While segregation and other discriminatory practices have long been illegal in the United States, the long-term effects of this and informal discrimination and redlining of communities, through discriminatory mortgage lending in particular, has taken a toll on health of individuals in different communities. Redlining still occurs but now new methods have also been created to measure inequality to housing and health so that they can be empirically demonstrated, although it is unclear what actions are being taken by government and others potentially involved in redlining.
A recent investigation into redlined communities in California has shown that such communities, where residents were effectively segregated into specific neighborhoods based on race, have faced greater health risks than other communities where redlining did not occur. This includes higher incidents of asthma for redlined areas with higher visits to the emergency room than comparable areas. Race and social class were used to keep people within predefined or designated areas that lenders were willing to provide resources for borrowers. The roots of redlining in California and elsewhere go back to the Great Depression era in the 1930s, when neighborhoods were defined by lending or investment risk using race and class. These neighborhoods faced historically higher rates of pollution, including more exposure to diesel and other pollutants from transport and factories, resulting in the higher rates of asthma.
Other documented cases of redlining and its effect on health have been determined. In Detroit, a study conducted showed that historical redlining has contributed to greater rates of foreclosures, including after the Great Recession of 2008-2009. In other words, redlining from many decades ago has also led to more recent higher rates of foreclosures. In this case, residents in Detroit neighborhoods were also redlined based on race and class starting in the early twentieth century, with higher relative rates of self-assessed incidence reporting showing health issues affecting the population more recently. There is a strong relationship between historical redlining, recent foreclosures, and long-term human health effects, with neighborhoods that were redlined facing higher rates of pollution similar to what was seen in California.
One recent work has highlighted higher rates of death from breast cancer in relation to redlined neighborhoods in the Milwaukee, Wisconsin metropolitan area. It is argued that differential lending continues and some recent work has also created a spatial index, using adaptive spatial filtering, where redlining could be measured along with racial bias in lending practices. Similar to the other cases, historical, long-term biases in lending are apparent and there is a link with human health repercussions as a lack of resources to health care and exposure to risks are more pronounced.
Other work has shown that health problems begin early, with children and adolescents demonstrating clear unhealthy patterns based on redlined neighborhoods. Much of the disparities revolved around health care access, similar to the other studies, as well as exposure to health risks. The relationship between historical roots, such as going back to Jim Crowe era laws, and modern segregation in communities are pervasive and research has demonstrated long-term health effects affecting young people and not only older adults.
Redlining has been a long-standing problem in the United States that has led to long-term health consequences and other inequalities. New spatial methods, such as using adaptive spatial filtering techniques, have enabled measures of inequality for neighborhoods to be created and used to demonstrate how health and well being differs in communities. While tools to assess such disparities and research projects on this topic have been ongoing, long-term disparities in many cities have yet to be fully addressed.
 For more on the study in California and redlining neighbourhoods, see: https://news.berkeley.edu/2019/05/22/historically-redlined-communities-face-higher-asthma-rates/
 For more on redlining in Detroit and its relationship to foreclosures and health, see: McClure, E., Feinstein, L., Cordoba, E., Douglas, C., Emch, M., Robinson, W., Galea, S., Aiello, A.E., 2019. The legacy of redlining in the effect of foreclosures on Detroit residents’ self-rated health. Health & Place 55, 9–19. https://doi.org/10.1016/j.healthplace.2018.10.004.
 For more on the study in Milwaukee on redlining and community health data on breast cancer survival, see: Beyer, K.M.M., Zhou, Y., Matthews, K., Bemanian, A., Laud, P.W., Nattinger, A.B., 2016. New spatially continuous indices of redlining and racial bias in mortgage lending: links to survival after breast cancer diagnosis and implications for health disparities research. Health & Place 40, 34–43. https://doi.org/10.1016/j.healthplace.2016.04.014.
 For more on health and young people and adolescents in relation to redlined neighbourhoods, see: Robinson, C.A., Trent, M., 2019. Adolescent Health Disparities: Historical Context and Current Realities, in: Barkley, L., Svetaz, M.V., Chulani, V.L. (Eds.), Promoting Health Equity Among Racially and Ethnically Diverse Adolescents. Springer International Publishing, Cham, pp. 29–54. https://doi.org/10.1007/978-3-319-97205-3_3