The Post performed a commendable public service in hiring a contractor to locate unprotected electrical junction boxes at Metrorail stations {front page, July 11}. Metrorail employees, of course, should have identified and remedied the potential safety problems on their own.

Metrorail has also been lax in another area of public health and safety. A quick tour of its stations will show very little notice to the public of Metrorail's no-smoking regulation.

There is a tiny, fist-size no-smoking symbol on some -- but not all -- refuse containers in the subway boarding areas. Many visitors to Washington are not familiar with the no-smoking rule, and smokers often do not see the small signs and begin smoking.

Could it be that the no-smoking signs are small because the cigarette companies pay plenty for large cigarette ads throughout the Metrorail and Metrobus systems? I hope Metro will put up some public-service posters about the hazards of smoking to help offset the influence of the posters that glorify smoking.

The surgeon general reported last year that "involuntary smoking is a cause of disease, including lung cancer, in healthy nonsmokers." I quit smoking to protect my health and now resent being forced to breathe others' hazardous smoke in public places. I also dislike having to confront Metrorail riders about their smoking.

The public deserves clean air in subway stations after spending billions of dollars on the construction of safe facilities. Metrorail should therefore post larger -- and many more -- no-smoking signs as soon as possible, and make an effort to enforce this common-sense rule.

RICHARD POWELSON

Rockville