Effect of processing on the disappearance of pesticide residues in fresh-cut lettuce: Bioavailability and dietary risk

The aim of this research is to establish the processing factors of six pesticides durong the preparation of fresh-cut lettuce and to assess the risk of ingestion of pesticide residues associated with the consumption of the same. A field study was carried out on the dissipation of three insecticides (imidacloprid, tebufenozide, cypermethrin) and three fungicides (metalaxyl, tebuconazole, azoxystrobin) during treatment conditions simulating those used for commercial fresh-cut lettuce. A simultaneous residue analysis method is validated using QuEChERS extraction with acetonitrile and CG-MS and LC-MS/MS analysis. The residues detected after field application never exceed the established Maximum Residue Limits. The processing factors were generally less than 1 (between 0.34 for tebufenozide and 0.53 for imidacloprid), indicating that the process, as a whole, considerably reduces residue levels in processed lettuce compared to fresh lettuce. It is confirmed that cutting, followed by washing and drying, considerably reduces the residues. A matrix effect in the dialyzation of the pesticides is observed and the in vitro study of bioavailability establishes a low percentage of stomach absorption capacity (<15%). The EDI/ADI ratios found in all cases were well below their ADI values, and the dietary exposure assessed (EDI) in fresh-cut lettuce showed no concerns for consumer health.     

Isolation and characteristics of sulfentrazone-degrading bacteria

This study aimed to isolate and characterize bacteria able to use sulfentrazone in the commercial formulation as their sole carbon source. The isolation of the potential sulfentrazone-degrading bacteria was made from soil samples with a recent history of herbicide application and from isolates identified through rDNA sequencing. Subsequently, we assessed the growth of the isolates and their sulfentrazone degradation ability using high-performance liquid chromatography. Twenty-six potential sulfentrazone-degrading bacterial isolates were obtained in pure culture. Through analysis of the rDNA sequences, the predominance of bacterial species of the genus Pseudomonas was found. The isolates presented a differentiated ability of sulfentrazone degradation. The presence of herbicide in the culture medium reduced the log phase of four isolates. Pseudomonas putida, Pseudomonas lutea, Pseudomonas plecoglossicida and three isolates of Pseudomonas sp. showed higher sulfentrazone degradation capacity, which varied from 4 to 15%. This is the first report of the Pseudomonas genre capable of sulfentrazone degradation. The isolates obtained present potential use in bioremediation programs for soil contaminated with sulfentrazone.     

Pattern recognition and classification of sediments according to their metal content using chemometric tools. A case study: the estuary of Nerbioi-Ibaizabal River (Bilbao, Basque Country)

Chemometrics are increasingly used in environmental monitoring studies, but are still far from being accepted as routine tools by field specialists. The multivariate character of usually highly correlated environmental data recommends the use of advanced chemometrics as part of the analytical methodology in order to get information on the basic structure of data. In this work, we have applied a battery of non-supervised (Principal Component Analysis (PCA)) and supervised (k-Nearest Neighbour (k-NN), Soft Independent Modelling of Class Analogies (SIMCA), Linear Discriminant Analysis (LDA) and Artificial Neural Networks (ANNs)) multivariate techniques on a specific environmental dataset. The dataset consists on the concentration of 14 elements (Al, As, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sn, V and Zn) in 95 sediments collected at eight different locations of the estuary of the Nerbioi-Ibaizabal River (Bilbao, Basque Country) during 12 sampling campaigns conducted every 3 months between 2005 and 2008. The study aims to present a simple methodology of general applicability which may result in a flexible and practical tool to assess chemical pollution in sediments of a given specific site.     

Between uncertainty and hope: Young leaders as agents of change in sustainable small-scale fisheries

The path to sustainable small-scale fisheries (SSF) is based on multiple learning processes that must transcend generational changes. To understand young leaders from communities with sustainable SSF management practices in Mexico, we used in-depth interviews to identify their shared motivations and perceptions for accepting their fishing heritage. These possible future decision-makers act as agents of change due to their organizational and technological abilities. However, young people are currently at a crossroads. Many inherited a passion for the sea and want to improve and diversify the fishing sector, yet young leaders do not want to accept a legacy of complicated socioenvironmental conditions that can limit their futures. These future leaders are especially concerned by the uncertainty caused by climate change. If fishing and generational change are not valued in planning processes, the continuity of fisheries, the success of conservation actions, and the lifestyles of young fishers will remain uncertain.Graphical abstract Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01639-2.     

