Human Health: Another Major Challenge of Global Soil Security.

Contamination is one of the threats affecting soil all over the World. Contaminants are resulting from human activities like industrial emissions, agricultural pesticides and fertilizers, waste treatment and storage, transport or traffic emissions. These contaminants can be directly transferred to soil or indirectly via air or water. Some of them, like persistent organic pollutants, due to their long-range transport potential and their ability to bio-accumulation, can pose high risk for soil quality, biodiversity, food security and safety and human health. Studying the relationships between soil contaminants and health is generally not straightforward and usually requires scientists from different fields like geochemistry, pedology, agronomy, toxicology and/or epidemiology.

The classical approach consists in studying what contaminant concentration in soil can people be exposed to without being subject to potential health risk. The exposure is evaluated either from direct measurement on population (biomonitoring) either from soil concentration measurement coupled with a multi-media fate model and exposure route scenarios. This approach is based on risk assessment of exceeding tolerable dose of contaminants during a certain period of exposure variable according to population age. The doses are assessed by international standard toxicological tests on contaminants but their values are different according to countries’ legislation. When spatialized at regional level, exposure assessment of soil contaminants allows for mapping environmental inequalities. Identifying the main factors of risk then helps in taking relevant actions of risk remediation. This action will be in the future, another major challenge of global soil security.