Waste, when it is not properly disposed and is left to accumulate, poses a serious health hazard affecting all forms of terrestrial and aquatic animals and human beings. A number of industries release toxins in the form of waste, which may be in the form of solid, liquid or gaseous waste. These toxins are very harmful to human health. They can cause cancer, developmental defects and reproduction problems.
People living near the accumulated heaps of waste are at a risk of infectious diseases, as the accumulated wastes produce an unpleasant odour and the decomposing material is highly infectious in nature. Waste workers or ragpickers have a higher risk of getting infections. People living close to waste dumps are at a risk of getting infected water supply, which has got contaminated due to leakage from landfill sites.
The biomedical wastes are also a source of infection. Contaminated needles, syringes and soiled cotton thrown away as waste have traces of infections and cause several diseases. Coloured plastics are harmful as their pigment contains highly toxic metals, such as copper, lead, cobalt, chromium and cadmium. That is why the government is banning the use of plastics, which are a health hazard.
Minamata disease is an example of serious impact of industrial waste on the life and health of human beings. A serious problem of mercury poisoning resulted from the industrial discharge of effluents from a large plastic plant located near the Minamata Bay of Japan.
The mysterious disease appeared in people living near the Minamata Bay, due to eating of fish from mercury polluted bay. The disease killed many people and caused physical and mental deformities in many more.
Generally, the harmful effects of pollution are not felt immediately, but occur after a length of time. They not only cause respiratory infections, but also affect the liver and kidney. Mosquitoes, flies, insects which breed in accumulated waste are carriers of diseases like malaria, dengue, etc.
There are many occupational hazards associated with the handling of accumulated waste of all types:
1. Skin and blood infections resulting from direct contact with waste and from infected wounds.
2. Eye and respiratory infections resulting from exposure to infected dust, especially during landfill operations.
3. Various diseases which are caused due to the bites of animals feeding on the accumulated waste.
4. Intestinal infections that are transmitted by flies or insects that are feeding on the accumulated waste.
Water pollution due to sewage and domestic waste is of major concern, because diseases such as typhoid, cholera, jaundice, dysentery, diarrhoea, etc. are infectious diseases which spread through contaminated water. Sometimes this leads to the outbreak of epidemics and mass illness.
As they spread through contaminated water, they are called waterborne diseases. About 60 per cent of all diseases in India are due to the presence of pathogenic bacteria in water.