Acaricide residues in beeswax. Implications in honey, brood and honeybee.

For beekeeping to be sustainable, the management of colonies for the production of bee products must be economically viable without endangering the lives of bees, and must include acceptable practices such as the treatment of hives with appropriate products. Occasionally, the use of acaricides to treat the hives against varroosis is uncontrolled and can accumulate in the hives, putting the colonies at risk. In this work, a screening of seven acaricides was carried out in different apiaries in Andalusia (Spain).

Neonicotinoid contamination in wildflowers collected from citrus orchards in a northwestern Mediterranean Region (Spain) after tree foliar treatments.

Ground-cover vegetation attracts and harbors beneficial insects to the agrosystem, playing an important role in conservation biological control. Integrated pest management (IPM) program guidelines recommend the implantation of sowed or resident wild covers in perennial crops. Given the high-quality fruit requirements, even in IPM programs, insecticides can be required in citrus crops.

Microbial Decontamination of Bee Pollen by Direct Ozone Exposure.

The bee pollen is a complete and healthy food with important nutritional properties. Usually, bee pollen is consumed dehydrated, but it is possible to market it as fresh frozen pollen, favoring the maintenance of its properties and greatly increasing its palatability, compared to dried pollen. However, fresh frozen pollen maintains a high microbiological load that can include some pathogenic genus to human health.

A three-year large scale study on the risk of honey bee colony exposure to blooming sunflowers grown from seeds treated with thiamethoxam and clothianidin neonicotinoids.

Despite the restriction of the use of neonicotinoids in the EU, including thiamethoxam and clothianidin, the debate over their risk on honey bees has not been fully settled. This study presents results of a three-year study working with 180 honey bee colonies in ten replicates. Colonies were sorted into three treatments (60 colonies per treatment) exposed to sunflower blooms grown from seeds treated with thiamethoxam, clothianidin and a non-treated control.

The toxic unit approach as a risk indicator in honey bees surveillance programmes: A case of study in Apis mellifera iberiensis.

The influence of genetic diversity and exposure to xenobiotics on the prevalence of pathogens was studied within the context of a voluntary epidemiological study in Spanish apiaries of Apis mellifera iberiensis, carried out during the spring season of years 2014 and 2015. As such, the evolutionary lineages of the honey bee colonies were identified, a multiresidue analysis of xenobiotics was carried out in beebread and worker bee samples, and the Toxic Unit (TUm) was estimated for each sampled apiary. The relationship between lineages and the most prevalent pathogens (Nosema ceranae, Varroa destructor, trypanosomatids, Black Queen Cell Virus; and Deformed Wing Virus) was analysed with contingency tables, and the possible relationships between TUm and the prevalence of these pathogens were studied by using a factor analysis.

Evaluation of Residue Levels of Imidacloprid and Thiamethoxam After Foliar Application to the Citrus Varieties Lane Late, Valencia Late, Rohde Summer, and Nules.

Neonicotinoids are used to protect citrus trees against pests. Dissipation and persistence of neonicotinoids in pollen and nectar of citrus trees after foliar applications and their potential exposure to pollinators have not been well characterized. Field studies were conducted using three orange and one mandarin varieties to compare the imidacloprid and thiamethoxam residue levels and their decline in pollen and nectar after treatments in pre-bloom close to flowering period and their persistence 1 yr after treatment.

Analysis of pesticide residues in honeybee (Apis mellifera L.) and in corbicular pollen. Exposure in citrus orchard with an integrated pest management system.

In the last years, the honeybee population is facing growing threats such as expansion of pathogens, incorrect use of phytosanitary products and environmental contaminants, loss or fragmentation of habitat, invasive species and climate change. The citrus cropping by Integrated Pest Management (IPM) in Spain combines strategies to reduce pest populations preventing environmental problems and reducing levels of damage by using chemicals only when it is strictly necessary. The goal of this study is to develop a simple analytical method to evaluate pesticide residue levels in honeybees and corbicular pollen when honeybees are exposed to plant protection products (PPPs) used in integrated pest management citrus orchards.

Viability of honeybee colonies exposed to sunflowers grown from seeds treated with the neonicotinoids thiamethoxam and clothianidin.

In this study, honeybee colonies were monitored in a field study conducted on sunflowers grown from seeds treated with the systemic neonicotinoids thiamethoxam or clothianidin. This field trial was carried out in different representative growing areas in Spain over a beekeeping season. The health and development of the colonies was assessed by measuring factors that have a significant influence on their strength and overwintering ability.

Uptake of azoles by lamb's lettuce (Valerianella locusta L.) grown in hydroponic conditions.

An uptake and translocation study of azole compounds was performed in lamb's lettuce (Valerianella locusta L.) grown in nutrient solution fortified with different azoles. Three azoles, (clotrimazole, fluconazole and propiconazole), which have different physico-chemical properties and are ubiquitous in the aquatic environment, were the compounds selected.

Fast ultrasound-assisted extraction combined with LC-MS/MS of perfluorinated compounds in manure.

A fast analytical method for the determination of perfluorinated compounds in poultry manure by LC-MS/MS was developed. The extraction was carried out by ultrasound-assisted extraction of 1 g of sample, during 2 × 15 min using low volume (5.5 mL) of a mixture of methanol and acetonitrile.

Review of sample preparation techniques for the analysis of pesticide residues in soil.

