In recent years, public concern over environmental deterioration has been rising. Many studies were conducted that environmental factors are now responsible for 40% of the deaths in the world (ENS, 1998). Public opinion polls in many countries indicate that consumers are purchasing environmentally friendly products to protect the environment and improve the quality of life for current and future generations. Dunlap (1991) reported that 55% of the consumers believe that the quality of the environment is worsening. Another poll found that approximately 74% of consumers surveyed are of the belief that the condition of the environment has deteriorated in the past 20 years.
