Two separate studies to emerge have highlighted exactly how dangerous smoking can be, in particularly to women it would seem. The first was conducted by a team at The University of Tromso, Norway, who analysed medical records from more than 600,000 men and women aged between 19 and 67 – all were surveyed for the Norwegian Institute of Public Health. The participants had provided answers to questions regarding their levels of physical activity, smoking habits and other general lifestyle choices. After a follow-up time of around 14 years, it was found by the study authors that 4,000 people had developed colon cancer, with a much higher risk for smokers - female smokers in particular. According to the findings published April 30 in Cancer Epidemiology, Biomarkers & Prevention, female smokers had a 19% higher risk of the disease compared to women who had never smoked, while for male smokers it was just 9%. The team, led by Dr. Inger Gram, a professor in the department of community medicine at the University of Tromso in Norway, also found that factors that greatly increased the risk of colon cancer were the number of years a woman had been smoking, what age she first started smoking, and how many packs of cigarettes a woman had smoked each year. Shockingly, women who had been smokers for 40 years or more increased the chances of developing colon cancer by nearly 50%. Dr. Gram says: “Women who smoke even 10 or fewer cigarettes a day increase their risks for colon cancer. Because colon cancer is such a common disease, even this moderate smoking accounts for many new cases. A lot of colon cancer can be prevented if people don't smoke - especially women.” The team that carried out the research say it is the first study to show women who smoke less than men are still more susceptible to colon cancer and may suggest women are more vulnerable to the thousands of chemicals contained in cigarettes. Sarah Williams of Cancer Research UK, gave her opinion on the findings, saying: “It's well established that smoking causes at least 14 different types of cancer, including bowel cancer. For men and women, the evidence is clear - being a non-smoker means you're less likely to develop cancer, heart disease, lung disease and many other serious illnesses.” A separate study focused on the already present knowledge that female smokers increase their risk of a heart attack more than men who also smoke. It is still unclear why this is so, however research published in the Journal of Clinical Endocrinology & Metabolism may have uncovered some of the reasons. A team based at the University of Western Australia have discovered that teenaged girls exposed to secondhand/passive smoking had less of the ‘good’ cholesterol that helps in lowering the risk of heart disease.  Interestingly, this effect does not seem to be the same for teenage boys. High-density lipoproteins (HDL) transport a surplus cholesterol in the blood stream to the liver where it is broken down. While low-density lipoproteins that cause waxy blockage to blood vessels, HDL cholesterol is an important factor for decreasing the risk of developing heart disease. Over 1,000 adolescents born between 1989 and 1992 in Perth, Australia were analysed for the study. Researchers looked at information regarding household smoking before the participants were even born, spanning all the way until they turned 17. Within this time period, almost half (48%) of the study subjects had been exposed to some degree of secondhand smoke. The teenagers' cholesterol levels were determined through blood tests. The study's lead author Doctor Chi Le-Ha, of the University of Western Australia, commented: “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. Secondhand smoke did not have the same impact on teenage boys of the same age, which suggests passive smoking exposure may be more harmful to girls. Considering cardiovascular disease is the leading cause of death in women in the western world, this is a serious concern.”