CHEMICAL QUALITY OF BEACH ESTE, HAVANA, CUBA Oralis Alburquerque Brooks, Ileana García Ramil, José Francisco Montalvo Instituto de Oceanología, Cuba Ave 3ra No 18604 e/ 184 y 186, Rpto Flores, Playa, 72725420 Email:oralis@oceano.inf.cu, oralisab@gmail.com ABSTRACT Pollution of beaches in Latin America and the Caribbean, caused by uncontrolled discharges of untreated domestic sewage, is a serious health problem for the population. You must consider that there are three main sources of human fecal contamination of sea water recreational use: domestic sewage, discharge of rivers and other waterways, and directly Bather. This study evaluates the chemical quality of beaches east. In situ temperature, salinity and pH measurements were made, the chemical oxygen demand, ammonium, total nitrogen, inorganic phosphorus and Total were determined. subsaturaciones oxygen were obtained in all seasons. Low concentrations of organic matter were reported as well as nitrogen and phosphorus which shows that eutrophication processes are not favorable. The low content of inorganic nitrogen in both samples at the sampling stations located in the Rincon de Guanabo, Guardafronteras, Agro-Guanabo and Mégano can lead to algae growth and nitrogen-fixing bacteria.