| Microorganisms | Health Effects* |
| | * Healthy individuals may have mild or no symptoms from these infections. They will usually recover without long-term health problems. However, persons with weakened immune systems may have more severe or life-threatening illnesses. |
Bacteria |
| Campylobacter |
· Diarrhea
(sometimes bloody), cramping, abdominal pain, and fever |
| Escherichia coli (E. coli) O157:H7 | · Bloody or non-bloody diarrhea, stomach cramps; little or no fever · Can cause hemolytic uremic syndrome (HUS) and kidney failure in young children or the elderly |
| Salmonella | · Diarrhea, typhoid fever, stomach cramps · Infection can spread from intestines to blood and other body sites,causing serious illness |
| Shigella | · Watery or bloody diarrhea, fever, upset stomach · Vomiting and stomach cramping may also occur |
| Viruses |
| Enterovirus | · Usually causes mild upper respiratory, “flu-like” symptoms with fever and muscle pains, or a rash · Meningitis is less common, and illnesses that affect the heart and brain may occur, but are very rare |
| Hepatitis A | · Jaundice (yellowing of eyes and skin), dark urine, tiredness, loss of appetite, nausea, vomiting, fever, stomach ache · Most infected adults will show symptoms while children often do not have symptoms (but could still pass the virus to others) |
| Norovirus (Norwalk) | · Upset stomach, cramps, vomiting, and diarrhea · Headache and low-grade fever may also occur |
| Rotavirus | · Vomiting, watery diarrhea, stomach cramps, fever |
| Protozoa |
| Cryptosporidium | · Diarrhea, loose or watery stool, stomach cramps, upset stomach, and fever
· Usually causes mild illness, but can be serious or fatal for people with weakened immune systems |
| Giardia | · Diarrhea, loose or watery stool, stomach cramps · Usually causes mild illness, but can be serious or fatal for people
with weakened immune systems |
| Chemicals | Health Effects** |
| | ** These health effects are caused by consuming large doses of chemicals. |
Atrazine | · Short-term: congestion of heart, lungs, and kidneys; low blood pressure; muscle spasms; weight loss; damage to adrenal glands · Long-term: weight loss, cardiovascular damage, eye and muscle degeneration; cancer |
| Arsenic | · Stomach pain, nausea, vomiting, diarrhea, numbness in hands and feet, partial paralysis, and blindness · Can also cause skin damage, circulatory system problems, and increased risk of cancer |
| Copper | · An essential nutrient at very low levels · High level exposure causes upset stomach, vomiting, diarrhea and stomach cramps · Long-term exposure at high levels can also cause liver and kidney problems |
| Lead | · Delayed physical and mental development in babies · Shortened attention span, hearing, and learning abilities of children · Slightly increased blood pressures in adults · Long-term exposure at high levels can include stroke, kidney disease and cancer |
| Mercury | · Kidney damage |
| Nitrate | · Methemoglobinemia – a blood disorder that causes shortness of breath and blueness of skin, and can lead to serious illness or death · Methmoglobinemia mainly affects infants and pregnant women · Long-term effects include increased urination and bleeding of the spleen |
| Radium | · Increases risk of cancer |
| Volatile Organic Compounds (VOCs) | · Drowsiness and decreased responsiveness · Skin irritation · Some cause cancer after long-term exposure |
