Genotoxic assessment on river water using different biological systems

This paper reports genotoxicity and toxicity data in water samples collected in Sinos River, an important water course in the hydrographic region of Guaíba Lake, Rio Grande do Sul State, south of Brazil. This river is exposed to intense anthropic influence by numerous shoes, leather, petrochemical, and metallurgy industries. Water samples were collected at two moments (winter 2006 and spring 2006) at five sites of Sinos River and evaluated using in vitro V79 Chinese hamster lung fibroblasts (cytotoxicity, comet assay and micronucleus test) and Allium cepa test (toxicity and micronucleus test). Comet and micronucleus tests revealed that water samples collected exerted cytotoxic, toxic, genotoxic and mutagenic effects. The results showed the toxic action of organic and inorganic agents found in the water samples in all sites of Sinos River, for both data collections. The main causes behind pollution were the domestic and industrial toxic discharges. The V79 and A. cepa tests were proved efficient to detect toxicity and genotoxicity caused by complex mixtures. This study also showed the need for constant monitoring in sites with strong environmental degradation caused by industrial discharges and urban sewages.     

The effect of continuous exposure of copper on the properties and extracellular polymeric substances (EPS) of bulking activated sludge

Introduction  

This study investigated the effect of copper on chemical oxygen demand (COD) removal efficiency and on the properties (mainly settling and dewatering) and the composition of extracellular polymeric substances (EPS) when 20 mg/L Cu(II) was continuously dosed to a sequencing batch reactor (SBR) inoculated with activated sludge.     

Determination of pharmaceuticals, personal care products, and pesticides in surface and treated waters: method development and survey

Water is fundamental to the existence of life since it is essential to a series of activities, such as agriculture, power generation, and public and industrial supplies. The residual water generated by these activities is released into the environment, reaches the water systems, and becomes a potential risk to nontarget organisms. This paper reports the development and validation of a quantitative method, based on solid-phase extraction and liquid chromatography tandem mass spectrometry, for the simultaneous analysis of 18 pharmaceuticals and personal care products (PPCPs) and 33 pesticides in surface and drinking waters. The accuracy of the method was determined by calculating the recoveries, which ranged from 70 to 120 % for most pesticides and PPCPs, whereas limits of quantification ranged from 0.8 to 40 ng/L. After the validation step, the method was applied to drinking and surface waters. Pesticides and PPCPs were found in concentrations lower than 135.5 ng/L. The evaluation of different water sources with regard to contamination by pesticides and PPCPs has been quite poor in southern Brazil.     

Bisphenol A migration from plastic materials: direct insight of ecotoxicity in Daphnia magna

Bisphenol A (BPA) is an endocrine disrupting chemical (EDC) whose migration from food packaging is recognized worldwide. However, the real overall food contamination and related consequences are yet largely unknown. Among humans, children’s exposure to BPA has been emphasized because of the immaturity of their biological systems. The main aim of this study was to assess the reproductive impact of BPA leached from commercially available plastic containers used or related to child nutrition, performing ecotoxicological tests using the biomonitoring species Daphnia magna. Acute and chronic tests, as well as single and multigenerational tests were done. Migration of BPA from several baby bottles and other plastic containers evaluated by GC-MS indicated that a broader range of foodstuff may be contaminated when packed in plastics. Ecotoxicological test results performed using defined concentrations of BPA were in agreement with literature, although a precocious maturity of daphnids was detected at 3.0 mg/L. Curiously, an increased reproductive output (neonates per female) was observed when daphnids were bred in the polycarbonate (PC) containers (145.1?±?4.3 % to 264.7?±?3.8 %), both in single as in multigenerational tests, in comparison with the negative control group (100.3?±?1.6 %). A strong correlated dose-dependent ecotoxicological effect was observed, providing evidence that BPA leached from plastic food packaging materials act as functional estrogen in vivo at very low concentrations. In contrast, neonate production by daphnids cultured in polypropylene and non-PC bottles was slightly but not significantly enhanced (92.5?±?2.0 % to 118.8?±?1.8 %). Multigenerational tests also revealed magnification of the adverse effects, not only on fecundity but also on mortality, which represents a worrying trend for organisms that are chronically exposed to xenoestrogens for many generations. Two plausible explanations for the observed results could be given: a non-monotonic dose–response relationship or a mixture toxicity effect.     

State of the Art Report on Mathematical Methods for Groundwater Pollution Source Identification

The reliable assessment of hazards or risks arising from groundwater contamination problems and the design of efficient and effective techniques to mitigate these problems require the capability to predict the behavior of chemical contaminants in flowing water. Most attempts at quantifying contaminant transport have relied on a solution of some form of a well-known governing equation referred to as advection-dispersion-reaction equation. To choose an appropriate remediation strategy, knowledge of the contaminant release source and time release history becomes pertinent. As additional contaminated sites are being detected, it is almost impossible to perform exhaustive drilling, testing, and chemical fingerprint analysis every time. Moreover, chemical fingerprinting and site records are not sufficient to allow a unique solution for the timing of source releases. The purpose of this paper is to present and review mathematical methods that have been developed during the past 15 years to identify the contaminant source location and recover the time release history.     

