Residue levels of fenitrothion and aminocarb in the air samples collected from experimental spray blocks in New Brunswick in 1982

Abstract

Fenitrothion and aminocarb formulations were aerially sprayed over mixed coniferous forests near Fredericton and Bathurst, New Brunswick, Canada. Insecticide concentrations inside the spray blocks were measured at intervals of time by trapping the airborne toxicants in a fritted‐glass bubbler containing dimethylformamide (DMF). The residues in DMF were analysed by gas chromatography. Concentrations of the insecticides in the air sampled decreased rapidly with time from peak levels of 1997 ng/m³ (fenitrothion) and 1201 ng/m³ (aminocarb). Concentrations of the two insecticides in the air samplers were dependent upon the nature of the chemicals, type of formulation used, spray timings and other environmental factors.     

LC-MS/MS determination of pesticide residues in fruits and vegetables

The aim of the research is to evaluate pesticide residue contamination of fresh and frozen fruits and vegetables, agricultural raw material, purchased from Polish farmers for production of frozen fruits and vegetables, and the estimation of the multiresidue method effectiveness expressed as the proportion of pesticides detected in food samples to the total number of pesticides analyzed by multiresidue methods. A total of 144 samples (of black currants, red currants, raspberries, cherries, strawberries, blackberries, cauliflowers and broccoli) were analyzed using LC-MS/MS method for the determination of 60 pesticides. QuEChERS extraction, matrix-matched calibration and dynamic multiple reaction monitoring method were used. Residues of 15 compounds, mainly fungicides and insecticides, were detected in 46 samples. The percentage of samples with residues above the maximum residue levels (MRL) was 15%, whereas samples with residues below MRL were 17%. A total of 13 samples contained more than one pesticide residue. Pesticide residues were detected most often in samples of black currants (50%), broccoli (36.4%), raspberries (29%) and red currants (21.8%). The most frequently detected pesticides were carbendazim and acetamiprid. The proportion of pesticides detected during our study to the total number of analyzed pesticides amounted to 25%. It was compared to literature findings. For three fourth of multiresidue methods, the proportion was below 50% for methods developed for the analysis of less than 100 pesticides, and below 30% for methods developed for the analysis of more than 100 pesticides. It appears that a lot of efforts and means is lost on pesticides never or rarely detected in examined samples. The workload and cost effectiveness of the development and application of multiresidue methods along with the range of pesticides covered by the method should be carefully and thoroughly considered anytime when a new method or workflow is developed. Including non-targeted screenings in pesticide residue control seems to be an alternative worth considering.     

Optimization and validation of enzyme-linked immunosorbent assay for the determination of endosulfan residues in food samples

In this study, an enzyme-linked immunosorbent assay (ELISA) was optimized and applied to the determination of endosulfan residues in 20 different kinds of food commodities including vegetables, dry fruits, tea and meat. The limit of detection (IC₁₅) was 0.8 μg kg^?1 and the sensitivity (IC₅₀) was 5.3 μg kg^?1. Three simple extraction methods were developed, including shaking on the rotary shaker at 250 r min^?1 overnight, shaking on the rotary shaker for 1 h and thoroughly mixing for 2 min. Methanol was used as the extraction solvent in this study. The extracts were diluted in 0.5% fish skin gelatin (FG) in phosphate-buffered saline (PBS) at various dilutions in order to remove the matrix interference. For cabbage (purple and green), asparagus, Japanese green, Chinese cabbage, scallion, garland chrysanthemum, spinach and garlic, the extracts were diluted 10-fold; for carrots and tea, the extracts were diluted 15-fold and 900-fold, respectively. The extracts of celery, adzuki beans and chestnuts, were diluted 20-fold to avoid the matrix interference; ginger, vegetable soybean and peanut extracts were diluted 100-fold; mutton and chicken extracts were diluted 10-fold and for eel, the dilution was 40-fold. Average recoveries were 63.13–125.61%. Validation was conducted by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The results of this study will be useful to the wide application of an ELISA for the rapid determination of pesticides in food samples.     

