Linkages between biodiversity loss and human health: a global indicator analysis

The association between health and biodiversity loss was explored by means of regression analysis on a global scale, with control for confounding by socio-economic developments. For this we selected indicators of human health (life expectancy, disability adjusted life expectancy, infant mortality rate and percentage low-birthweight babies), biodiversity (percentage threatened species, current forest as a percentage of original forest, percentage of land highly disturbed by man) and socio-economic development (health expenditure as percentage of GNP, percentage one-year olds immunized, illiteracy rate, GNP per capita and development grade) on a country level. After controlling for relevant socio-economic confounders, both current forest as a percentage of original forest and the percentage of land highly disturbed by human activities had no relationship with one of the health indicators. The logarithm of the percentage threatened species, showed a positive association with life expectancy and disability adjusted life expectancy. The present study was not able to provide any empirical proof of a negative association between loss of biodiversity and human health at the global scale. This does not mean, however, that no such relationship exists, because there may be several reasons for our findings, like possible non-linearity of the relationship, lack of suitable indicators, non-randomness in the sample of countries and the limitations of regression analysis in proving causality.