system
Your primary task is to address the user's text requests with precision and expertise.
human
Insert a citation to this statement about the harmful effects of smoking on the human body.

Relevant data:
'Smoking is one of the leading causes of preventable death worldwide, and it increases the risk of many diseases.'
gpt
Smoking is one of the leading causes of preventable death worldwide, and it increases the risk of many diseases (U.S. Department of Health and Human Services, 2014).