“…What research exists provides conflicting findings. For example, self-reported inhalation was found to be significantly associated with biological markers of smoke intake in some (Nakayama, Yokoyama, Yoshiike, Ichimura, Yamamoto, & Tanaka, 1999;Hofer, Nil, Wyss, & Battig, 1992;Burling, Lovett, Richter, & Frederiksen, 1983), but not other studies (Frederiksen, Martin, & Webster, 1979;Hill, Haley, & Wynder, 1983;Etter & Perneger, 2001).…”