Dieldrin Research Articles

An approach for restoration of the water quality with emphasis on the removal of organochlorine pesticides and eutrophic conditions in tropical rivers

This work deals with an approach for the water quality restoration with emphasis on the removal of organochlorine pesticides and eutrophic conditions in tropical rivers, causing influence on the management of the central-regional aqueduct, as a source of water supply for human consumption (4 million people) and industrial production in the states of Carabobo, Cojedes and Aragua, Venezuela, testing the phytoremediation techniques through Vetiveria zizanioides (VZ) species and coupled bioreactors, Sequencing Batch Reactor (SBR) followed by an Upflow Anaerobic Filter in Three Separate Stages (UAF-3SS). Five rivers are involved known as Chirgua, Paito Guacara, Ereigüe, and Tucutunemo, whose waters have been classified as hypereutrophic, and containing organochlorine pesticides (OCPs). As a sample, for Tucutunemo River, OCPs included to DDT (dichlorodiphenyltrichloroethane) and its isomers and DRINs (Aldrin, Endrin and Dieldrin) dissolved in water and sorbed on sediments, which were measured during the dry and rainy seasons in the period 2013 to 2016, in three monitoring stations distributed in a reach of 15 km. The results indicated that p.p′-DDT concentration dissolved in water was increased up to 10 times from rainy to dry seasons, indicating that a permanent use of it is being carried out by farmers in the agricultural activity development. Steady concentrations of the DTT isomers (e.g., p.p′-DDD and p.p′-DDE) and Aldrin isomers (e.g., Dieldrin) demonstrated that the anaerobic and aerobic biodegradation processes occurred along the river and between climatic seasons. At experimental scale, VZ hydroponic system developed over a period of 6 months for the removal of nutrients demonstrated moderately low to high removal efficiencies. With respect coupled bioreactors, each bioreactor has been experimentally tested, demonstrating satisfactory performance in Chemical Oxygen Demand (COD) removal from industrial wastewater containing recalcitrant and inhibitory substances (46%–98%), which was estimated in the influent ranging from 3500 to 5500 mg/L, evidencing that coupling of bioreactors might lead to a effluent COD complying with environmental regulations.

Criticisms About Pesticide Use

Recently there has been more complaints about how pesticides are used throughout the World with concerns about their presence in soils, in harvested produce and the possibility that various illnesses were caused by exposure to pesticides. The initial criticisms date back to Rachel Carson (1962) who was concerned about the impact of DDT and other chlorinated hydrocarbon insecticides. This led to the establishing of the Rotterdam Convention about the movement of highly hazardous pesticides and established standards of information exchange, essentially to warn countries not to import these chemicals. A subsequent Stockholm convention considered the wider problem of persistent chemicals in the environment. Nevertheless, the agrochemical industry has continued to market a wide range of these pesticides. In the countries with a more temperate climate, the requirement of training those applying the pesticides, usually with tractor equipment and use of protective clothing, problems caused by using many pesticides have not been so evident compared with more tropical countries, using mostly manually carried and operated sprayers with little or no training on how or when pesticides should be applied.

A Pest or Otherwise? Encounter of Oryctes rhinoceros (Coleoptera: Scarabaeidae) with Persistent Organic Pollutants.

Simple SummaryA native, widely spread beetle, Oryctes rhinoceros, in Southeast Asia may clean up some of the persistent organic pollutants (POPs) for us if guarded in a controlled manner. Some xenobiotics persisting in our environment may cause harmful effects to the living creatures within their food web via a so-called “bioaccumulation effect”. The encounter of wild creatures with the POPs appears inevitable. Luckily, this study revealed that the proper breeding of the commonly seen beetle could degrade more than 95% of some studied POPs simply by ingestion. The beetle larvae tolerated different POPs at various extents, yet through an acclimation operation, the beetle’s mortality rate could be greatly reduced. Even though O. rhinoceros is considered a pest for some valuable corps, its removal of POPs in a natural, efficient and passive (i.e., fewer energy inputs) manner makes this alternative promising and deserving of further explorations.The potential use of invertebrates as bioreactors to treat environmental pollutants is promising and of great interest. Three types of the persistent organic pollutants (POPs), namely pentachlorophenol (PCP), PAHs (naphthalene and phenanthrene) and dieldrin (DLN), were spiked in soil and treated by using Oryctes rhinoceros larvae, a known pest of coconut trees in southeast Asia, and also the indicators of POP toxicity and the fate and degradability of the ingested POPs were assessed. The larvae were tested at various levels of the POPs and went through an acclimation process. Without acclimation, the tolerance limits of the larvae toward PCP, PAHs and DLN were 200, 100 and 0.1 mg/kg-soil, respectively, yet with acclimation, the tolerance levels increased to 800, 400 and 0.5 mg/kg-soil, respectively. Biodegradation rates of all the tested POPs were >90% by week 2, with <5% and nearly 0% remaining in the feces and body of the larvae, respectively. The results suggest that the use of the beetle larvae in soil POP decontamination is doable.

