Issues related to environmental hazards posed by plastic waste have been assessed by several committees. The problem created by the use of plastics bags is primarily due to shortcomings in the waste management system. Indiscriminate chemical additives  pose environmental problems including choking open drains, ground water contamination, etc. Plastic itself is a chemically insert substance, used world –wide for packaging and is not per-se hazardous to health and environment. Recycling of plastic, if carried out as per approved procedures and guidelines, may not be an environmental or health hazard.

What are Plastics?     

            Plastics are polymers i.e. large molecules consisting of repeating units called monomers. In the case of plastic bags, the repeating units are ethylene. When ethylene molecules are polymerized to form polyethylene, they form long chains of carbon atoms in which each carbon is also bonded to two hydrogen atoms.

What are plastic bags made of? 

            Plastic bags are made from one of the three basic types of polymers -polyethylene- High Density polyethylene (HDPE), Low Density Polyethylene (LDPE), or Linear Low-Density Polyethylene (LLDPE). Grocery bags are generally of HDPE, and bags from the dry cleaner are LDPE. The major difference between these materials is the degree of branching of the polymer chain. HDPE and LLDPE are composed of linear, un-branched chains, while LDPE chains are branched.

Are plastics harmful to health?

Plastics are not intrinsically toxic or harmful. But plastic carry bags are manufactured using organic and inorganic additives like colourants and pigments, plasticizers, antioxidants, stabilizers and metals.

            Colourants and pigments are industrial azodyes which are used to give bright colour to plastic carry bags. Some of these are carcinogenic and likely to contaminate food stuffs, if packed in these carry bags. Heavy metals such as Cadmium contained in pigments can also reach out and prove to be a health hazard.      

            Plasticizers are organic esters of low volatile nature. They can migrate to food stuffs as a result of leaching. Plasticizers are also carcinogenic.

            Antioxidants and Stabilizers are inorganic and organic chemicals to protect against thermal decomposition during manufacturing process.

            Toxic metals like cadmium and lead  when used in manufacturing of plastic bags also leach out and contaminate the food stuffs. Cadmium when absorbed in the low doses can cause vomiting and heart enlargement. Lead exposure in long term may cause degeneration of brain tissues.

Problems posed by Plastic Carry Bags

            Plastic bags if not disposed properly may find their way into the drainage system resulting into choking of drains, creating unhygienic environment and causing water borne diseases. Recycled /coloured plastic bags may contain certain chemicals, which can leach to the ground and contaminate soil and sub-soil water. Units not equipped with environmentally sound techniques for recycling may create environmental   problems due to toxic fumes generated during reprocessing. Some of the plastic bags which contain leftover food or which get mixed up with other garbage are eaten by animals resulting in harmful effects. Because of the non-biodegradable and impervious nature of plastics, if disposed in the soil, they could arrest the recharging of ground water aquifers. Further, to improve the properties of plastic products and to inhibit degradation reactions, additives and plasticisers, fillers, flame retardants and pigments are generally used, these may have health impacts. 

Strategies for Plastics Waste Management

            Many states have prescribed thicker bags. The inflow of plastic bags into the solid waste stream would be substantiality reduced, as rag pickers would be keen to segregate the same for recycling purposes. Thin plastic bags have little value and their segregation is difficult. If the thickness of plastic bags is increased, it would make plastic bags expensive and check their usage. The plastic Manufacture Association could also be involved in the waste collection and disposal system using the principle of extended prouder responsibility.

Littering of Plastic carry bags, water bottles, plastic pouches have been a challenge for municipal solid waste management. Many hilly States (Jammu & Kashmir, Sikkim, West Bengal) have banned use of plastic carry bags/bottles in tourist  places. In Himachal Pradesh the State Government of has taken a cabinet decision to ban plastics in all over the State since 15.08.2009 under the HP non- biodegradable Garbage (Control) Act, 1995.

The Central Government too, has made assessment of the extent of damage caused to environment by plastic waste in the country by constituting Committees and a Task Force which studied the issue and made recommendations.

The Ministry of Environment and Forests issued the Recycled Plastics Manufacture and Usage Rules 1999, and amended it in 2003 under the Environment (Protection) Act, 1986 for regulating and managing plastic carry bags and containers. The Bureau of Indian Standards (BIS) has notified 10 standards on biodegradable plastics.

Alternatives to Plastic

            The use of jute or cloth bag as alternatives to plastic paper bag should be popularized and prompted through fiscal incentives; however, it needs to be noted that paper bag involve cutting of trees and their use is limited.  Ideally bio-degradable plastic bags alone should be used and research work is on to develop biodegradable plastics.

RTS/VN

SS-47/SF-47/22.02.2010