The city of Nogales, Arizona is the seat of county government and home to 66% of the residents in Santa Cruz County. According to the 2000 census, Nogales is 93.6% Hispano/Latino with a per capita income of $10,178 (as compared to the state per capita income of $20,275). Santa Cruz County is comprised of 80.8% Hispano/Latinos with a growing population of 38,381 residents. The State of Arizona population is more than 5.1 million souls, of which, 25.3% are Hispano/Latinos. The sister city of Nogales, Sonora has an estimated ten times the population of the Arizona side, but lacks the infrastructure to support the large numbers of migrants who come to the U.S./Mexico border. This migration challenges local government to keep pace with the increasing needs for housing, water and sewage systems, health care and infectious disease control, education, and law enforcement. Collectively, the sister cities are known as Ambos (Both) Nogales reflecting the interdependent nature of the two cities and spillover of issues of concern, particularly those related to the environment and health care.

Poor economic conditions, coupled with serious environmental concerns are associated with the high incidence of certain types of cancer and lupus, which have been recorded in Nogales, Arizona by the Arizona Department of Health Services in collaboration with the Arizona Cancer Center at the University of Arizona. Nogales, Arizona is a medically underserved and a health personnel shortage area based on federal government classification. Since the unemployment rate in Santa Cruz County is consistently high (18.4% compared with 3.4% for the state [1999 figures]), it is not surprising that 30.8% of the population in Nogales is below the Federal Poverty Guidelines compared to 9.9% for the state. Additionally, 46% of the population between the ages of 18 and 44 is uninsured or underinsured.