Lessons from the Malaria Vector Control Program Based on Indoors Residual Spraying with DDT or Dieldrin in the Pilot Zone of Bobo-Dioulasso: Failure or Success?

RésuméPendant cinq ans, à partir de 1953, un grand programme d'aspersions pariétales intradomiciliaires s'est déroulé dans la zone pilote de Bobo-Dioulasso avec du DDT ou de la dieldrine (DLN) avec une évaluation conceptuellement entomologique et parasitologique [18].Par rapport à la zone témoin, le DDT a induit une réduction d'environ 95% et 67% du taux de piqûres d'Anopheles gambiae, respectivement à l'intérieur et à l'extérieur des maisons. Mais du fait de son action irritante, le DDT a augmenté de cinq fois le coefficient d'exophagie de ce vecteur. La DLN n'a eu aucun impact sur le taux de piqûres d'An. gambiae aussi bien à l'intérieur qu'à l'extérieur, vu la résistance de l'espèce anophélienne à cet insecticide. L'indice sporozoïtique d'An. gambiae a été réduit de 96% dans les zones traitées au DDT et de 70% dans le secteur traité à la DLN.Le DDT a réduit de 98% et de 91% le taux de piqûres d'Anopheles funestus, respectivement dans les maisons traitées et à l'extérieur. Avec la DLN, ces réductions ont été respectivement de 98% et 97%. L'indice sporozoïtique d'An. funestus a été réduit de 95% dans les zones traitées au DDT.La lutte antivectorielle a permis de réduire la transmission due à An. gambiae et An. funestus de quelques 99,8% dans les villages traités au DDT par rapport aux villages témoins. La DLN a permis de réduire de 99,9% la transmission due à An. funestus, mais quasiment pas celle due à An. gambiae . La lutte antivectorielle basée sur les aspersions intradomiciliaires de DDT ou de DLN a permis de réduire de 99,9% la transmission des Plasmodium humains assurée par les deux vecteurs majeurs, An. gambiae et An. funestus dans les villages de la zone pilote.Chez les enfants de 2–9 ans l'indice splénique a été de 84,3% (n= 979) en zone témoin et 44,4% (n = 8920) en zones traitées (différence: -47,3%), la prévalence plasmodiale a été de 60,6% (n = 946) en zone témoin et 38,0% (n = 7242) en zones traitées (différence: – 37%) mais les indices gamétocytiques sont restés aux mêmes niveaux (3,28%, n = 946 en zone témoin et 3,04%, n = 7242 en zones traitées) indiquant le maintien du « réservoir de virus » et des possibilités de transmission.Par rapport à la zone témoin, « l'indice de contamination nouvelle » a été significativement moindre chez les nourrissons de 0-3 mois et de 4 à 6 mois dans les villages traités au DDT mais pas chez les nourrissons 7 à 12 mois démontrant que la lutte antivectorielle avait eu une certaine efficacité dans la prévention de l'infection plasmodiale mais « tous les nouveau-nés étaient infectés dans l'année », donc la transmission de P. falciparum n'avait pas été complètement stoppée.Les aspersions intradomiciliaires avec le DDT ont été d'une grande efficacité dans la réduction de la transmission mais les vecteurs sont restés présents et la transmission, même fortement réduite, s'est maintenue de sorte que dans l'optique de l'éradication, le programme avait été considéré comme un « semi–échec » avec la décision d'adopter un changement complet de stratégie de lutte contre le paludisme et de se centrer sur la chimiothérapie de masse plutôt que sur la lutte antivectorielle.Ces opérations de lutte antivectorielle d'aspersions pariétales de DDT peuvent être considérées comme un succès entomologique, avec ses limites indiquées par le maintien d'un certain niveau de transmission et des indices spléniques et plasmodiques ainsi que d'une incidence observée chez les nourrissons. Cinquante ans après, en l'absence de vaccins, cette recommandation de lutte intégrée et coordonnée contre les vecteurs et les Plasmodium est toujours d'actualité en bénéficiant, entre autres, des moustiquaires imprégnées et des traitements à base d'artémisine.

