Imbued with metals
Industrial advancement has no doubt improved the standard of living of human beings, but in the process the crucial environmental balance established by nature over a millenium has been inadvertantly disturbed. The concentration and distribution pattern of metals within the ecosystem is especially important. Metals are a unique class of toxicants, since they cannot be broken down to non-toxic forms. Once the ecosystem is contaminated by them, they remain a potential threat for many years. There is rising evidence linking many diseases to the environmental factors which are injurious to biosystems. Most of these factors are anthropogenic in nature and among these, human activity concerning heavy metals constitutes a major health hazard.
Toxic distribution Atmospheric concentrations (ng/m3) of some metals/metalloids in different parts of the world | ||||
| Metal/ Metalloid | Greenland (used as reference) | North America | Europe | North India |
| Aluminium (Al) Arsenic (As) Beryllium (Be) Cadmium (Cd) Chromium (Cr) Cobalt (Co) Copper (Cu) Iron (Fe) Lead (Pb) Manganese (Mn) Mercury (Hg) Nickel (Ni) Silver (Ag) Tin (Sn) Uranium (U) Vanadium (V) Zinc (Zn) (1 ng = 10-9g) | NA 0.007 NA 0.003-0.63 0.6-0.8 NA 0.03-0.06 166-171 15-22 2.8-4.5 NA NA NA NA NA 0.8-1.4 18-41 | 1 2.40 0.2 21 60 3 100 829-2,000 2,700 150 2 100 1 20 0.2 400 500 | 1 1.5-5.3 2 20 25 2 340 130-5,900 120 43 1 25 1 20 0.02 30 1,200 | NA NA NA 330-21,000 11-194 NA 208-2,682 NA 25-3,677 27-3,259 NA 12-321 NA NA NA NA 241-8,549 |
Sick of metals Metal-related human diseases | ||
| Metal/ Metalloid | Deficiency | Diseases |
| Aluminium | - | Alzheimer"s disease Dialysis dementia Dialysis osteodystrophy |
| Arsenic | - | Black-foot disease |
| Cadmium | - | Itai-Itai disease |
| Chromium | Aging (?) Atherosclerosis (?) Diabetes mellitus (?) | Bronchial asthma Contact dermatitis Skin allergies |
| Cobalt | pernicious anaemia | Beer drinker"s disease Polycythemia |
| Copper | Menke"s kinky hair disease or Trichopoliodystrophy | Grape garden sprayer"s disease Indian childhood cirrhosis Schizophrenia (?) Wilson"s disease |
| Iron | Microcytic hypochromic anaemia | Haemochromatosis Porphyria cutanea tarda Sideroblastic anaemia |
| Lead | - | Leaad encephalopathy Lead palsy Learning disability Mental retardation |
| Manganese | - | Parkinson"s disease-like syndrome Sclerosis amoytrophic lateralis |
| Mercury | - | Minamata disease Pink disease |
| Nickel | - | Dermatitis Pneumonia |