Pesticides

FOR CITATION: Indoor air pollution sources (particularly Skunk) and their impacts on health and the environment in the Occupied Palestinian Territories,” In: M.F. Yassin (Ed.), “Proceeding of Workshop on Air Quality in Hot Arid Climate (IAQHAC).” (pp: 204-221), Kuwait Institute for Scientific Research (KISR), Shuwaikh, Kuwait City, Kuwait, 3–4 April 2017. URL: ABSTRACT: Air pollution (AP) is generally defined as “the presence in, or introduction into the air of, a substance that has harmful or poisonous effects.” Outdoor air pollution (OAP) can be defined as “the presence of solids, liquids, or gases in outdoor air in amounts that are injurious or detrimental to human health and/or the environment,” or as “the substance (such as smoke, dust, and obnoxious odors) that interferes with the comfortable enjoyment of life and/or property.” Indoor air pollution (IAP) is defined as “the pollution that refers to chemical, biological, and physical contamination of indoor air.” As related to the 1967- Occupied Palestinian Territories (OPT), the air pollution’s (OAP and IAP) situation can be simply described as “catastrophic”, due to the several sources of OAI and IAP, resulted in health and environmental related impacts. However, something uniquely characterizes indoor air pollution in the OPT, in particular, which is the substance known as “Skunk”, with reference to the animal “Skunk”. What makes Skunk a unique IAP’s source is the fact that Skunk is used only in the OPT, and it is also beyond the control of the Palestinian people living in the OPT under the Israeli occupation. Skunk is a liquid with obnoxious odor that has become one of the characteristic weapons that frequently-used against innocent, nonviolent Palestinians in the OPT since August 2008, i.e. since it was first used in the West Bank’s village of Ni'lin. Since then, the Israeli occupation forces (IOF) regularly hose down Palestinian crowds and homes with the Skunk liquid in cities, towns, villages, and refugee camps, which raises suspicions that this practice has been regularly and indiscriminately used as a punitive measure against the Palestinians. As witnessed, reported, and documented by Israeli and international civil- and human-rights organizations, the Skunk liquid has been sprayed by the IOF at Palestinian protestors, homes, shops, schools, hospitals, hotels, restaurants, entire neighborhoods, and even at funeral processions. After Skunk makes contact with persons or objects, its putrid stench can stay for days and even weeks, making inside homes and neighborhoods smell very badly for long periods of time, and causing nausea, vomiting, skin rash, irritation and redness, eye irradiation, abdominal pain, suffocation, excessive coughing, headaches, ataxia, etc. In addition to the health and environmental harms that Skunk causes, the use of Skunk is also intended to cause humiliation to the Palestinians. The odor of the Skunk’s noisome substance is overpowering, as it feels like the smell of a mixture of raw sewage, sulfur, and rotten animal corpses. In this study, indoor air pollutants, particularly “Skunk”, are investigated, analyzed, and discussed, with respect to their health and environmental impacts, and in view of the geopolitical situation in the region. Such impacts have become even more damaging due to the effects of other factors, such as high temperatures, aridity and semi-aridity climate conditions affecting the region, and the OAP’s sources, such as sand- and dust-storms, stone industry, etc.

OBJECTIVES: Stillbirth is an undesirable outcome of pregnancy. In light of the increasing use of pesticides and growing concerns about the possible health effects of agricultural pesticides, we investigated the effect of exposure to pistachio pesticides on stillbirth in pregnant mothers. METHODS: This case-control study was conducted in Rafsanjan, Iran from 2011 to 2012. A total of 125 females who had a recent stillbirth were included as the case group, and 250 controls were selected from females who had a recent live birth. For each case, two controls with the nearest propensity score to the case were selected. Data were collected using a protocol developed by the researcher that involved interviewing respondents and reviewing their medical records. Conditional multivariate and univariate logistic regression analysis were performed and odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. RESULTS: The ORs of stillbirth in mothers living in pistachio gardens and thos...