Organochlorine Pesticides Negatively Influenced the Cellular Growth, Morphostructure, Cell Viability, and Biofilm-Formation and Phosphate-Solubilization Activities of Enterobacter cloacae Strain EAM 35.

An in vitro study was conducted to assess the impact of organochlorine pesticides (OCPs) on cellular growth, morphology, cell viability, biofilm-formation activity, and growth-regulating substances of a soil bacterium. Phosphate-solubilizing EAM 35 isolated from rhizosphere soil was molecularly identified as Enterobacter cloacae (accession number MT672578.1). Strain EAM 35 tolerated varying levels of OCPs, viz., benzene hexachloride (BHC), chlorpyrifos (CP), dieldrin (DE), and endosulfan (ES). The toxicity of OCPs to strain EAM 35 was displayed in a concentration-dependent manner. Among the OCPs, ES at a concentration of 200 μM showed a higher toxicity, where it maximally reduced the bacterial synthesis of indole-3-acetic acid (IAA), salicylic acid (SA), and 2,3-dihydroxy-benzoic acid (DHBA) by 73% (p ≤ 0.001), 85% (p ≤ 0.005), and 83% (p ≤ 0.001), respectively, over the control. While comparing the toxicity of OCPs to P-solubilizing activity of E. cloacae after 10 days of growth, the toxicity pattern followed the order ES (mean value = 82.6 μg mL–1) > CP (mean value = 93.2 μg mL–1) > DE (mean value = 113.6 μg mL–1) > BHC (mean value = 127 μg mL–1). Furthermore, OCP-induced surface morphological distortion in E. cloacae EAM 35 was observed as gaps, pits on both cellular facets, and fragmented and disorganized cell structure under a scanning electron microscope (SEM). The membrane-compromised cells increased as the concentrations of OC pesticides increased from 25 to 200 μM. Additionally, microbial counts (log10 CFU/mL) were also affected after pesticide exposure and decreased with increasing concentrations. While assessing the impact of OCPs on inhibition (%) of log10 CFU/mL, 150, 175, and 200 μM concentrations of ES completely reduced the growth of E. cloacae. Similarly, while comparing the toxicity of higher concentrations of OCPs to bacterial growth, sensitivity followed the order ES > DE > CP > BHC. In addition, the biofilm-formation ability of strain EAM 35 was inhibited in a pesticide-dose-dependent manner, and it was statistically (p ≤ 0.05, p ≤ 0.005, and p ≤ 0.001) significant. Conclusively, the present study clearly suggests that before applying pesticides to soil, their recommended dose should carefully be monitored.

The 2014 national survey of pesticides in groundwater in New Zealand

A total of 165 wells were sampled as part of the 2014 national survey of pesticides in groundwater, a survey that is conducted on a four-yearly basis. The survey aims were to update the national overview of pesticides in New Zealand’s groundwater systems, to investigate temporal variation in pesticide concentrations, and to identify environmental factors associated with pesticide contamination. Samples were analysed for around 80 pesticides using gas chromatography with mass spectrometry detection. Pesticides were detected in 28 wells (17%), with two or more pesticides detected in 10 wells (6%). Pesticides were detected in wells from six of the 13 regions sampled. One well contained a pesticide (dieldrin) at a concentration greater than the maximum acceptable value (MAV) for drinking water. Twenty-one different pesticides were detected, with most concentrations being less than 0.1 mg m-3. Only four of the 51 pesticide detections exceeded a con centration of 1 mg m-3. Comparisons with earlier surveys indicate similar levels of pesticide detections in groundwater over the last 12 years, with higher levels of detections before that time. The majority of wells sampled in each national survey have not had pesticides detected; where detected, the concentrations were mostly less than 0.1 mg m-3 and, with the exception of dieldrin and terbuthylazine, less than 5% of MAVs.

