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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Which one of the following statements about influence of smoking on risk of coronary heart disease (CHD) is not true?
assistant
The correct answer is  park's textbook of preventive and social medicine 23rd edition . 

there is evidence that influence smoking not only independent of but also synergistic with other risk factors such as hypertension and elevated serum cholesterol.this means that the effect are more than additive.