The paper reflects the problem of adverse environmental factors on human health, including those on the prevalence of myasthenia and on the blood levels of trace elements in the patient. It outlines the environmental status in the Orenburg Region, which is most unfavorable in the Eastern and Central areas. Myasthenia morbidity trends for its increase are covered in 1967 to 2006. The paper also shows the prevalence of myasthenia, with predominance per 100,000 individuals in the Eastern and Central areas, which coincides with the highest anthropogenic load in these areas. The data of a preliminary analysis of trace elements, such as copper, zinc, manganese, nickel, lead, strontium, chromium, cadmium, cobalt, iron, in the blood of patients with myasthenia as compared with those in controls and by regions reflect a general trend for the blood levels of these trace elements to be decreased, as well as their imbalance by the areas of the Orenburg Region.