Background The American Cancer Society estimates that about 25% of all US cancer deaths will be due to lung cancer – more than from cancers of the colon, breast, and prostate combined.

Methods We ascertained county-level age-adjusted and age-specific death rates and 95% confidence intervals from the Centers for Disease Control and Prevention Compressed Mortality File. Multiple regression analyses were used to estimate the strength and direction of relationships between county poverty, smoking, fine particulate matter (PM_2.5) air pollution, and US Census divisions and race- and sex-specific lung cancer deaths.

Results Poverty, smoking, and particulate matter air pollution were positively and significantly related to lung cancer deaths among white men, but of these, only poverty and smoking were significantly associated with lung cancer deaths among white women. Residence in the South Atlantic, East South Central, and West South Central US Census divisions at the time of death was significantly associated with lung cancer deaths for both white men and white women. As with white men, poverty and smoking were associated with lung cancer deaths among black men, but of these, only adult smoking had a statistically significant association among black women.

Conclusions The results support the need for further research, particularly in high-risk areas, to better differentiate factors specific to race and sex and to understand the impact of local risk factors.