Validity of self-reported intensity of exposure to second-hand smoke at home against environmental and personal markers.

The objective of this study was to assess the validity of two questions about the perception of intensity of exposure to secondhand smoke (SHS) at home using as a reference environmental markers (airborne nicotine and benzene) and biomarkers of exposure (cotinine in saliva and urine). This was a cross-sectional study in a convenience sample of 49 non-smoking volunteers. We found a high correlation between self-reported SHS exposure and airborne nicotine (rsp=0.806, p<0.05), salivary cotinine (rsp=0.752, p<0.05), and urinary cotinine (rsp=0.626, p<0.05). We did not find differences between the score question and the conventional ones (p >0.05). In conclusion, the significant correlation of the two questions proposed with environmental markers and personal markers indicates their potential validity to assess exposure to SHS at home.