air pollution is a growing problem throughout the world. indoor air pollution is one of leading causes of lung cancer. families is developing countries use open stoves for cooking and heating their home. these home do not have proper ventilation. the smoke which full of chemical and carcinogens get trapped inside where family eat and sleep. outdoor pollution also cause disease and illness. especially in industrial cities such as beijing china where cancer is the leading cause of death. china relies heavily on coal. which is considered the dirtiest source of energy. according the european union only 1% urban dwellers in china breathe clean air on and average day. neighboring countries including japan and korea receive much of china pollution in form of acid rain. this pollution result mainly form the coal powered factories. which produce inexpensive goods for north america and european consumers. outdoor pollution is also concern in many wealthy countries. those who live and work in urban center such as los angeles or toronto experiences many warm day beneath a layer of smoke. soil pollution is also major concern. both in industrial and developing countries pollutant such as matal pesticides seep into earth soil and contaminate the food supply. soil pollution causes major health risk to entire ecosystem. this type of pollution reduces the amount of suitable for agricultural production and contributes to global food storages.