Lead chronic

Arthritis is the leading chronic condition reported by the elderly however, more than half of those with arthritis are under the age of sixty-five. 

Unlike the neurotoxicological, developmental, and other toxic effects of lead, chronic lead nephropathy was historically viewed as a disease of adults, particularly lead workers, and children were generally considered to be at low risk. The exception to this view was kidney tubular injury in early, acute childhood Pb poisoning in the form of Fanconi Syndrome. 

Benzodiazepines. Several BZs have anticonvulsant activity and ate used for the treatment of epilepsy producing their anticonvulsant actions via interactions with the GABA /BZ receptor complex to enhance inhibitory GABAergic transmission (1). The anticonvulsant actions of the BZs tend to tolerate upon chronic usage in six months, and BZs also lead to withdrawal symptomatology. Other side effects include sedation, ataxia, and cognitive impairment. 

Two compounds associated with particular industrial risks are iron(III) oxide, Fe202, and iron pentacarbonyl, Fe(CO). Chronic inhalation of iron(III) oxide leads to siderosis. Adequate ventilation and mechanical filter respirators should be provided to those exposed to the oxide. Iron pentacarbonyl is volatile and highly toxic. 

Exposure to excessive amounts of lead over a long period of time (chronic exposure) increases the risk of developing certain diseases. The parts of the body which may be affected include the blood, nervous system, digestive system, reproductive system, and kidneys. These effects include anemia, muscular weakness, kidney damage, and reproductive effects, such as reduced fertiHty in both men and women, and damage to the fetus of exposed pregnant women. 

Workers who produce or use lead should be aware of possible ha2ards. Symptoms of chronic lead poisoning include fatigue, headache, constipation, uneasy stomach, irritabiHty, poor appetite, metallic taste, weight loss, and loss of sleep. Most of these same symptoms also occur in many common illnesses, such as the flu, thus a physician must rely on tests, such as blood lead analysis, to determine chronic lead poisoning. 

The alimentary symptoms may be overshadowed by neuromuscular dysfunction, accompanied by signs of motor weakness that may progress to paralysis of the exterior muscles or the wrist (wrist drop), and less often, of the ankles (foot drop). Encephalopathy, the most serious result of lead poisoning, frequendy occurs in children as a result of pica, ie, ingestion of inorganic lead compounds in paint chips this rarely occurs in adults. Nephropathy has also been associated with chronic lead poisoning (147). The toxic effects of lead may be most pronounced on the developing fetus. Consequendy, women must be particulady cautious of lead exposure (148). The U.S. Center for Disease Control recommends a blood level of less than 10 p.m per 100 mL for children. 

Lead is toxic to the kidney, cardiovascular system, developiag red blood cells, and the nervous system. The toxicity of lead to the kidney is manifested by chronic nephropathy and appears to result from long-term, relatively high dose exposure to lead. It appears that the toxicity of lead to the kidney results from effects on the cells lining the proximal tubules. Lead inhibits the metaboHc activation of vitamin D in these cells, and induces the formation of dense lead—protein complexes, causing a progressive destmction of the proximal tubules (13). Lead has been impHcated in causing hypertension as a result of a direct action on vascular smooth muscle as well as the toxic effects on the kidneys (12,13). 

Magnesium vanadates, as vanadium compounds in general, are known irritants of the respiratory tract and conjunctiva. The threshold limit value (TLV) for vanadium compounds in air recommended by the National Institute of Occupational Safety and Health is 0.05 mg/m based on a typical 8-h workday and 40-h workweek (7,147). Chronic inhalation can lead to lung diseases such as bronchitis, bronchopneumonia, and lobar pneumonia. These dust-related effects can be avoided by use of individual respirators in areas where exposure is likely. 

Workers in the metals treatment industry are exposed to fumes, dusts, and mists containing metals and metal compounds, as well as to various chemicals from sources such as grinding wheels and lubricants. Exposure can be by inhalation, ingestion, or skin contact. Historically, metal toxicology was concerned with overt effects such as abdominal coHc from lead toxicity. Because of the occupational health and safety standards of the 1990s such effects are rare. Subtie, chronic, or long-term effects of metals treatment exposure are under study. An index to safety precautions for various metal treatment processes is available (6). As additional information is gained, standards are adjusted. 

The first implantable pacemaker, introduced in 1960, provided a permanent solution to a chronic bradyarrhythmia condition. This invention had a profound impact on the future of medical devices. The pacemaker was the first implantable device which became intrinsic to the body, enabling the patient to lead a normal life. 

Vanadium compounds, including those which may be involved in the production, processing, and use of vanadium and vanadium alloys, are irritants chiefly to the conjuctivae and respiratory tract. Prolonged exposure may lead to pulmonary compHcations. However, responses are acute, never chronic. Toxic effects vary with the vanadium compound involved. For example, LD q (oral) of vanadium pentoxide dust in rats is 23 mg/kg of body weight (24). 

The principal mechanism of the hypotensive effect of diuretics (qv) is salt and fluid depletion, leading to reduction in blood volume (200,240). Acute effects lead to a decrease in cardiac output and an increase in total peripheral resistance. However, during chronic adrninistration, cardiac output and blood volume return toward normal and total peripheral resistance decreases to below pretreatment values. As a result, the blood pressure falls. The usual reduction in blood volume is about 5%. A certain degree of sustained blood volume contraction has to occur before the blood pressure decreases. The usual decrease in blood pressure achieved using a diuretic is about 20/10 mm Hg (2.7/1.3 kPa) (systoHc/diastoHc pressures. 

The effects of dmgs and adjuvants must be assessed, both in short-term administration and during chronic treatment. Local effects include changes in mucocihary clearance, cell damage, and irritation. Chronic erosion of the mucous membrane may lead to inflammation, hyperplasia, metaplasia, and deterioration of normal nasal function (76). 

Air-poUutant effects on neural and sensory functions in humans vary widely. Odorous pollutants cause only minor annoyance yet, if persistent, they can lead to irritation, emotional upset, anorexia, and mental depression. Carbon monoxide can cause death secondary to the depression of the respiratory centers of the central nervous system. Short of death, repeated and prolonged exposure to carbon monoxide can alter sensory protection, temporal perception, and higher mental functions. Lipid-soluble aerosols can enter the body and be absorbed in the lipids of the central nervous system. Once there, their effects may persist long after the initial contact has been removed. Examples of agents of long-term chronic effects are organic phosphate pesticides and aerosols carrying the metals lead, mercury, and cadmium. 

There is no criterion for lead, due to the chronic nature of the health effects of concern. 

The nonvisual or subtle effects of air pollutants involve reduced plant growth and alteration of physiological and biochemical processes, as well as changes in the reproductive cycle. Reduction in crop yield can occur without the presence of visible symptoms. This type of injury is often related to low-level, long-term chronic exposure to air pollution. Studies have shown that field plantings exposed to filtered and unfiltered ambient air have produced different yields when no visible symptoms were present (5). Reduction in total biomass can lead to economic loss for forage crops or hay. 

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