Fishing for Hg and harvesting Pb – Consequences of human activity

It is my first time attending the Goldschmidt conference and I am impressed by the variety of topics that can be accommodated under the umbrella of Geochemistry. From the Origin of Solar System and Mantle Geochemistry to Paleoclimate and Ocean Chemistry. But what drew my attention were sessions related to Medical Geochemistry and particularly topics discussing the metal contamination and the impact on human health.


Lead and mercury can end up in our dish from various sources, with fruit, vegetables and fish to be only a few of them. When was the last time you got a lead or mercury dietary supplement? Obviously never! These two elements are toxic to humans even in small amounts.


Mercury has been released in the oceans from human activity and it accumulates in the soft tissue of the fish. Large fish, such as tuna, contain particularly high concentrations of mercury. Studies have shown that consuming large amounts of big fish poses an increased risk of cardiovascular disease in humans. But this is not a reason to stop eating fish. According to Prof.  Elsie Sunderland, we are exposed to equally high health risk when we preclude big fish from our diet and instead consume processed food. Prof. Sunderland gave a keynote in the session of Medical Geochemistry, where she talked about ‘‘Linking Global Mercury Releases to Local Human Health Outcomes’’.


In addition to mercury, lead is particularly toxic to the human body. Prof. Mark Taylor from Macquarie University presented his work on lead contamination in Australia where he studies the lead content in wine. He also noted a shift in the Pb isotopic composition of wine produced in Australia during the second half of the 20th century. Prof. Taylor has also identified a similar geochemical signature in honey bees.


Later on, Prof. Jane Entwistle from Northumbria University presented her work on the concentration of lead in garden soils and its relationship with the blood lead level of gardeners. This research concerns allotments across Newcastle (UK), a city with long industrial activity.