Rafael Grossi Botelho

Effects of atrazine and picloram on grass carp: acute toxicity and histological assessment

The aim of this study was to evaluate the acute toxicity of atrazine and pícloram separately to grass carp (Ctenopharyngodon idella). Firstly, fingerlings were exposed to nominal concentrations of these herbicides to determine the lethal concentration (LC50) (96 h). After this, the animals were treated with sub-acute concentrations of the herbicides to measure the effects on gill histology. The LC50 (96 h) of the atrazine and picloram were, respectively, 37 mg L−1 and 4.4 mg L−1. Four types of alterations were found in gills exposed to atrazine, which were epithelial lifting, partial cell proliferation, lamellar fusion, and aneurysm. Nominal concentrations of picloram caused epithelial lifting, partial cell proliferation, and lamellar fusion.

Acute toxicity of sugarcane vinasse to aquatic organisms before and after pH adjustment

The purpose of this study was to investigate the toxicity of vinasse to cladocerans and fish before and after pH adjustment using an acute toxicity test. Linear and quadratic regression models were adjusted to demonstrate the concentration–response relationship between vinasse and the endpoints evaluated. The median lethal concentrations (LC50–48h) of vinasse before pH adjustment for Ceriodaphnia dubia and Daphnia magna were 0.67% and 0.80% respectively, and the median lethal concentrations (LC50–96h) for Danio rerio was 2.62%. After pH adjustment, the values increased for all organisms, demonstrating a decrease in toxicity. This study reported marked toxicity for vinasse to aquatic organisms with toxicity reduction after pH adjustment.

Study of spatial and temporal distribution of antimicrobial in water and sediments from caging fish farms by on-line SPE-LC-MS/MS

ABSTRACT An on-line solid phase extraction liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) method for the determination of 12 antimicrobials in sediment and surface water was developed and validated. Furthermore, the spatial and temporal antimicrobials distributions in the sediment and in the water of four fish farms located in the hydroelectric dam of Ilha Solteira Reservoir in Brazil were investigated over four seasons in three sampling sites: at the fish cages, 100 and 1,000 m downstream far from the cages. The method was performed using an Agilent Zorbax 80 SB-C8 column (9.4 × 15 mm, 5 µm) as the loading column, and the Agilent Zorbax Eclipse Plus C18 column (3.0 × 100 mm, 3.5 µm) as a separation column within a run time of 13 min. The limits of quantification were less than 9 ng·L−1 for the antibiotics in water and 16 µg·kg−1 in sediment; the recovery ranged from 80 to 119%, with a variation coefficient less than 11%, and the repeatability was lower than 15%. Oxytetracycline was found in the water in all sample seasons. However, florfenicol was identified in April and October 2013 and January 2014, and tetracycline was present in July 2013. Regarding the sediment, oxytetracycline and tetracycline were found in all sampling periods, but chlortetracycline was only identified in January 2014. The spatial distribution of antimicrobials showed that the main pollution source came from the fish farms. This study demonstrated that the proposed method is reliable for the monitoring of antimicrobials in water and sediments and it showed contamination in both matrices from Ilha Solteira Reservoir.

Herbicides and the Aquatic Environment

The quality of water resources is perhaps currently the most discussed topic when it comes to environmental preservation, since aquatic ecosystems have been suffering changes worldwide in most cases irreversible. Such changes are often associated with human activities such as deforestation, release of industrial and domestic effluents, and even the use of pesticides in agricultural fields, which is one of sources that most contributes to the fall of quality of water resources.

Atrazine levels in the Jaboticabal water stream (São Paulo State, Brazil) and its toxicological effects on the pacu fish Piaractus mesopotamicus / Razine atrazina u vodotoku Jaboticabal (São Paulo, Brazil) i njihovi toksikološki učinci na ribu Piaractus mesopotamicus

Abstract The aim of this study was to determine the environmental concentration of atrazine (ATZ) in five streams located in the north of São Paulo state (Brazil) and evaluate its toxicological impact on young specimens of the pacu fish Piaractus mesopotamicus. Samples of water were collected on three occasions between 2010 and 2011, corresponding to periods signifying the beginning, middle, and end of rain season. ATZ levels were estimated by a high-performance liquid chromatography coupled with a mass spectrometry (HPLC-MS/MS) triple quadrupole. Later, the quotient of environmental risk (QR) was determined based on the medium lethal concentration (LC50 48 h), non-observable effect concentration (NOEC), and the estimated environmental concentration (EEC) of ATZ detected in the environment. Histological changes in gills and liver were also studied, along with the brain activity of the enzyme acetylcholinesterase (AChE). The highest concentration of ATZ measured was 10.4 μg L-1. The ATZ LC50 (48 h) for young P. mesopotamicus was 24.46 mg L-1 and the QR was classified as “safe”. Although the QR indicated that ATZ could be safe for the tested species, it caused many histological alterations in the liver and gills of the exposed specimens, and an increase in the AChE levels. Predmet ovoga istraživanja bio je odrediti okolišne koncentracije atrazina u pet vodotoka na sjeveru brazilske savezne države São Paulo te ocijeniti njihove toksikološke učinke na ribu Piaractus mesopotamicus. Uzorci vode prikupljeni su u tri navrata između 2010. i 2011. godine, i to na početku, usred i pri kraju kišne sezone. Razine atrazina mjerene su trostrukim kvadrupolom s vezanim sustavom tekućinska kromatografija visoke djelotvornosti-spektrometrija mase (HPLCMS/ MS). Potom je izračunat kvocijent okolišnog rizika (QR) na temelju srednje smrtonosne koncentracije (LC50 48 h), maksimalne koncentracije bez učinka (NOEC) te procijenjene okolišne koncentracije (EEC) atrazina pronađenog u okolišu. Nadalje, istražene su histološke promjene u škrgama i jetri te izmjerena aktivnost enzima acetilkolinesteraze (AChE) u mozgu. Najviša izmjerena razina atrazina bila je 10.4 μg L-1. LC50 (48 h) atrazina za mlade jedinke P. mesopotamicus bio je 24.46 mg L-1, a QR je klasificiran kao „siguran“. Premda QR upućuje na to da bi se atrazin mogao okarakterizirati sigurnim za ispitanu vrstu, uzrokovao je ne samo brojne histološke promjene u jetri i škrgama izloženih jedinki, nego i porast razina AChE u mozgu.

