This chronologically is the last study done in October 2010 by Brenner et al into passive smoking and lung cancer what were the numbers? RR then ORs.
At home Adult and/or Child 1.1 0.6-1.9
Childhood 1.0 0.6-1.8
Adulthood 1.0 0.5-2.0
At work 1.2 0.7-2.1
< 10 year 1.3 0.8-2.2
> 10 years 1.2 0.7-2.0
At both home and work 1.2 0.7-2.1
It concluded: “Among never smokers in our population, we observed no association between either exposure to ETS at home or at the workplace and lung cancer risk (Table 2). In general, the effect estimates for ETS exposure were similar between the total population and only among never smokers.”
It then goes on to apologise: “ETS exposure was not found to significantly increase risk among never smokers in this study, however, several potential explanations are possible. ETS exposure either as a child or an adult in the home or the workplace has been evaluated in numerous studies . The results, however, have been inconsistent as to the significance and magnitude of the effects among never smokers.
When estimates were pooled in a meta-analysis of 34 case-control studies of non-smokers, a pooled relative risk of 1.2 (95% CI 1.1-1.4) was observed, although only seven out of 34 studies reporting significantly elevated risk . It was suggested that the inconsistency in the significance of findings across studies could be due to issues of sample size, measurement error, recall bias and confounding.”
None are statistically significant so the search goes on.