Plastic is biodegradable — study

Of the 3,928,000 tons of solid wastes generated in Metro Manila every year, some 120,000 tons are of plastic material which is a problem. Fumes from burning plastic can cause a wide range of ailments including skin diseases, asthma and some forms of cancer.

Burning plastic releases noxious smoke that may release cancer-causing gases into the air which people downwind have to breathe. Burying plastic with other garbage can contaminate soil and groundwater. Even recycling, widely endorsed to reduce solid wastes, does not effectively reduce the volume of used plastics.

Plastic is an extremely versatile synthetic material made from the polymerization of organic compounds. The process is chemical wherein a compound or a substance is made adding smaller molecules of nonrenewable petroleum and natural gas.

Plastic contains additives such as colorants, stabilizers and plasticizers that may include toxic substances that can harm human health. Plastic chemicals such as ethylene dichloride and vinyl chloride used to produce vinyl are considered to be cancer causing. They may also trigger other health problems such as liver, kidney and neurological damage.

But there is good news yet. Scientists from the Institute of Biological Sciences in the University of Los Baños — Virginia C. Cuevas, Rodolfo Managilod, Virginia C. Cuevas and Ma. Theresa Clutario — in their studies have discovered fungal species that can decompose or cause plastic to rot.

The method is called biodegradation. It is a process of degrading waste material through the use of microorganisms such as fungi and bacteria. They isolated two kinds of bacteria–penicillium sp. and aspergillus sp and one type of fungi called xylaria sp.

Among the microorganisms, xylaria sp performed the best in degrading plastic sheets at 25 degrees centigrade and pH5. The scientists found out that the fungus grew vigorously using a mineral medium with 0.5 percent glucose and plastic strips as co-carbon source. Fifty days after incubation, the scientists reported that plastic strips were embedded in the mycelial mat and results of scanning electron microscopy showed there were already visible damages on the surface of the plastic strips. – Ramon Ma. Epino