The Post's news story {Sept. 6} about a recent study concerning exposure to environmental tobacco smoke by nonsmokers inside and outside the home missed the true significance of the study's conclusions.

From a regulatory standpoint the key findings of the study were: 1) "no adverse effect to exposure to environmental tobacco smoke during adulthood, including exposure to a spouse who smoked"; 2) "no adverse effects of exposure to tobacco smoke in the workplace"; and as to exposure in social settings, 3) "a statistically significant inverse association between environmental tobacco smoke and lung cancer."

These findings, which are not mentioned in the story, are consistent with most epidemiological studies, which report no statistically significant association between nonsmoker lung cancer and exposure to environmental tobacco smoke. The findings do not support the claim that exposure to environmental tobacco smoke is a cause of lung cancer in healthy nonsmokers.

As the story indicated, the study did note a higher incidence of lung cancer among nonsmokers who reported growing up in a household with two parents who smoked. This small increased risk was the only negative report among the 11 exposure groups in the study's tables. But The Post's story failed to mention several facts that undermine the study's suggested association between lung cancer and parental smoking -- facts the study's authors candidly acknowledged.

First, the authors noted that "problems of recall and other potential biases may have influenced the results." Second, the authors point out that they knew of no "specific mechanism" that would explain the association between parental smoking and an offspring's lung cancer. Third, as the authors recognized, their findings were inconsistent with a 1987 Swedish study that had detected "little evidence of an elevated risk of lung cancer among nonsmokers whose parents had smoked."

In short, the study does not clearly establish an association between lung cancer and parental smoking. And, far from supporting additional curbs on smoking in workplaces and other public places, the study indicated that such restrictions are not warranted.

THOMAS LAURIA Assistant to the President The Tobacco Institute Washington