Impact of cypermethrin on stream fish populations under field-use in biotech-soybean production

The impact of biotech-soybean technology on freshwater ecosystems is being evaluated in the Rolling Pampas region, Argentina. The effect of cypermethrin, the main soybean insecticide, on low-order temperate-stream fish populations was investigated for two consecutive crop cycles under field-use conditions in biotech-soybean production. Cypermethrin was unable to induce mortality or behavioral effects on any of the fish species resident in a first-order stream across a crop field (pulsed acute exposure scenario) sprayed according to conventional practices. No spatially or temporally dependent effects were observed on population parameters (size-class structure, abundance, survival, sex and immature/mature ratio, condition factor) of resident or caged Cnesterodon decemmaculatus after spraying or rainfall events, not even one year after, at the beginning of the next crop cycle. Although cypermethrin was "very highly toxic" to C. decemmaculatus in laboratory water (96h-LC(50)=0.43microg/l), its toxicity was reduced in filtered (78%) and unfiltered (92%) stream water. Changes in LC(50) values were mainly correlated with the OC content of each water fraction (r(2)=0.99; p<0.01; n=9), showing that both DOC and TOC contributed proportionally to toxicity reduction. Protective effects of stream water (12-fold reduction LC(50) values) explained the lack of effects on fish populations in the field, despite cypermethrin water concentrations after spraying reached values comparable with the 96h-LC(50). Therefore, cypermethrin under field-use conditions in transgenic-soybean production represents a low risk of acute exposure for fish populations inhabiting low-order temperate-streams rich in TOC. The relationship between LC(50) and TOC could be a convenient way to improve risk estimation based on laboratory toxicity testing.     

Study of metals concentration levels in Patella piperata throughout the Canary Islands, Spain

In order to assess the extent of metal contamination at rocky shores of the Canarian Archipelago, metal concentrations have been measured in Patella piperata (Gould, 1846), using the standard atomic absorption spectrophotometer technique. Ranges of elements concentrations measured (in μg g⁻¹) found in the biota were: Cd (0.36 ± 0.26 μg g⁻¹ dry wt.), Cu (2.05 ± 0.91 dry wt.), Pb (1.57 ± 1.14 μg g⁻¹dry wt.) and Zn (10.37 ± 4.60 μg g⁻¹ dry wt.). Variation in metal concentrations in Patella, was tested by using non-parametric statistical methods. Cd content had a maximum in the Archipelago Chinijo, northward of Lanzarote Island. The metal concentrations recorded at the clean stations may be considered carefully if they are used like background levels.     

Influence of copper status on the accumulation of toxic and essential metals in cattle

The aim of the present study was to assess whether the use of pig slurry and associated copper accumulation in calves grazing pastures fertilized with pig slurry from the Deza region in NW Spain has a significant influence on toxic metal and essential metal levels, and to investigate whether copper accumulation is correlated with the levels of these other metals. Correlations between copper, toxic metals (cadmium, lead) and essential metals (molybdenum, iron, zinc, selenium, manganese and cobalt) concentrations were evaluated in liver and kidney of 195 calves from the region of Deza. Metal concentrations were determined by ICP-OES and correlations between pairs of elements by Pearson correlation analysis. There was a strongly significant positive association between copper and lead in the liver. Considering the trace metals, copper in the liver showed significant positive correlations with cobalt in both liver and kidney, and with molybdenum in the liver. In addition, significant correlations were observed between copper and most essential metals in kidney. These associations are similar to those found in different animal species experimentally dosed with copper and other metals, as well as in cattle exposed to normal copper concentrations.     

A full-scale study of treatment of pig slurry by composting: kinetic changes in chemical and microbial properties

Since the indiscriminate disposal of pig slurry can cause not only air pollution and bad odours but also nutrient pollution of ground waters and superficial waters, composting is sometimes used as one environmentally acceptable method for recycling pig manure. The aim of this study was to evaluate the effect of composting pig slurry on its sanitation (evaluated by ecotoxicity assays and pathogen content determination), as well as to determine the effect of a carbon-rich bulking agent (wood shavings, WS) and the starting C/N ratio on the changes undergone by different chemical (volatile organic matter, C and N fractions) and microbiological (microbial biomass C, ATP, dehydrogenase activity, urease, protease, phosphatase, and beta-glucosidase activities) parameters during composting. Pig slurry mixed with bulking agent (P+WS) and the solid faction separated from it, both with (PSF+WS) and without bulking agent (PSF), were composted for 13 weeks. Samples for analysis were taken from composting piles at the start of the process and at 3, 6, 9, and 13 weeks after the beginning of composting. The total organic carbon, water soluble C and ammonium content decreased with composting, while Kjeldahl N and nitrate content increased. The nitrification process in the PSF+WS pile was more intense than in the PSF or P+WS composting piles. The pathogen content decreased with composting, as did phytotoxic compounds, while the germination index increased with compost age. Piles with bulking agent showed higher values of basal respiration, microbial biomass carbon, ATP and hydrolase activities during the composting process than piles without bulking agent.     

