Read the following passage and choose the best option to answer each of the following questions.

Smoking is one of the biggest causes of death and illness in the UK. Every year around 78,000 people in the UK die from smoking and many more live with smoking-related illnesses. It increases your risk of developing more than 50 serious health conditions. Some may be fatal, and others can cause irreversible long-term damage to your health. You can become ill if you smoke yourself or if people around you smoke (passive smoking). Smoking causes around 7 out of every 10 cases of lung cancer (70%). It also causes cancer in many other parts of the body, including the throat or voice box (larynx). Moreover, smoking damages your heart and your blood circulation, increasing your risk of developing conditions such as coronary heart disease and heart attack. Breathing in secondhand smoke, also known as passive smoking, increases your risk of getting the same health conditions as smokers. For example, if you have never smoked but you have a spouse who smokes, your risk of developing lung cancer increases by about a quarter. Babies and children are particularly vulnerable to the effects of secondhand smoke. A child who’s exposed to passive smoke is at increased risk of developing chest infection, meningitis, persistent cough and, if they have asthma, their symptoms will get worse.

1. What is the main idea of the passage?