Urban residents are exposed to air pollution from motor vehicles every day. Research suggests that elevated exposure to air pollution may contribute to the development of respiratory and cardiovascular disease, particularly in the elderly and children, and to adverse pregnancy outcomes. Exposure levels depend on how much pollution is in the environment, where people live, and their daily activities. For example, high levels of air pollution around urban homes near busy streets have been linked to low birth weight babies and preterm births. Elizabeth Nethery is specifically looking at the levels and effect of air pollution exposure on pregnant women in urban centres. While air pollution studies generally use computer models based on neighbourhood monitoring stations and home location to estimate individual exposures, Elizabeth is the first person to evaluate the accuracy of these estimates for pregnant women by comparing predicted to actual exposures. The results will provide more accurate information on the air pollution levels pregnant women inhale, and could lead to regulatory strategies, health protection measures, and policies to improve the health of women, children and the general population.