Chelate-induced phytoextraction of metal polluted soils with Brachiaria decumbens

Chelate-induced phytoextraction with high biomass plant species has been proposed for the clean-up of heavy metal polluted soils. In the current work, the effect of the application of two different chelating agents, i.e. EDTA and EDDS, on the metal phytoextraction capacity of Brachiaria decumbens was studied. Although EDTA was, in general, more effective in soil metal solubilization, EDDS, a chelate less harmful to the environment, was more efficient inducing metal accumulation in B. decumbens shoots than EDTA. Indeed, in a moderately heavy metal polluted soil, EDDS caused a 2.54, 2.74 and 4.30-fold increase in Cd, Zn, and Pb shoot metal concentration, respectively, as compared to control plants. In this same soil, EDTA caused a 1.77, 1.11 and 1.87-fold increase in Cd, Zn, and Pb shoot metal concentration, respectively, as compared to control plants. EDDS was also more effective than EDTA in stimulating the translocation of metals from roots to shoots. B. decumbens plants were able to grow in the metal polluted soils showing no visible symptoms of phytotoxicity, which suggests their metal tolerance. Finally, B. decumbens, a fast-growing, high biomass, aluminum tolerant plant species, that has a well-established agronomic system, fulfills most of the requirements for chemically-induced phytoextraction.     

Occurrence of <Emphasis Type="Italic">Pepper Mild Mottle Virus</Emphasis> (PMMoV) in Groundwater from a Karst Aquifer System in the Yucatan Peninsula,Mexico

The Yucatan Peninsula of Mexico hosts a karst aquifer system that is the only source of freshwater for the area; however, it is vulnerable to human-mediated contamination. Pepper mild mottle virus (PMMoV) is one of the most abundant RNA viruses associated with human feces, making it a viable indicator for tracking fecal pollution in aquatic environments, including groundwater. In this study, groundwater samples collected from a karst aquifer from fresh and brackish water locations were analyzed for fecal indicator bacteria, somatic and male F+ specific coliphages, and PMMoV during the rainy and dry seasons. Total coliform bacteria were detected at all sites, whereas Escherichia coli were found at relatively low levels <40 MPN/100 ml. The highest average concentrations of somatic and male F+ specific coliphages were 920 and 330 plaque forming units per 100 ml, respectively, detected in freshwater during the rainy season. PMMoV RNA was detected in 85% of the samples with gene sequences sharing 99–100% of nucleotide identity with PMMoV sequences available in GenBank. Quantification of PMMoV genome copies (GC) by quantitative real-time PCR indicated concentrations ranging from 1.7 × 10¹ to 1.0 × 10⁴ GC/L, with the highest number of GC detected during the rainy season. No significant correlation was observed between PMMoV occurrence by season or water type (p > 0.05). Physicochemical and indicator bacteria were not correlated with PMMoV concentrations. The abundance and prevalence of PMMoV in the karst aquifer may reflect its environmental persistence and its potential as a fecal indicator in this karst aquifer system.     

Gill and liver transcriptomic responses of Achirus lineatus (Neopterygii: Achiridae) exposed to water-accommodated fraction (WAF) of light crude oil reveal an onset of hypoxia-like condition

Environmental Science and Pollution Research - Crude oil is one of the most widespread pollutants released into the marine environment, and native species have provided useful information about the...     

Elucidation of adsorption mechanisms and mass transfer controlling resistances during single and binary adsorption of caffeic and chlorogenic acids

Environmental Science and Pollution Research - In this work, the potential of activated carbon to remove caffeic and chlorogenic acids in aqueous solution was investigated. The study focused on...     

Heavy metals and metalloid levels in the tissues of yellow-legged gulls (Larus michahellis) from Spain: sex,age, and geographical location differences

Environmental Science and Pollution Research - In the present study, mercury (Hg), cadmium (Cd), lead (Pb), selenium (Se), and arsenic (As) were measured in liver, kidney, and feathers of adult,...