Karina Scurupa Machado

Occurrence of selected estrogens in mangrove sediments

This paper presents results related to the occurrence and distribution of estrogens along the Brazilian coast. Three mangrove areas were chosen to evaluate the presence of estrogens in surface sediments of mangrove forests. The presence of estrogens was observed in all studied sites. 17-α-Ethinylestradiol (EE2), a synthetic estrogen, was the most common and has been found in higher concentration (0.45-129.78 ng/g) compared to 17-β-estradiol (E1) and estrone (E2) (both being natural estrogens). The concentrations of E1 and E2 ranged from 0.02 to 49.27 ng/g and 0.03 to 39.77 ng/g, respectively. Theoretically, under anaerobic conditions EE2 can be reduced to E1 even in environments such as sediments of mangrove forests, which are essentially anaerobic. Even if the concentrations of estrogens seem to be insignificant in some samples, the effects remain uncertain.

Health risk assessment of inhabitants exposed to PAHs particulate matter in air

The presence of polycyclic aromatic hydrocarbon compounds (PAHs) was investigated in the particulate matter of samples taken at six sampling sites in the city of Curitiba (southern Brazil). The concentrations of suspended particulate matter ranged from 11.02 to 177.27 ng/m3. The analysis showed that 14 of the 16 PAHs are considered a priority compound by the USEPA (US Environmental Protection Agency). The mixture of PAHs was predominantly composed of PAHs with 3 and 4 aromatic rings. Isomer pair ratios show that the main source of PAHs was from burning fossil fuels (gasoline and diesel oil), although other sources may have contributed also. Benzo(a)pyrene, (BaP), regarded one of the most toxic PAHs, was present in all samples, but with concentrations lower than the maximum concentrations defined by some EU Countries. The risk assessment was conducted using the toxic equivalent factor (TEF) considering the toxicity of the individual PAHs compared to BaP. The BaPeq for all samples was between 0.42–1.12 ng/m3. The equivalent BaPeq indicated low health risk associated with exposure to the total PAHs content in air. The incremental lifetime cancer risk (ILCR) model was used to find the risk level for workers close to the emitting pollution sources. Outdoor exposure showed no risk for the amount of PAHs emitted. The acceptable risk is 10−6; however, all results were lower than this value.

Polycyclic aromatic hydrocarbons (PAHs) in airborne particulate matter in Curitiba, Brazil and benzo(a)pyrene toxic equivalency factors (TEFs)

The concentration of PAHs in particulate matter was investigated in the city of Curitiba, located in south of Brazil. Urban atmospheric particulate matter was collected at six sampling sites whose characteristics were representative of the prevailing conditions. The concentration of particulate matter varied from 11.02 to 177.27 ng/m3. Particulate matter was basically composed of PAHs with 3 and 4 aromatic rings and it agrees with results of air quality monitoring performed in other cities around the world. Molecular ratios, such as (Benzo(ghi)Perilene/Indene(cd)Pyrene, B(ghi)P/I(cd)P, indicate that the source of PAHs is gasoline engines in the downtown area and diesel engines in surrounding sites representing a heavy traffic situation. It was also investigated the toxic level of particulate matter using the BaP equivalency factor. The BaPeq for all samples was between 0.42 to 1.12 ng/m3. The equivalency BaPeq indicated low health risk associated with exposure to the total PAHs content in environmental air.

Assessment of historical fecal contamination in Curitiba, Brazil, in the last 400 years using fecal sterols.

A 400-year sedimentary record of the Barigui River was investigated using fecal biomarkers and nutrient distribution. The temporal variability in cholesterol, cholestanol, coprostanol, epicoprostanol, stigmastanol, stigmasterol, stigmastenol, sitosterol, and campesterol between 1600 and 2011 was assessed. Anthropogenic influences, such as deforestation and fecal contamination from humans and livestock, were observed from 1840. The sterol ratios exhibit evidence of hens, horses, cows, and an unknown herbivore, which may be a capybara (Hydrochoerus hydrochaeris), from 1820 and has been observed more markedly from 1970 onward. Human fecal contamination was detected from 1840 and was observed more markedly from 1930 due to population growth. Thus, the sanitation conditions and demographic growth of Curitiba seemed to be the main factors of human sewage pollution, as the coprostanol concentration over time was strongly correlated with the population growth (r=0.71, p<0.001) although diagenetic processes have also been observed.(1.)

