Secondhand smoke causes serious adverse effect on teenage girls as compared to teenage boys. This implies that passive smoking is more detrimental to girls.

Mainstream smoke- the smoke that is exhaled by the smoking person
Sidestream smoke- smoke arising from the ignited end of cigarette or cigar
Secondhand smoke or passive smoke is not only hazardous for the smokers but also for non-smokers. Recently a research published in the Journal of Clinical Endocrinology & Metabolism (JCEM), has highlighted an important fact that passive exposure to harmful cigarette smoke is highly dangerous for teenage girls as compared to teenage boys.
The scientists at the University of Australia have analyzed 1,057 non-smoker teenagers who were born between 1989 and 1992. The blood samples of all the male and female teens were collected and were chemically analyzed for the levels of ‘good’ cholesterol or high density cholesterol (HDL).
HDL or good cholesterol is beneficial for us as it removes surplus cholesterol from the blood circulation while LDL or bad cholesterol enhances the deposition of cholesterol in the blood vessels. The experts also collected information about smoking in the teens ‘households beginning before they were born, when their mothers were 18 weeks into their pregnancies’.
The experts noted that about 40 percent of teenagers who were exposed to secondhand smoke were at the threat of developing health hazards.
Dr. Chi Le-Ha, of the University of Western Australia and the lead author of the study mentioned, "In our study, we found 17-year-old girls raised in households where passive smoking occurred were more likely to experience declines in HDL cholesterol levels."
Dr. Le Ha firmly said, "We need to redouble public health efforts to reduce young children's secondhand smoke exposure in the home, particularly girls' exposure." According to scientists secondhand smoke can increase the threat of high blood pressure in infants and can adversely affect individual’s genes. SHS can even cause dementia.
The scientists said that further research was required to identify why secondhand smoke has different roles in teenage girls compared to teenage boys.
Source-Medindia