Mercury dosing

Keywords Fluorescent lamps Mercury dosing Producer Responsibility Fund Producer Responsibility Organization... 

The entire equation set was solved numerically using Gear s method for stiff differential equations (Gear 1971). The initial mercury dose was administered at 100% methylmercury, administered as a bolus to the gut lumen compartment. The mass transport parameters listed in Table 2-6 were multiplied by the time-dependent compartment volumes to give the mass transport parameters used in the model equations. 

Halbach (1994) examined the data from 14 independent studies and concluded that the probable mercury dose from amalgam is less than 10 g/day. When combined with the 2.6 g/day background intake estimated by WHO (1990) for persons without amalgam fillings and with an estimated methylmercury intake of 5 g/day from food, Halbach noted that the sum of all those inputs still falls within the WHO s 40 g/day acceptable daily intake (ADI) level for total mercury. For the ADI of 40 g total mercury exposure inhaled, approximately 30 g would be absorbed, assuming 80% absorption (Halbach 1994 WHO 1976). 

The differences in these studies highlight the importance of interpreting epidemiology results and, indeed, all study results on mercury toxicity within a fairly comprehensive context of the numerous factors that might affect the toxicokinetics and the amount absorbed (e.g., form of mercury, route of exposure, age, diet of population exposed, health status, other potential sources of exposure to mercury, dose duration, constancy of dose amount over time, etc.)... 

Geier DA, Geier MR. A comparative evaluation of the effects of MMR immunization and mercury doses from thimerosal-containing chEdhood vaccines on... 

Akagi H, Grandjean P, Takizawa Y and Weihe P (1998) Methyl mercury dose estimation from umbilical cord concentrations in patients with Minamata disease. Environ Res 77 98—103. Akagi H, Malm O, Branghes FJP, Kinjo Y, Kashima Y, Guimaraes JRD, Oliveira RB, Haragughi K, Pfeiffer WC, Takizawa Y and Kato H (1995) Human exposure to mercury due to goldmining in the Tapajos River basin, Amazon, Brazil Speciation of mercury in human hair, blood and urine. Water Air Soil Pollut 80 85-94. 

Halbach S (1995) Estimation of mercury dose by a novel quantitation of elemental and inorganic species released from amalgam. Int Arch Occup Environ Health 67 295 - 300. 

PoGAREv SF, Ryzhov V, Mashyanov N, Sholupov S and Zharskaya V (2002) Direct measurement of the mercury content of exhaled air a new approach for determination of the mercury dose received. Anal Bioanal Chem 374 1039-1044. 

Paracelsus, a Swiss physician of the sixteenth century, stated that everything is toxic, it is just the dose that matters. This statement still holds true 500 years after Paracelsus developed it to defend the use of toxic compounds such as lead and mercury in the treatment of serious diseases such as syphilis. Chemical compounds cause their toxic effects by inducing changes in cell physiology and biochemistry, and an understanding of cellular biology is a prerequisite if one wishes to understand the nature of toxic reactions. 

FIGURE 5.51 Dose-response relationships for methyl mercury.(Used with permission.)... 

FAS is normally characterized by growth retardation, anomalies of the head and face, and psychomotor dysfunctions. Excessive consumption of ethyl alcohol may lead to malformations of the heart, extremities, and kidneys. Since consumption of ethyl alcohol is socially acceptable and prevalent even in pregnant women, the risks associated with the use of ethyl alcohol are remarkable. However, it should be kept in mind that there are several chemical compounds in tlie occupational environment that may also cause malformations even at low doses. The oc-cupationally-important known human teratogens include methyl mercury, ethyl alcohol, PCB compounds, tobacco smoke, lead, TCDD, 2,4,5- F, carbon monoxide, nitrogen dioxide, gasoline, and fluoride. 

UV irradiation of this bacterial cells using a broadband mercury-quartz lamp through an interference filter (bandwith 254 nm), provided preferential DNA damage with minimal effects on other subcellular structures. The exposure time ranged from 0 to 180 minutes in increments of 60 minutes, which gave total dose of UV exposure 1.21, 2.43 and 3.64 J/ m. ... 

Monteiro, L.R. and Furness, R.W (2001). Kinetics, dose-response, excretion and toxicity of methyl mercury in free living Cory s shearwater chicks. Environmental Toxicology and Chemistry 20, 1816-1824. 

Dieter MP, Ludke JL. 1975. Studies on the combined effects of organophosphates and heavy metals in birds. I. Plasma and brain cholinesterase in Cotumix quail fed methyl mercury and orally dosed with parathion. Bull Environ Contam Toxicol 13 257-262. 

The antagonistic effects of sodium pentothal on the blood pressure and the respiratory effects of chlordan are illustrated in Figure 1, C. The intermittent severe tremors with concomitant Cheyne-Stokes type of respiration produced by the injection of chlordan were decreased or entirely abolished, and both the respiratory rate and depth were restored to near normal. A dose of barbiturate sufficient to diminish the tremors appreciably and to restore the respiration to normal also produced a temporary drop of 10 to. 40 mm. of mercury in blood pressure. 

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