Tag: biology

Biomedical waste, if not handled properly is a potent source of diseases like AIDS, TB, Hepatitis and other bacterial disease causing serious threat to human health. Therefore this waste needs prime attention for its safe and proper disposal. So the Government of India published Biomedical waste (Management and Handling) Rules on July 27, 1998.

Non biodegradable wastes are non-decomposable in nature. They are not degraded by microbes. They pile up and accumulate in nature. 

Wastes can be distinguished as decomposable and non decomposable waste. Ash is decomposable while rest are non decomposable.

One of the side effects of developing civilisation can be observed in the form of presence of non-biodegradable material which cannot be broken down into simple, harmless substance by the action of bacteria. They are lethal to land where they are dumped and last for centuries, burning of them release poisonous gases injurious to human and animals health in various possible ways. Entry of such substances pollute water bodies because of their non-depleting nature they occupy space in water bodies and consumed by animals causing severe health condition and death. Polythene, plastic is some deadly non-biodegradable waste.

The pollutants which cannot be broken down into simpler, harmless substances in nature, are called non-biodegradable pollutants. DDT, plastics, polythene, bags, insecticides, pesticides, mercury, lead, arsenic, metal articles like aluminium cans, synthetic fibres, glass objects, iron products, and silver foils are non-biodegradable pollutants.

DDT is an organochlorine pollutant used as insecticides and has several environmental impacts. Chemicals in DDT do not degrade easily and remain in the soil for a long time after its application because it cannot be broken down by the action of microorganism and thus persists and is lethal to human and animal life.

Composite waste is a heterogeneous mix of trash composed of different types of materials. Composite waste includes waste clothing, Tetra Packs, waste plastics such as toys.

The three R's - reduce, reuse and recycle - saves our environment and they all help to cut down on the amount of waste generated in the environment.

Reduce the consumption of various resources wherever possible. For example- we can reduce the consumption of electricity by switching off lights and other appliances when they are not required. 
Recycle- There are many items which can be recycled again and again. Recycling is another way of reducing the demand for natural resources. For example- by recycling paper, we reduce the demand for wood and thus, help in saving the forest.
Reuse- Many items can be reused, many times. For example, the old newspaper can be used for packing many items. We can use one side printed sheets for our rough work at home/work.

The sieve tubes are supporting cells in the conducting tissue of the plant and are characterised by the absence of a nucleus.