1. Korea Forest Service, Government Complex 1, 189 Cheongsa-ro, Daejeon 302-701, Republic of Korea
2. Forestry and Forest Products Research Institute, 1 Matsunosato, Tsukuba 305-8687, Japan
3. College of Agriculture and Life Sciences, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764, Republic of Korea
4. Department of Hygiene and Public Health, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan
5. Center for Environment, Health and Field Sciences, Chiba University, 6-2-1 Kashiwanoha, Kashiwa, Chiba 277-0882, Japan
6. Finnish Forest Research Institute (METLA), P.O. Box 18 (Jokiniemenkuja 1), 01301 Vantaa, Finland