They say where there's smoke, there's fire. But even if there's not smoke, there could still be a problem — when you're talking about tobacco and kids, that is.
A recent study found that one in 20 high school and middle school students use smokeless tobacco.
Further, the students were much more likely to use smokeless products if their friends used it or if someone in their household used it.
In addition, a much lower percentage of smokeless tobacco users said they believed all tobacco use was harmful, compared to those who didn't use the products.
This study, led by Israel T. Agaku, DMD, MPH, of the Center for Global Tobacco Control at Harvard School of Public Health, looked at how common smokeless tobacco use was among middle school and high school students.
The researchers used data from the 2011 National Youth Tobacco Survey, which included 18,866 students from 178 schools throughout the US. About 43 percent were middle schoolers.
The students answered questionnaires in their classrooms related to their use of tobacco products, including "conventional" and "novel" forms of smokeless tobacco.
Conventional smokeless tobacco includes chewing tobacco, snuff or dip. Novel smokeless tobacco includes snus and dissolvable tobacco products.
Overall, 5.6 percent of the students reported using any kind of smokeless tobacco. Most of these students (5 percent of the total responders) used chewing tobacco, snuff or dip.
Only 0.3 percent used dissolvable tobacco products, and 1.9 percent used snus.
Students were more likely to use smokeless tobacco as they got older. While only 2.2 percent of students aged 9 to 11 used smokeless tobacco, 10.8 percent did among those aged 18 or older.
The rate for smokeless tobacco use among high schoolers was 7.7 percent, compared to 2.6 percent among middle schoolers.
More than four times as many boys reported using smokeless tobacco than girls. The rate among boys was 9 percent, compared to 2 percent among girls.
Blacks were the least likely to use smokeless tobacco while whites and Native Americans were more likely.
Within the group of those who used smokeless tobacco, more than half (64 percent) exclusively used conventional forms, and about a quarter (27 percent) used both conventional and novel forms.
Almost three quarters (72 percent) of those who used smokeless tobacco also smoked cigarettes or cigars.
Yet only 40 percent of them said they planned to quit using all tobacco products.
The strongest influence identified for the students' tobacco use appeared to be their friends' use.
Those whose peers also used smokeless tobacco were nearly ten times more likely to use smokeless tobacco themselves, compared to those without peers using tobacco.
If smokeless tobacco was used in their household, students were a little more than three times more likely to use it themselves.
Students who believed that all forms of tobacco are harmful were half as likely as other students to use smokeless tobacco.
Among nonusers of any smokeless tobacco product, 92 percent reported believing that all tobacco products are harmful. But among smokeless tobacco users, only 67 percent reported this belief.
"Conventional smokeless tobacco products remain the predominant form of smokeless tobacco use," the researchers wrote.
"Smokeless tobacco use was associated with lower perception of harm from all tobacco products and pro-tobacco social influences, indicating the need to change youth perceptions about the use of all tobacco products and to engage pediatricians in tobacco use prevention and cessation interventions," they wrote.
This study was published August 5 in the journal Pediatrics. The research was funded by the National Cancer Institute. The authors declared no conflicts of interest.
Photo accompanying story is by Theo Stephen of the US Smokeless Tobacco Company in Nashville.