Concentrations, sources and risks of polycyclic aromatic hydrocarbons in sediments from the Parnaiba Delta basin, Northeast Brazil.

The Parnaíba River is the main river in the Parnaíba Delta basin, the largest delta in the Americas. About 18 polycyclic aromatic hydrocarbons (PAHs) were identified and the environmental risk associated with the sediments was evaluated. The study found that PAHs levels ranged from 5.92 to 1521.17 ng g-1, which was classified as low to high pollution, and that there were multiple sources of pollution along the river, with pyrolytic sources predominating, mainly from urban activity such as trucking, although the influence of rural activity cannot be ruled out. PAHs correlated with black carbon and organic matter and showed high correlation with acenaphthylene, phenanthrene, pyrene, benzo(a)anthracene, chrysene, benzo(ghi)perylene, and ∑PAHs. The benzo(a)pyrene levels were classified as a risk to aquatic life because the threshold effect level and the probable effect level were exceeded. In addition, the sediments were classified as slightly contaminated with a benzo(a)pyrene toxicity equivalent value of 108.43 ng g-1. Thus, the priority level PAH exhibited carcinogenic and mutagenic activity that posed a potential risk to human health.

An integrated assessment to reconstruct the history of changes influenced by multiple anthropogenic activities (City of Fortaleza, Ceará, Brazil).

In this study, the multi-marker approach was used for the first time with a highly urbanized lake located in the city of Fortaleza, Brazil, to provide a comprehensive view of temporal trends in sources of pollutants and evaluate the relation between the influence of anthropogenic activities and socioeconomic development. Total concentrations of the markers analyzed ranged from 21.0 to 103.8 ng g-1, 450.2 to 2390.2 ng g-1, and 233.8 to 9827.3 ng g-1 for ∑PAHs, ∑n-alk, and ∑sterols, respectively. Concentrations and patterns of PAH, AH, and sterol ratio distribution changed over time and may be associated with different episodes in the history of the city of Fortaleza. The marker ratio distribution in the sediment core revealed an overlap of natural and anthropogenic sources, with degraded oil, biogenic inputs, pyrogenic processes, and fecal contamination from humans and animals in the past changing to petroleum fossil inputs and high contamination from sewage in the present day. The distribution of markers and the chronological history of Fortaleza revealed two distinct periods related to human activities during the development of the city. In the first period (prior to the 1950s), the main human activities were animal breeding and the use of biomass for domestic activities, public and cargo transportation, and commercial activities, especially food production. In the second period (after the 1950s), expansion of the city occurred due to the so-called Brazilian economic miracle and the main human activities were industrialization and urbanization processes, involving deforestation, paving, sewage discharge, and petroleum combustion.

Dealing with complex contamination scenarios: using a multi-geochemical approach to assess environmental quality and identify pollution sources in a semi-arid estuary from Brazil.

The Jundiaí-Potengi Estuary (EJP) is located on the semi-arid coast of northeastern Brazil and is influenced by multiple sources of contamination. The sediment quality of EJP was assessed by using a multi-geochemical approach during the dry and wet seasons. Sediments were analyzed for concentrations of nutrients, metals, polycyclic aromatic hydrocarbons (PAHs), pesticides, hormones (natural and synthetic), and sterols. The results were integrated by multivariate methods. The sediment was altered by the presence of contaminants from anthropogenic and natural sources. The middle and lower estuarine areas were considered more degraded in both seasons. In these regions, metals, hormones, sterols, and PAHs were found, indicating that these regions are severely affected by industrial, sanitary and aquaculture effluents, combustion of fossil fuels, and oil spills. The upstream region was contaminated by pesticides. The contamination pattern along the EJP shows the prevalence of local sources which continuously release the chemicals into the estuary. Worse conditions occurred during the rainy season, when the runoff from urban and rural areas is more intense and carries a greater load of contaminants to the EJP.

Levels, source appointment, and ecological risk of petroleum hydrocarbons in tropical coastal ecosystems (northeast Brazil): Baseline for future monitoring programmes of an oil spill area.

We reviewed 20 years of levels, sources, and environmental risks related to the main petroleum hydrocarbons in the northeast region of Brazil. The aim of this study was to conduct a systematic review to serve as a comprehensive baseline for future monitoring programmes related to the oil spill disaster in 2019/2020. Most contamination levels of both PAHs and AHs were classified as low, except those in specific areas influenced by human activities, such as ports, highly urbanised mangroves, or rivers of medium-sized cities with inadequate liquid and solid waste treatment. Most hydrocarbons were linked to natural sources and burning processes, except in regions of extraction activities and petrochemical facilities as well as highly urbanised areas, where degraded petroleum and oil hydrocarbons predominated. Only 2.5% of the samples exceeded threshold effect levels for ∑16-PAHs and no samples exceeded probable effect levels. When regional threshold levels were used, however, the probable effect for the ∑16-PAHs measured was high, ranging from 5.8 to 6.1%. The few studies reporting biological responses showed that hydrocarbons from anthropogenic sources can induce adverse effects on marine organisms even at low to moderate levels. As the region has recently received a considerable quantity of crude oil, studies should be prioritised for a more precise assessment of the impact of this oil spill.

Influence of anthropogenic activities and risk assessment on protected mangrove forest using traditional and emerging molecular markers (Ceará coast, northeastern Brazil).

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.

Emerging and Traditional Organic Markers in Areas with Multiple Anthropogenic Activities: Development of an Analytical Protocol and Its Application in Environmental Assessment Studies.

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 Acaraú 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.