Irritant mechanical irritation

No toxic effects of rhodium have been reported from observations of human beings. Workers wearing rings coated with rhodium showed negative rhodium patch tests while all other metals in the rings gave positive results. It has been reported that inhalation of excessive amounts of fine rhodium metal powder or dust may cause irritation of the respiratory system, and that eye contact with fine powder or dust may cause irritation (mechanical irritation). 

Ammonia—water systems operate under moderate pressures and care must be taken to avoid leaks of the irritating and toxic ammonia (qv). Sometimes a third material with a widely different density, eg, hydrogen, is added to the cycle in order to eliminate the need for mechanical pumping. 

Acute effects of overexposure are as follows. Exposure to dust may cause mechanical irritation of the eye. PPS is essentially nonirritating to the skin, although freshly molded material may occasionally cause dermatitis. Inhalation of PPS dust may cause mechanical irritation to mucous membranes of nose, throat, and upper respiratory tract. 

Primary irritants cause inflammation. Inflammation is one of the body s defence mechanisms. It is the reaction of a tissue to harm which is insufficient to kill the tissue and is typified by... 

The particle size is the most important factor that contributes to the clearance of particles. For particles deposited in the anterior parts of the nose, wiping and blowing are important mechanisms whereas particles on the other areas of the nose are removed with mucus. The cilia move the mucus toward the glottis where the mucus and the particles are swallowed. In the tracheobronchial area, the mucus covering the tracheobronchial tree is moved upward by the cilia beating under the mucus. This mucociliary escalator transports deposited particles and particle-filled macrophages to the pharynx, where they are also swallowed. Mucociliary clearance is rapid in healthy adults and is complete within one to two days for particles in the lower airways. Infection and inflammation due to irritation or allergic reaction can markedly impair this form of clearance. 

The interactions may be physicochemical without the participation of biological mechanisms for example, deep lung exposure to highly soluble irritative gases, such as sulfur dioxide, may become enhanced due to adsorption of the gas onto fine particles. Biological interactions may occur at all stages and body sites. For example, toxicity is increased when adverse effects are due to some reactive metabolic intermediate and exposure to another agent stimulates its metabolic activation (enzyme induction). 

Inhaled gaseous compounds are absorbed in all parts of the respiratory system whereas particle size determines how deep into the airways the parti cles will he transported in the airstrearn. Shortness of breath is a typical sign of a chemical exposure that has affected the lungs, and it may be evoked through iminunological mechanisms (e.g., formaldehyde, ethyleneoxide), or through toxic irritation (formaldehyde, isocyanates, sulfur dioxide, nitrogen dioxide, Frequently the mechanism depends on the concentration ol the com... 

The pain appears to arise from the formation of melittin pores in the membranes of nociceptors, free nerve endings that detect harmful ( noxious —thus the name) stimuli of violent mechanical stress, high temperatures, and irritant chemicals. The creation of pores by melittin depends on the nociceptor membrane potential. Melittin in water solution is tetrameric. However, melittin interacting with membranes in the absence of a membrane potential is monomeric and shows no evidence of oligomer... 

In a similar way, my question in this article will be to be to ask to what extent the periodic table of the elements can be explained strictly from first principles of quantum mechanics without assuming any experimental data whatsoever. I suspect that some readers and fellow contributors to this volume might well experience some irritation at the almost perverse demands which I will make on what should be derivable from the current theory. If so, then I apologize in advance. 

Chitosan acetate and lactate salt films have been tested as wound-healing materials. Mechanical, bioadhesive and biological evaluation of the films were carried out. The results were compared to Omiderm . Chitosan lactate exhibited a lower tensile strength, however, it was more flexible and bioadhesive than chitosan acetate. Chitosan lactate and Omiderm did not cause any allergic reactions in contrast, chitosan acetate produced skin irritation clearly due to the anion. Nevertheless, no sign of toxicity was encountered when the extracts of three preparations were administered parenterally [244]. 

Exposure to fiime and the precipitated silica (amorphous silica) causes fatal bronchial response as these are respirable. Repeated exposure dries the skin and causes mechanical irritation to eyes. Sol-gel silica, as an alternative to this, ceases the floating problem and avoids unnecessary contamination. 

Mechanical irritation of the skin (rubbing, scratching, friction)... 

Contairis in-depth coverage of the bask prindpics, mechanisms and basis for stareoinduction, scope arid Irritations strategies perspectives for future developrrwnt... 

Primary irritants cause inflammation. Inflammation is one of the body s defence mechanisms. It is the reaction of a tissue to harm which is insufficient to kill the tissue and is typified by constriction of the small vessels in the affected area, dilation of the blood vessels, increased permeability of the vessel walls, and migration of the white blood and other defensive cells to the invading harmful chemical. The aim is to concentrate water and protein in the affected area to dilute the effect and wash away the chemical. Production of new cells is speeded up and contaminated surface cells are shed. 

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