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| Author(s): |
Mariana Frari Ragazzi
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Ribeirão Preto. |
| Institution: | Universidade de São Paulo (USP). Escola de Enfermagem de Ribeirão Preto (PCARP/BC) |
| Defense date: | 2012-01-30 |
| Examining board members: |
Susana Segura Muñoz;
Cristina Filomêna Pereira Rosa Paschoalato;
Angela Maria Magosso Takayanagui
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| Advisor: | Susana Segura Muñoz |
| Abstract | |
Several regions of the planet suffer from a shortage of natural drinking water. However, population growth and environmental pollution have aggravated this situation. In that context, a practice to use wastewater in the agriculture has been extend in several countries. The aim of this study was to compare the parasitological and toxicological quality of vegetables grown with recycled water and vegetables sold in street markets in the city of Ribeirão Preto - SP. To this end, we collected 20 samples of lettuce (Lactuca sativa) and 20 of rocket salad (Eruca sativa) in a streets markets and experimental garden built in the Sewage Treatment Station of Ribeirão Preto, where the vegetables were irrigated with treated and chlorinated effluent to 0,1 mgL-1. In total, were collected 80 samples. For parasitological analysis we used the Spontaneous Sedimentations Technique and the Technique of Immunomagnetic Separation with use of Immunofluorescence Microscopy and Phase Contrast (USEPA, Method 1623) for analysis of Cryptosporidium spp. and Giardia spp. Metals concentration was detected by Inductively Coupled Plasma with Mass Spectrometry (ICP-MS). The results showed that vegetables collected in free markets and those produced in the experimental garden were positive for parasitological contamination, especially helminths. Specifically for Cryptosporidium spp. and Giardia spp., the Method 1623 showed that there was contamination by Giardia spp. only in the experimental garden vegetables, with densities ranging from 6 to 15 cists/50g. and Cryptosporidium spp. with a density of 3 oocists/50g. Analyses of metals showed a significant difference of the metals Cd, Pb, Mn and Fe in lettuce and rocket salad, with higher concentrations in samples from experimental garden. The results showed Pb concentration near or above the Maximum Tolerance Limit, according to Federal Decree 55871/1965, in both vegetable groups analyzed. We concluded that the chlorination to 0,1 mgL-1 of the treated effluent do not eliminated the persistent pathogens of conventional treatment. To enable the use of treated wastewater in the culture of vegetables is necessary to search a form of complementary treatment to eliminate pathogenic microorganisms present in the effluent. It also showed the need for constant monitoring of metal concentrations in the effluent and vegetables produced considering temporal variations that characterize the urban sewage, since these elements can be transferred to the food chain. This study highlights the need to continue seeking for alternative uses for recycled water, in order to correct existing problems of water scarcity and ensuring the preservations of water sources in the future. (AU) | |
| FAPESP's process: | 09/12560-5 - Comparative study of parasitological and bacteriological quality between vegetables grown with wastewater and vegetables from market gardens in Ribeirão Preto - SP |
| Grantee: | Mariana Frari Ragazzi |
| Support Opportunities: | Scholarships in Brazil - Master |