| Metal contaminant |
Permissible limits for industrial effluent discharge (in mg/L) (DOE Malaysia, 1979) [7] | Permissible limits for drinking water (in mg/L) (WHO, 2011) [6] | Health hazards | A | B | WHO |
| Arsenic | 0.05 | 0.01 | 0.01 | Carcinogenic, producing liver tumors and skin and gastrointestinal effects |
| Mercury | 0.005 | 0.05 | 0.006 | Corrosive to skin, eyes, and muscle membrane, dermatitis, anorexia, kidney damage, and severe muscle pain |
| Cadmium | 0.01 | 0.02 | 0.003 | Carcinogenic, cause lung fibrosis, dyspnea, and weight loss |
| Lead | 0.1 | 0.5 | 0.01 | Suspected carcinogen, loss of appetite, anemia, muscle and joint pains, diminishing IQ, cause sterility, kidney problem, and high blood pressure |
| Chromium | 0.2 | 1 | 0.05 | Suspected human carcinogen, producing lung tumors, and allergic dermatitis |
| Nickel | 0.2 | 1 | 0.07 | Causes chronic bronchitis, reduced lung function, cancer of lungs, and nasal sinus |
| Zinc | 1 | 1 | 3 | Causes short-term illness called “metal fume fever” and restlessness |
| Copper | 0.2 | 1 | 2 | Long term exposure causes irritation of nose, mouth, and eyes, headache, stomachache, dizziness, and diarrhea |
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