Arsenic occurs naturally in rocks and soil, water, air, and plants and animals. It can be further released into the environment through natural activities such as volcanic action, erosion of rocks and forest fires, or through human actions. Because it occurs naturally in the environment and as a by-product of some agricultural and industrial activities, it can enter drinking water through the ground or as runoff into surface water sources. Human exposure to arsenic 賽默飛iCAP Q ICP-MS Thermo Fisher ICAP-7200 電感耦合等離子發(fā)射光譜儀 Thermo Scientific iCAP 7000