"Its particles ranging in from five to 120 microns get airborne very fast and prolonged inhalation of these causes fibrosis of lungs, bronchitis and pneumonitis and other diseases," a six-member expert committee of Central Public Works Department (CPWD) has said in its report. It said "flyash deposition corrodes structural surfaces and affects horticulture and if settled in lagoons and tanks, it becomes breeding grounds for mosquitoes and bacteria."

The report said disposal of flyash had become a major problem requiring large tracts for dumping and would reduce the availability of agricultural land besides contaminating underground water resources with traces of toxic metals.

Considering these problems the committee has suggested measures for better use of the material including making ofbricks, cement, filling up roads and use as manure. "Since chemical composition of flyash does not differ much from clay, a large quantity of flyash can be disposed off easily and profitably by making clay-bonded bricks for construction purpose," the report said. It said that the brick industry could use the flyash as an alternative because the quality of these bricks was superior to the conventional clay bricks in respect of weight, water absorption and crushing strength.

Standard quality flyash could be used as a raw material in cement to the extent of 25 per cent for better efficiency, it said.