SBIR-STTR Award

Widespread occupational exposure risk to toxic airborne metal aerosols and dusts exists due to the lack of rapid and cost-effective monitoring methods. Chromium (VI) is a particularly toxic metal that is commonly found in environmental samples. However, current personal sampling methods are expensive and time-consuming; exposure data are not available until one to several days after exposures occur. This program proposes development of an automated sampling and extraction platform integrated with an adsorptive-catalytic voltammetric analysis technique, to provide rapid, on-site automated quantification of airborne chromium metals for less than 10% of the cost of a typical laboratory analysis. The Phase I project will quantitatively determine feasibility of the proposed method by fabrication and testing of a small, portable, inexpensive instrument that is suitable as the basis for automated ambient air analysis, personal filter cartridge analysis, and surface dust analysis. The instrument will automatically extract and analyze the heavy metal concentration of the filters, and calculate the exposure based on the sample air volume (or surface area) for comparison with Permissible Exposure Limits. The Phase II program would then consist of development of an analytical protocol to differentiate Cr(lll) and Cr(VI), extensive field validation of the analyzer, and a study to estimate the effectiveness of the analytical tool to assist in exposure prevention protocols. Based on bench-scale testing completed to date, the limit of quantitation is projected to be less than 0.1 ug/m3. The analysis time is projected to be 5-10 minutes per sample compared to 24 hours or more using current methods. Sample costs are projected to be $0.75/filter as compared to $15-$25 with current methods. Industry has been clear in communicating its need for improved methods for personal air monitoring of heavy metals. An independent market study has already been conducted and has identified over 10,000 commercial/industrial sites in the mining, metallurgical, military, electronics, and coatings industries.

Thesaurus Terms:
air pollution, air sampling /monitoring, biomedical equipment development, chromium, occupational hazard, occupational health /safety air filtration, analytical chemistry, analytical method, portable biomedical equipment

Occupational exposures to hexavalent chromium, Cr(VI), occur during the production and use of stainless steel, chromate chemicals, and chromate pigments and operations such as chrome plating and coating processes. NIOSH considers all Cr(VI) compounds to be potential occupational carcinogens, and an increased risk of lung cancer has been demonstrated in exposed workers. Compliance with occupational exposure protection requirements for toxic metals is currently very difficult for industrial and government facilities to achieve. The purpose of this program is to create an automated, low-cost method for rapidly quantifying potential exposures to chromium via respiratory pathways. This will be accomplished by developing and field-testing analytical instrumentation and methodology to assist facilities in reducing the potential for occupational exposures to airborne chromium. The ultimate goal of the program is the creation of approved NIOSH and ASTM methods for automated airborne chromium analysis using ultrasonic extraction and adsorptive stripping voltammetry. This research plan is expected to firmly establish the technical basis for the new method, and will provide a capability in this field that does not currently exist. The potential for commercial application of this technology is extremely high due to its excellent sensitivity, rapid sample turnaround time, and low cost. All instrument functions are performed automatically, which differentiates the approach from any other method, and projects to a much more user-friendly design for use by industrial and government facilities. This program will also be instrumental in supporting the broader objective of developing a series of approved methods for automated monitoring and rapid analysis of other metals that pose health risks in occupational environments. A series of analyzers and methods based on ultrasonic extraction/electrochemical detection techniques is envisioned, which broadens the impact beyond chromium and supports the goal of effective, low-cost methods for the entire range of toxic respirable metals