Respiratory infections are the disease associated the secondhand exposure to infants and children.
The second hand smoke contains more than 7000 chemicals which is very harmful for the children and infants. The health issues that is associated with the any diseases such as asthma, ear infections, respiratory infections.
So, respiratory infections is associated with the children and infants who is being exposed to secondhand smoke.
One should have the right tool in teaching.As one select a tool to know if it is formal or informal it will help someone to direct one's assessment toward children's interests. Hope this is the right answer and would be of help.