Joining forces with First Lady Nancy Reagan, PBS is declaring war on school-age drug and alcohol abuse in The Chemical People (PBS, Wednesday Nov. 2 and Wednesday Nov. 9, 8-9 p.m., check local listings). Mrs. Reagan narrates the program and has done much to promote it.
Program 1, ''The Chemical Society,'' is designed to inform and motivate people by hitting them hard with a straightforward overview of the widespread use among young people of alcohol, marijuana, LSD, amphetamines, cocaine, and heroin, among many other drugs.
The second hour, ''Community Answers,'' focuses on what task forces of local men and women can do to help solve the problem.
Hosts for both programs, along with Mrs. Reagan, who is the overall narrator, include Bill Bixby, Michael Landon, Rita Moreno, Bruce Weitz, Willie Stargell, and Sandy Duncan.
Using split-screen techniques, talking-head interviews, and dramatized simulations of various types of group encounters, the two-program series in its own calmly expository way sounds a frightening alarm about the epidemic of chemical abuse that is victimizing the nation's youth.
''The Chemical People'' is earnest, well-meaning, and probably especially valuable to parents of afflicted youngsters. However, in what appears to be an attempt to make the program less repetitious and more of an entertainment, dramatized segments are used. These only serve to confuse viewers, who may find it difficult to distinguish actors from real parents, teachers, social workers, and even addicts.
The second hour, which focuses on local parent-teacher task forces which swap information about prevention, treatment, intervention, and education, attempts to force some sort of commitment from viewers, urging them to do something about the problem. But in some instances, the constant repetition, the by-the-numbers confessions of former users, the incessant talking heads may prove to be counterproductive to all but those parents immediately involved in the problem. Of course, those are the people targeted by the program.
However, it should be noted that the information contained in the programs can be of some crucial value to just about everybody in every community. I wonder, though, why nicotine was not included in this alarm-sounding public-service program. Certainly smoking is just as epidemic as drinking among young people - and probably just as harmful.