People are most often exposed to mercury in water, amalgam dental fillings, vaccines with ethylmercury as a preservative and in methylmercury containing fish. Foetuses and children are most susceptible to toxic mercury, which passes to their organisms through the placenta or with mother’s milk. Distribution of mercury in organs depends on the type of compound absorbed and duration of exposure. Mercury is mainly absorbed through the respiratory system. There are two types of mercury poisoning: acute and chronic. The critical organs for acute poisoning with mercury vapour are the lungs. Acute poisoning develops when large amounts of mercury are inhaled, which may lead to acute bronchitis, bronchiolitis and pneumonia. Chronic exposure to mercury vapour primarily affects the central nervous system. Mercury is considered as a contributing factor in aetiology of numerous disorders, including neurologic, renal, immunological, cardiologic, reproductive or even genetic abnormalities. Studies have demonstrated the correlation between mercury toxicity and pathogenesis of Alzheimer’s or Parkinson’s disease, autism and multiple sclerosis. Mercury may be involved in four processes which lead to genotoxicity: generation of free radicals and oxidative stress, effects on microtubules and on DNA repair mechanisms as well as direct interaction with DNA molecules.

19.1.2014