The underground use of diesel equipment introduces high concentrations of toxic gases such as CO, NO and NO2 into a confined atmosphere. The National Institute of Occupational Safety and Health (NIOSH) has determined that diesel exhaust is a potential human carcinogen, based on a combination of chemical, genotoxicity, and carcinogenicity data. This is due to the particulate matter in the diesel exhaust. In addition, acute exposures to diesel exhaust have been linked to health problems such as eye and nose irritation, headaches, nausea, and asthma. Many of these symptoms can be associated with the gaseous components of diesel exhaust. Currently, underground miners can be exposed to over 100 times the typical environmental concentration of diesel exhaust and over 10 times that measured in other workplaces. In addition, miner exposure to diesel emissions promises to become more widespread as diesel equipment becomes more prevalent within the mining industry. In a Phase I SBIR program Giner, Inc. demonstrated the feasibility of developing a lightweight, compact low cost instrument that can simultaneously monitor CO, NO, and NO2 in diesel exhaust underground. In addition, since diesel engines require O2 for the combustion process, the instrument will also monitor O2 levels. Unlike other multigas sensors that require separate sensor cells for each gas, the novel feature of this instrument is the use of a single sensor cell to detect all 4 gases, resulting in a considerable cost savings, compared to commercially available instruments. Additional instrument development is proposed for Phase II. The final instrument can either be a battery-powered, handheld, portable instrument, or can be designed to be mounted in a fixed location on a wall or suspended from the mine ceiling. The aims of the Phase II program are: 1: To conduct additional advanced sensor cell assembly development, 2: To conduct sensor cell testing, 3: To fabricate complete prototype instruments, 4: To conduct complete instrument parametric and life testing, 5: To compare the prototype instrument response to that of a commercial instrument, and 6: To conduct an economic analysis. To satisfy these aims, we propose to fabricate complete instruments that incorporate the advanced sensor cell that contains multiple sensing electrodes. In this Phase II program we will conduct additional multigas sensor cell development and incorporate the sensor cell into a complete instrument. The response of the advanced sensor will be compared to that of a commercially available, MSHA and UL-approved instrument. Finally, an economic analysis will be conducted to predict the manufacturing price of both the multigas sensor cell and the complete sensing instrument. All technical work will be conducted at Giner, Inc. with specialized fabrication being performed at select vendors. PUBLIC HEALTH RELEVANCE: Underground miners can be exposed to over 100 times the typical environmental concentration of gaseous diesel exhaust components and over 10 times that measured in other workplaces. The development of a compact, low-cost, lightweight instrument is proposed to monitor these levels;the instrument can be used underground, as well as above ground to measure toxic gas concentrations in the workplace.