Organochlorine chemical residues and elemental contaminants were measured in northern pike (Esox lucius), longnose sucker (Catostomus catostomus), and burbot (Lota lota) from 10 sites in the Yukon River Basin (YRB) during 2002. Contaminant concentrations were compared to historical YRB data and to toxicity thresholds for fish and piscivorous wildlife from the scientific literature. A risk analysis was conducted to screen for potential hazards to piscivorous wildlife for contaminants that exceeded literature-based toxicity thresholds. Concentrations of total DDT (sum of p,p¢-homologs; 1.09-13.6 ng/g), total chlordane (0.67-7.5 ng/g), dieldrin (<0.16-0.6 ng/g), toxaphene (<11-34 ng/g), total PCBs (<20-87 ng/g), TCDD-EQ (£1.7 pg/g), arsenic (0.03-1.95 lg/g), cadmium (<0.02-0.12 lg/g), copper (0.41-1.49 lg/g), and lead (<0.21-0.27 lg/g) did not exceed toxicity thresholds for growth and reproduction in YRB fish. Concentrations of mercury (0.08-0.65 lg/g), selenium (0.23-0.85 lg/g), and zinc (11-56 lg/g) exceeded toxicity thresholds in one or more samples and were included in the risk analysis for piscivorous wildlife. No effect hazard concentrations (NEHCs) and low effect hazard concentrations (LEHCs), derived from literaturebased toxicity reference values and avian and mammalian life history parameters, were calculated for mercury, selenium, and zinc. Mercury concentrations in YRB fish exceeded the NEHCs for all bird and small mammal models, which indicated that mercury concentrations in fish may represent a risk to piscivorous wildlife throughout the YRB. Low risk to piscivorous wildlife was associated with selenium and zinc concentrations in YRB fish. Selenium and zinc concentrations exceeded the NEHCs and LEHCs for only the small bird model. These results indicate that mercury should continue to be monitored and assessed in Alaskan fish and wildlife.

Organophosphorus pesticides and pyrethroids are widely used in German agriculture and residential settings. Their occurrence in human biological samples can be used as an indicator for the exposure of children to these compounds. Using multivariate evaluation the routes of exposure can be identified. In the pilot study of GerES IV, metabolites of pyrethroids and organophosporus pesticides were analysed in urine of children aged 2-17 years (n ¼ 396 and 363). The 95th percentiles for the metabolites of the pyrethroids in urine were: cis-DCCA 0.74 mg/l, trans-DCCA 1.7 mg/l, DBCA 0.52 mg/l, F-PBAo0.1 mg/l, and 3-PBA 2.4 mg/l. 3-PBA was detected in 90% of the samples. The 95th percentiles for the organophosphorus metabolites in urine were: DMP 118 mg/l, DEP 20 mg/l, DMTP 124 mg/l, DETP 11 mg/l, DMDTP 11 mg/l, DEDTPo1.0 mg/l. DMTP was the metabolite most frequently detected in the samples (90%).

door survey was conducted in Costa Rica 3 identib consumer attitudes and concerns about the safety of fruits and vegetables available in the marketplace. m e sample (n = 98) was randomly selected from a panel of 255 households in urban and rural areas. More than half the respondents (54%) expressed confidence in the safety of the produce available in the marketplace, while a minority (11 %) reported avoiding the consumption of some produce due to food safety concerns. A majority of respondents (64% agreed that the only way farmers control pests today is by using pesticides and that these are used indiscriminately (57%). Yet, 53% of the sample agreed that growers today use many practices to protect the environment and provide safe food. Consumers (48%) perceived farmers to be concerned about the environment and safe food, and agree (43 %) that farmers carefully manage the use of chemicals and other techniques to produce clean, safe, fresh food. m e majority (65%) of respondents were aware of the training programs and technical assistance provided to farmers on the use of chemicals by the Ministry of Agriculture and Cattle (MAG). Information sources on which consumers rely are television (92 %), radio (73 %), and newspapers (63%). mese findings show that while many consumers are not completely confident in the chemical safety of produce, few have reduced produce consumption. Consumers are also concerned with the perceived indiscriminate use of pesticides by farmers. Since public confidence appears to be high for MAG, the government may want to use MAG and the mass media to provide consumer education programs on food safety that specifically address the use of pesticides by farmers.

The photochemical behavior of oxyfluorfen [2-chloro-1-(3-etoxy-4-nitrophenoxy)-4-(trifluoromethyl) benzene] on two Greek soils was investigated. Soils were sampled from Nea Malgara and Preveza regions, characterized by a different organic matter content. Soils were spiked with the diphenyl-ether herbicide and irradiation experiments were performed either in the laboratory with a solar simulator (xenon lamp) or outside, under natural sunlight irradiation; other soil samples were kept in the dark to control the retention reaction. Kinetic parameters of both retention and photochemical reactions were calculated using zero-, first- and second- (Langmuir-Hinshelwood) order equations, and best fit was checked through statistical analysis. The soil behaviors were qualitatively similar but quantitatively different, with the soil sampled from the Nea Malgara region much more sorbent as compared with Preveza soil. All studied reactions followed second-order kinetics and photochemical reaction...

