Construction in Mumbai has lead to higher amounts of pollution and an increased susceptibility to cancer for its residents. Cancer causing particulates for the years 2009-10 increased dramatically. There was a chlorine gas leak from the Sewri industrial area and many people were poisoned by chlorine gas. An oil spill occurred off the Mumbai coast on Aug. 7 2010 when two cargo ships collided. Mumbai is located near the largest chemical industry zone in Asia, exposing people to toxic and carcinogenic chemicals. Due to the fact that Mumbai attracts migration for its trade and commerce, its population is over 18 million. There are more vehicles adding to the pollution levels and industries are adding to the pollution as well. Premature deaths have been linked to poor air quality. Respiratory illnesses have increased as well as blood pressure, nervous system and kidney problems.