Current Research and Scholarly Interests
Dr. Rull is an epidemiologist whose research focuses on assessing and validating exposures to hazards such as metals, pesticides, traffic emissions, and other pollutants and evaluating whether these exposures affect the risk of cancer. In his research, geographic information systems (GIS) and mapping technologies play a critical role in improving the quality of exposure assessment and linking exposures to health outcomes. Dr. Rull also employs complex statistical methods such as hierarchical regression models to estimate the effects of combinations of exposures and improve precision.
Prior to joining CPIC, Dr. Rull gained extensive experience in environmental epidemiology as a doctoral student and researcher at UCLA, where he developed a GIS-based model for assessing exposures to pesticides by linking residential locations with the locations of agricultural pesticide use and crops. His dissertation examined whether women residing near specific agricultural crop types or pesticide applications during early pregnancy increased the risk of neural tube defects. In addition, he worked on studies assessing the effects of air pollutants on frequent and severe asthma symptoms in a population of asthmatic respondents to the 2001 California Health Interview Survey.
Dr. Rull is currently conducting a study examining the effect of cadmium, a carcinogenic metal that exhibits estrogen-like activity, on the risk of breast cancer in the California Teachers Study cohort. The major sources of non-occupational exposure to cadmium include cigarette smoke, diet, and inhalation of contaminated ambient air. This study is one of the few studies that will use dietary intake, environmental exposure, and a biological marker (cadmium in urine) of exposure to develop a measure of total exposure from multiple sources.
Dr. Rulls other research activities include a Stanford Cancer Center pilot study to identify urinary biomarkers of environmental exposure to diesel exhaust, a carcinogenic pollutant. In addition, Dr. Rull is conducting a study that will use GIS to construct geographic areas within the nine-county Greater Bay Area Cancer Registry region that will allow for the mapping and analysis of cancer incidence in areas smaller than the county. These newly defined areas will have a sufficiently large base population that will allow for more reliable estimation of cancer incidence while preserving the confidentiality of cancer cases. In collaboration with Dr. Peggy Reynolds, Dr. Rull is also working on the Northern California Childhood Leukemia Study, the largest and most comprehensive study to date of risk factors for leukemia in children, where they are using GIS to evaluate the impacts of exposures to agricultural pesticides, indoor and outdoor air pollution, and other environmental hazards.