Limitations in the determination of maximum residue limits and highest residues of pesticides: Part I

The pesticide usages are controlled by comparing residue concentrations in treated commodities to legally permitted maximum levels (MRLs) determined based on supervised trials designed to reflect likely maximum residues occurring in practice following authorised use. The number of trials available may significantly affect the accuracy of estimated maximum residues. We conducted a study with synthetic lognormal distributions with mean of 1 and standard deviations of 0.8 and 1.0, which reflect the residue distributions observed in practice. The likely residues in samples were modelled by drawing random samples of size 3, 5, 10 and 25 from the synthetic populations. The results indicate that the estimations of highest residues (HR), used for calculation of short-term intake, and the MRLs, serving as legal limits, are very uncertain based on 3–5 trials indicated by the calculated HR_0.975/HR_0.025 and MRL_0.975/MRL_0.025 ratios of 12 and 9, and 13 and 10, respectively, which question the suitability of such trials for the intended purpose. As the 95% range of HR and MRL rapidly decreases with number of trials, ideally ≥15 but minimum 6–8 trials should be used for estimation of HR and MRL according to the current typical practice of Codex Alimentarius.     

Contribution to the food products' analysis: A research and evaluation on the hemolytic effect of some pesticides used in Lebanon

Pesticides are a real concern for the society as their use has become critical, leading sometimes to their accumulation as residues in fruits and vegetables. After examining the pesticides sold in Northern Lebanon, this study is focused on the analysis and identification of pesticides residues in fruits and vegetables that are harvested in this region and treated with the locally sold pesticides. Results show: first, (i) a use of Zineb by the name of another pesticide Micronized Sulfur to avoid prosecution; (ii) a significant presence of Metalaxyl in lemons and oranges; (iii) a significant presence of Trifluralin in strawberries; and (iv) a significant presence of Zineb in lemons and tomatoes. Second, with the use of hemolytic tests on human blood results show: (i) a critical concentration and a significant hemolytic effect of some pesticides used in Lebanon; and (ii) an absence of hemolytic effect in the collected fractions of the different analyzed fruit extracts containing pesticides. Finally, this work is the first step for pesticides' analysis in vegetables and fruits in Lebanon, initiating a wider analytical study in order to control and examine the use of pesticides which, according to our results, could have an adverse effect on human health over a long term.     

Chemometric characterization of soil and plant pollution: Part 1: Multivariate data analysis and geostatistical determination of relationship and spatial structure of inorganic contaminants in soil

Geostatistical and multivariate methods of data analysis are used to describe patterns of soil pollution with inorganic contaminants in Celje County, Slovenia. Groups of contaminants and polluted sites were identified using cluster analysis and confirmed with multidimensional variance and discriminant analysis. Factor analysis yields an identification of not directly observable relationships between the contaminants. The spatial structure and distribution of contaminants were assessed by applying semivariogram analysis and kriging interpolation method. Zinc, Cd and Cu were identified as a pollutant emitted from the zinc smelter, Pb also from other sources, and Cr and Ni mostly from geological parent material.     

Application of nanobalance technique and principal component analysis for detection of the soil fumigant Telone residues in the air

Quartz crystal nanobalance (QCN) technique is considered as a powerful mass sensitive sensor for monitoring of materials in the sub-nanogram level. In the current study, a method based on QCN technique developed to determine Telone in air. Various coating materials including methyl phenyl silicon, 75% phenyl (OV25) and molecularly imprinted polymer (MIP) were employed. The frequency shift of OV25-modified quartz crystal was found to be linear against organohalogen compounds [Telone (soil fumigant), Koril (Herbicide), Endosulfan (organochlorine insecticide) and Chloroform (solvent)] concentrations in the range of 2.4 to 48 mg L^?1 for Telone vapor and 4.8–24 mg L^?1 for three other vapors. The correlation coefficients for Telone, Koril, Endosulfan and Chloroform were 0.992, 0.996, 0.989 and 0.991, respectively. The principal component analysis was also utilized to process the frequency response data of the organic vapors. Using principal component analysis, it was found that more than 93.85% of the data variance could still be explained by use of two principal components (PC1 and PC2). Subsequently, the successful discrimination of Telone and other compounds was quite possible through the principal component analysis of the transient responses of the OV25-modified electrode. In the second method, a molecularly imprinted polymer-coated sensor for Telone was developed. Molecularly imprinted polymer coated quartz crystal (MIP-QCN) showed a selective response to Telone and gave a linear relationship between frequency shift and amount of Telone from 1 to 48 mg L^?1. In this investigation, the proficiency of MIP-QCN and OV25-modified QCN sensors were compared.     

