In recent years alarm has been raised from different corners of the universe about the pollution of environment through several agencies including those due to presence of heavy metals from different sources. The amount of certain heavy metals or pollutants is being increased with time in bio, geo, atmos, and hydrospheric systems either from human activities or from natural sources. Use of metal enriched chemicals, fertilizer, and organic amendments repeatedly causing contamination at a large scale by means of sewage sludge and waste water. These increase the entry of toxic metals into the food chain. The literature on this aspect is rare. Hence in this book some efforts have been made to create certain specific characteristic visible symptoms of Cd, Cr, Co, Ni and Pb excess on several important agricultural crop plants which may be helpful in identifying and diagnosing them under field conditions. Further to support this, a table containing critical values of toxicity of these pollutants for some crop plants have been included here. This may help in predicting the amount of excess metal usually present within the plants.