No abstract

No abstract

An analytical method using high-performance liquid chromatography separation with inductively coupled plasma mass spectrometry (ICP-MS) detection previously developed for the determination of Cr(III) and Cr(VI) has been adapted to allow the determination of As(III), As(V), Se(IV), Se(VI), Cr(III), and Cr(VI) under the same chromatographic conditions. Using this method, all six inorganic species can be determined in less than 3 min. A dynamic reaction cell (DRC)-ICP-MS system was used to detect the species eluted from the chromatographic column in order to reduce interferences. A variety of reaction cell gases and conditions may be utilized with the DRC-ICP-MS, and final selection of conditions is determined by data quality objectives. Results indicated all starting standards, reagents, and sample vials should be thoroughly tested for contamination. Tests on species stability indicated that refrigeration at 10 °C was preferential to freezing for most species, particularly when all species were present, and that sample solutions and extracts should be analyzed as soon as possible to eliminate species instability and interconversion effects. A variety of environmental and geological samples, including waters and deionized water [leachates] and simulated biological leachates from soils and wildfire ashes have been analyzed using this method. Analytical spikes performed on each sample were used to evaluate data quality. Speciation analyses were conducted on deionized water leachates and simulated lung fluid leachates of ash and soils impacted by wildfires. These results show that, for leachates containing high levels of total Cr, the majority of the chromium was present in the hexavalent Cr(VI) form. In general, total and hexavalent chromium levels for samples taken from burned residential areas were higher than those obtained from non-residential forested areas. Arsenic, when found, was generally in the more oxidized As(V) form. Selenium (IV) and (VI) were present, but typically at low levels.

Table 1. (continued) Material Examples of potential exposure sources Primary exposure routes Health effects References Volcanic ash Atmospheric particulates generated by eruptions. Natural and anthropogenic disturbance of volcanic ash deposits, such as earthquakes, landslides, construction activities. Inhalation. Irritation of respiratory tract; asthma; potential effects of crystalline silica within ash. Weinstein and Cook (2005), and their references. Volcanic gases, vog, laze Sulfur dioxide, hydrogen fl uoride, hydrogen chloride, other acid gases emanating from active volcanoes. Acidic aerosol droplets formed when hot lava contacts seawater and causes it to boil. Inhalation, contact with exposed mucous membranes or moist skin. Irritation of eyes, throat, respiratory tract; ulceration of mucous surfaces. Effects largely tied to acidity of the gases and droplets. If gases are in suffi ciently high concentration, toxic effects can also result. Weinstein and Cook (2005), and their references. Wildfi re smoke, and ash Particulate matter (including smoke, ash, and fi ne soil particulates) and gases generated by forest fi res. Inhalation. Asthma, irritation of respiratory tract; possible increased susceptibility to infection of respiratory system; possible long term increased cancer risk. Most studies have focused on organic constituents of smoke; less work has been done on mineral particles and heavy metals in smoke.