Safe Drinking Water Act Latino and African American populations are at higher risk of exposure to drinking water contaminants. Contaminants found in the drinking water of such communities include nitrates, coliform, and lead, which have been linked to cancer, reproductive health problems, gastrointestinal illness, and other health problems. One study found that levels of contaminants in the drinking water of two Nebraska Native American reservations were significantly higher than regional contaminant levels. Another study found that Latino residents in Tucson, Arizona, had higher than average levels of contaminants in their drinking water, which were linked to higher rates of cancer and neurological disorders among
Drinking water needed and free from contamination". By 2015, 5.2 billion people representing 71% of the global population used safely managed drinking water service. The terms 'improved water source' and 'unimproved water source' were coined in 2002 as a drinking water monitoring tool by the JMP of UNICEF and WHO. The term, improved water source refers to "piped water on premises (piped household water connection located inside the user’s dwelling, plot or yard), and other improved drinking water sources (public taps or standpipes, tube wells or boreholes, protected dug wells, protected springs, and rainwater collection)". Improved sources are also monitored based on