Chronic Vs Acute

Chronic – health effects that are seen after many years of ingesting water with contaminants greater than the maximum contaminant level (long term).  Many different water contaminants, consumed over time, can lead to an increased risk of cancer.  Other severe health problems associated with long-term exposure to water contaminants includes liver and kidney problems, reproductive difficulties, and problems with the nervous system.

Acute – health effects which can occur within hours or days of exposure (short term).  Microbes such as E. coli and cryptosporidium are examples of contaminants that can cause an acute health risk.  Some chronic-type contaminants can also fall in this category if they present at high enough concentration to cause immediate health effects.  For example, nitrate levels over the MCL can cause blue-baby syndrome in children less than 6 months.