Direct spectral analysis and determination of high content of carcinogenic bromine in bread using UV pulsed laser induced breakdown spectroscopy

Laser induced breakdown spectroscopy (LIBS) was applied for the detection of carcinogenic elements like bromine in four representative brands of loaf bread samples and the measured bromine concentrations were 352, 157, 451, and 311 ppm, using Br I (827.2 nm) atomic transition line as the finger print atomic transition. Our LIBS system is equipped with a pulsed laser of wavelength 266 nm with energy 25 mJ pulse^?1, 8 ns pulse duration, 20 Hz repetition rate, and a gated ICCD camera. The LIBS system was calibrated with the standards of known concentrations in the sample (bread) matrix and such plot is linear in 20–500 ppm range. The capability of our system in terms of limit of detection and relative accuracy with respect to the standard inductively coupled plasma mass spectrometry (ICPMS) technique was evaluated and these values were 5.09 ppm and 0.01–0.05, respectively, which ensures the applicability of our system for Br trace level detection, and LIBS results are in excellent agreement with that of ICPMS results.     

Two-stage chemical fractionation method for the analysis of elements and non-volatile inorganic ions in PM10 samples: Application to ambient samples collected in Rome (Italy)

A two-stage micro-analytical scheme for the determination of metals and ions in atmospheric particulate matter collected on only one Teflon filter was developed. In the first stage the collected particles are chemically fractionated for their solubility in a pH-buffered extracting solution; in the second stage the residue is mineralised. The major non-volatile inorganic ions (Cl⁻, NO₃⁻, SO₄²⁻, Na⁺, NH₄⁺, Ca²⁺, Mg²⁺) are determined in the first fraction by ion-chromatography (IC), while metals and metalloids (Al, As, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, S, Sb, Se, Si, Ti, V, Zn) are determined in both the acetate extractable and the mineralised residual fractions by inductively coupled plasma optical emission spectroscopy (ICP-OES).The procedure was applied to ambient 24-h PM₁₀ samples collected on Teflon filters during two field campaigns carried out at two sites in the area of Rome (Italy). The variations in the chemical composition of the collected particles during the two periods were interpreted in the light of the dilution properties of the lower atmosphere and of the back-trajectories of the air masses. The difference in the results between the two locations was interpreted in the light of their proximity to the emission sources. It was found that the acetate extractable and the mineralised residual fraction of some metals exhibit a different temporal pattern, suggesting the existence of different emission sources of the two fractions.     

Human exposure to dioxins and furans: application of the substance flow analysis to health risk assessment

Substance Flow Analysis (SFA) is an important instrument that allows for the undertaking of environmental management for a specific contaminant. 'Control Analysis' is a tool that assesses the effect on a target flow of changes in flows forming part of a control basis set. The purpose of the present study was to perform a modeling of the annual PCDD/F flows in Tarragona Province and to apply the model for human health risk assessment. The validation of the model has been evaluated by comparing estimated fluxes with experimental values. Eleven subsystems, as well as a set of 88 flows of the system in Tarragona Province were considered. The total PCDD/F accumulation in Tarragona Province was between 62.6 and 159.5 g I-TEQ/y. Accumulation in sediments (27.9-74.6 g I-TEQ/y) and soils (35.0-80.8 g I-TEQ/y) are the two principal modes of deposition. Estimated flow in human adipose tissue means a mean intake of PCDD/F (via ingestion and inhalation) of 243 pg I-TEQ/person/day. The food chain pathway accounts for 99% of the total daily intake. As a result of the simulation, a 100% decrease in industrial emissions would cause a 1.7% reduction in the PCDD/F accumulation in humans. In turn, a 100% reduction of PCDD/Fs in the industrial waste waters would cause only an insignificant 0.1% decrease in the accumulation of PCDD/Fs in humans.     

