If you are really concerned about your health theoretically any exposure to any carcinogen increases the chances of cancer like alcohol for liver, processed meat for colon cancer. And the funny thing is if u wants to prevent from skin cancer, I think you have to get out only at nights or at cloudy days to prevent from harmful solar radiation.
Smoking is also considered as a carcinogen for many cancers mostly lungs. Smoking a half pack or pack of cigarettes per day probably somewhat lead to some health consequences. Some may claimed that I am a very light smoker may be 1-4 cigarettes per day. So how much it is safe to smoke 1-4 cigarettes per day?
In one study, 30 years follow up done in age group of 35-49 years (around 24 thousand male and 20 thousand female) who smoke 1-4 cigarettes per day in Norway shows that about 3 people from each sex died from ischemic heart disease like heart attack and about 3 in men and 5 in female died from lung cancer. About 1-2 in number from each sex died from other types of cancer when compare with the person who never smoke. So, many of us just find enough enjoyment smoking knowing its risks. So it’s up to you to decide. You might be lucky may not get any disease related to smoking.
Reference: Tobacco Control