Search

18 polycyclic aromatic hydrocarbons (PAHs) were evaluated in the Jaguaribe River to explore the influence of grain size, organic carbon, humic and fulvic acids and black carbon on their adsorption onto sediment. The ∑PAHs concentrations variated from 0.6 to 3752.0 ng g−1 with highest concentrations in the estuarine zone. The PAHs predominant source along the river was from mixed sources, mainly related to biomass combustion, small oil spills related to recreational nautical activities and runoff from cities. Organic and inorganic parameters presented influence on PAHs distribution along the river, with humic acid as a determinant factor. These research findings are of importance to an assessment of the fate and transport of PAHs in estuarine systems.

Made available in DSpace on 2019-10-06T16:08:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-03-15 Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Anthropogenic molecular markers were used to assess chemicals inputs and ecological risks associated from multiple sources to sediments in one of the largest tropical mangrove forests of South America, with a particular focus on lesser studied compounds resulting from rural activities. Total concentrations ranged from 23.4 to 228.2 ng g−1 for polycyclic aromatic hydrocarbons (∑PAHs), 750.4 to 5912.5 ng g−1 for aliphatic hydrocarbons (∑AHs), 32.4 to 696.6 ng g−1 for pesticides (∑pesticides), 23.1 to 2109.7 ng g−1 for coprostanol and sterols (∑sterols), 139.3 to 580.2 ng g−1 for naturals hormones (∑natural hormones) and 334.1 to 823.4 ng g−1 for synthetics hormones (∑synthetic hormones). The PAHs and AHs used as traditional anthropogenic markers showed a mixture between natural and anthropogenic sources, related mainly to inputs from higher plants, phytoplankton and both, biomass and petroleum combustion. Rural activities linked to agricultural pest control are the predominant source of pesticides, although minor inputs from pesticides used in urban public health campaigns and household activities were also detected. Synthetic hormones levels are two to three orders of magnitude greater than natural hormones levels and no correlations were observed between the main sewage markers and synthetic hormone concentrations, rural activities such as animal husbandry, which use drugs in management, may be the predominant anthropogenic sources of these compounds in the region. Traditional markers failed to detect ecological risks in rural areas, where synthetic substances (e.g. pesticides and hormones) are widely used and introduced in the environment. Instituto Oceanográfico Universidade de São Paulo, Praça do Oceanográfico, 191 Instituto de Ciências do Mar Universidade Federal do Ceará, Av. Abolição, 3207 Departamento de Química Analítica e Físico-Química Universidade Federal do Ceará Centro de Investigação em Ecotoxicologia Aquática e Poluição (NEPEA) São Paulo State University (UNESP Campus do Litoral Paulista), Praça Infante Dom Henrique, s/n. Department of Marine Chemistry and Geochemistry Woods Hole Oceanographic Institution, 266 Woods Hole road Centro de Investigação em Ecotoxicologia Aquática e Poluição (NEPEA) São Paulo State University (UNESP Campus do Litoral Paulista), Praça Infante Dom Henrique, s/n. Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico: 150.01.00/09 CNPq: 480583/2012-9 CNPq: 484171/2010-0

This work describes the development of an analytical protocol combining cleanup by liquid–solid extraction and GC–MS for the determination of emerging and traditional multi-molecular markers. The procedure was used for the environmental assessment of a coastal region with multiple human activities. Global recovery rates ranged from 45.49% to 119.4% for the 46 substances analyzed: pesticides (73.7%–97.7%), PAHs (52.5%–93.7%), sterols (66.7%–119.4%) and natural and synthetic hormones (45.5%–119.1%) and the rates were compared to those reported in studies on both individual classes and multi-classes of contaminants. The analytical protocol demonstrated satisfactory efficiency and could be used successfully in environmental assessments and source assignment studies. The environmental assessment study revealed that the Acarau River in northeastern Brazil is influenced by the combination of urban and rural activities. The sources of PAHs are vehicular traffic and the burning of biomass; pesticides stem from pest control in agribusiness and public health campaigns; sterols and hormones stem from a combination of natural inputs, human sewage (treated and raw) and animal husbandry activities.

