A study by two School of Public Health researchers indicates that the level of particulate matter in cigarette-smoke-filled rooms is much lower than had previously been believed.

The study, whose results appear in the current issue of the New England Journal of Medicine, was conducted by Dr. William C. Hinds, assistant professor of Environmental Health Engineering, and Dr. Melvin W. First, professor of Environmental Health Engineering.

Hinds said yesterday that, according to his study, nonsmokers in enclosed public places inhale a smaller amount of the particulate material present in cigarette smoke than previous experiments had indicated.

"The levels of smoke which we found while conducting our study were still high, and probably would be very irritating to most people," Hinds said.

He cited "some 2000 compounds" present in cigarette smoke, including "unpleasant gases" whose effects were not measured in his study but which may be responsible for the adverse reactions of many nonsmokers to cigarette smoke.

The published report indicates that a nonsmoker in a smoke-filled room would have to spend 100 to 1000 hours in the room in order to inhale the amount of particulate matter contained in one cigarette.

"Most of the smoke in a crowded nightclub, for example, comes from the burning ends of cigarettes, and just drifts off into the room." Hinds explained. "We measured the weight of smoke particles actually detected in a room, and found it to be comparatively small."

According to Hinds, the study was carried out in indoor public places where concentrations of smoke are traditionally the most dense, including restaurants, bars, waiting rooms and nightclubs.

Smoke concentrations were measured by means of a book-sized smoke sampler, invented by Hinds and First for use in this experiment. Hinds said the device had the dual convenience of being both portable and inconspicuous.

"We really didn't find anything dramatic in this study, in terms of the danger of cigarette smoke to non smokers," he added.

Hinds said that future studies will focus on the role of other substances present in cigarette smoke which may have more pernicious effects on nonsmokers.