Previous studies have suggested that the reduction in the root/shoot ratio that accompanies the shade avoidance response may reduce the tolerance of individuals to subsequent nutrient or moisture limitations. In this work, we examined the impact of the shade avoidance response on maize seedling growth and development and the response of these plants to a subsequent abiotic stress. Seedlings were grown in a field fertigation system under two light quality environments, ambient and a low red to far-red ratio, which were designed to simulate weed-free and weedy conditions, respectively. This system also enabled the controlled restriction of water and nutrients, which reduced the relative growth rate of the crop and created a secondary stress. Results of this study indicate that, while the shade avoidance response did reduce the root/shoot ratio in maize, this effect did not reduce plant tolerance to subsequent abiotic stress. Rather, the apparent additivity or synergism of shade avoidance and the secondary stressor on yield loss depended on whether the net effect of these two stressors was sufficiently large to shift the population toward the point where reproductive allometry was broken. Nomenclature: Maize, Zea mays L.

The OECD guideline for studies on percutaneous penetration to be used in hazard and risk evaluations prescribes experimental conditions with optimal barrier integrity of the skin, which in many occupational settings probably is not true. Thus, workers may have compromised skin due to chemical or mechanical damage, due to different medical conditions (eczema, dermatitis, skin irritation) or related to occupational scenarios involving prolonged wet work. The present study used the OECD guideline procedures to study the in vitro percutaneous penetration through human skin of a number of model substances (glyphosat, caffeine, benzoic acid, malathion) covering a range of solubilities. Further, we studied the extent to which a slightly damaged skin would change the rate, the amount absorbed during dermal exposure and the distribution of chemical deposition between epidermis and dermis. The present study demonstrates that a limited damage to the skin significantly increases the permeability coefficient (K p) as well as total percutaneous penetration of chemicals, and most significantly for those compounds that due to their physicochemical characteristics (the most hydrophilic as well as the most lipophilic) have low penetration rates through intact skin. The present experiment not only confirms the proportionality between lipophilicity and potential for percutaneous penetration, but also illustrates that at a certain degree of lipophilicity of a model compound, the different skin compartments become more attractive for temporary deposition of model compounds. Moreover, a clear change from epidermal deposition towards a dominating dermis deposition of chemicals temporarily deposited within the skin is seen following damage to the skin barrier. Thus, the distribution of chemicals within the skin compartments is affected by the physicochemical characteristics of the chemicals as well as by the integrity of the skin. This observation may have implications when evaluating the possibility of removing chemicals from the skin through different cleansing procedures following unintended dermal exposures.

Soil fumigation has recently been shown to affect the greenhouse gas balance by increasing emissions of nitrous oxide (N 2 O) following chloropicrin (CP) application. However, the exact mechanisms of this increase were not investigated. The purpose of this study was to elucidate potential mechanisms of CP-induced N 2 O production through laboratory incubations using chemical inhibitors (acetylene, antibacterial, antifungal, and oxygen), isotopically labeled 15 N-CP, and pH modifications of a forest nursery soil. Results showed that N 2 O production increased by 12.6 times following CP fumigation. Microbial activity contributed 82% to the CP-induced N 2 O production, with the remaining 18% from abiotic processes as determined by incubation with sterilized soil. Inhibitor studies suggested that 20% of the N 2 O production was from bacteria and 70% from fungi. There were no significant differences in N 2 O production following CP fumigation under various levels of acetylene (0, 10, and 10 kPa), suggesting that traditional nitrification and denitification reactions did not significantly contribute to N 2 O production following CP fumigation. 15 N labeled studies indicated that 12% of fumigant source N was incorporated into the produced N 2 O. No enrichment in N 2 was observed, indicating that N 2 O was one of the terminal biotic mineralization products of CP. Production of N 2 O is aerobic and production rates increased with increasing oxygen concentrations. Our data strongly suggested that fungal mediated denitrification reactions under aerobic conditions were the primary mechanism for CP-induced N 2 O production.

