Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Aplastic Anemia


Overview

Aplastic anemia is the failure of the bone marrow to produce blood cells (red blood cells, white blood cells, and platelets) because the stem cells have been damaged. Stem cells are precursor cells from which all blood cell lines develop. Because fewer new blood cells are produced, the old blood cells at the end of their life spans are not replaced. This results in a decrease in the number of all blood cell types within the circulating blood (pancytopenia). Without red blood cells, anemia develops, and oxygen cannot be distributed throughout the body. Without white blood cells, infections cannot be fought. Without platelets, blood does not clot normally.

Aplastic anemia may be acquired, inherited (congenital), or self-originating (idiopathic). The congenital form is called Fanconi anemia; for individuals to be affected, they must inherit one gene from each parent (autosomal recessive disease). Congenital aplastic anemia (Fanconi) develops before the ages of 30 to 40 in predisposed individuals. In addition to pancytopenia, individuals with Fanconi anemia often have other physical anomalies involving the skin, heart, genitourinary tract, skeletal system, central nervous system, growth, and mental capacity. It is estimated that 1 individual in 100 to 600 have the gene for this disease (are carriers), although they are not affected.

Acquired aplastic anemia is more common. Damage to the stem cells may be caused by a variety of external agents such as ionizing radiation, the chemical benzene and its derivatives, chemotherapeutic cancer drugs, certain antibiotics, and other toxic chemicals like inorganic arsenic. Other agents only occasionally associated with aplastic anemia include a wide variety of drugs and chemicals such as some antibiotics, analgesics, and insecticides. Certain infections are also associated with aplastic anemia, including non-A, non-B, and non-C hepatitis; Epstein-Barr virus; HIV; and parvovirus B19. Acquired aplastic anemia may also result from an immune reaction in which an individual's own immune system attacks the stem cells. Aplastic anemia can develop during pregnancy and may be associated with the accompanying rise in the female hormone estrogen. In more than half the cases of acquired or idiopathic aplastic anemia, the cause is never determined.

Incidence and Prevalence: Although there is no accurate prospective data on the national incidence of aplastic anemia, several studies based on reviews of death registries suggest that the US incidence ranges from 0.6 to 6.1 cases per million population; in Europe and Israel, the incidence is 2 individuals per million, and in some parts of Asia, the incidence is 4 individuals per million (Bakhshi). It is believed that the increased incidence of aplastic anemia in Asia is due to exposure to toxic substances, rather than genetic factors.

Source: Medical Disability Advisor