Table 3 Standards for chemical contaminants in drinking water according to World Health Organization (WHO) and United States Environmental Protection Agency (USEPA)
Heavy metal and other metals | WHO/USEPA maximum acceptable concentration (mg/L) | The health implications of ingesting some of these chemicals (if they exceed the maximum acceptable limit) |
|---|---|---|
Mercury (Hg) | USEPA/WHO 0.002 | Headache, abdominal pain and diarrhea, paralysis, and gum inflammation Kidney damage |
Silver (Ag) | USEPA/WHO 0.1 | Skin discoloration |
Arsenic (As) | USEPA/WHO 0.01 | Serious skin problems, endocrine disruptor Causes cancer—skin, bladder, lung, kidney, liver, prostate Harms cardiovascular and nervous systems |
Cadmium (Cd) | USEPA 0.005 and WHO 0.003 | Kidney Damage Carcinogenic, causes lung fibrosis, dyspnea |
Zinc (Zn) | USEPA/WHO 5 | Stomach cramps, skin irritations, vomiting and nausea, Respiratory disorders, anemia and mental fever |
Lead (Pb) | USEPA 0.015 and WHO 0.01 | Infants and children may experience delays in physical or mental development, as well as minor attention span and learning deficiencies Kidney disorders and high blood pressure in adults |
Uranium (U) | USEPA/WHO 0.03 | Kidney toxicity Increased risk of cancer |
Antimony (Sb) | USEPA/WHO 0.006 | Increase in blood cholesterol Decrease in blood sugar |
Chromium (Cr) | USEPA 0.1 and WHO 0.05 | Nausea, gastrointestinal distress, stomach ulcers, skin ulcers, allergic dermatitis Kidney and liver damage Reproductive problems Lung and nasal cancer |
Copper (Cu) | USEPA 0.1 and WHO 0.05 | Acute copper poisoning can cause symptoms of nausea, vomiting, diarrhea, gastrointestinal illness, abdominal and muscle pain Severe cases of copper poisoning have led to anemia, liver poisoning, and kidney failure |
Cyanide (CN−) | USEPA/WHO 0.2 | Nerve damage Thyroid problems |
Thallium (Tl) | USEPA/WHO 0.002 | Hair loss Changes in blood Kidney, intestine, or liver problems |
Fluoride (F−) | USEPA 4.0 and WHO 1.5 | Skeletal fluorosis, from long-term consumption > 4 mg/L (a serious bone disorder resembling osteoporosis and characterized by extreme density and hardness and abnormal fragility of the bones) Children may get mottled teeth (i.e., Mottling (discoloration) of teeth in children under 9 years of age (from long-term consumption at > 2 mg/L) |
Nitrate (\({\text{NO}}_{3}^{ - 1}\)) and Nitrate (\({\text{NO}}_{2}^{ - 1}\)) | \({\text{NO}}_{3}^{ - 1}\) USEPA 10.0 and WHO 11.3 | Methemoglobinemia (blue baby syndrome) Most potential health effects are seen in infants under the age of 6Â months |
\({\text{NO}}_{2}^{ - 1}\) USEPA 1.0 and WHO 1.0 | ||
Barium | USEPA 2.0 and WHO 0.7 | Difficulties in breathing Increased blood pressure and changes in heart rhythm Stomach irritation, brain swelling, muscle weakness Damage to the liver, kidney, heart, and spleen |