The experiment was conducted at the Research Farm of the Punjab Agricultural University, Ludhiana in rabi seasons of 2005-06 and 2006-07 to study the efficacy of tank mix application of 2, 4-D, carfentrazone and metsulfuron with isoproturon in managing weeds of irrigated barley. Minimum weed dry weight was recorded in isoproturon 1000 g+metsulfuron 4 g/ha which was statistically on par with isoproturon 1000 g/ha, isoproturon 1000 g+carfentrazone 20 g/ha and isoproturon 1000 g+2, 4-D 500 g/ha during 2005-06. In 2006-07, minimum weed dry weight was recorded in two hand weedings which was statistically on par with isoproturon 1000 g+metsulfuron 4 g/ha, isoproturon 1000 g/ha, isoproturon 1000 g+carfentrazone 20 g/ha, and isoproturon 1000 g+2,4-D 500 g/ha. Highest test weight and barley grain yield were recorded in isoproturon 1000 g+metsulfuron 4 g/ha which were statistically on par with isoproturon 750 g+metsulfuron 4 g/ha, isoproturon 750 g+2,4-D 500 g/ha, isoproturon 1000 g+2, 4-D 500 g/ha and two hand weedings. The highest net returns of Rs. 29063 with isoproturon 1000 g+metsulfuron 4 g/ha and Rs. 39581 were recorded in isoproturon 1000 g+2, 4-D 500 g/ha as tank mix in 2005-06 and 2006-07, respectively.

The effects of paraquat on rat brain were studied. Activities of complex I (NADH: ubiquinone oxidoreductase) in mitochondrial electron transport system, lipid peroxidation and the amount of catecholamines in rat brain were measured after acute paraquat exposure. Complex I activities were significantly lower and lipid peroxides were higher in the brains of a paraquat-treated group than in those of a control group. Lipid peroxide in rat serum, however, did not increase after paraquat exposure. A study of the time dependency of paraquat effects disclosed that mitochondrial complex I activities in rat brain as well as those in rat lung and liver gradually decreased prior to the appearance of respiratory dysfunction. As compared to controls, the dopamine in rat striatum was significantly lower in the paraquat-treated group. These results suggest that paraquat after crossing the blood-brain barrier might be reduced to the radical in rat brain, which may damage the brain tissue, especially dopaminergic neurons in striatum. We therefore propose that cerebral damage should be taken into consideration on paraquat exposure. Patients may therefore need to be followed up after exposure to high doses of paraquat.

It has been developed a general strategy for the determination of pesticides in agrochemicals by Fourier transform near infrared (FT-NIR) spectroscopy. The methodology is based on previous extraction of the active principles through sonication with acetonitrile and direct determination by transmission measurements, using glass vials as measurement cells and univariate calibration at selected wavenumbers as a function of the pesticide to be analyzed. Chlorsulfuron, metamitron, iprodione, pirimicarb, procymidone and tricyclazole were used as test molecules and data obtained by FT-NIR for 20 samples containing one of these active principles compare well with those found by reference liquid chromatography (HPLC) procedures. In short, FT-NIR provides relative standard deviations between 0.04 and 0.7% and limit of detection values ranging from 0.004 to 0.17 mg g −1 with recovery values between 96.4 and 100.5%. On the other hand, FT-NIR offers a 10 times faster methodology than chromatography ones and an environmentally friendly alternative which reduces the reagent consumption to 1 mL acetonitrile per sample.

Drugs, hormones and pesticides are chemical compounds used for alleviation of various diseases in animals. There are many classes of drugs which have been used and in the case of natural steroid hormones these have been used to increase mass gain by stimulating protein anabolism. Pesticides have been used for many years in the control of ectoparasites which transmit important human and livestock diseases. The purpose of the present article is to review procedures for management of veterinary products to facilitate national and international trade.

H ard red wheat (Triticum aestivum L.) is grown on more than 12 million hectares in the Great Plains region of the United States and weed control is an important management consideration for wheat producers each year (USDA-National Agriculture Statistic Service, 2006). Weeds, particularly annual grasses, can be diffi cult to selectively control in wheat. Development of herbicide-resistant crops has resulted in new opportunities for selective weed control in many crops including wheat, and, in some cases, has simplifi ed weed management. Herbicide-resistant crops allow for expanded use of certain broad spectrum herbicides with favorable environmental profi les (

Under laboratory conditions, the effects of thiamethoxam were investigated in larvae, pupae and emerging honey bees after exposure at larval stages with different concentrations in the food (0.00001 ng/μL, 0.001 ng/μL and 1.44 ng/μL). Thiamethoxam reduced the survival of larvae and pupae and consequently decreased the percentage of emerging honey bees. Thiamethoxam induced important physiological disturbances. It increased acetylcholinesterase (AChE) activity at all developmental stages and increased glutathione-S-transferase (GST) and carboxylesterase para (CaEp) activities at the pupal stages. For midgut alkaline phosphatase (ALP), no activity was detected in pupae stages, and no effect was observed in larvae and emerging bees. We assume that the effects of thiamethoxam on the survival, emergence and physiology of honey bees may affect the development of the colony. These results showed that attention should be paid to the exposure to pesticides during the developmental stages of ...

