section 1. Regional introduction and overview -- section 2. Arsenic occurrence and genesis in sedimentary and hard-rock aquifers -- section 3. Analytical methods for arsenic and laboratory studies -- section 4. Arsenic in soil, plants and food chain issues -- section 5. Toxicology and metabolism -- section 6. Treatment and remediation of arsenic-rich groundwater -- section 7. Innovative and sustainable options for arsenic mitigation : some experiences.