There are several different methods for defining the differences between rural and urban areas. The following list is not exhaustive, but will give you a place to start.
A database collecting resources on rural issues, includes a FAQ on health disparities
AgriSafe Network - "builds the competency of health and safety professionals to deliver exceptional occupational agricultural health care" Browse resources on PPE and air-quality monitoring, young ag workers, health risk assessments, wildfires and more.
National Center for Farmworker Health - Mission is "to improve the health status of farmworker families through appropriate application of human, technical, and information resources." Houses the Journal of Agromedicine
National Children's Center for Rural and Agricultural Health and Safety - one of 11 NIOSH-funded agricultural centers, and the only center dedicated to childhood agricultural injury prevention. Housed within the National Farm Medicine Center (link below).
National Farm Medicine Center - housed within the Marshfield Clinic Research Institute in Wisconsin, browse resources on return to work, seguridad, veteran ag workers and more
NIOSH Safety and Health Topic Agriculture - National Institute for Occupational Safety and Health
Rural Assistance Center Agricultural Health & Safety - part of the Rural Information Hub administered by the Center for Rural Health within UND. Contains resources on covid-19 and ag health, childhood ag injuries, psychological stressors and more
Collaborative Research Center for American Indian Health (CRCAIH) - Helps tribal communities and health professionals plan and perform research addressing the health issues of American Indians in South Dakota, North Dakota, and Minnesota
Great Plains Tribal Epidemiology Center - The Tribal Epidemiology Centers (TEC) which serves North Dakota, South Dakota, and Nebraska. TECs are Indian Health Service organizations that serve American Indian/Alaska Native Tribal and urban communities by managing public health information systems, investigating diseases of concern, managing disease prevention and control programs, responding to public health emergencies, and coordinating these activities with other public health authorities