A solid-phase microextraction (SPME)-GC procedure has been developed for the analysis of four selected pesticides (propanil, acetochlor, myclobutanil and fenoxycarb) in water samples. Mass spectrometry (MS) was used and two different instruments, a quadrupole MS system and an ion trap operating in the MS-MS mode, were compared. A Carbowaxdivinylbenzene SPME fiber was used. The performances of the two GC-MS instruments were comparable in terms of linearity (in the range of 0.1-10 mg / l in water samples) and sensitivity (limits of detection were in the low ng / l range); the quadrupole MS instrument gave better precision than the ion trap MS-MS system, but generally the relative standard deviations for replicates were acceptable for both instruments (,15%). Specificity with these two instruments was comparable in the analysis of ground water samples. Recovery tests were made to assess the applicability of the SPME procedure in the quantitative analysis of contaminated groundwaters.

This study addresses the potential risks to the aquatic ecosystem posed by pesticides currently used in The Netherlands. The study used a novel method to predict aquatic exposure to pesticides based on a geographic information system (GIS) map of agricultural land use, comprising 51 crops used in open-canopy areas. Through the application of species-sensitivity distributions for aquatic organisms, in combination with rules for mixture-toxicity calculation, the modeled exposure results were transformed to risk estimates for aquatic species. The majority of the predicted risks were caused by pesticides applied to potato cropland, and approximately 95% of the predicted risk was caused by only 7 of the 261 pesticides currently used in The Netherlands. For risk verification, local toxic-risk estimates were compared with observed species composition in field ditches. The field verification study was not able to draw firm conclusions regarding the predicted impact of pesticide use on overall biodiversity. A toxicity-related shift from sensitive to more tolerant or opportunistic species could be observed for a few species.

This report describes separation and detection of chlorophenoxy acid herbicides spiked in drinking water by the technique combining solid-phase extraction, fieldamplified sample stacking, capillary electrophoresis, and potential gradient detection. The herbicide solution (400 mL) was concentrated to 0.1 mL by the solid-phase extraction procedure. The buffer containing 3 mM ammonia and 0.3 mM hydroxypropyl-bcyclodextrin was adjusted to pH 9.0 with ammonia. The sample solution was injected into the capillary to 30% of the whole length, and 29 kV and 9 kV were employed for field-amplified sample stacking and separation, respectively. The herbicides were baseline separated and the detection limits with the above combined techniques were in the range of 1-4610 22 ng/mL.

Both visible near-infrared (VNIR) and mid-infrared (MIR) spectroscopy have been claimed to better predict pesticide sorption in soils than other methods. We compared the performances of VNIR and MIR spectroscopy for predicting both organic carbon content (f OC ) and the sorption affinity (K d ) of diuron in 112 surface soils from South Australia. Separate calibration models were developed between VNIR and MIR spectra, and f OC and K d using partial least-squares (PLS) regression. MIR clearly outperformed VNIR for predictions of both f OC and K d in soils. Correlation (R 2 ) and accuracy (RPD) indices were 0.4 and 1.3 for the VNIR-PLS model versus 0.8 and 2.3 for the MIR-PLS model, respectively, for K d prediction. PLS loadings for sorption prediction were compared in terms of the soil information they contained. While VNIR loading did not include any direct spectral information regarding soil minerals, MIR loading included peaks associated with sand, clays, and carbonates. Perhaps by better predicting f OC and integrating the effects of OC as well as minerals, the MIR-PLS model provided a better prediction for diuron K d values in our calibration set.

