Effect on the growth and development and induction of abnormalities by a glyphosate commercial formulation and its active ingredient during two developmental stages of the South-American Creole frog, Leptodactylus latrans.

We evaluated the acute lethal and sublethal effects of technical-grade glyphosate (GLY) and the GLY-based commercial formulation Roundup ULTRA MAX® (RU) on two Gosner stages (Gss) 25 and 36 of the South-American Creole frog, Leptodactylus latrans. Bioassays were performed following standardized methods within a wide range of concentrations (0.0007-9.62 mg of acid equivalents per liter-a.e./L-of RU and 3-300 mg/L of GLY). The endpoints evaluated were mortality, swimming activity, growth, development, and the presence of morphologic abnormalities, especially in the mouthparts. No lethal effects were observed on larvae exposed to GLY during either Gs-25 or Gs-36. The concentrations inducing 50 % lethality in RU-exposed larvae at different exposure times and Gss ranged from 3.26 to 9.61 mg a.e./L. Swimming activity was affected by only RU. Effects on growth and development and the induction of morphologic abnormalities-like oral abnormalities and edema-were observed after exposure to either GLY or RU. Gs-25 was the most sensitive stage to both forms of the herbicide. The commercial formulation was much more toxic than the active ingredient on all the endpoints assessed. Effects on growth, development, and the induction of morphologic abnormalities observed in the range of environmental concentrations reported for agroecosystems of Argentina constitute an alert to the potential detrimental effects of the herbicide that could be affecting the fitness and survival of anurans in agroecosystems.

Toxicity assessment of four insecticides with different modes of action on pupae and adults of Eriopis connexa (Coleoptera: Coccinellidae), a relevant predator of the Neotropical Region.

Pesticides can be toxic to nontarget organisms including the natural enemies of agricultural pests, thus reducing the biodiversity of agroecosystems. The lethal and sublethal effects of four insecticides with different modes of action-pyriproxyfen, teflubenzuron, acetamiprid, and cypermethrin-were evaluated on pupae and adults of Eriopis connexa, an effective predator in horticultural crops. Pupal survival was reduced by pyriproxyfen (26 %) and cypermethrin (41 %). Malformations in adults emerged from treated pupae were observed after acetamiprid (82.7 and 100 % for 100 and 200 mg a.i./l, respectively), pyriproxyfen (48.6 %), and cypermethrin (13.3 %) treatments. A longer mean oviposition time was also observed in adults emerged from pupae treated with cypermethrin. Moreover, the latter insecticide as well as teflubenzuron did not reduce reproductive parameters, whereas females emerged from pyriproxyfen-treated pupae were not be able to lay eggs even when females showed large abdomens. Upon exposure of adults, survival was reduced to approximately 90 % by acetamiprid, but no reduction occurred with pyriproxyfen, teflubenzuron, or cypermethrin though the fecundity at fifth oviposition time of the female survivors was reduced. Pyriproxyfen decreased the hatching at all the oviposition times tested, whereas fertility was reduced in the fourth and fifth ovipositions by teflubenzuron and in the first and third ovipositions by cypermethrin. In conclusion, all four insecticides tested exhibited lethal or sublethal effects, or both, on E. connexa. The neurotoxic insecticides were more harmful than the insect-growth regulators, and pupae were more susceptible than adults. The toxicity of insecticides on the conservation of predators in agroecosystems of the Neotropical Region is discussed.

Screening concentration of E1, E2 and EE2 in sewage effluents and surface waters of the "Pampas" region and the "Río de la Plata" estuary (Argentina).

Concentrations of estrone (E1), 17ß-estradiol (E2) and 17α-ethinylestradiol (EE2) were investigated for the first time in sewage effluents and receiving waters of the "Río de la Plata" estuary and neighboring areas by means of LC-MS/MS. E2 and EE2 were ubiquitous in the evaluated sewage effluent samples showing concentrations ranging between 122-631 and 65-187 ng/L, respectively. In surface waters, these estrogens were only detected in the "Girado" stream (Chascomús) at 369 and 43 ng/L, respectively. No significant relationship was found among the size of the served population and the concentration of the estrogens in the sewage effluent. The detection of these estrogens in receiving waters was dependent on the dilution capacity of the system. The studied estrogens were undetectable at the La Plata City water supply station. Conversely, concentrations found at the "Girado" stream indicate a potential ecotoxicological risk of these estrogens to the local aquatic biota.

