00363nam a22001217a 4500020001500000082001500015100001900030245005400049260006400103300000800167490004000175650002600215  a9555890072  a363.73 ILE  aIlleperuma,A.O  aEnvironmental Pollution and the future of mankind  aPeradeniyabScience education unit faculty of sciencec1995  a38p  aPeradeniya science publication No.1  aenvromental pollution