The estimated number of deaths due to smoking in the 20th century was around 100 million people. This estimate is based on data from various sources, including the International Mortality and Smoking Statistics (IMASS), the Institute of Health Metrics and Evaluation (IHME), and the World Health Organization (WHO). These organizations have collected data on tobacco product consumption, smoking prevalence, and related mortality, often spanning back 100 years.
The death rates from smoking have shown significant variation across different regions of the world, with higher rates observed in Asia and Eastern Europe. These rates have been influenced by factors such as the prevalence of smoking in the population, differences in smoking habits between genders, and the impact of smoking on health conditions like lung cancer.
It's important to note that the trends in smoking-related deaths have changed over time. The rise and fall of smoking rates in various countries, especially in the early to mid-20th century, had a significant impact on health. However, in recent decades, there has been a decline in smoking-related death rates in most countries, reflecting global efforts to reduce smoking prevalence and mitigate its health impacts.
For more detailed information and data visualizations, you can refer to Our World in Data's extensive coverage on smoking and its consequences oai_citation:1,Smoking - Our World in Data oai_citation:2,Smoking - Our World in Data.