Long term exposure to arsenic in water may increase cardiovascular disease and especially heart disease risk even at exposure levels below the federal regulatory limit (10µg/L) according to a study at Columbia University Mailman School of Public Health. Long term exposure to arsenic in water may increase cardiovascular disease and especially heart disease risk even at exposure levels below the federal regulatory limit (10µg/L) according to a study at Columbia University Mailman School of Public Health. Environment Phys.org – latest science and technology news stories