarettes.

And the e-cigarettes contain chemicals not normally inhaled, which studies might eventually discover are harmful.

“On the surface, it seems that it’s not very healthy,” said Dr. Richard Bell, a recently retired lung specialist in Berks County. “There’s a strong suspicion [the vapor] isn’t totally clean. Certainly, the concern of most people is that it’s a gateway type of device and can lead to higher amounts.”

Bell also said, “They certainly do mimic regular smoking. They are a nicotine delivery device. Yes, it is lesser amounts of nicotine that is being delivered. But it is still nicotine. It is still an addictive type of situation.”

A committee of the American Medical Association recently wrote, "Whether e-cigarettes can safely help people quit smoking is also unknown, but with their fruit and candy flavors, they have a clear potential to entice new smokers."

Regarding the second-hand effects of e-cigarettes, Foulds said they are likely far less severe than those of regular cigarettes, although science has yet to provide definite answers.

It might, he said, produce at least minor irritation for people with lung conditions such as asthma, and might be more harmful to someone with a heart condition.

Coming later today: Are e-cigarettes a breakthrough for breaking the smoking habit?

Coming tomorrow: Are kids using e-cigarettes to smoke pot?