The degree to which occupational exposure to carcinogens causes cancer is uncertain, but many researchers believe that only a small fraction of occupationally related cancers are reported to workers’ compensation systems. The primary challenge in studying occupational cancer is assessing exposure. In the past, most studies used qualitative methods to compare health risks of workers with differing levels of exposure to carcinogens. With today’s lower levels of exposure in the workplace, quantitative assessment is becoming more important. But there is a lack of standardized methods for quantitatively assessing exposure. Melissa Friesen is developing standardized methods — particularly including the use of statistical modeling — to improve the precision and specificity of quantitative exposure estimates. She will test the methods on data from three large studies of contaminants at BC. Melissa will also work with the US National Cancer Institute to apply the methods to data from case-control studies. This research will lead to improved methods for quantitative exposure assessment, which are necessary for public policy initiatives such as assessing risk, establishing preventative strategies and setting exposure limits.