Avaliação sanitária e físico-química das águas para irrigação de hortaliças no Agreste e Brejo Paraibanos.

Abstract

The sanitary and physico-chemical quality of water used in the irrigation of vegetable crops was evaluated in 5 farms in 2 municipalities of the State of Paraíba, Brazil. The irrigation water presented high fecal load (FC: 104 CFU 100 mL-1) contaminating the vegetables. The contamination occurred due to the fact that domestic sewage is discharged into the water streams, resulting in indirect reuse of wastewater in the agriculture. Lettuce (Lactuca sativa L.) irrigated with such waters showed high levels of fecal contamination (FC: 1,0 x 103 and 1.6 x 106 MPN g-1 and E. coli: 2.5 x 102 and 2.5 x 104 MPN g-1), exposing the consumers of these vegetables to health hazards, however the lettuce in the public markets presented fecal coliformes between 7,5 x 103 and 3,8 x 104 MPN g-1 and there were no significant differences with that of vegetable gardens. The high levels of fecal coliformes in the organic manure (mean value between 1.3 x 105 and 2.6 x 106 MPN g-1) used in cultivation also contributed towards contamination of lettuce. Although the waters contained considerable concentrations of salts they did not present high risks of salinization or sodification of the soil.