Toxic concrete

SWEDES are at risk from toxic chemicals leaking out of old concrete towers, according to the Swedish Environmental Protection Agency (SEPA). Concentrations of polychlorinated biphenyls (PCBs) in soil close to a block of flats in capital Stockholm have been found to be 20 times higher than the country's safety limit and 1,000 times the normal levels. These toxic chemicals can harm the immune and reproductive systems, hamper mental development in children and may even cause cancer. PCBs had been widely used in sealing material for filling the gaps between

Better alternatives

DLF, a real estate and construction company based in New Delhi, has developed cellular lightweight concrete, an eco-friendly product that offers a more cost-effective alternative to bricks. K P Singh, chairperson and managing director, DLF, said that the new product not only saves the topsoil, which gets eroded during the manufacture of bircks, but also combines environmentally hazardous flyash with cement, sand and water. The resultant product is lighter than brick and the buildings attain earthquake resistance even in quake-prone zones.