Louis F. Fieser, a member of the Surgeon General's Advisory Committee on Smoking and Lung Cancer, said yesterday that Lark cigarettes were probably safer than all other brands.

Fieser, Sheldon Emery Professor of Organic Chemistry, recommended that smokers who were unable to quit should switch to Larks.

According to Fieser, the charcoal for the Lark filter was specially developed to screen out gases known to depress the action of cilia in the respiratory tract. While Larks are currently the only cigarette to use this special charcoal, there is no reason why other cigarette manufacturers could not add the substance to their filters and thereby achieve the same probable level of safety as Larks.

Speaking as a scientist," Fieser stated, "this filter represents a definite encouraging advance." He emphasized, however, that at least 20 years would have to lapse before mortality statistics of the type reviewed by the Surgeon General's committee would be available on the new filter.

The cause of lung cancer is still unknown, but there is clinical evidence linking cancer with foreign matter in the respiratory system. Cilia are thin hairs that prevent such particles from lodging in the tract. The charcoal granules in the compartmentalised Lark filter adsorb such gases as hydrogen, cyanide, formaldehyde, acrolein, and ammonia, which interfere with this process.

Fieser said that he currently smokes Larks and, occasionally, a pipe. Though he stated that the safest course of action would be to stop smoking he refused to say whether he had any plans to quit.

The report of the Surgeon General's committee, of which Fieser is a member, concluded that "cigarette smoking is a health hazard of sufficient importance in the United States to warrant appropriate remedial action."