Water Quality Assessment in Piracicamirim Creek Upstream and Downstream a Sugar and Ethanol Industry Through Toxicity Tests With Cladocerans

An environmental impact study was conducted to determine the Piracicamirims creek water quality in order to assess the influence of effluents from a sugar industry in this water body. For this, toxicity tests were performed with a water sample upstream and downstream the industry using the microcrustaceans Daphnia magna, Ceriodaphnia dubia and Ceriodaphnia silvestrii as test organisms, as well as physical and chemical analysis of water. Results showed that physical and chemical parameters did not change during the sampling period, except for the dissolved oxygen. No toxicity was observed for D. magna and reproduction of C. dubia and C. silvestrii in both sampling points. Thus, the industry was not negatively impacting the quality of this water body.

Veterinary Antibiotics in the Environment

In recent years, pharmaceutical pollution in the environment has been a great concern due to the potential effects on the human and animal health. Some of the most used classes such as antibiotics, which are used to prevent and treat bacterial infections and promote the growth of livestock, deserve to be highlighted since their intensive use has contaminated environmental matrices such as soil, water, sediment, plants, and animals with effects on the biota. To better understand the potential ecological risk of antibiotics in environments and to develop management strategies for these substances searching to reach the reduction of these compounds in aquatic systems, one of the most important steps is to determine the environmental concentrations of these compounds in the envi‐ ronments through analytical methods and evaluate their effects on the biota. The goal of this chapter is contribute with information about the effects of these compounds on the biota as well as its environmental behavior and bacterial resistance in additional to the main techniques for samples preparation and quantitative and confirmatory methods for its determination in the environment.

Dissolved Heavy Metal Determination and Ecotoxicological Assessment: A Case Study of the Corumbataí River (São Paulo, Brazil)

The aim of this one-year study (August 2009 to July 2010) was to evaluate the Corumbataí River water polluted by anthropogenic sources and see how it affects the reproduction of the microcrustacean Ceriodaphnia dubia (Richard, 1984) in laboratory conditions over seven days of exposure to water samples collected monthly at six different locations. We determined the concentrations of zinc (Zn), copper (Cu), nickel (Ni), lead (Pb), and cadmium (Cd), as well as physicochemical parameters such as dissolved oxygen, conductivity, water temperature, and pH. Dissolved oxygen and conductivity demonstrated anthropogenic influence, as dissolved oxygen concentration decreased and conductivity increased from the upstream to the downstream stretch of the river. The effects on C. dubia were observed in the months with high precipitation, but the toxicity cannot be associated with any particular contaminant. Heavy metal levels kept well below the limit values. Zn and Pb had the highest concentrations in the water during the sampling period, probably due to the industrial and agricultural influence. However, these levels do not seem to be associated with precipitation, which suggests that their primary source was industry. Physicochemical parameters, the ecotoxicological assay, and determination of heavy metals proved to be efficient tools to evaluate aquatic environments.The aim of this one-year study (August 2009 to July 2010) was to evaluate the Corumbatai River water polluted by anthropogenic sources and see how it affects the reproduction of the microcrustacean Ceriodaphnia dubia (Richard, 1984) in laboratory conditions over seven days of exposure to water samples collected monthly at six different locations. We determined the concentrations of zinc (Zn), copper (Cu), nickel (Ni), lead (Pb), and cadmium (Cd), as well as physicochemical parameters such as dissolved oxygen, conductivity, water temperature, and pH. Dissolved oxygen and conductivity demonstrated anthropogenic influence, as dissolved oxygen concentration decreased and conductivity increased from the upstream to the downstream stretch of the river. The effects on C. dubia were observed in the months with high precipitation, but the toxicity cannot be associated with any particular contaminant. Heavy metal levels kept well below the limit values. Zn and Pb had the highest concentrations in the water during the sampling period, probably due to the industrial and agricultural influence. However, these levels do not seem to be associated with precipitation, which suggests that their primary source was industry. Physicochemical parameters, the ecotoxicological assay, and determination of heavy metals proved to be efficient tools to evaluate aquatic environments.