Industrial dust inhalation

The inorganic tin compound that has received the most study from a toxicological viewpoint is stannic oxide. Autopsies performed on workers in the tin mining and refining industry, who inhaled tin oxide dust for as long as 20 yr, disclosed no pulmonary fibrosis (57). Inhalation for long periods produces a benign, symptomless pneumoconiosis with no toxic systemic effects (58). 

PNEUMOCONIOSIS A gi oup of lung diseases of a ehronie fibrotie eharaeter due to die inhalation and retention in die lungs of a variety of industrial dusts. The main diseases are asbestosis, silieosis, eoalworkers pneumoeoniosis and mixed-dust pneumoeoniosis less eommon pneumoeonioses are assoeiated with tale, elay or aluminium. 

The toxicity of a substance is its capacity to cause injury once inside the body. The main modes of entry into the body by chemicals in industry are inhalation, ingestion and absorption through the skin. Gases, vapours, mists, dusts, fumes and aerosols can be inhaled and they can also affect the skin, eyes and mucous membranes. Ingestion is rare although possible as a result of poor personal hygiene, subconscious hand-to-mouth contact, or accidents. The skin can be affected directly by contact with the chemicals, even when intact, but its permeability to certain substances also offers a route into the body. Chemicals accorded a skin notation in the list of Occupational Exposure Limits (see Table 5.12) are listed in Table 5.2. Exposure may also arise via skin lesions. 

Industrial (outdoor worker) Dust inhalation 2.35x107Dt (2.35x10 Dip for DNT)... 

The PPLVs applicable to industrial scenarios would possibly be water ingestion (as in the case of residential housing), and more likely dust inhalation. A conservative approach would be to use the equation applied to DNT for worker exposure to dust,... 

IBT. 1972a. Acute dust inhalation toxicity study with biomet (tri-n-butyltin fluoride) in albino rats. Report to M and T Chemicals, Inc., Rahway, NJ, by Industrial Bio-Test Laboratories, Inc.,... 

An increase in permeability of the alveolar membrane is seen in a number of pulmonary disease states including adult respiratory distress syndrome and fibrosis. Conversely, asthma does not appear to alter alveolar membrane permeability. Increased permeability will be seen in association with inflammatory reactions, where there is an influx of polymorphs and other cells into the airways. Inhalation of toxicants, such as smoke and industrial dusts, is associated with increased permeability. 

Cobalt is an essential nutrient at low levels ( 40mgday ). In industrial settings, inhalation of high concentrations of cobalt compounds has led to hard-metal pneumoconiosis, which may result in interstitial fibrosis. Workers with this condition typically develop hypersensitivity to cobalt compounds (symptoms include coughing and wheezing). A few workers have developed skin hypersensitivity after dermal contact with cobalt and its compounds. Cobalt can cause cardiomyopathy and (if inhaled as a dust) interstitial lung disease. 

A baseline risk assessment is conducted to assess the potential human health and environmental impacts associated with soil contamination. The primary exposure pathways evaluated for explosives contaminated surface soils are dust inhalation, soil ingestion, and dermal absorption. Reasonable Maximum Exposure (RME) concentrations are based on the 95% upper confidence interval (UCI) on the arithmetic mean of soil sampling data. The land use scenarios quantitatively evaluated may include industrial and residential use, utilizing EPA standard default exposure parameters. 

The general population takes up germanium mainly from food, and the daily intake can vary between 0.4 and 3.5 mg (Schroeder and Balassa 1967, Swennen etal. 2000). Ysart etal. (1999) reported about a daily total dietary exposure of only 0.004 mg in the UK population. Values will depend on the provenance of food and potential industrial contaminants. Inhalation is a potential hazard of occupational exposure (Rods and Buchet 2001). Dust containing up to 7 mg m has been found in the production of Ge monocrystals (Gerber, 1988). 

The effects of land contamination are widespread and past industrial activity is the most significant factor. Soil transport and reaction processes are relatively slow compared to air and water, so contamination tends to persist at the point of deposition for a long period. Table 9.5 summarizes common hazards and examples of contaminants. These contaminants can affect humans by absorption into the body through oral, inhalation or skin adsorption pathways. For volatile compounds and dusts, inhalation is the most important pathway. This is of particular concern with young children playing on contaminated land. The re-use of derelict, industrial sites has emphasized many of these problems . 

Lead in dust, especially interior dusts, is a major pathway for lead exposure of risk populations such as very young children through hand-mouth activity and ingestion or by direct inhalation. Industrial dusts provide exposures for lead workers on the job. 

While levels of beryllium in smoke are generally low owing to the limited use of this element in industry, where there is a specific industrial source of dispersal, acute problems can arise. Inhalation of beryllium compounds which are present in some industrial dusts is known to cause chronic pulmonary damage, and effects on the lungs have been reported by Conradi et al. [160]. 

Cd waste enters the air, water, and soil through industrial and household wastewater and waste incineration, burning of fossil fuels, and biomass. The primary form of Cd in occupational exposures is Cd oxide (CdO), which is predominantly inhaled from industrial dust and fumes. Improved technologies and regulations mean little Cd now enters air and water in Western Europe or Northern America. But it is still a major source of contamination in developing and newly industrializing countries. 

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. 

Health and Safety Factors. Terephthahc acid has a low order of toxicity. Inhalation by rats for 6 h/d, 5 d/wk for 4 wk produced no fatahties at a dust exposure level of 25 mg/m. The mean acute oral toxicity for rats is over 18 g/kg (86), and for mice over 6 g/kg (87). When terephthahc acid was fed as 3% of the diet to rats, urinary calcuh formed in 90 d, some of which led to cancer. High doses of terephthahc acid lead to formation of calcium terephthalate at levels exceeding its solubihty in urine. This insoluble material leads to the calcuh and provides a threshold below which cancer is not observed (88). Normal precautions used in handling industrial chemicals should be observed with terephthahc acid. If ventilation is inadequate, a toxic-dust respirator should be used to avoid prolonged exposure. 

Elemental tellurium and the stable teUurides of heavy nonferrous metals are relatively inert and do not represent a significant health hazard (43—47). Other, more reactive teUurides, including soluble and volatile teUurium compounds such as hydrogen teUuride [7783-09-7] teUurium hexafluoride [7783-80-4] and alkyl teUurides, should be handled with caution. Some of these materials can enter the body by absorption through the skin or by inhalation and ingestion of dust or fumes. No serious consequences or deaths have been reported in workers exposed to teUurium and its compounds in industry (48). 

Short-term inhalation of PVA dust has no known health significance, but can cause discomfort and should be avoided in accordance with industry standards for exposure to nuisance dust. The dust is mildly irritating to the eyes. There are no known dermal effects arising from short-term exposure to either soHd PVA or its aqueous solutions. 

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