For years, researchers have warned of the health consequences of smoking. In the past 20 years, however, the focus of research has shifted to the effects of second-hand smoke on individuals who don't smoke, particularly on babies, toddlers and young children. Many authorities have warned of the dangers of environmental tobacco smoke (ETS) on the development and growth of these children.

Second-hand smoke, or ETS has been identified as a causative factor in respiratory illnesses, including childhood asthma owing to the harmful substances and irritants identified in the smoke.

Because of their immature immune systems, children are at greater risk when exposed to pollutants, because their cells are more vulnerable than adults' cells to chemical alteration.

Aside from nicotine, there are other harmful chemicals in ETS that can cause cancer, including:

• Arsenic
• Lead
• Formaldehyde
• Benzene

Many studies have addressed children's health problems caused by ETS. One study concluded that children younger than 3 years old who had exposure to ETS had smaller airway tubes and, thus, lower airway function. Further research has determined nearly half of all children who have respiratory diseases such as asthma, ear infections and pneumonia live in homes in which their parents smoke.

Women who are pregnant and who either smoke or live or work in an environment where they breathe in tobacco smoke are at risk of producing children who have slow lung growth and are low in birth-weight.

We try to protect our children from obvious dangers but exposing them to the unseen dangers of ETS increases their risk of sudden infant death syndrome (SIDS), chest infections, and developing allergies and asthma.