Lead poisoning through chronic exposure is characterized by gastrointestinal disturbance, anemia, insomnia, weight loss, motor weakness, muscle paralysis, and neuropathy. Ingestion of large quantities may produce death Increased urinary lead excretion indicates excessive lead exposure, regardless of clinical presentation. Erythrocyte protoporphyrin and whole blood lead levels are probably more sensitive indicators of excessive lead exposure. In cases of borderline blood levels, an EDTA lead mobilization test may be considered. Chelation therapy monitoring may be indicated. Lead and organic lead compounds have numerous commercial and industrial applications, use in paints, plastics, storage batteries, bearing alloys, insecticides, and ceramics. Exposure may also occur through the inhalation of dust containing lead emitted by automobile exhausts. A common source of lead exposure among children is derived through the mouthing of inanimate objects, specifically objects with paint and paint chips that contain lead. Acute lead exposure is rare; however, toxicity may occur through acute ingestion of a lead salt or acetate. Urine is suggested specimen in which chronic lead poisoning may be monitored.  BEI® are reference values intended as guidelines for evaluation of occupational exposure. BEI® represent biological levels of chemicals that correspond to workers with inhalation exposure equivalent to the threshold limit value (TLV®) of the chemicals. TLVs refer to the airborne concentrations of substances and represent conditions under which it is believed that nearly all workers may be repeatedly exposed, day after day, without adverse health effects.