Label-free and iTRAQ proteomics analysis in the liver of zebrafish (Danio rerio) following dietary exposure to the organochlorine pesticide dieldrin

The organochlorine dieldrin (DLD) bioaccumulates in lipid-rich tissues and is associated with immunosuppression, altered metabolism, and cancer. The objective of this study was to determine the effect of DLD on the hepatic proteome in zebrafish following dietary treatment as the liver is central to metabolism. Females were fed a control dose or one of three doses of DLD-contaminated food pellets over 21 days. Both label-free and iTRAQ proteomics were conducted as two complementary methods to expand coverage of the proteome. Label-free proteomics quantified 1563 proteins: 6 proteins showed a linear dose-response with DLD. iTRAQ quantified >3500 proteins; 5 proteins were decreased and 34 proteins were increased in abundance within the liver with all three doses. Overall, DLD reduced the abundance of proteins associated with glucose and cholesterol metabolism, lipid oxidation, liver function, and immune-related processes. Few proteins were identified by both methods as being altered (~1%), suggesting that each method detected different subsets of proteins. Protein responses in the liver were largely dependent on dose, however proteins related to liver and organ function, centrosome separation, glucose/energy metabolism, and immune-related pathways were confirmed by each independent technique and were suppressed with DLD exposure. This study identifies proteomic responses that are associated with organochlorine-induced hepatotoxicity. Biological significanceEnvironmental contaminants cause hepatotoxicity because the liver is the major organ for detoxification. The legacy pesticide dieldrin significantly bioaccumulates in tissues, and can affect molecular processes that can lead to liver pathology. LC MS/MS proteomics identified protein networks related to tumors, energy homeostasis, and chromosomal separation as those affected by dietary exposure to dieldrin. We applied two orthogonal mass spectrometry-based methods to more completely survey the liver proteome, strengthening data interpretation. These data improve understanding as to the effects of organochlorine pesticide toxicity in the liver and the study identifies proteome networks that can contribute to adverse outcome pathways for pesticide exposure.

Ashwagandha reverses the dieldrin-induced cognitive impairment by modulation of oxidative stress in rat brain

Dieldrin (DLD) is an organochlorine pesticide heavily used in agriculture to control pests. Widespread exposures of DLD to human population are likely to contribute in neurological disorders. Withania somnifera (WSF), commonly known as “ashwagandha,” is used for its broad spectrum of pharmacological activity. The present study was designed to investigate the effect of WSF (100 mg/kg) on DLD (5 mg/kg)-induced modulation of cognitive function and oxidative stress in male Wistar rats. Cognitive function was measured using step-down latency (SDL) on a continuous avoidance apparatus and transfer latency (TL) on an elevated plus maze. Oxidative stress was estimated by measuring brain malondialdehyde (MDA) level, protein carbonyl (PC), and reduced glutathione (GSH) activity. Significant reduction in both acquisition and retention in SDL was found for the DLD-treated group at the end of the exposure study as compared to the control (P Abbreviations Used: DLD: Dieldrin; GSH: Reduced glutathione; LD: Lethal dose; LPO: Lipid peroxidation; MDA: Malondialdehyde; OCP: Organochlorine pesticide; PC: Protein carbonyl; SDL: Step-down latency; SFZ: Shock-free zone; TL: Transfer latency; WSF: Withania Somnifera.

Acid- and base-stable porous mechanically interlocked 2D metal–organic polyrotaxane forin situorganochlorine insecticide encapsulation, sensing and removal

The encapsulation and removal of extremely toxic dieldrin by compound1.