Triadimefon is a triazole fungicide that produces hyperactivity in both mice and rats similar to that seen following administration of compounds with catecholaminergic activity (e.g., d-amphetamine). To determine whether the triadimefon-induced hyperactivity is due to an action on CNS catecholaminergic systems, we evaluated the effects of combined treatment of triadimefon with either the tyrosine hydroxlase inhibitor d,l-a-methyl-p-tyrosine methyl ester HCl

The production of coca and poppy as well as the processing and production of cocaine and heroin involve significant environmental impacts. Both coca and poppy are grown intensively in a process that involves the clearing of land in remote areas, the planting of the crop, and protection against pests such as weeds, insects, and pathogens. The aerial spray program to control coca and poppy production in Colombia with the herbicide glyphosate is conducted with modern state-of-the-art aircraft and spray equipment. As a result of the use of best available spray and navigation technology, the likelihood of accidental off-target spraying is small and is estimated to be less than 1% of the total area sprayed. Estimated exposures in humans resulting from direct overspray, contact with treated foliage after reentry to fields, inhalation, diet, and drinking water were small and infrequent. Analyses of surface waters in five watersheds showed that, on most occasions, glyphosate was not present ...

Background: Clinical investigations have shown prognostic heterogeneity within the non-Hodgkin's lymphomas (NHLs) according to histology, but few descriptive studies have considered NHLs by subgroup. Our purpose is to assess the demographic patterns and any notable increases in population-based rates of different histologic subgroups of NHL. Methods: Using data collected by the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute, we calculated incidence rates for the major clinicopathologic categories of NHL by age, race, sex, geographic area, and time period. Results: Among the 60 057 NHL cases diagnosed during the period from 1978 through 1995, total incidence (per 100 000 person-years) was 17.1 and 11.5 among white males and females, respectively, and 12.6 and 7.4 among black males and females, respectively. However, rates for follicular NHLs were two to three times greater among whites than among blacks, with little sex variation. Blacks demonstrated much higher incidence than whites for peripheral T-cell NHL, with the incidence rates higher in males than in females. For other NHL subgroups, the incidence rates for persons less than 60 years of age were generally higher among males than among females, with little racial difference; at older ages, the rates were higher among whites than among blacks, with little sex difference. Highgrade NHL was the most rapidly rising subtype, particularly among males. Follicular NHL increased more rapidly in black males than in the other three race/sex groups. Overall, the broad categories of small lymphocytic, follicular, diffuse, high-grade, and peripheral T-cell NHL emerged as distinct entities with specific age, sex, racial, temporal, and geographic variations in rates. Conclusions: Findings from our large, population-based study reveal differing demographic patterns and incidence trends according to histologic group. Future descriptive and analytic investigations should evaluate NHL risks according to subtype, as defined by histology and new classification criteria. [

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of ...

The effects of prescribed burning, herbicide application, and thinning treatments were examined in upland Quercus stands with a replicate block field study. Two site types were analyzed: (1) nonsuccessional with a Quercus overstory and Quercus understory, and (2) successional with a Quercus overstory and an Acer saccharum understory. Treatments were examined for their effects on vegetation structure and composition, especially with respect to altering the natural succession from Quercus communities to mesophytic species. In addition, impacts of burning on soil nutrients were examined prior to and immediately following burn treatments. Results from the study indicate that fire had little effect on A horizon soil nutrients following burns. The data suggest fire plays a more important role as a decomposer for nutrient release in February burns than in November burns. Natural precipitation and leaching from the litter layer in the fall rendered similar nutrient dynamics as burning in November. The structural changes to vegetation following fire were more noticeable than compositional changes. Thinning of the canopy was generally necessary for the understory to respond to burning treatments. Burning did not affect stems >3.8 cm dbh (diameter at breast height). Density of most woody species <3.8 cm dbh decreased with burning, but increased with burning and thinning, indicating the stress of shaded conditions. Thus, burning prior to thinning may be an effective method for controlling an A. saccharum invasion into Quercus stands. Herbaceous, seedling, sapling, and overstory strata diversity were unaffected by the treatments. Data indicated that the community responds with species extant at the time of treatment. Thus, the initial conditions prior to disturbance were important factors in the response of the stand to disturbance. Although fire has played a major role in upland forest dynamics prior to settlement, forest structure and composition can no longer be maintained by fire. Succession without fire has resulted in a different structure and composition to oak forests, altering both fuels and fuel moisture levels. Species normally considered intolerant of fire have reached size classes large enough that they tolerate cool to moderate burns. More severe disturbance techniques, or combinations of techniques, are necessary for sustainable oak forest management in the central hardwood region.

