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| Author(s): |
Ana Paula Francisco
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Saúde Pública (FSP/CIR) |
| Defense date: | 2017-06-13 |
| Examining board members: |
João Vicente de Assunção;
Roy Edward Bruns;
Helena Ribeiro;
Ligia Cristina Gonçalves de Siqueira;
João Paulo Machado Torres
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| Advisor: | João Vicente de Assunção |
| Abstract | |
Introduction: Dioxins, furans and polychlorinated biphenyls are toxic pollutants for human health including risks of cancer incidence, neurodevelopmental effects, dermal lesions, chloracne. These compounds are persistent organic pollutants (POPs) that can be transported to long distances from the emission source and they are bioaccumulated in ecosystems. Recently, the outdoor air pollution were classified as carcinogenic to humans by the World Health Organization, showing the importance of its characterization for toxic compounds. However, active air monitoring has a high cost for POPs, and there is a few calibration studies which support that substitution. Objective: To assess the equivalent toxicity of the atmosphere regarding the measurement of dioxins, furans and polychlorinated biphenyls, using active and passive air samplers, and to evatuate the contrasting concentrations at urban, urban/industrial and background sites. Method: Air samples were collected, using active and passive samplers, over two consecutive periods of four months: from September to December 2014 (period 1) and from May to August 2015 (period 2) at three cities in São Paulo, SP, covering urban, urban/industrial and background sites. All samples were extracted with toluene:acetone (9:1) in a Soxhlet apparatus for 24 hours and surrogate standards (13C12-PCDD/F and 13C12-PCBs) were spiked on each sample media prior to extraction procedure. The extracts were purified on an silica column (40 per cent H2SO4 and 10 per cent AgNO3) followed by an alumina column. The analytical procedure was carried out using HRGC/HRMS (High Resolution Gas Chromatograph/High Resolution Mass Spectrometer) operating in electron impact ionization with an energy of 35 eV in SIM (selected ion monitoring) mode and 10.000 resolution power. Results show that (1) there are seasonal variations for PCDD/F concentrations in air between period 1 and 2 (p=0.03), whereas dl-PCB levels were not statistically different (p=0.52) in those periods. (2) PCDD/F and dl-PCB air levels are in the following order: < urban < urban/industrial for both active and passive samplers; (3) PCDD/F and dl-PCB concentrations in active air samples ranged from 9.34 to 221 fg TEQ/m³ in period 1, and between 7.76 and 453 fg TEQ/m³ in period 2; in the passive air samples, these concentrations ranged from 6.11 to 32.2 fg TEQ/m³ in period 1, and between 48.6 and 298 fg TEQ/m³ in period 2; (4) the estimation of sampling rate using two approachs for PCDD/Fs showed differences. Conclusions: the passive air sampling can replace the active sampling to assess the equivalent toxicity regarding PCDD/Fs and dl-PCBs at different sites, since the two techniques are in agreement with the homologue profile and with the contrasting concentrations at urban, urban/industrial and background sites. The toxicity of the atmosphere regarding the PCDD/Fs at central urban site of city of São Paulo in 2014 and 2015 did not show tendency to decrease compared with the years of 2000, 2001 and 2006. Conclusions: the passive sampling method used in this study can replace the active sampling method to verify the equivalent toxicity to PCDD/Fs and dl-PCBs in different locations, since the two techniques are in agreement with the profile of the homologue groups as well as with the concentration gradient in the urban, urban/industrial and background sites. The toxicity of the atmosphere to the PCDD/Fs in the urban environment of the city of São Paulo in 2014-2015 did not show a tendency to decrease in relation to the years 2000-2001 and 2006. (AU) | |
| FAPESP's process: | 13/20299-0 - Equivalent toxicity of the atmosphere for dioxins, furans and polychlorinated biphenyls, using two air sampling techniques, passive and active |
| Grantee: | Ana Paula Francisco |
| Support Opportunities: | Scholarships in Brazil - Doctorate |