Overcoming low EIA performance - A diagnostic tool for the deliberate development of EIA system capacities in low and middle income countries

Overcoming low EIA performance - A diagnostic tool for the deliberate development of EIA system capacities in low and middle income countries

Identifying different mechanisms in the control of a nitrogen–vacancy center system

The nitrogen–vacancy (NV) center system has shown great potential in quantum computing due to its long decoherence time at room temperature by encoding the qubit in dressed states [28]. The corresponding control mechanisms, which is expressed by the pathways linking the initial and target states, can be naturally investigated with the Hamiltonian-encoding and observable-decoding (HE–OD) method in the interaction adiabatic representation. This is proved by the fact that the mechanisms change slightly with different detunings, magnetic and driving field intensities, and the dominant pathway is always |g〉→|d〉→|g〉, with |g〉 and |d〉 as the first two lowest dressed states. Cases are different in the diabatic representation. The orders of dominant pathways increase the driving field intensities. Tendencies of quantum pathway amplitudes with driving fields, magnetic fields and detunings change at different conditions, which can be analyzed from the Dyson series. HE–OD analysis show that the two states |g〉 and |d〉 in the interaction adiabatic representation are preferable to be employed as a qubit than the state pair |0〉 and |−1〉 in the diabatic representation under the current Hamiltonian and parameters.

Dieldrin-induced neurotoxicity involves impaired mitochondrial bioenergetics and an endoplasmic reticulum stress response in rat dopaminergic cells

Mitochondria are sensitive targets of environmental chemicals. Dieldrin (DLD) is an organochlorine pesticide that remains a human health concern due to high lipid bioaccumulation, and it has been epidemiologically associated to an increased risk for Parkinson’s disease (PD). As mitochondrial dysfunction is involved in the etiology of PD, this study aimed to determine whether DLD impaired mitochondrial bioenergetics in dopaminergic cells. Rat immortalized dopaminergic N27 cells were treated for 24 or 48h with one dose of either a solvent control, 2.5, 25, or 250μM DLD. Dopaminergic cells treated with 250μM DLD showed increased Casp3/7 activity at 24 and 48h. DLD also caused a dose dependent reduction in cell viability of ∼25–30% over 24h. No significant effects on cell viability, apoptosis, nor cytotoxicity were detected at 24 or 48h with 2.5μM DLD. Following a 24h exposure to 2.5 and 25μM DLD, viable cells were subjected to a mitochondrial stress test using the Seahorse XFe24 Extracellular Flux Analyzer. Following three independent experiments conducted for rigor, dopaminergic cells that were treated with 2.5 and 25μM DLD consistently showed a reduction in maximum respiration and spare capacity compared to the control group. Molecular responses were measured to determine mechanisms of DLD-induced mitochondrial dysfunction. There were no changes in transcripts associated with mitochondrial membrane potential and permeability (e.g. Ant, Hk1, Tspo, Vdac), nor PI3 K/Akt/mTor signaling or mitochondrial-associated apoptotic factors (Bax, Bcl2, Casp3). However, transcript levels for Chop/Gadd153 (DNA Damage Inducible Transcript 3), an apoptotic gene activated following endoplasmic reticulum (ER) stress, were 3-fold higher in N27 cells treated with DLD, suggesting that DLD-induced mitochondrial dysfunction is related to ER stress. Dopamine cells were also assessed for changes in tyrosine hydroxylase (TH) protein, which did not differ among treatments. This study demonstrates that DLD impairs oxidative respiration in dopamine cells, and ER stress is hypothesized to be associated with the DLD-induced mitochondrial dysfunction. This is important as ER stress is also linked to PD. This study presents mechanistic insight into pesticide-induced mitochondrial dysfunction using a chemical that is reported to be associated to a higher risk for neurodegenerative disease.

Two dechlorinated chlordecone derivatives formed by in situ chemical reduction are devoid of genotoxicity and mutagenicity and have lower proangiogenic properties compared to the parent compound.

