Read more from The Guardian here.
Doctors have known that cancer and smoking were linked as early as 1912
Authors details Dr Janine Nip, ASPIRE Aotearoa Research Centre, and Department of Public Health, tkou Whakaihu Waka | University of Otago Prof Richard Edwards, ASPIRE Aotearoa Research Centre, and Head of Public Health of the College of Medicine & Public Health, Flinders University Prof Janet Hoek, Co-Director of ASPIRE Aotearoa Research Centre, and Department of Public Health, tkou Whakaihu Waka | University of Otago Assoc Prof Andrew Waa, Co-Director of ASPIRE Aotearoa Research Centre, and Department of Public Health, tkou Whakaihu Waka | University of Otago Lani Teddy, ASPIRE Aotearoa Research Centre, and Department of Public Health, tkou Whakaihu Waka | University of Otago Appendix 1
International travel is a different story (with a little more complicated drug import rules)