Environmental exposures during early life could determine an individual's sensitivity and risk of developing diseases later in life. Prevention is the most effective Iranian health approach for increasing the community health. Some potential early-life factors during (or before) the period of fetal development (endocrine disruptors, maternal diet, smoking or alcohol), infancy (breast- or bottle feeding, exposure to moulds and damp) and during childhood and adolescence (environmental toxins, diet and levels of physical activity, passive exposure to tobacco smoke and own initiation of smoking and alcohol consumption) might influence on adult health. The developmental origins of health and disease (DOHaD) hypothesis suggested that exposures in early life associated with the risk of developing diseases in adulthood. Some non-communicable diseases including cardiovascular disease, various cancers, respiratory disease, cognitive decline and psychological health, have been associated with early-life exposures. Our project is now ongoing in the population of Semnan city (central area of Iran). Semnan is the capital city of Semnan Province, Iran. It is located 216 kilometers east of Tehran in north central of Iran. Researchers of Semnan University of Medical Sciences along with other selected academic centers in Iran have supported and supervised the study. Semnan University of Medical Sciences affiliated to the Ministry of Health, Treatment and Medical Education that is one of the medical universities located in the east of Iran. It was founded in 1989.