Chlordecone (CLD) is a chlorinated hydrocarbon insecticide, now classified as a persistent organic pollutant. Several studies have previously reported that chronic exposure to CLD leads to hepatotoxicity, neurotoxicity, raises early child development and pregnancy complications, and increases the risk of liver and prostate cancer. In situ chemical reduction (ISCR) has been identified as a possible way for the remediation of soils contaminated by CLD. In the present study, the objectives were (i) to evaluate the genotoxicity and the mutagenicity of two CLD metabolites formed by ISCR, CLD-5a-hydro, or CLD-5-hydro (5a- or 5- according to CAS nomenclature; CLD-1Cl) and tri-hydroCLD (CLD-3Cl), and (ii) to explore the angiogenic properties of these molecules. Mutagenicity and genotoxicity were investigated using the Ames's technique on Salmonella typhimurium and the in vitro micronucleus micromethod with TK6 human lymphoblastoid cells. The proangiogenic properties were evaluated on the in vitro capillary network formation of human primary endothelial cells. Like CLD, the dechlorinated derivatives of CLD studied were devoid of genotoxic and mutagenic activity. In the assay targeting angiogenic properties, significantly lower microvessel lengths formed by endothelial cells were observed for the CLD-3Cl-treated cells compared to the CLD-treated cells for two of the three tested concentrations. These results suggest that dechlorinated CLD derivatives are devoid of mutagenicity and genotoxicity and have lower proangiogenic properties than CLD.

The legacy pesticide dieldrin acts as a teratogen and alters the expression of dopamine transporter and dopamine receptor 2a in zebrafish (Danio rerio) embryos

Dieldrin (DLD) is a lipophilic pesticide that shows environmental persistence. The objectives were to determine the effects of DLD on GABAergic and dopaminergic systems in developing zebrafish. Both chorionated and dechorionated embryos (~24h post-hatch) were exposed to a single concentration of DLD (0.347–3470μM) for 48h. Following exposure, a subset of larvae was placed into clean water for 6days (i.e. depuration phase). Chorionated embryos showed <15% mortality while dechorionated embryos showed higher mortality (>30%), suggesting that the chorion protected the embryos. Over a 6day depuration phase, there was a dose dependent effect observed in both the “dechorionated and chorionated embryo” treatments for larval mortality (>60%). At the end of depuration, there was no detectable change in neuro-morphological endpoints that included the ratio of notochord length to body length (%) and the ratio of head area to body area (%). However, DLD did induce cardiac edema, skeletal deformities, and tremors. GABA-related transcripts were not affected in abundance by DLD. Conversely, the relative mRNA levels of dopamine transporter (dat1) and dopamine receptor drd2a mRNA were decreased in dechorionated, but not chorionated, embryos. These data suggest that DLD can alter the expression of transcripts related to dopaminergic signaling. Lastly, GABAA receptor subunits gabrB1 and gabrB2, as well as dopamine receptors drd1 and drd2a, were inherently higher in abundance in dechorionated embryos compared to chorionated embryos. This is an important consideration when incorporating transcriptomics into embryo testing as expression levels can change with removal of the chorion prior to exposure.

Development of dieldrin, endosulfan, and hexachlorobenzene‐imprinted polymers for dye‐displacement array sensing

ABSTRACTDue to the toxicity associated with the exposure to organochlorine pesticides, new materials capable of selectively capturing and detecting these compounds are highly desirable. In this study, imprinted polymers were prepared using three organochlorine pesticides—dieldrin (DE), endosulfan (EN), or hexachlorobenzene (HCB) as templates. The MIPs were polymerized via precipitation polymerization. The yields were over 90% with particle sizes ranging from 62 to 214 nm. Binding studies combined with GC‐ECD analysis showed that each template is more selective to its corresponding MIP compared with the other two structurally homologous templates. These results were consistent with those obtained using UV–vis where more bromocresol green (BCG) dye was released when higher template concentrations were introduced to the corresponding BCG‐impregnated MIPs. Since unique selectivity response pattern for each of the MIPs was obtained, this demonstrated that the MIPs were selective and can be potentially used in dye‐displacement array sensing. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44401.

