Air nicotine and saliva cotinine as indicators of workplace passive smoking exposure and risk.

We model nicotine from environmental tobacco smoke (ETS) in office air and salivary cotinine in nonsmoking U.S. workers. We estimate that: an average salivary cotinine level of 0.4 ng/ml corresponds to an increased lifetime mortality risk of 1/1000 for lung cancer, and 1/100 for heart disease; > 95% of ETS-exposed office workers exceed OSHA's significant risk level for heart disease mortality, and 60% exceed significant risk for lung cancer mortality; 4000 heart disease deaths and 400 lung cancer deaths occur annually among office workers from passive smoking in the workplace, at the current 28% prevalence of unrestricted smoking in the office workplace.

Respiratory health effects of exposure to environmental tobacco smoke.

During the last 25 years, several hundred papers have been published on the respiratory health effects of environmental tobacco smoke (ETS). Various independent assessments have concluded that ETS causes lung cancer in adult nonsmokers and increases the risk of various noncancer effects, principally in children. The effects on children include pneumonia, bronchitis and bronchiolitis in young children; chronic middle ear effusion; increased frequency and severity of attacks among asthmatics; possible induction of asthma in previously asymptomatic individuals; small reductions in lung function; and symptoms of upper respiratory tract irritation. In nonsmoking adults, ETS exposure is associated with irritation of the eyes, nose, and throat, and with wheezing, symptoms of bronchitis, shortness of breath, and decreased lung function. The results of recent studies not only confirm and strengthen the above findings but also provide strong suggestive evidence that ETS causes sinonasal cancer and is a risk factor for sudden infant death syndrome. To mitigate such a preventable environmental health impact, public health measures to reduce involuntary ETS exposure are warranted.

Respiratory health effects of passive smoking: EPA's weight-of-evidence analysis.

After an extensive review and assessment of the scientific evidence on the respiratory health effects of passive smoking, the U.S. Environmental Protection Agency has determined that the widespread exposure to environmental tobacco smoke in the United States presents a serious and substantial public health impact. The Environmental Protection Agency concluded that environmental tobacco smoke causes lung cancer in adult nonsmokers and increases the risk for a variety of noncancer respiratory disorders, especially in children. This article reviews evidence presented in the Environmental Protection Agency's 1992 report on the respiratory health effects of passive smoking and responds to critical allegations levied by Gio Gori in his article "Science, policy, and ethics: the case of environmental tobacco smoke", appearing in the same issue of this journal. Several recent studies appearing since the cutoff date for inclusion in the EPA report are also discussed.

Organ culture with proinflammatory cytokines reproduces impairment of the beta-adrenoceptor-mediated relaxation in tracheas of a guinea pig antigen model.

The challenge of previously sensitized guinea pigs with aerosolized ovalbumin resulted in impairment of the beta-adrenoceptor-mediated relaxation as measured by the in vitro isometric assay of tracheas preconstricted with endothelin-1 or carbamylcholine. Numbers and affinities of beta-adrenoceptors in lung membranes of these animals were not altered under these conditions, although the antigen challenge caused an inflammatory response, as evident from the accumulation of inflammatory cells in the bronchoalveolar lavage fluids. In order to investigate the pathophysiologic role of inflammation in hyperreactive airways, isolated guinea pig tracheas were cultured with proinflammatory cytokines such as human recombinant tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), or interleukin-2 (IL-2). None of these cytokines affected the contractile response of tracheas to carbamylcholine. After preconstriction with carbamylcholine, the TNF-alpha- and IL-1 beta-pretreated tissues produced a significant reduction in the maximal relaxation induced by isoproterenol, whereas the IL-2 pretreatment had no effect. The reduction of the isoproterenol-mediated relaxation by the IL-1 beta treatment was time and dose dependent. Our present observations suggest that in vitro incubation of naive tracheas with proinflammatory cytokines is able to reproduce apparent beta-adrenoceptor impairment as seen in the airways of antigen-challenged guinea pigs of asthma model.