1 Department of Statistics, Iowa State University, 1212, Snedecor Hall, 2438 Osborn Dr, Ames, IA, 50011, USA.
2 Department of Geography, University of Oregon, Eugene, OR, 97403, USA.
3 Environmental Health Research Department, Environmental Health Research Division, National Institute of Environmental Research, Incheon, Korea.
4 Department of Cancer Control and Population Health, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang-si, Gyeonggi-do, Korea. sykim@ncc.re.kr.