Correlation of Breast Cancer Incidence with the Number of Motor Vehicles and Consumption of Gasoline in Korea

While several reproductive and lifestyle-related factors are already well-known as established risk factorsfor breast cancer, environmental factors have attracted attention only recently. The objective of the currentstudy was to assess the association between the breast cancer incidences in females, the mortality rate and thenumber of motor vehicles on the one side and the consumption of gasoline which could work as a major sourceof air pollution at the other side. The breast cancer incidences and the mortality trends were compared withvarious indices of westernization like dietary patterns or industrialization with 10 years lag of time. Geographicalvariations with 10, 15 and 20 years lag of time were assessed between the breast cancer incidence in 2010and the number of motor vehicles as well as the consumption of gasoline. The upward trend of motor vehiclenumbers proved to be comparable to those of breast cancer incidence and mortality. However, the consumptionof gasoline started to decrease since the mid-1990s. The geographic distribution of motor vehicle numbers andgasoline consumption in 1990 is in a positive correlation with the breast cancer incidence rates in 2010 and the20-year lag time (R2 0.379 with the number of motor vehicles and 0.345 with consumption of gasoline). In a linearrelationship between the breast cancer incidences in 2010 and the log transformed number of motor vehicles, thelog transformed consumption of gasoline in 2000 also showed a positive relationship (R2 0.367 with the numberof motor vehicles and 0.329 with consumption of gasoline). The results of the current study indicate that theremay be a positive relation between the number of vehicles, gasoline consumption and the incidence of breastcancer from the aspects of long-term trends and geographical variation.