Spatial and Temporal Variation of Heavy Metals Contamination in RecentSediments from Barigui River Basin, South Brazil

Heavy metals (Cd, Cr, Cu, Pb, Mn and Zn) and artificial radionuclides (137Cs and 210Pb) were investigated in three sediment cores from the Barigui river Basin, South Brazil, in order to reconstruct the spatial and temporal evolution of the pollution by heavy metals. According to the reference standards established by the Canadian quality guidelines, the area presents levels of pollution considered significant. Enrichment factors (EFs) were calculated to estimate the level of contamination in these sediment storages over time. EFs showed a steady increase from bottom to core top throughout the years and this pattern is present in all cores. The magnitude of the EFs suggests that higher contamination is observed in the central and lower parts of the basin, due to regional history and geographic characteristics. The evolution of the contamination by heavy metals is more intense as from the middle of the 19th due to the high demographic, economic and industrial growth in the region. This study clearly contributes to understand when the anthropogenic activities became harmful for the environment in South Brazil, which events were more significant and which parts of the studied area were more affected.

Avaliação do transporte do ácido 2,4-diclorofenoxiacético através de um lisímetro

The objective of this study was to evaluate the transport of one of the most toxic and best-selling herbicides in Brazil. The active ingredient 2,4-dichlorophenoxyacetic acid (2,4-D) was applied onto the surface of a tank-type lysimeter, filled with undisturbed soil, in Curitiba, Parana State. Samples of infiltration and runoff water were obtained during rain simulations. The concentrations of the active ingredient 2,4-D showed a rapid decrease in the environment, with mass losses of 29.12% by infiltration and 0.87% by runoff.

Tracking capybara (Hydrochoerus hydrochaeris) feces contribution method in aquatic environments using sterols

The monitoring of fecal contamination (human and animal) is an incessant challenge. In this approach, microbiological methods play an important role, though with substantial limitations. Organic compounds, such as sterols, are often used to trace fecal contamination. Although the fecal sterols profiles of some animals are already known, capybara, a typical mammal from South America, is a significant contributor to aquatic fecal contamination because of its water dependence; and still there is no one way, scientifically speaking, to trace its fecal contribution. The aim of the present study was to provide a tool to measure the temporal fecal contribution of capybara in aquatic systems. We examined the sterol content of capybara feces and compared with another species (sheep, cow, horse, pig, hen, duck, cat, dog, opossum, and human). From numerical relationships among fecal sterols, 6 ratios were delineated and tested to assess their potential to identify the capybara feces contribution in contaminated environments. Statistical analysis showed that 3 ratios were able to differentiate capybara feces from other sources. Such ratios were applied in samples of a sediment core from an urban area in south Brazil with a large capybara population. The temporal trend showed a significant contribution of capybara feces in the last 100 yr. Environ Toxicol Chem 2018;37:353-361.

Distribution and Characterization of Sex Hormones in Sediment and Removal Estimate by Sewage Treatment Plant in South Brazil

Sex hormones are a group of endocrine disruptors excreted by humans and animals. These compounds have been detected in surface waters and sewage treatment plant (STP), all over the word. Due their physicochemical properties significant amount is deposited in the sediment of surface waters acting as reservoirs able to contaminate the water column. Although these compounds have origin in different sources, it is widely accepted that the main source of these contaminants is STP effluents. Despite toxicity and high input of this compound in the aquatic systems, little information is available on their concentration in the sediment and how these compounds are distributed in the environment. In this study, natural and synthetic female sex hormones (estrone - E1, 17β-estradiol - E2, 17α-Ethinylestradiol – EE and progesterone - PG) were monitored in the sediment of three rivers from the Iguacu river basin, South Brazil. Also, a removal estimate of these compounds by the local STP was performed. The results showed significant concentrations of hormones, mainly E2, in the sediment samples and an inefficient removal by the STP, resulting in some cases, in the increasing of estrogens. An assessment of the sediment-water partition coefficient (Kd) showed high mobility in the environment for the estrogens, in contrast to the higher affinity for the sediment of the progesterone.

Degradation of Organochlorine Compounds Using Zero Valent Iron (ZVI) Nano Particles Impregnated in Hydrophobic Modified Bentonite

The degradation of perchloroethylene (PCE) adsorbed on hydrophobic modified bentonite was investigated. The degradation occurred via reduction of iron particles with zero valence (ZVI) incorporated in hydrophobic surface of bentonite. We compared two different systems, one containing ZVI and another without ZVI. The degradation of PCE was accompanied by decreasing concentrations of PCE and the increase of resulting compounds such as trichloroethylene (TCE), 1,2-dichloroethylene, trans and cis forms, (1,2-cis-DCE and 1,2- trans-DCE). The results show that the PCE is rapidly adsorbed and in contact with ZVI particles is degraded to less toxic compounds, while in the systems without ZVI no significant decrease of PCE was observed, clearly demonstrating that the degradation process occurs through the reduction with ZVI. The rate constant for the system containing ZVI was 0.215 h−1, while for the system without ZVI it was only 0.031 h−1. The results agree with other research, however the reaction was conducted in columns and the clay was zeolite. It can be concluded that the system impregnated with ZVI is extremely interesting as an alternative application for removal of organic compounds containing chlorine due to their persistence and toxic effect on the microorganisms. The system can also be applied as barrier content.