Toxicity of the effluent from an anaerobic bioreactor treating cereal residues on Lactuca sativa.

Effluents generated during the process of anaerobic digestion should be treated before their disposal into the environment. The aim of this study was evaluating the effectiveness of the effluent treatment system from an anaerobic bioreactor, assessing the toxicity reduction with the Lactuca sativa seed germination and root elongation inhibition test. Three sampling points were selected along the effluent treatment system: inflow into the first treatment pond, outflow from the third pond and recirculated flow to the bioreactor. Effluent dilutions tested for each sampling point were 25% and 50% (v/v), undiluted sample and controls. The pH, conductivity, temperature, dissolved oxygen, BOD5 and COD were measured. The decrease in the organic and inorganic loads was correlated with a reduction in the phytotoxicity. The use of the seed toxicity test allows evaluating the quality and effectiveness of the studied effluent treatment system.

Contaminación atmosférica y salud infantil en áreas urbanas e industriales de La Plata, Argentina / Air pollution and children's health in urban and industrial areas of La Plata, Argentina

El impacto de la exposición a contaminantes ambientales sobre la salud humana ha sido ampliamente investigado, encontrándose que muchos problemas de salud están relacionados con la contaminación del aire. En el presente trabajo se analizan los resultados obtenidos de un relevamiento empleando cuestionarios epidemiológicos a niños en edad pre-escolar de la ciudad de La Plata, capital de la Provincia de Buenos Aires, Argentina, y sus alrededores. Para el estudio se consideraron cuatro zonas, una típicamente urbana, otra con influencia industrial, otra de característica semi-rural y una residencial. Los resultados obtenidos evidencian, en cuanto a las enfermedades asociadas a las zonas en estudio, correlaciones significativas entre la zona industrial y dos tipos de afecciones: bronquitis crónica y piel fotosensible. Estos resultados están en concordancia con el elevado nivel de partículas, compuestos orgánicos asociados con las mismas y compuestos orgánicos volátiles hallados en la zona industrial en comparación con las zonas control. Otras correlaciones significativas encontradas se refieren a mayor predisposición a padecer bronquitis en la población que utiliza querosén como combustible para cocinar y calefacción doméstica y el desarrollo de bronquiolitis en zonas con tránsito vehicular congestionado. Estos resultados contribuyen con información de base de gran utilidad para contextualizar futuros estudios epidemiológicos en la región.

The influence of air pollution on human health has been studied during the last decades. In this sense, several epidemiological studies have shown an association between air pollutants and various diseases. In the present study an epidemiological questionnaire was applied to a population of children between 3 and 6 years of La Plata and its neighbouring areas, in Buenos Aires, Argentina. Four different areas were considered: urban, industrial, semi-rural and residential. Results show significant correlations between industrial area and chronic bronchitis and skin photosensitivity. These results depend on the high levels of particles, organic compounds bound to particles and volatile organic compounds found in the industrial area compared to control zones. Other significant correlations are related to the use of kerosene for heating and cooking, and a predisposition to develop bronchitis. Besides, the analyses of questionnaires show a correlation between bronchiolitis and heavy traffic. This investigation contributes with preliminary information to future epidemiological studies in the region.

Susceptibility of Chrysoperla externa eggs (Neuroptera: Chrisopidae) to conventional and biorational insecticides.

Chrysoperla externa (Hagen) is a generalist predator in agroecosystems. We assessed the effect of cypermethrin, endosulfan, methoxyfenozide, and spinosad on immature development time, survivorship, sex ratio, fecundity, and fertility on this organism in laboratory toxicity tests. Effects on second-generation organisms were also studied. Exposures were realized by dipping