4,4′-Dichlorodiphenyltrichloroethane (DDT) and 4,4′-dichlorodiphenyldichloroethylene (DDE) promote adipogenesis in 3T3-L1 adipocyte cell culture

4,4′-Dichlorodiphenyltrichloroethane (DDT), a chlorinated hydrocarbon insecticide, was extensively used in the 1940s and 1950s. DDT is mainly metabolically converted into 4,4′-dichlorodiphenyldichloroethylene (DDE). Even though most countries banned DDT in the 1970s, due to the highly lipophilic nature and very stable characteristics, DDT and its metabolites are present ubiquitously in the environment, including food. Recently, there are publications on relationships between exposure to insecticides, including DDT and DDE, and weight gain and altered glucose homeostasis. However, there are limited reports regarding DDT or DDE and adipogenesis, thus we investigated effects of DDT and DDE on adipogenesis using 3T3-L1 adipocytes. Treatment of DDT or DDE resulted in increased lipid accumulation accompanied by increased expression of CCAAT/enhancer-binding protein α (C/EBPα), peroxisome-proliferator activated receptor-γ (PPARγ), fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), adipose triglyceride lipase, and leptin. Moreover, treatment of DDT or DDE increased protein levels of C/EBPα, PPARγ, AMP-activated protein kinase-α (AMPKα), and ACC, while significant decrease of phosphorylated forms of AMPKα and ACC were observed. These finding suggest that increased lipid accumulation caused by DDT and DDE may mediate AMPKα pathway in 3T3-L1 adipocytes.

Peregrine falcon egg pollutants: Mirror Stockholm POPs list including methylmercury

The role of the peregrine falcon (Falco peregrinus) as a bioindicator for the accumulation of organohalogen compounds and other persistent organic pollutants has been established in field studies. Biometric indices for damage caused by pollutants such as the shell thickness and the shell index were determined and the egg contents were analyzed for various pollutants by gas chromatography/mass spectrometry. A wide range of chemically activated luciferase expression (CALUX®) bioassays were performed on subsamples of the eggs.The following organohalogen compounds were found in the eggs of 2009: dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethane, heptachlor epoxide, hexachlorobenzene, dieldrin, hexachlorocyclohexane, polychlorobiphenyls and polychlorodibenzodioxins and polychlorodibenzofurans, polybromodiphenyl ethers, hexabromocyclododecane, tetrabromobisphenyl A, perfluoro compounds, and mercury. The DDT metabolite, dichlorodiphenyldichloroethene (DDE) (11,800 ng/g dry matter),...

20 Years of Air–Water Gas Exchange Observations for Pesticides in the Western Arctic Ocean

The Arctic has been contaminated by legacy organochlorine pesticides (OCPs) and currently used pesticides (CUPs) through atmospheric transport and oceanic currents. Here we report the time trends and air-water exchange of OCPs and CUPs from research expeditions conducted between 1993 and 2013. Compounds determined in both air and water were trans- and cis-chlordanes (TC, CC), trans- and cis-nonachlors (TN, CN), heptachlor exo-epoxide (HEPX), dieldrin (DIEL), chlorobornanes (ΣCHBs and toxaphene), dacthal (DAC), endosulfans and metabolite endosulfan sulfate (ENDO-I, ENDO-II, and ENDO SUL), chlorothalonil (CHT), chlorpyrifos (CPF), and trifluralin (TFN). Pentachloronitrobenzene (PCNB and quintozene) and its soil metabolite pentachlorothianisole (PCTA) were also found in air. Concentrations of most OCPs declined in surface water, whereas some CUPs increased (ENDO-I, CHT, and TFN) or showed no significant change (CPF and DAC), and most compounds declined in air. Chlordane compound fractions TC/(TC + CC) and TC/(TC + CC + TN) decreased in water and air, while CC/(TC + CC + TN) increased. TN/(TC + CC + TN) also increased in air and slightly, but not significantly, in water. These changes suggest selective removal of more labile TC and/or a shift in chlordane sources. Water-air fugacity ratios indicated net volatilization (FR > 1.0) or near equilibrium (FR not significantly different from 1.0) for most OCPs but net deposition (FR < 1.0) for ΣCHBs. Net deposition was shown for ENDO-I on all expeditions, while the net exchange direction of other CUPs varied. Understanding the processes and current state of air-surface exchange helps to interpret environmental exposure and evaluate the effectiveness of international protocols and provides insights for the environmental fate of new and emerging chemicals.

