Medical marijuana trade associations, dispensary owners and advocacy groups are concerned that full legalization of the drug will negatively impact their industry, according to Politico. In some cases, these groups are actively opposing state ballot initiatives and legislation that would legalize the recreational use of marijuana.

Medical marijuana is legal in 18 states. Recreational marijuana is legal in Colorado and Washington state, and activists hope to pass full legalization measures in six additional states by 2016, the article notes.

This year, the Medical Marijuana Caregivers of Maine opposed a state measure that would legalize possessing small amounts of the drug. The group said if the bill passed, criminal organizations would start to smuggle marijuana to neighboring states. They also opposed the bill's tax plan, saying it was unfair and unworkable.

The National Organization for the Reform of Marijuana Laws, which advocates for full legalization of the drug, argues medical marijuana groups oppose allowing wider use of the marijuana because they would lose money.

Government researchers are studying the effect of marijuana on drivers, USA Today reports. The findings will help regulators decide on guidelines for drugged driving.

The study is looking at the effect of marijuana alone, as well as the combination of marijuana and alcohol. The data has been collected and is now being analyzed. The study is similar to research that was conducted to determine the legal limit for drivers' blood alcohol levels.

Study participants did not drive on real roads, the article notes. They used a simulator that mimics real driving conditions. Before using the simulator, participants consumed specific combinations of marijuana and alcohol, or a placebo. They used a vaporizer to consume their marijuana because the study took place at the University of Iowa, which is smoke-free.

The study included 19 participants who gave blood and saliva tests so researchers could verify their intoxication levels. The investigators hope to have preliminary data available by October.

A new Gallup poll finds 22 percent of Americans support a complete ban on smoking, The Huffington Post reports. Only 9 percent of smokers support a complete ban.

The poll found 55 percent of Americans would make it illegal to smoke in all public places. There were regional differences in the public's support of a complete ban on smoking. People living in the western and eastern sections of the country were most supportive, while people in the Midwest liked the idea the least.

The concept of making smoking illegal has become more popular since 2007, when 12 percent of the public supported it. The vast majority of Americans know that smoking is harmful. The poll found 82 percent of Americans say smoking is very harmful for adults, and 13 percent say it's somewhat harmful. Only 4 percent say it is not too or not at all harmful. Gallup found 63 percent of smokers say smoking is very harmful.

The poll found 39 percent of nonwhites back a total ban on smoking, compared with 15 percent of whites. A total ban is more popular among Democrats than Republicans, and with people with a high school degree or less, compared with people with more education. In addition, the poll found 59 percent of Americans believe secondhand smoke is very harmful, up from 36 percent in 1994.

Teens whose parents have ever smoked are more likely to become smokers, even if their parents quit before they were born, according to a new study. Teens with an older sibling who smokes are also more likely to start using cigarettes.

The study followed 214 participants starting in 1988, when they were high school freshmen, until 2011. The researchers also studied 314 of their children ages 11 and older. Participants took annual surveys about their smoking habits, and their children were surveyed in 2011.

The researchers found in homes with a parent who was a persistent heavy smoker, the oldest sibling was influenced to smoke, which increased the odds that young siblings would also smoke by six times, HealthDay reports.

The study found a smoking rate of 23 percent among children whose parents started smoking as teens and who had quit or cut back on their smoking by age 38. Among children whose parents started smoking in their 20s, the smoking rate was 29 percent. The smoking rate among children whose parents had never smoked was 8 percent.

The findings appear in Pediatrics.