Estimating the potential of wild foods for nutrition and food security planning in tropical areas: Experimentation with a method in Northwestern Colombia

Wild foods contribute to the food security of multiple communities in tropical areas of Africa, Asia and Latin America. However, wild foods are not regularly considered in the planning of strategies for food and nutrition security mainly due to the lack of technical and/or scientific knowledge so that they can be considered suitable for human consumption. This paper proposes a multidisciplinary method that estimates the potential of wild foods as alternative resources when planning interventions in favour of food and nutrition security in tropical forest territories. When designing the method, four dimensions were identified in science, technology and innovation (STI) that define this potential as well as ten assessment criteria. The wild foods chosen for applying the method were Alibertia patinoi (a fruit commonly known as Borojó) and Proechimys semispinosus (Mouse of thorns), which are two of the main wild foods traditionally used by human communities in a tropical forest territory in the northwest of Colombia. In both cases, although there are significant advances in STI, compliance with some criteria is still required to regard them as viable alternatives for nutrition and food security within this territory. This research is useful for promoting the inclusion of wild food in food security programmes for communities where this food is already included in their traditional pattern of consumption and identifies the progress needed in STI to achieve this purpose. It may also promote the early recognition of possible traditional and cultural practices with high risk of transmission of pathogenic elements by the handling and/or inadequate consumption of wild foods. This early recognition could contribute to the prevention of diseases of wild animal origin, including those of rapid global spread.     

Distribution of PCDDs and PCDFs in Soils Collected from the Denver Front Range - Principal Components Analysis of Diffuse Dioxin Sources (10 pp)

Background, Aims and Scope The Rocky Mountain Arsenal (RMA) is a US Army facility located northeast of Denver, Colorado that has been listed on the National Priorities List (NPL). It is currently being re-mediated under the authority of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) and the Superfund Amendments and Reauthorization Act of 1986 (SARA). As part of the remediation activities at RMA, indications were found that a source of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) had existed on the RMA. As a result, investigations were undertaken to assess the possible nature and extent of any potential sources of PCDDs and PCDFs on the RMA site. In addition, other studies were conducted that examined PCDD/PCDF contamination in the Denver area. The goal of these studies was to examine nature and extent of PCDD/PCDF contamination both on the RMA as well as in the surrounding Denver area. The intent of this study was to characterize sources of dioxins (PCDDs) and dibenzofurans (PCDFs) at low environmental concentrations which might have originated from diffuse sources in the Denver Colorado area and in particular, the Rocky Mountain Arsenal (RMA) using Principal Component Analysis (PCA). Methods Over 200 soil samples were collected from the RMA and the Denver area. From the RMA, soil was collected as part of three studies that included a (1) random site-wide sampling of the RMA, (2) soils from the Western Tier Parcel (WTP), and (3) soils from Historic Use areas. Denver area soil samples were collected from five different land use categories: Residential, Agricultural, Open Space, Commercial, and Industrial. PCA was conducted on concentrations of 17 2,3,7,8-substuituted PCDD and PCDF congeners in 220 soil samples collected from the RMA and the Denver Front Range region. Results and Discussion PCA demonstrated the presence of possible minor sources of dioxins on the RMA. Current remediation efforts on RMA will result in the removal of these sources. Samples from the RMA were identified by the presence of a congener profile containing higher chlorinated PCDFs while the Denver Front Range areas were characterized by the presence of higher chlorinated PCDD congeners. The presence of a PCDF signature for the RMA samples does not necessarily indicate a major source of these contaminants on-site. Indeed, the relatively diffuse nature of the sample clusters would argue strongly against the presence of a single large source. Instead, the predominance of the PCDF congeners probably indicates the mixed industrial activities that took place on and near the site. Conclusion PCA results indicate that PCDD/PCDF profiles in soils collected from the RMA differed from those collected from the outlying Denver areas but that a major source of these contaminants was not present. Rather, the diffuse nature of sample clusters from the PCA indicated that the congener profile of RMA samples was most likely a result of the mixed industrial activities that historically have taken place on and near the site. PCA also indicated that many of the 'open area' (peripheral site-wide) RMA soils samples did not differ from Denver are reference congener profiles. This finding was also true for samples collected from the WTP that were essentially indistinguishable from Off-RMA reference samples. In addition, total TEQ concentrations in soils collected from WTP were similar to those measured in soils collected from the Denver Front Range areas indicating that lack of a major source of PCDD/PCDF within the WTP zones of the RMA. Recommendation and Outlook Analytical as well as statistical results of the soil congener data indicate that the WTP soils are indistinguishable from soils collected from non-industrial areas in the Denver area. This finding would support the recent 'de-listing' of the WTP from the other RMA areas and its' transfer to other authorities in the Denver area.