This paper reviews the sample preparation techniques used for the analysis of pesticides in soil. The present status and recent advances made during the last 5 years in these methods are discussed. The analysis of pesticide residues in soil requires the extraction of analytes from this matrix, followed by a cleanup procedure, when necessary, prior to their instrumental determination.

Influence of moisture on the availability and persistence of clotrimazole and fluconazole in sludge-amended soil.

Applying sewage sludge to soil is a common practice in many parts of the world. Thus, pharmaceutical compounds, such as azoles, can be released into the environment after sludge is applied to soil. To understand the fate of clotrimazole and fluconazole (pharmaceuticals used as antifungals in humans) in soil after its amendment with sludge, a reliable and sensitive method has been developed to determine these compounds in the solid and aqueous phases of soil.

Determination of azoles in sewage sludge from Spanish wastewater treatment plants by liquid chromatography-tandem mass spectrometry.

A simple and rapid analytical method for the determination of 16 azoles in sewage sludge has been developed and validated. The method was based on ultrasound-assisted extraction followed by dispersive solid-phase extraction cleanup and liquid chromatography-electrospray tandem mass spectrometric detection. The azoles were selected by their intensive usage as biocides (tebuconazole, propiconazole, cyproconazole and thiabendazole), antimycotic pharmaceuticals (ketoconazole, econazole, fluconazole and clotrimazole) or fungicides in agriculture (difenoconazole, flusilazole, hexaconazole, prochloraz, bromuconazole, epoxiconazole and triticonazole).

Determination of pesticide residues in sewage sludge: a review.

Pesticides are widely applied to protect plants from diseases, weeds, and insect damage, and they usually come into contact with soil where they may undergo a variety of transformations and provide a complex pattern of metabolites. Spreading sewage sludge on agricultural lands has been actively promoted by national authorities as an economic way of recycling. However, as a byproduct of wastewater treatment, sewage sludge may contain pesticides and other toxic substances that could be incorporated into agricultural products or be distributed in the environment.

Application of ultrasound-assisted extraction to the determination of contaminants in food and soil samples.

The application of ultrasound-assisted extraction (UAE) to the sample preparation of environmental and food samples has increased in the last years. This technique has been used in the development of methods for the analysis of numerous contaminants, including organic compounds (pesticides, pharmaceuticals, polycyclic aromatic hydrocarbons, polyhalogenated flame retardants, etc.) and heavy metals.

Determination of hexabromocyclododecane isomers in sewage sludge by LC-MS/MS.

A method has been developed to determine alpha, beta and gamma diastereoisomers of hexabromocyclododecane (HBCD), a brominated flame retardant, in sewage sludge, based on the ultrasonic-assisted extraction (UAE) of samples with dichloromethane-ACN (1:1) and the subsequent clean-up of extracts by dispersive solid phase extraction with primary-secondary amine. Levels of HBCD diastereoisomers were determined by LC coupled with ESI MS/MS. Evaluation of the matrix effect showed a high ion suppression for all the diastereoisomers studied, which was counteracted by using a mixture of labelled HBCD diastereoisomers as internal standards.

A combination of ultrasonic assisted extraction with LC-MS/MS for the determination of organophosphorus pesticides in sludge.

A method has been developed for the analysis of a wide polarity range of the currently used organophosphorus pesticides (OPs) and their metabolites in sewage sludge samples. Extraction was carried out using ultrasonic assisted extraction (UAE) with different solvents. The levels of OPs in sludge were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) using electrospray ionization (ESI) in positive or negative ion mode.

Evaluation of laboratory assays for the assessment of leaching of copper and chromium from ground-contact wood.

Laboratory studies were conducted to assess the leaching of Cu and Cr from wood, treated with a Cu-Cr-B preservative, when placed in contact with soil. Two laboratory assays were performed: Wood in contact with soil solutions over 30 d, and wood in direct contact with soil over 30 weeks. The influence of several factors, such as soil type and fertilizer use, was studied in both assays.

Leaching of copper, chromium, and boron from treated timber during aboveground exposure.

Field studies were conducted to evaluate leaching of Cu, Cr, and B from timber treated with a Cr, Cu, and B wood preservative and exposed aboveground in Spanish weathering conditions during one year with a total rainfall of approximately 500 mm. The effect of timber orientation (horizontal for decks and vertical for fences) on metal leaching was assessed. Leaching of metals after one year was higher for decks than for fences, with total amounts of metals leached being 226.

Influence of leaching medium and drying time between successive leaching periods on the emission of chromium, copper, and boron from treated wood.

Laboratory studies were conducted to determine leaching of Cu, Cr, and B from pine sapwood treated with Cr-Cu-B (CCB) preservative in different leaching media (ultrapure water [UPW], rainwater [RW], and soil water [SW]). Losses of metals from CCB-treated wood, expressed in percentage of initial content, were always highest for B (11.2-63.

Influence of organic fertilizer application on pendimethalin volatilization and persistence in soil.

Laboratory studies were undertaken to evaluate the influence of fertilizers on pendimethalin volatilization and persistence in soil. Various organic fertilizers such as liquid humic substances and urea were used at doses of 100 L/ha or 170 kg of N/ha, respectively. Herbicide residues were determined in air, soil solution, and soil samples by GC-ECD; the recovery of pendimethalin from spiked fertilized or control samples was found to be 81-103%.