Mercuric particulate matter

In the atmosphere, particulate bound mercury constitutes only 2% of total mercury in the air and has normally been found to be less than 0.1 ngm in regions unaffected by local sources. Some other mercury compounds, which may exist in the atmosphere, are mercuric chloride, mercuric bromide, mercuric hydroxide, mercuric sulfide, and mercuric cyanide. The rest is elemental mercury in the gaseous phase. In remote areas over the Atlantic and Pacific oceans, mercury bound to particulate matter concentrations are generally at or below the picogram per cubic meter level. 

Samples with particulate matter may present quite serious problems, and it may be desirable to remove particles, for example, by centrifugation, and examine this fraction by procedures applicable to solid phases which are discussed in Section 2.2.5. Tangential-flow high-volume filtration systems have been used for analysis of particulate fractions (>0.45 jum) where the analytes occur in only low concentration (Broman et al. 1991). Attention has already been drawn to artifacts resulting from reactions with cyclohexene added as an inhibitor to dichloromethane. It has also been suggested that under basic conditions, Mn2+ in water samples may be oxidized to Mn(III or IV) which in turn oxidized phenolic constituents to quinones (Chen et al. 1991). Serious problems may arise if mercuric chloride is added as a preservative after collection of the samples (Foreman et al. 1992) since this has appreciable solubility in many organic solvents, and its use should therefore be avoided. 

Exposures to xenobiotics have been associated with the onset of several autoimmune diseases. Lupus [systemic lupus erythematosus (SLE)], scleroderma (systemic sclerosis), rheumatoid arthritis, and other maladies have been strongly associated with exposures to single chemicals and mixtures of chemicals. The single chemicals include sihca dust, VC, mercuric chloride, trichloroethylene, HCB, hydrazine, and tartrazine. Mixtures include epoxy resins, hair dyes, paint thinners and other (unspecified) organic solvent mixtures, industrial emissions, airborne particulate matter, and hazardous waste-site emissions [27-32],... 

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