Pollution in general and air pollution in particular is a major global issue. This is a challenge for both developed and developing countries. Its negative consequences are varied and include among others, global warming with all its corollaries, reduce agricultural yields and direct health issues. When exposed to pollution for example, children, the elderly and especially pregnant women are more vulnerable. Exposure to fine particulate matter (PM2.5) in the ambient air have been found to be associated with several birth outcomes morbidity such as low birth weight, preeclampsia and placental abruption. As PM2.5 is a complex mixture of several chemicals it is believe that our exposure is not limited to one chemical at the time but to possibly many chemicals that form a mixture. In the literature there are no satisfactory methods of chemical mixtures identification. We propose a new method of identifying mixtures and study their association with some birth outcomes morbidities.