Are plastic roads a safe environmental option?
In October, the Government of India announced an investment of Rs 6.9 trillion ($11 billion) to build 83,677 km of roads over the next five years. After this announcement was made, infrastructure analysts said the Centre must explore a tested technology that uses plastic waste for asphalting the roads. This, they argued, will reduce costs and make roads more durable and safer.
“Plastic roads will not only withstand future monsoon damage but will also solve the problem of disposing of non-recyclable plastic,” Isher Judge Ahluwalia, former head of a government committee on urban infrastructure, wrote in a piece along with Almitra Patel. “Each kilometre of a single-lane tar road can consume one tonne of plastic waste, and the plastic can double or even triple the life of the road”.
States have also shown interest in plastic roads. A recent news report in Hindustan Times said that if all goes according to Yuva Sena chief Aaditya Thackeray’s plan, the Brihanmumbai Municipal Corporation may soon start using confiscated plastic bags and straws for road construction and other public amenities. The state government recently announced a blanket ban on plastic bags from March next year.
More than 1,600 tonnes of plastic had been used to lay over 1,000 km length of roads in Tamil Nadu in the last five years as part of the state government’s thrust on effective use of plastic waste.
PLASTIC ROADS: IS IT A WORKABLE IDEA?
The sustainable use of plastic waste for road and construction activities has environmental and economic advantages. Plastics are typically an organic polymer of high molecular mass, but they often contain other substances. Research studies indicate that the plastic granules with up to 5% content can be used for road, pavement, and sidewalk construction; if they are mixed with supplementary amounts with construction wastes.
Waste plastic materials can be a promising alternative for asphalting roads but they are similar to the use of plastic microbeads in cosmetics and health care products. The environmental consequences of using plastic microbeads in cosmetics were not thoroughly investigated until they had found their way to the ocean, harming the environment. This led the US government to pass the Microbead-Free Waters Act of 2015, banning their usage in cosmetics.
Similarly, rigorous testing is needed to ensure the use of plastic in asphalting roads is not environmentally unsafe. There must be field-scale testing of plastic under different soil and climatic conditions (temperature and rainfall pattern), with particular attention to the release of micro-and nanoparticles from plastics and their long-term accumulation in soils and their effects on soil quality near the road and agricultural land. In addition, it is also important to explore their impact on air quality.
Prabhakar Sharma is with School of Ecology and Environment Studies, Nalanda University, Rajgir, Nalanda, Bihar
The views expressed are personal