Mercury can enter the food chain either from agricultural products or from seafood. It was widely used in agriculture, and at least 459 people are known to have died in Iraq after grain treated with a fungicide containing mercury was imported in 1971 and used to make flour (Greenwood, 1985). Those who showed the greatest effects were the children of women who had eaten contaminated bread during pregnancy. Human groups at risk include the millions of ASGM miners across the world, where mercury compounds are used in production. However, a far greater number of people whose main source of protein is fish or other marine creatures may be exposed to contamination (UNEP-WHO, 2008). The Food and Agriculture Organization says: “Just over 100 million tonnes of fish are eaten world-wide each year, providing two and a half billion people with at least 20% of their average per capita animal protein intake. This contribution is even more important in developing countries, especially small island states and in coastal regions, where frequently over 50% of people’s animal protein comes from fish. In some of the most food-insecure places – many parts of Asia and Africa, for instance – fish protein is absolutely essential, accounting for a large share of an already low level of animal protein consumption” (FAO, 2010). Mercury can seriously harm human health, and is a particular threat to the development of fetuses and young children. It affects humans in several ways. As vapour it is rapidly absorbed into the blood stream when inhaled. It damages the thyroid, kidneys, lungs, immune system, eyes, gums and skin. Neurological and behavioural disorders may be signs of mercury contamination, with symptoms including tremors, insomnia, memory loss, neuromuscular effects, headaches, and cognitive and motor dysfunction. Recent studies have also shown mercury to have cardiovascular effects (McKelvey and Oken, 2012). In the young it can cause neurological damage resulting in symptoms such as mental retardation, seizures, vision and hearing loss, delayed development, language disorders and memory loss.
From collection: Mercury - Time to act