Certified in Public Health (CPH) Practice Exam

Which of the following factors had the greatest impact on average life expectancy?

1. Vaccinations for infectious diseases

2. Improvements in sanitation and hygiene

3. Advances in medical care technology

4. Health education

The correct answer is: Improvements in sanitation and hygiene

Improvements in sanitation and hygiene have had a profound impact on average life expectancy, particularly during the late 19th and early 20th centuries. Prior to these advancements, infectious diseases such as cholera, dysentery, and typhoid fever were rampant due to poor sanitation and contaminated water supplies. The implementation of clean water systems, proper sewage disposal, and public health measures focused on hygiene played a crucial role in dramatically reducing the incidence of these diseases. As a result of these improvements, many infectious diseases that once significantly lowered life expectancy were controlled or eliminated, leading to longer, healthier lives for individuals. The relationship between sanitation and health is well-established, highlighting that a clean environment is essential for preventing diseases and promoting overall public health. While vaccinations, medical advances, and health education are all vital components of public health, their significance cannot be fully realized without a foundation of sanitation and hygiene. Without these fundamental improvements, the effectiveness of medical interventions and health education would be severely compromised. Thus, sanitation and hygiene stand out as the most impactful factors in the improvement of life expectancy historically.