Environmental contaminants in foods and feeds in the light of climate change

Introduction: Environmental contaminants are groups of unwanted, ubiquitous chemicals, found in food via weathering of the earth's crust, combustion (natural or anthropogenic), industrial uses or as unwanted bi-products of manufacturing processes. Evidence suggests that the climate is becoming hotter and more variable, resulting in rising sea levels, warmer oceans, more forest fires and more extreme events such as floods, storms, cyclones, droughts and landslips.

Methods: Sources of environmental contaminants into food or feeds are described. The impact of climate change on the formation, distribution or uptake of these contaminants is addressed with reference to the scientific literature.

Results: Climate change may result in increased atmospheric release and mobilization of environmental contaminants, an increased rate of mercury methylation, changes in biological systems and increased applications of contaminants to soils and crops from water re-use. Conversely, climate change policies, to reduce carbon emissions, are driving energy efficiencies, leading to reduced emissions of dioxins, polycyclic aromatic hydrocarbon and heavy metals.

Conclusion: Climate change is likely to increase human exposure to arsenic, cadmium, lead, mercury, dioxins, polycyclic aromatic hydrocarbons and polychlorinated biphenyls where food and feeds may be contaminated by forest fires, water re-use or increased methylation (mercury only). The extent of this change is yet to be quantified.