Median lethal concentration of formaldehyde and its genotoxic potential in bullfrog tadpoles (Lithobates catesbeianus)

In order to avoid that contaminated frog farms animals escaping in the environment and become potential vector of emergent diseases, studies with disinfection protocol are strictly necessary. The formaldehyde is one of the compounds tested in fungal disinfection protocols and also used in aquaculture. This study aimed to determine the median lethal concentration (LC_50–96h) of formaldehyde in bullfrog tadpoles and to evaluate the possible genotoxic effects in acute exposition. Accordingly, the animals were exposed to formaldehyde in the concentrations of 6, 9, 12, 15, and 18 mg L^?1, and after 96 h blood samples were drawn for the micronucleus (MN) test. The LC_50–96h was 10.53 mg L^?1, and the MN frequency increased in proportion to the formaldehyde concentrations, with an estimated frequency in the negative control being 1.35 MN/individual. We concluded that formaldehyde is genotoxic to tadpoles of bullfrogs in the tested concentrations, and the choice of this chemical should be contemplated before its use in animals in captivity.     

Leaf morphoanatomy of species tolerant to excess iron and evaluation of their phytoextraction potential

Setaria parviflora (Poir.) Kerguélen and Paspalum urvillei Steudel are grasses that grow naturally in a soil with high iron contents. This study aimed to characterize morphoanatomically and histochemically the iron phytotoxicity on leaves and evaluate the phytoextraction potential of these grasses. Saplings were cultivated in hydroponic solution with and without excess Fe-EDTA. Regarding measurements taken on leaves, reduction was observed among treatments of Fe-EDTA on height values of abaxial epidermis and bundle sheath in both species. As for iron histolocalization, stronger reaction was observed in leaves of S. parviflora, in comparison with P. urvillei. Anatomical damage, such as protoplast retraction, irregular xylem, changes in cell volume, and cell collapse, and visual symptoms, like leaf bronzing, chlorosis, and necrosis, were similar in both species when exposed to excess iron; however, P. urvillei showed more severe damage. This species accumulated more iron in shoots than S. parviflora and therefore is more favorable for use in phytoextraction. The root system of both species accumulated higher iron concentrations in relation to shoots.     

Adapting a rapid assessment protocol to environmentally assess palm swamp (Veredas) springs in the Cerrado biome,Brazil

The exploitation and degradation of natural environments exert intense pressure on important ecosystems worldwide. Thus, it is necessary developing or adapting assessment methods to monitor environmental changes and to generate results to be applied to environmental management programs. The Brazilian Veredas (phytophysiognomies typical to the Cerrado biome) are threatened by several human activities; thus, the aim of the present study is to adapt a rapid assessment protocol (RAP) to be applied to Veredas springs, by using the upper course of the Vai-e-Vem stream watershed (Ipameri County, Goiás State, Brazil). Therefore, several springs in the study site were visited and 11 of them were considered Veredas springs. After the RAP was adapted, the instrument was validated and used to environmentally assess the springs in order to demonstrate its applicability. The present study has provided an instrument of option to monitor Veredas springs.     

Detection of hormones in surface and drinking water in Brazil by LC-ESI-MS/MS and ecotoxicological assessment with <Emphasis Type="Italic">Daphnia magna</Emphasis>

The growing use of pharmaceutical drug is mainly due to several diseases in human and in animal husbandry. As these drugs are discharged into waterways via wastewater, they cause a major impact on the environment. Many of these drugs are hormones; in which even at low concentrations can alter metabolic and physiological functions in many organisms. Hormones were found in surface water, groundwater, soil, and sediment at concentrations from nanograms to milligrams per liter of volume—quantities known to cause changes in the endocrine system of aquatic organisms. This study aimed to develop a methodology for hormone detection (estriol, estrone, 17β-estradiol, 17α-ethinylestradiol, progesterone, and testosterone) on surface and treated water samples. Sample toxicity was assessed by ecotoxicology tests using Daphnia magna. A liquid chromatograph coupled to a mass spectrometer with an electrospray ionization source (LC-ESI-MS/MS) was used for the analysis. The results showed that samples were contaminated by the hormones estriol, estrone, progesterone, 17β-estradiol, and 17α-ethinylestradiol during the sampling period, and the highest concentrations measured were 90, 28, 26, 137, and 194 ng·L^?1, respectively. This indicates the inflow of sewage containing these hormones at some points in the Piracicaba River in the State of Sao Paulo—Brazil. Results indicated little toxicity of the hormone estriol in D. magna, indicating that chronic studies with this microcrustacean are necessary.