They do a lot of good work at the University of North Carolina at Chapel Hill, and valuable if disturbing information is to be found in one particular piece of that work -- a nationwide survey of employees between 14 and 18 years of age, 866 of them, that shows many of these kids are doing jobs they shouldn't be doing without the supervision they ought to have.

This is some shocking stuff, and it shouts out to parents of working kids everywhere, whether that work is in retail sales or service jobs.

Consider the comments of Carol Runyan, director of the university's Injury Prevention Research Center and the lead author of this survey: "In the same way we worry about sex, drugs, alcohol and driving, we should worry about (teenagers') work life...we need to make sure they are working in jobs that are good for them." So she told The News & Observer's David Ranii.

And too many are not. As the four researchers from UNC-CH and one from N.C. State University found, some employees were assigned to jobs, at least occasionally, that people under 18 aren't supposed to do. Others were exposed to a variety of hazards. Nearly half of the workers surveyed said they had done things that were prohibited by law.

For example, 17 percent of female workers had sold or served alcohol at places where it is consumed, though persons under 21 aren't supposed to do that. Over 19 percent of the boys in the survey, and nearly 16 percent of the females, had used a power slicer or grinder. Other significant percentages showed up in use of other machines that can be hazardous -- box crushers, balers or compactors, dough-mixing and rolling machines. This is prohibited by federal child labor law. And over a quarter of those surveyed said they had worked without an adult supervisor at least one day a week.

The machines pose obvious hazards, and a lack of supervision compounds them. Kids can be overconfident, and doubtless in some cases younger workers may have pushed for the chances to do more complicated and harder jobs -- and ones that were more dangerous. But that doesn't mean responsible supervisors should allow them to do so.

Just as "hazardous" in some ways were the indications from some respondents that they had worked past the hours they were supposed to. Labor laws say kids under 16 can't work past 7 p.m., but over a third of respondents said they had done so. Some worked well past the cutoff.

The perils this brings to keeping up with schoolwork are obvious. Kids have pressures, it's true, to make money -- most of them having to do with cars, with of course some exceptions where a youngster might be contributing to the family welfare. Businesses like younger workers because they are less expensive, and readily available. Many parents don't keep a close enough eye on their kids' working, and figure that a job teaches responsibility.

But this valuable survey shows that local and state regulators need to pay closer attention, and so do parents, to how much their kids are working and what they're doing when they're on a job. Employers have a responsibility as well to know the law and to follow it. Kids may benefit from some job experience, within reason, but they should not get it at risk to their health or welfare.