Release dust extracts

Community protection Risk to community not increased by remedy implementation, but, contaminated water may reach the residents within 1—3 yr Temporary increase in dust production through cap installation contaminated soils remain undisturbed Soil would remain uncovered during vapor extraction for 3-5 yr Temporary increase in dust production during cap installation Similar to Alternative 3 Fixation may result in dust and odor increase Soil would remain uncovered during incineration (about 1 yr) excavation and fixation would release dust and odors to the atmosphere... 

Histamine is released from whole rabbit blood by both cotton extracts and endotoxins, however, the ability of AECD to release histamine is greater than would be expected from endotoxin content alone. Antweiler (63), however, was unable to show in vivo histamine release by endotoxins obtained from cotton extracts in rabbits nor could he show an acute fall in blood pressure of cats after I.V. endotoxin injection, as occurred with subsequent injections of compound 48/80 or other dust extracts. He concludes that endotoxins are not responsible for any histamine releasing activity of cotton dust. 

Both histamine and 5-HT have been demonstrated in extracts 5-HT is responsible for some of the bronchoconstrictor activity of cotton dust extracts. Brom-lysergic acid, a specific 5-HT inhibitor, partially reduces activity, suggesting the presence of an "unknown contractor." This does not appear to be acetylcholine or bradykinin. Thus, although histamine, 5-HT, and the "unknown contractor" can cause immediate contractor responses, delayed onset contractions may still be due to secondary release of histamine (105). 

Histamine release from pig lung occurs in response to extracts from cotton pericarp, seed, leaf, root and bract (112). Extracts of sisal release histamine from both pig and human lung, but the reactivity is less than cotton dust extracts. The use of chopped lung for histamine assay is not always reliable, however, nor is it sufficiently sensitive. 

Pig platelets have recently been shown to release histamine when exposed to cotton dust or plant extracts (115) and this assay compares closely with chopped lung assays. Mill dust and gin trash extracts give some release and extracts of leaves from other plant sources, including pecan and grape, give similar reactions. Byssinosan (116). an aminopolysaccharide isolated from cotton dust, and THF antigen (83) are relatively inactive. 

Small airway constriction and recruitment of leukocytes on pulmonary surfaces are prominent, documented responses to the inhalation of cotton dust. Currently, one or both of these effects are generally ascribed to endotoxin (8-10), to antigen-antibody reactions (11), to lacinilene C-7 methyl ether (1, 13), to a low molecular weight ( 1000 daltons), neutral, highly water soluble substance that is stable in boiling water and found in cotton bracts (14), to chemotaxins present in cotton mill dust extracts (15, 16) or to histamine releasing substances (17). 

The platelet hist UIline release assay demonstrated that cotton mill dust extract, cotton bract extract, cotton leaf extract, dialyzed CMD extract, polyphenols, compound 48/80, rutin, trimethylamine HCl, quercetin, catechin, tannic acid, ellagic acid and sodium metasilicate all release histamine directly (48). Thus not only do tannin compounds induce histamine release, but they may also form higher molecular weight polymers and contain components that survive acid hydrolytic conditions (48). Tannins are widely distributed in the plant kingdom. 

Antweller ( ) in 1961 injected Salmonella abortus equl and E. coll endotoxins Intraperltoneally into rats and looked for mast cells in the mesentery and the histamine content of the abdominal fluid. Negative results were obtained with amounts of the endotoxins (up to 10 yg) thought to be similar to that in cotton dust although large doses of endotoxin were known to cause rapid histamine release in cats and dogs. He concluded that endotoxins did not produce histamine release or the biological effect of cotton dust extracts. 

Weighing of solid substances will release dust. A dust extract cabinet, equipped with a High Efficiency Particulate Air (HEPA) or Ultra Low Particulate Air (ULPA) filter (see Table 27.4) in the rear wall or in the exhaust, or both, will limit the exposure of operators to active substances. Additional options are the wearing of respirators (see Sect. 26.4.1) and a closed weighing vessel. 

Aqueous extracts of cotton bract and mill dust are leuco-tactic (15,40). In experimental animals, aqueous extracts of cotton dust (AECD) attract PMNs to airways in a dose dependent fashion beginning at 3 hours, and reaching a peak at 18-24 hours. Macrophage levels Immediately drop and remain low until 18 hours post-exposure when a modest increase occurs. Cell infiltration, with subsequent release of intracellular enzymes and mediators, is thought to be important in the pathology of byssinosis (15). 

Prevalence of byssinosis correlates better with airborne endotoxin concentration than with total dust (65). Also, gramnegative bacteria levels in the mill correlate well with disease (66). It has been hypothesized that endotoxins elicit symptoms of byssinosis by activation of both the classical and the alternative pathway of complement with subsequent release of anaphylatoxins, which lead to airway narrowing, and chemotaxins, which cause the influx of PMNs followed by release of lysosomal enzymes and, ultimately, tissue damage. In experiments with guinea pigs using bract, cotton, and gin mill trash extracts, there is a strong correlation between number of PMNs recruited to airways and level of endotoxin (67). 

Histamine Releasing Agents in Extracts of Cotton Mill Dust and Cotton Bract... 

Soil usually contains between 4 and 80 parts of nickel in a million parts of soil (ppm 1 ppm is 1,000 times greater than 1 ppb). The highest soil concentrations (up to 9,000 ppm) are found near industries where nickel is extracted from ore. High concentrations of nickel occur because dust released to air from stacks during processing settles on the ground. You may be exposed to nickel in soil by skin contact. Children may also be exposed to nickel by eating soil. 

The method by Wells and Alexander uses lower air velocities (the extraction rate is only 50 litres/minute) and does not, therefore, require a deflector plate. The method does not necessarily release all of the potentially airborne particles in the sample in fact, the dust release may be constant in many repeated pourings of the same sample. Either total airborne dust samples may be collected on a filter (i.e. all particles that are still airborne on leaving the box, i.e. smaller than about 10 microns) or only the respirable fraction may be collected by extraction through the Hexhlet sampler. 

PERSONAL PROTECTION wear impervious protective clothing, including boots, chemical-resistant gloves, sleeves, apron or coveralls materials such as nitrile and neoprene are recommended for protection against coal tar extracts wear dust- and/or splash-proof safety goggles and face shield enclose operations and/or use local exhaust ventilation at site of chemical release at concentrations above the NISOH REL, wear self-contained breathing apparatus that has a full face-piece and is operated in positive-pressure mode maintain eye wash baths and safety showers in work area. 

When soluble extracts of dust fi om the Earth s cmst, desert, wind-generated, foothills, and high mountain (Uinta) dust were cultured with BEAS 2B lung epithelial cells, more 1L6 and IL8 were released than when endotoxin alone was cultured (6). These data suggested that soluble material extracted from this dust caused cytokine release from more than endotoxin alone, compared with soluble extracts from manure mat dust. This supports the hypothesis that some ambient dusts from geological sources can cause cell death and cytokine release in a lung cell line that is widely used as an in vitro model to study mechanisms of environmental respiratory injury (6). 

The first conclusion to be drawn from those results was that much needs to be done concerning the testing material, since the histamine release was well below that obtained with the conventional allergens, such as pollen and house dust mite extracts. Secondly, the negative results in two-thirds of the patients could either be due to the poor test allergens used, or that the clinical diagnosis blaming the local anaesthetic for these reactions was incorrect. 

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