PCDD/Fs and PCBs in Soils: a Study of Case in the City of Belo Horizonte‑MG

Abstract

Dioxins (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs)) are substances that represent a global concern due to their ubiquitous presence and toxicity. Industrial processes and other human activities as well as uncontrollable accidents are the main sources that release these pollutants into the environment. The presence of these compounds has been reported in soils from Europe, Asia and Africa, but currently, there is not much information of dioxin levels in soils from Brazil. This paper presents the levels of PCDD/Fs, dioxin-like PCBs (dl-PCBs) and non-dioxin-like PCBs (ndl-PCBs) in soils collected from urban areas of Belo Horizonte city, Minas Gerais State, Brazil. Total toxic equivalents (TEQ) observed ranged from 0.43 to 4.54 ng TEQ kg -1 d.m. The highest concentration TEQ found was 2.68 (± 1.63) ng TEQ kg -1 d.m. The low total TEQ achieved suggests that the locations evaluated are not being affected by possible sources of dioxin emissions, although Belo Horizonte is surrounded by a number of them.

Urban soils in Brazil: A review

“…Publications associated with soil contamination generally present quantification of total inorganic elements, especially Zn, Pb, Cu, Cr, Ba and Ni. However, other analyses are eventually available, such as sequential extraction of metals, soil mineralogy and/or organic contaminants (Oliveira and Brilhante, 1996;Wilcke et al, 1999;Aniceto and Horbe, 2012;Pussente et al, 2017). Other types of data are provided in publications centered on soil mapping and/or geological risk, such as spatial information related to landforms (Digital Elevation Model, hypsometry, slope gradient, landform types, anthropic interventions), which are obtained by satellite images and/or aerial photography (without a complete morphological description).…”

“…Higher concentrations are commonly related to higher presence of SOM in the surface horizons, but the HCH concentrations do not directly accompany the progressive decrease in SOM down in the profile. Polycyclic aromatic hydrocarbon (PAH) in Uberlândia (MG) (Wilcke et al, 1999) and polychlorinated biphenyls (PCBs) in Uberlândia (MG) and Belo Horizonte (capital of MG State) (Wilcke et al, 1999;Pussente et al, 2017) show lower contents, especially when compared with urban soils located in industrial nations under temperate climate. Wilcke et al (1999) attribute the results to stronger leaching, higher volatilization and faster degradation of these substances in tropical than temperate zones.…”

Simultaneous Determination of 2,3,7,8-TCDD and 2,3,7,8-TCDF in Water Samples by LLE-LTP and HPLC-DAD

“…31 In Brazil, the toxic equivalency (TEQ) of PCDD/Fs was determined in soil samples (0.43 to 4.54 ng TEQ kg -1 ) using accelerated solvent extraction and GC-HRMS. 5 Previous works quantified PCDD/Fs (0.96 to 3.17 TEQ pg g -1 (2,3,7,8-TCDD) and 1.91 pg g -1 (2,3,7,8-TCDF)) in fresh milk from southwest Iran using liquid-liquid extraction and HPLC-UV. 23,24 The presence of PCDD/Fs in real samples depends on several factors such as matrix type, analyte concentration, sample collection period and extraction and detection methodologies used; therefore, most of the literature studies did not quantify PCDD/Fs in real samples.…”

“…[1][2][3][4] Their congeners with chlorine atoms in the 2, 3, 7 and 8-positions of the aromatic rings are considered the most toxic and they have been detectable in almost all ecosystems. 1,5 These compounds are mainly formed by thermal processes involving chlorine organic compounds such as burning urban waste and forest fires. These compounds have also been formed in pulp and paper companies, as well as by chemical and pesticide industries.…”