Change in thyroid cancer death rates versus change in median urinary iodine concentration. Correlation plot of change in age-adjusted (world population) death rates from thyroid cancer (TC) at all ages in a women and b men between 2000 and 2010 versus national or large subnational population median urinary iodine concentration (UIC) (μg/L) for the same time periods. Each data point represents one country. National thyroid cancer death rates are from La Vecchia et al.  and UIC data are from the Iodine Global Network  and WHO VMNIS . Coefficient of determination r2 and p-value are derived from the linear regression model.