An existing method for the determination of glyphosate and its main metabolite aminomethylphosphonic acid (AMPA) in water has been improved. It is based on precolumn derivatization with the fluorescent reagent 9-fluorenylmethylcloroformate (FMOC) followed by large-volume injection in a coupled-column LC system using fluorescence detection (LC-LC-FD). The derivatization step was slightly modified by changing parameters such as volume and/or concentration of sample and reagents to decrease the limits of quantification (LOQ) of glyphosate and AMPA to 0.1 g/l. Additionally, the use of Amberlite ® IRA-900 for preconcentration of glyphosate, prior to the derivatization step, was investigated; the LOQ of glyphosate was lowered to 0.02 g/l. Drinking, surface and ground water spiked with glyphosate and AMPA at 0.1-10 g/l concentrations were analysed by the improved LC-LC-FD method. Recoveries were 87-106% with relative standard deviations lower than 8%. Drinking and ground water spiked with glyphosate at 0.02 and 0.1 g/l were analysed after preconcentration on the anion-exchange resin with satisfactory recoveries (94-105%) and precision (better than 8%).

This Opinion paper briefly summarizes the views of the authors on the directions of research in the area of plant protection chemistry. We believe these directions need to focus on (1) the discovery of new pesticide active ingredients, and (2) the protection of human health and the environment. Research revenues are discussed thematically in topics of target site identification, pesticide discovery, environmental aspects, as well as keeping track with the international trends. The most fundamental approach, target site identification, covers both computer-aided molecular design and research on biochemical mechanisms. The discovery of various classes of pesticides is reviewed including classes that hold promise to date, as well as up-to-date methods of innovation, e.g. utilization of plant metabolomics in identification of novel target sites of biological activity. Environmental and ecological aspects represent a component of increasing importance in pesticide development by emphasizing the need to improve methods of environmental analysis and assess ecotoxicological side-effects, but also set new directions for future research. Last, but not least, pesticide chemistry and biochemistry constitute an integral part in the assessment of related fields of plant protection, e.g. agricultural biotechnology, therefore, issues of pesticide chemistry related to the development and cultivation of genetically modified crops are also discussed.

Adherence with permethrin-treated bed net (ITN) use and their proper deployment was directly observed in 2,178 individuals (784 households) participating in a large-scale trial of ITNs on child mortality in western Kenya. The ITNs were distributed free of charge to ensure high coverage, resulting in a ratio of 1.46 persons per ITN. Approximately 30% of ITNs present were unused. The overall percentage adherence was 72.3%. The probability of adherence by individuals depended strongly on age (relative risk [RR] ‫ס‬ 0.86, 95% confidence limit [CL] − 0.78-0.94), in which children less than five years of age were less likely to use ITNs than older individuals, and temperature, in which ITNs were more likely to be used in periods of cooler weather. A marginally significant diminution in adherence during the second year of the project was also observed (RR ‫ס‬ 0.83, 95% CL ‫ס‬ 0.68-1.01). Mosquito numbers, relative wealth, number of house occupants, and the educational level of the head of the household had no effect on adherence. In unstructured questioning of house residents, excessive heat was often cited as a reason for not deploying the child's ITN. The most important reason for non-adherence was disruption of sleeping arrangements, indicating that ITNs were not readily redeployed in the face of shifting sleeping patterns due to visitors, funerals, house construction, and other events. Challenges faced by health education programs to maximize adherence with ITN use are discussed.

Concentrations of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and its metabolites, chlordanerelated compounds (CHLs), mirex, hexachlorocyclohexane isomers (HCHs), dieldrin, and hexachlorobenzene (HCB) were determined in blubber of harbor seals (Phoca vitulina concolor) from the northwestern Atlantic coast. PCBs, DDTs, and CHLs were the major persistent organochlorines in harbor seal blubber, while mirex, HCHs, dieldrin, and HCB were minor contaminants. Highest concentrations were found in the adult males, followed by the pups, yearlings, adult females, and fetuses. DDT and PCB concentrations have declined from the high levels reported in the early 1970s, but no declines were observed in our samples over the ten-year period 1991-2001. DDT/PCB ratios were indicative of a more rapid decline of DDTs than PCBs, while ratios of p,p 0 -DDE/DDT were indicative of a metabolic ''weathering'' of DDT. The population appears to be susceptible to disease outbreaks, as evidenced by a recurrence of viral epizootics since the late 1970s. The PCB burdens in these seals are similar to levels reported in seals from polluted regions of Europe and Asia, and exceed the estimated threshold levels for adverse reproductive and immune system effects in the species.

