Lead respiratory system

RESPIRATORY SENSITIZER (asthmagen) A substance which can cause an individual s respiratory system to develop a condition which makes it over-react if the substance is inhaled again. Such an individual is sensitized over-reaction is then likely to occur at concentrations of the substance which have no effect on unsensitized persons and lead to characteristic symptoms, e.g. rhinitis (a runny nose), conjunctivitis or in severe cases asthma or alveolitis. 

When kaolin or aluminum is administered widi die lincosamides, die absorption of the lincosamide is decreased. When the lincosamides are administered with the neuromuscular blocking drag (drag diat are used as adjuncts to anesthetic drag diat cause paralysis of the respiratory system) die action of die neuromuscular blocking drug is enhanced, possibly leading to severe and profound respiratory depression. 

Symptoms of intoxication in humans caused by accidental ingestion of Kou-Wen plants have been described as follows. The effect on the digestive system starts with loss of appetite and turn of the stomach, and continues to severe abdominal pain and intestinal bleeding. The effect on the respiratory system presents as breathing difficulties which finally lead to death by respiratory failure. The effect on muscle innervation usually results in generalized muscular weakness and paralysis of the limbs. The effect on the circulatory system starts with heartbeat disorders and a drop in blood pressure, but heart failure is not a common cause of death. In addition to dilation of pupils, a drop in body temperature and proliferation of white blood cells have also been obseryed (70). 

Reliable correlations were found between lead concentrations in the soil and the incidence rates in the population of Dnepropetrovsk. In the adults, the pollution levels were associated with complications in pregnancy and delivery, diseases of urogenital, nervous and bone-and-muscular system, blood problems and tumors. In the children, the blood, blood forming organs, respiratory system and the muscles and bones were most frequently affected. 

Intermediate-Duration Exposure.No studies are available on the adverse health effects from intermediate-duration exposure in humans by any route. Studies in animals indicate that exposure to endrin via inhalation can be lethal and causes effects on the nervous and respiratory systems, the liver, the brain, adrenals, and kidneys (Treon et al. 1955). Since systemic effects were observed at levels which caused death, data are not sufficient to derive an intermediate-duration inhalation MRL. Animal studies also demonstrate that oral intermediate-duration exposure can lead to death in several species (rat, mouse, hamster, rabbit, monkeys, cat) (Treon et al. 1955). Endrin was lethal in rabbits following dermal exposure (Treon et al. 1955). No other treatment-related disorders are known. Additional studies for oral and dermal routes using a range of exposure levels would be useful in identifying potential target tissues. 

Gamble J, et al Epidemiological-environmental study of lead acid battery workers. HI. Chronic effects of sulfuric acid on the respiratory system and teeth. Environ Res 35 30-52, 1984... 

Effect on respiratory system Salicylates stimulate respiration by increasing the consumption of oxygen primarily by skeletal muscles and this results in increased production of carbon dioxide, which leads to direct stimulation of the respiratory centre in the medulla oblongata producing an increase in the depth and to some extent in the rate of respiration. Toxic doses depress the respiratory centre. 

Larger particles (several micrometers in size) are deposited in the ciliated portion and are cleared from the respiratory system by muco-ciliary action into the gastronomical tract, but may produce systemic toxic effects by absorption in body fluids. Finer particles reach the lower non-ciliated portion of the lungs, are cleared very slowly, and are responsible for diseases such as pneumoconiosis and lung cancer. Metallic lead (Pb), tellurium ( ), selenium (Se), and platinum (Pt) are known to cause both systemic and respiratory toxicity in laboratory animals and several cases of acute and chronic poisoning among metal workers have also been documented. 

FIGURE 10.1 Schematic representation of the lower respiratory system. The trachea leads into the bronchioles that branch and finally reach the alveolar sacs only on one side of the bronchial tree. Inset represents the alveolar tubules and alveolar sacs present at the terminal portions of the bronchial tree. 

Barbiturates are referred to as sedative-hypnotics. These drugs will induce sleep which can lead to even deeper sedation (hypnosis) and can cause a fatal depression of the RAS affecting the respiratory system. The sleep which is encountered does not have the normal cycles of slow wave and rapid eye movement activity, so it is not always restful. However, these agents prove to be useful in anesthesia for both short and longer durations of time. Many of you may have been given thiopental prior to wisdom tooth extraction. Thiopental "wears off quickly and so the actual anesthetic for the time of the extraction is usually nitrous oxide. 

Volatile irritants such as ammonia and chlorine initially cause constriction of the bronchioles. These two gases are water soluble, are absorbed in the aqueous secretions of the upper airways of the respiratory system, and may not cause permanent damage. Irritant damage may however lead to changes in permeability and edema, the accumulation of fluid. Some irritants such as arsenic compounds cause bronchitis. 

In addition, size reduction can also enhance delivery of poorly water-soluble APIs to the respiratory tract. SpeciLcally, aerosolized particles should have aerodynamic diameters in the range of 1-5(xm. With larger particles, deposition occurs primarily on the back of the throat, which can lead to systemic absorption and undesired side effects. 

Toxic or potentially toxic agents may be inhaled into the respiratory tract where they may cause localized effects such as irritation (e.g., ammonia, chlorine gas), inflammation, necrosis, and cancer. Chemicals may also be absorbed by the lungs into the circulatory system, thereby leading to systemic toxicity (e.g., CO, lead). 

Inorganic lead may be absorbed through the GI tract, the respiratory system, and the skin. Ingested inorganic lead is absorbed more efficiently from the GI tract of children than that of adults, readily crosses the placenta, and in children penetrates the blood-brain barrier. Initially, lead is distributed in the blood, liver, and kidney after prolonged exposure, as much as 95% of the body burden of lead is found in bone tissue. 

The gas irritates the respiratory system, leading to headache, dizziness, rapid pulse, nausea, vomiting, unconsciousness, convulsions, and death, depending on exposure. The gas irritates the eyes, causing lachrymation. Prevent inhalation of gas.5 TLV-TWA 10 ppm (21 mg/m3).6... 

The vapor may irritate the respiratory system and, in high concentrations, have narcotic action. Chronic exposure can lead to loss of sensation in hands and feet. Irritant to skin, eyes, and the gastrointestinal tract. Experimental teratogenic, reproductive effects.3,5,6 TLV-TWA 50 ppm (176 mg/m3).7... 

Public concern for the hazards of particle suspensions in the indoor and outdoor environment has produced regulations limiting particle concentrations and exposure levels. In the workplace, dust hazards are constrained by total mass concentration as well as concentration of specific toxic chemicals. In the ambient air, protection is stipulated in terms of total mass concentration of suspended particles andcertain chemical species, namely, lead and sulfate. Recently, measures of exposure have begun to distinguish between fine particles less than 2.5 fxm and coarse particles between 2.5 and 10 fxm. This separation relates to the ability of particles to penetrate the human respiratory system, and to different sources of fine and coarse particles. 

---