Mercury vapor contamination

Waffarn F and Hodgman JE (1979) Mercury vapor contamination of infant incubators a potential hazard. Pediatrics 64 640—642. 

Waffarn, F. and Hodgman, J.E. (1979) Mercury vapor contamination of infant incubators A potential hazard. Pediatrics 64, 640-642. Warkany, J. and Hubbard, D.E. (1948) Mercury in the urine of children with acrodynia. Lancet 1, 829-830. 

Direct reading samplers include simple devices such as colorimetric indicating tubes in which a color change indicates the presence of the contaminant in air passed through the tube, or instruments which are more or less specific for a particular substance. In the latter category are carbon monoxide indicators, combustible gas indicators (explosimeters) and mercury vapor meters, as well as a number of other instruments. 

The MRU technology is not applicable to heavy-metal-contaminated soils nor to radioactive waste contamination. The one exception to heavy-metals remediation is mercury. The vaporization temperature for mercury is well within the operating range of the MRU, and because of closed chamber construction, it is ideally suited for the removal and reclamation of mercury from contaminated soil. 

One strategy for avoiding these problems is to use the services of a mercury recycler such as Quicksilver Products, Inc. of Brisbane, CA This company is an EPA licensed handler of mercury wastes that is able to extract the mercury from fluorescent tubes and mercury vapor lamps, as well as from batteries, switches, thermometers, contaminated soil, and other sources. 

The loss of mercury from water samples on storage has been shown to be a serious problem by many workers [24—26]. These losses of mercury are caused by rapid adsorption on container walls [25, 29] and reduction of mercury to the atomic state followed by volatilization from solution [29], Lo and Wai reported that 81% of mercury in untreated samples was lost to the walls of the polyethylene containers and the remaining 19% was volatilized to the atmosphere [29], Bothner and Robertson observed mercury contamination of seawater samples due to the diffusion of mercury vapor from the laboratory into the polyethylene containers [31]. 

Ultraviolet light is frequently employed to reduce airborne microbial contamination. Surface sterilization is usually achieved by employing a mercury vapor lamp with an emitted light of 253.7 run. 

In studying the chemisorption of hydrogen on carefully reduced nickel the author has actually observed that a minute quantity of the vapor of stop-cock grease or of mercury vapor from a pressure gage appreciably affect the rate of chemisorption in so far as these contaminants reduce considerably the rate of adsorption and produce the effects typical for the so-called activated adsorption. Incomplete reduction of nickel oxide to the metal leads to a similar result. This can be avoided by repeated reduction and subsequent evacuations of the metal sample at 400°C. for a week. A typical result obtained with an exhaustively reduced nickel specimen is shown in Fig. 1. In view of these findings, the activated adsorption of hydrogen on other reduced metal catalysts frequently reported in the earlier literature might have been caused by contamination effects. 

Potential sources of human exposure to mercury include food contaminated with mercury, inhalation of mercury vapors in ambient air, and exposure to mercury through water, soil and sediment. Dietary intake is by far the most important source of exposure to mercury for the general population. Fish and other seafood products are the main source of methylmercury in the diet studies have shown that methylmercury concentrations in fish and shellfish are 10-100 times greater than in other foods, including cereals, potatoes, vegetables, fruits, meats, poultry, eggs, and milk. As of December 1998, mercury was the chemical contaminant responsible, at least in part, for the issuance of 1931 fish consumption advisories by 40 states, including the US territory of American Samoa. Almost 68% of all advisories issued in the United States are a result of mercury contamination in fish and shellfish. Advisories for mercury have increased steadily by 115% from 899 advisories in 1993 to 1931 advisories in 1998. The number of states that have issued mercury advisories also has risen steadily from 27 states in 1993 to 40 states in 1997, and remains at 40 states for 1998. Advisories for mercury increased nearly 8% from 1997 (1782 advisories) to 1998 (1931 advisories). 

It is possible for you to be exposed to metallic mercury vapors from breathing contaminated air around hazardous waste sites, waste incinerators, or power plants that bum mercury-containing fuels (such as coal or other fossil fuels), but most outdoor air is not likely to contain levels that would be harmful. Exposure to mercury compounds at hazardous waste sites is much more likely to occur from handling contaminated soil (i.e., children playing in or eating contaminated surface soil), drinking well-water, or eating fish from contaminated waters near those sites. Not all hazardous sites contain mercury, and not all waste sites that do contain mercury have releases of mercury to the air, water, or surface soils. 

If small amounts of mercury are spilled, be very careful cleaning it up. Do not try to vacuum spilled metallic mercury. Using a vacuum cleaner to clean up the mercury causes the mercury to evaporate into the air, creating greater health risks. Trying to vacuum spilled metallic mercury also contaminates the vacuum cleaner. Also, take care not to step on the mercury and track it into other areas of the home. Metallic mercury vapors are very toxic and have no odor. Do not remain unnecessarily in that room, and try not to let metallic mercury contact your eyes, skin, or clothing. If you think you have been exposed directly to metallic mercury, wash yourself... 

Occupational mercury exposures generally occur when workers inhale metallic mercury vapors. Some dermal absorption may occur from skin contact with contaminated air, but the rate is low (less than 3% of the inhaled dose). Dialkyl mercury compounds, which are not normally found in hazardous waste sites, are rapidly and extensively absorbed from both dermal and inhalation routes of exposure. 

Metallic mercury vapors are very toxic and are virtually odorless. Inhalation of mercury-laden dust, vapor, or mist should be avoided. Metallic mercury not should not come in contact with eyes, skin, or clothing. If children are exposed directly to metallic mercury, the contaminated body area should be thoroughly washed, and contaminated clothing should be removed and disposed of in a sealed plastic bag (ATSDR 1997). ATSDR and EPA recommend very strongly against the use of any uncontained metallic (liquid) mercury in homes, automobiles, day care centers, schools, offices, and other public buildings. If a child has metallic mercury on his or her clothing, skin, or hair, the fire department should be advised and the child should be properly decontaminated (ATSDR 1997). 

Adults may receive higher mercury exposures from dermal contact if they work with mercury-contaminated soils. Mercury has been detected in soil and sediment at 350 and 208 sites, respectively, of the 714 NPL sites where it has been detected in some environmental media (HazDat 1998). No experimental information on dermal exposure related to the bioavailability of mercury or mercury compounds sorbed to soils was found. However, Hursh et al. (1989) conducted a study to determine the role of dermal exposure in the uptake of mercury vapor from air. These authors estimated that during an 8-hour day, a person would absorb through the skin only 2.6% of the mercury vapor retained by the lungs exposed to the same atmosphere. These authors also noted that half of the dermal uptake is lost through normal shedding of the stratum comeum. Therefore, dermal uptake of mercury adsorbed to soil is likely to be minor compared to other exposure pathways. Recent information from Hamly et al. (1997) showed that urine mercury levels in a Native American population living near an inactive mercury mine in Clear... 

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