SACRAMENTO — Citing the ill health effects of secondhand smoke, Gov. Pete Wilson on Monday banned smoking in most state buildings--including the prisons and thousands of offices from San Diego to Crescent City.

Wilson's edict--in the form of an executive order signed by the governor--applies to all indoor premises leased or owned by the state, except buildings controlled by the courts, the Legislature or the state's two university systems. The ban will take effect Dec. 31.

Although many state buildings already prohibit smoking, the policy has been applied on a case by case basis at the discretion of building managers. The new order takes the form of an outright ban, applying to more than 20,000 buildings where about 180,000 state workers are employed.

"Secondhand smoke threatens the health of non-smoking state employees," Wilson said. "It is the nation's third leading preventable cause of death and raises the costs for employers--in this case, the taxpayers who employ our public servants."

Wilson cited a recent U.S. Environmental Protection Agency report on secondhand smoke, which says passive inhalation of tobacco smoke causes an estimated 3,000 fatal cases of lung cancer each year in the United States.

"We're not interested in prohibiting adults from smoking if they want," said Wilson, who smokes an occasional cigar. "But smokers shouldn't impose their habits and their smoke on their co-workers."

Smoking in the workplace, the governor added, increases cleaning costs, damages furniture and carpets, and raises the risk of fire.

After signing the order, Wilson tacked up a symbolic no-smoking sign on the door to his suite of offices, where smoking indoors was already prohibited. Other Capitol offices will be permitted to allow smoking to continue because they are under the control of the Legislature, though some individual legislators and other office managers prohibit smoking.

The Assembly banned smoking on the floor several years ago, but the rule is routinely ignored by a handful of lawmakers.

The most dramatic effect of Wilson's order is likely to be in the state prisons, where more than 110,000 inmates and 13,500 guards live and work in closely controlled conditions.

Although inmates still will be able to smoke outside in prison yards, their access to those yards is limited. For some prisoners, the indoor ban may make it all but impossible to smoke. In addition, many correctional officers who work eight-hour shifts indoors without a break will not be able to smoke.