Chronic dietary exposure to pesticide residues in the United States

Discussions as to the extent of pesticide residue contamination in the food supply often rely on results of government residue monitoring programs focusing primarily upon the percentages of samples containing pesticide residues and the number of violative residues identified. Such an approach does not adequately convey the likelihood of pesticide residues posing consumer risks since residue regulatory limits are not safety standards and violative pesticide residues rarely constitute residues of health concern. It is more appropriate to develop estimates of actual dietary exposure to pesticides and to compare such estimates to established toxicological criteria such as the Chronic Reference Dose (RfD). The U.S. Food and Drug Administration’s (FDA) Total Diet Study (TDS) previously provided such information but last published its findings in 1995 to estimate dietary exposure to pesticides detected between 1986 and 1991. This paper provides updated estimates of dietary exposure to pesticides in the United States using the most recent TDS findings on pesticide residues. A total of 77 specific pesticides were detected from market basket samples of 2240 TDS food items analyzed by FDA in 2004 and 2005. All estimated exposures to the 77 pesticides for the General US population were well below chronic RfD levels. Only 3 of the 77 pesticides showed exposures greater than 1 % of chronic RfDs, while 14 showed exposures between 0.1 and 1 % of chronic RfDs and 19 had exposures between 0.01 and 0.1 % of chronic RfDs. The remaining 41 pesticides had exposures below 0.01 % of chronic RfDs. Compared with 1986–1991 findings, dietary exposure to six environmentally persistent chlorinated hydrocarbon insecticides were reduced by factors of 47 to 96 % in 2004–2005. Exposures to 15 different population subgroups were estimated and indicated that children, particularly two year-olds, frequently receive higher exposures to pesticide residues in their diets than do adults. Chronic dietary exposure to pesticides in the diet, according to results of the FDA’s 2004–2005 TDS, continue to be at levels far below those of health concern. Consumers should be encouraged to eat fruits, vegetables, and grains and should not fear the low levels of pesticide residues found in such foods.

Toxicity induced by dieldrin and chlorpyrifos in the freshwater crayfish Cambarellus montezumae (Cambaridae).

The toxicity induced by insecticides in aquatic organisms is of utmost relevance because it may give a clue about the degree of health or damage of the involved ecosystem. In the present report, we determined the effect of dieldrin (DD) and chlorpyrifos (CP) on the freshwater crayfish, Cambarellus montezumae. The organisms (4-6 cm in diameter) were collected in the Ignacio Ramirez Reservoir, situated at 50 km Northeast of Mexico City, in the Rio Lerma Basin. Initially, we determined the LC50 value with the Probit method, then the DNA damage with single cell gel electrophoresis (comet assay applied at 24, 48, and 72 h of exposure) to the brain and hepatopancreas of animals exposed (in reconstituted water) to 0.05 and 0.5 microg/L of each insecticide. In the hepatopancreas of the same organisms, we determined the lipid peroxidation by applying the TBARS test. DNA damage and lipid peroxidation were also evaluated with the same methods to organisms exposed in water from the reservoir. In regard to the LC50, at 72 h of exposure, we found a value of 5.1 microg/L and a value of 5.62 microg/L for DD and CP, respectively. The comet assay applied at different exposure times showed significant DNA damage to both organs, with respect to the control level. In the case of DD, statistical significance was observed for the two doses in the whole evaluated schedule. CP was genotoxic in the brain with the high dose at 72 h, and in the hepatopancreas with the two tested doses at all evaluated exposure times. Also, a significant lipid peroxidation increase was detected with the two doses of insecticides. In the study with water from the reservoir, a more pronounced DNA damage was detected. Our results showed strong DNA damage induced by both insecticides in the crayfish, as well as a correlation with the lipid peroxidation effect, suggesting that oxidative stress is involved in the genotoxic alteration. Our results also showed the usefulness of the studied organism as well as the applied tests for the evaluation of toxicological effects, and suggested the pertinence of applying the comet assay to other freshwater organisms to evaluate the bioaccumulation of insecticides.