On December 9, 2014, ∼94 000 gallons of furnace oil spilled into the Shela River in Bangladesh, a designated World Heritage Site by the United Nations Educational, Scientific and Cultural Organization. It was the largest recorded oil spill in the Sundarbans region. Visually, furnace oil appears similar to heavy fuel oil, but little is known about its composition even though it is heavily utilized worldwide. A shift in global oil production to heavier, less well-known feeds (i.e., heavy oil and bitumen) requires molecular-level knowledge for efficient response, damage assessment, and restoration in the event of any oil spill. However, little is known about the chemical composition of furnace oil in chronic and acute releases. For the first time, we catalog the molecular-level composition of a relatively unknown furnace oil collected immediately after the 2014 Bangladesh spill and compare it to a well-characterized intermediate fuel oil (IFO) spilled in Texas City, Texas (U.S.A.) in March 2014. Through a co...

This manuscript is a bibliographic review about analyses of different classes of pesticide in fruits using QuEChERS as sample preparation methodology. The aim is to clarify different trends and facilitate decision-making by the scientific community in order to carry out further studies in this field. It is well known that different countries have different pesticides regulations for maximum level of pesticide residue permitted. The comparative analysis amongst the main producer countries reveals that for some fruits they are not studied enough. Recent improvements to QuEChERS make it possible to minimize the pesticides instability due the matrix pH, and achieving cleaner extracts. Regarding the detection systems, the tandem MS are preferred once they have high sensitivity and selectivity, although traditional techniques (GC-ECD and HPLC-DAD) are still commonly used due to their accessibility and good sensitivity to some pesticides. Also, studies involving metabolites usually show that they are more toxic than their precursor compounds.

Molecular markers are useful tools to characterize natural and anthropogenic impacts on coastal zones. Distribution of n-alkanes showed that the Pacoti River was predominantly influenced by terrigenous input. Distribution of polycyclic aromatic hydrocarbon (PAH) indices showed a mix of natural sources, especially pyrogenic influences. Sterol and hormone levels showed sewage discharge. Integrated geographic assessment showed that pyrogenic process and sewage discharge are predominant along the river because of natural and different anthropogenic activities. The upstream region is influenced by rural activities such as livestock and discharge from the sewage treatment plant, whereas the estuarine region is influenced by urban and industrial activities, predominantly the discharge of treated or untreated sewage, vehicle traffic, and manufacture of red ceramics. On the other hand, on the river mouth, there is the predominance of aquaculture activities. Traditional anthropogenic markers are not sufficient for producing a comprehensive assessment of anthropogenic impacts in areas with multiple activities.

The first diagnosis of risk of environmental contamination was conducted for an area of intense agricultural activity in the semiarid cearense (Baixo Jaguaribe and Litoral de Aracati area). We verified the use of 201 rural products (pesticides) in the region, comprising 151 active ingredients. Regarding the active ingredients evaluated, 15.9% were associated with sediment and 29.8% were dissolved in surface water. The study showed that 13.2% to 36.4% of the active ingredients evaluated were classified as potential contaminants of groundwater resources. The study also revealed the most abundant pesticides and which environmental compartment must be evaluated.

Between the 1940s and 1990s, immeasurable amounts of organochlorine pesticides (OCPs) were used in endemic disease control campaigns and agriculture in the tropical semi-arid regions of Brazil. The present study evaluated the legacy of banned OCP usage, considering the levels, ecological risk and dependence on sediment physicochemical properties for the fate and distribution in the Jaguaribe River. The sum concentration of OCPs (ΣOCPs) ranged from 5.09 to 154.43 ng·g(-1), comparable to the levels found in other tropical and subtropical regions that have traditionally used OCPs. The environmental and geographical distribution pattern of p,p-DDT, p,p-DDD and p,p-DDE shows that the estuarine zone contained more than 3.5 times the levels observed in the fluvial region, indicating that the estuary of the Jaguaribe River is a sink. The temporal pattern indicates application of dichloro-diphenyl-trichloroethanes (DDTs) in the past; however, there is evidence of recent input of these pesticides. High ecological risk was observed for levels of γ-hexachlorocyclohexanes (γ-HCH) and heptachlor, and moderate ecological risk was observed for levels of DDTs in sediments from the Jaguaribe River. The heptachlor, γ-HCH and hexachlorobenzene (HCB) concentrations depend on the organic and inorganic fractions of sediment from the Jaguaribe River, whereas the p,p-DDE, p,p-DDD, p,p-DDT and α-endosulfan concentrations depend solely on the organic fraction of the sediment.