Exposure of nonsmoking women to environmental tobacco smoke: a 10-country collaborative study

Abstract

The interpretation and interpretability of epidemiologic studies of environmental tobacco smoke (ETS) depend largely on the validity of self-reported exposure. To investigate to what extent questionnaires can indicate exposure levels to ETS, an international study was conducted in 13 centers located in 10 countries, and 1,369 nonsmoking women were interviewed. The present paper describes the results of the analysis of self-reported recent exposure to ETS from any source in relation to urinary concentrations of cotinine. Of the total, 19.7 percent of the subjects had nondetectable cotinine levels, the median value was 6 ng/mg, and the cut-point of the highest decile was 24 ng/mg. The proportion of subjects misreporting their active smoking habit was estimated at between 1.9 and 3.4 percent, depending on whether cut-points of 50 or 100 ng/mg creatinine were used. Large and statistically significant differences were observed between centers, with the lowest values in Honolulu, Shanghai, and Chandigarh, and the highest in Trieste, Los Angeles, and Athens. Mean cotinine/creatinine levels showed a clear linear increase from the group of women not exposed either at home or at work, to the group of those exposed both at home and at work. Values were significantly higher for women exposed to ETS from the husband but not at work, than for those exposed at work but not from the husband. The results of linear regression analysis indicated that duration of exposure and number of cigarettes to which the subject reported being exposed were strongly related to urinary cotinine. ETS exposure from the husband was best measured by the number of cigarettes, while exposure at work was more strongly related to duration of exposure. After adjustment of number of cigarettes for volume of indoor places, a similar increase in cotinine (5 ng/mg) was predicted by the exposure to 7.2 cigarettes/8 h/40 m3 from the husband and 17.9 cigarettes/8 h/40 m3 at work. The results indicate that, when appropriately questioned, nonsmoking women can provide a reasonably accurate description of ETS exposure. Assessment of individual exposure to ETS should focus on daily duration and volume of indoor places where exposure occurred.

Lifetime residential and workplace exposure to environmental tobacco smoke and lung cancer in never-smoking women, Canada 1994-97

“…We did not collect ETS data in the detail that some studies designed exclusively to evaluate passive smoking have. However, a key strength of our study is that we did systematically collect lifetime ETS information for the 2 sources most relevant in previous biomarker studies 32,33 and collected them for each residence and job.…”

Assessment of exposure to environmental tobacco smoke

“…Based on the available data, a categorization of saliva cotinine concentrations into four groups was suggested: 1) undetectable cotinine is associated with the absence of active or passive smoking; 2) cotinine concentrations <10 ng·mL -1 usually result from exposure to ETS without active smoking; 3) cotinine concentrations ranging 10-100 ng·mL -1 usually result from infrequent active smoking or regular active smoking with low nicotine intake, but heavy passive exposure to tobacco smoke can result in levels ≥10 ng·mL -1 ; and 4) levels >100 ng·mL -1 are the result of regular active smoking [63]. Detectable cotinine levels have been measured in 80-91% of the samples in different studies, and ETS exposure has been shown to take place at home, in the workplace and in a number of other settings [3,4,6,7]. In addition to plasma, saliva and urine, cotinine has also been detected in cervical fluid of women exposed to ETS [64] and in semen of men reporting ETS exposure [65].…”

“…For example, among adult populations the mean urinary cotinine concentrations have been shown to increase with the degree of selfreported exposure [66], and with the number of selfreported exposures to ETS during the previous 4 days, as shown in figure 5 [3]. Among nonsmoking women in a 10-country collaborative study, urinary cotinine/creatinine levels rose with self-reported ETS exposure from no exposure through exposure at work alone and exposure only at home, to exposure both at home and at work [4]. The results of a linear regression analysis indicated that reported duration of ETS exposure and the number of cigarettes to which the subject reported being exposed were strongly related to the urinary cotinine level.…”

“…Evidence has accumulated on ill-health associated with ETS, and such exposure has now been documented among children and adults in many countries [1][2][3][4][5][6][7][8]. A major difficulty in studying the ill-health effects of ETS has been assessing exposure, since this may occur in multiple settings with highly variable concentrations and exposure profiles may vary considerably during different age periods.…”

Estimation of environmental tobacco smoke exposure during pregnancy using a single question on household smokers versus serum cotinine

“…Studies that determine exposure using a biomarker are more difficult to conduct and more expensive than questionnaire data. Studies have examined the agreement between self -reported ETS exposure and biochemical markers of ETS exposure (Coultas et al, 1988;Coultas et al, 1989;Coghlin et al, 1989;Haley et al, 1989;Riboli et al, 1990;Becher et al, 1992;Emmons et al, 1994;Kemmeren et al, 1994), and a few have examined this association in pregnant women (O'Connor et al, 1995;Rebagliato et al, 1995b ). However, the analytic methods used to determine biochemical markers of ETS exposure in many of these studies were not as sensitive as can be obtained currently.…”