a ten-fold increase in the last 150 years in levels in belugas, ringed seals, polar bears and birds of prey. Over 90 per cent of the mercury in these animals, and possibly in some Arctic human populations, is therefore believed to have originated from human sources. The average rate of increase in wildlife over the past 150 years is one to four per cent annually. The re- port is clear about the implications for human health: “The fact that trends are increasing in some marine species in Canada and West Greenland despite reductions in North American emissions is a particular cause for concern, as these include species used for food” (AMAP, 2011). A recent study of the preschool children in three regions of the Arctic showed that almost 59% of chil- dren exceeded the provisional tolerable weekly intake (PTWI) level for children (Tian et al., 2011; WHO, 1998).
Mercury can seriously harm human health, and is a particular threat to the development of fetuses and young children. It af- fects humans in several ways. As vapour it is rapidly absorbed into the blood stream when inhaled. It damages the central nervous system, thyroid, kidneys, lungs, immune system, eyes, gums and skin. Neurological and behavioural disorders may be signs of mercury contamination, with symptoms including trem- ors, 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 re- sulting in symptoms such as mental retardation, seizures, vision and hearing loss, delayed development, language disorders and memory loss. The Inuit population of Quebec has among the highest levels of exposure to mercury of any population in the world. Scientists recently concluded that children with higher levels of contamination are more likely to be diagnosed with at- tention deficit hyperactivity disorder (Boucher et al., 2012).
In cases of severe mercury poisoning, as occurred in the Mi- namata case in Japan, symptoms can include numbness in the hands and feet, general muscle weakness, narrowing of the field of vision, and damage to hearing and speech (EINAP). In extreme cases, insanity, paralysis, coma and death have been known to ensue rapidly. People may be at risk of inhaling mer- cury vapour from their work (in industry or ASGM), or in spills, and may be at risk through direct contact of mercury with the skin. The most common form of direct exposure for humans, however, is through consuming fish and sea food contami- nated with methylmercury. Once ingested, 95 per cent of the chemical is absorbed in the body.