Validation of a GC-MS/MS method for simultaneous determination of 86 persistent organic pollutants in marine sediments by pressurized liquid extraction followed by stir bar sorptive extraction

A multiresidue method for the analysis of 86 persistent pollutants in marine sediments at ultra-trace level has been developed and validated using pressurized liquid extraction (PLE) and stir-bar sorptive extraction (SBSE) coupled with thermal desorption and gas chromatography-triple quadrupole mass spectrometry (TD-GC-MS/MS QqQ). The compounds analyzed belong to various families such as polychlorinated biphenyls, polycyclic aromatic hydrocarbons, polybrominated diphenylethers, organophosphorus and organochlorine pesticides and other pesticides such as urons, and triazines. The analytes have very different polarities and log K_ow values, which is an important parameter in the optimization of a SBSE method. Due to PLE high efficiency and throughput rates, along with the proven ability for multiresidue analysis and excellent sensitivity of SBSE, we present an efficient method. The limits of quantification obtained ranged from 0.014 to 1.0 ng g⁻¹, with detection limits below pg g⁻¹ levels. In order to validate the proposed methodology, quality parameters such as recovery, linearity and reproducibility were studied. Recoveries ranged from 63% to 119%, reproducibility (in terms of Relative Standard Deviation for ten determinations) was lower than 35% in all cases, and determination coefficients higher than 0.990 for all analytes. The main factors that affect PLE, SBSE and GC-MS/MS procedures were optimized. The method was applied to the analysis of nine marine sediments obtained from the nine main submarine wastewater discharge points (emissaries) presents along the coast of Tenerife Island (Canary Islands, Spain).     

Government and voluntary policymaking for sustainability in mining towns: A longitudinal analysis of Itabira,Brazil

The socio‐economic fabric of single‐company mining towns needs to be carefully considered by both Government and companies in sustainability policymaking. Policy design and effectiveness in such towns are significantly impacted by the city's economic dependence on a single company. This paper explores the perceived effectiveness of government and voluntary private sector mining policies for pursuing sustainability in the historic mining town of Itabira, Brazil over a period of 20 years. Itabira serves as a worthwhile case study because it allows for an in‐depth and longitudinal analysis that can reveal valuable lessons to policymakers of different sectors and jurisdictions located elsewhere. Based on extensive face‐to‐face interviews and literature reviews, study results indicate that changes to the state environmental licensing policies in the 1990s led to significant socio‐environmental improvements in the area. The globalization of the mining company also contributed to an increase in the quantity and quality of voluntary industry policies. Recent technological improvements in the beneficiation processes of the mining company promises to extend the life of the mine to 2050. Although there are significant incremental socio‐environmental policies and programmes, sustainability remains an elusive vision in Itabira, with no clear objectives or monitoring and accountability mechanisms. The paper concludes by recommending a more formal integrated policymaking framework.     

Prenatal diagnosis of autosomal dominant polycystic kidney disease using flanking DNA markers and the polymerase chain reaction

A prenatal diagnosis was carried out on a 9-week-old fetus at risk for autosomal dominant polycystic kidney disease (ADPKD). Ten members of the family were previously typed using five DNA markers linked to the PKD1 locus on chromosome 16, and one marker linked to the putative PKD2 locus on chromosome 2. The polymerase chain reaction (PCR) was used to amplify the D16S125 locus. Pairwise and multipoint lod scores indicated that the family was most likely segregating a PKD1 mutation. The fetus inherited the disease haplotype from the affected parent. Diagnostic accuracy was greater than 99 per cent, taking into account the possibility of genetic heterogeneity.     

Mating behaviour in a slave-making ant, Rossomyrmex minuchae (Hymenoptera, Formicidae)

The mating behaviour of the ant Rossomyrmex minuchae, a rare, protected slave-making species in Spain, seems to be significantly affected by its particular life history and patchy habitat. The mating behaviour of the entire genus Rossomyrmex is virtually unknown. We present here the results of a 3-year study of mating behaviour in R. minuchae.Behavioural observations and limited nest excavations revealed that R. minuchae does not produce sexuals every year, the number of sexuals is low, and the sex ratio tends to be female biased. Females typically exhibit two distinct activity periods. The first, the mating period, takes place in early afternoon: the ants call near the natal nest, mate and then return to their nest. The second, the dispersal period takes place in late afternoon: the mated females exit their nest and fly in search of a new, non-parasitized Proformica longiseta host nest. Males are highly active during the mating period, but will remain inactive in the dispersal period even if experimentally presented with virgin females. It appears that females are monogamous, while males are polygamous. When males are late arriving at the female calling site, the females will frequently congregate presumably calling in chorus.The low reproductive efficiency exhibited by R. minuchae, coupled with the postulated low genetic variation in the population, as sisters may mate with the same male, could result in a low survival rate and risk of eventual extinction. The observed decrease in nest density we observed during the 2004 season may be indicative of such a process.