To be able to predict the degradation (rate) of organic chemicals (e.g. pesticides) in the ®eld, knowledge of the environmental conditions that are of in¯uence on the degradation process are of importance. In the present study an experimental system is described which is used to study the degradation of organic pollutants in mixed bacteria cultures originating from surface water. With this system the degradation of compounds can be followed for relatively long experimental periods (months). In addition, it is possible to vary dierent environmental parameters in order to investigate their in¯uences on the degradation of the chemical. These preliminary experiments show that growth and ÔcompositionÕ of the bacteria culture have comparable patterns in parallel experiments. The ®rst order degradation rate constant for the test compound dichloran, as calculated from these experiments under these circumstances, is about 0.002 h À1 . Ó

The Tradescantia-Micronucleus (Trad-MCN) test is a simple short-term bioassay for various gaseous and liquid forms of chemical agents, and physical agents such as radiation. 140 agents, directly or indirectly related to human health, were screened for their mutagenicity. Plant cuttings of young inflorescences, in which the pollen mother cells undergo various stages of meiosis, were maintained in nutrient solution for experimentation. Treatments were made either by absorption of the soluble agents through the stem, by diffusion of gaseous agents through the leaves and buds, by exposure to internal/external radiation or by in situ exposure to air pollutants. Micronuclei formed from damaged chromosomes served as the indicators of mutagenicity. Results of 140 agents tested are listed in 9 different categories. (1) Carcinogens/mutagens, (2) common beverages, (3) common chemicals, (4) drugs, (5) pesticides, (6) common household chemicals, (7) radiation and radioisotopes, (8) in situ monitoring, (9) complex environmental mixtures. Out of 140 agents tested, 52 showed positive, 20 showed borderline positive responses and 5 showed strong toxicity. Test results of 41 agents in the present study showed 67% congruity with Ames test results found in the literature.

Animal products like milk and meat are often found to be contaminated with residues of persistent pesticides and other toxic substances. The major source of entry of these compounds to animal body is the contaminated feed and fodder. So, unless the residues are managed at this stage, it is very difficult to prevent contamination in milk and meat. Therefore, the status of residue level of most persistent organochlorinated pesticides (OCP) in feed and fodder should be monitored regularly. The frequency of occurrence and contamination levels of OCP residues in different kinds of animal concentrate feed and straw samples collected from Bundelkhand region of India were determined. Out of 533 total samples, 301 i.e. 56.47% samples were positive containing residues of different OCPs like hexachlorocyclohexane (HCH) isomers, dichlorodiphenyltrichloroethane (DDT) complex, endosulfan and dicofol. Among different HCH isomers, the mean concentration of β-HCH was highest, and total HCH varied from 0.01 to 0.306 mg kg −1 . In case of DDT complex, i.e. DDD, DDE and DDT, the concentration ranged between 0.016 and 0.118 mg kg −1 and the pp | isomers were more frequently encountered than their op | counterparts. Endosulfan was also found in some samples in concentration ranging from 0.009 to 0.237 mg/kg, but dicofol could be recorded in very few samples. Although feed samples were found to contain OC residues, after comparing their levels in positive samples with the limiting values of respective pesticides, only very few were found to exceed the threshold level. Otherwise, they were mostly within safe limits.

Because aquatic macroinvertebrates may be exposed regularly to pesticides in edge-of-the-field water bodies, an accurate assessment of potential adverse effects and subsequent population recovery is essential. Standard effect risk assessment tools are not able to fully address the complexities arising from multiple exposure patterns, nor can they properly address the population recovery process. In the present study, we developed an individual-based model of the freshwater amphipod Gammarus pulex to evaluate the consequences of exposure to 4 compounds with different modes of action on individual survival and population recovery. Effects on survival were calculated using concentration-effect relationships and the threshold damage model (TDM), which accounts for detailed processes of toxicokinetics and toxicodynamics. Delayed effects as calculated by the TDM had a significant impact on individual survival and population recovery. We also evaluated the standard assessment of effects after short-term exposures using the 96-h concentration-effect model and the TDM, which was conservative for very short-term exposure. An integration of a TKTD submodel with a population model can be used to explore the ecological relevance of ecotoxicity endpoints in different exposure environments.

Crown rust (Puccinia coronata f. sp. avenae) is the most important disease of oats in Brazil. In susceptible oat cultivars, fungicides are needed to control the disease efficiently. However, spray at low volumes may reduce fungicide performance significantly. A field experiment with the oat cultivar UPFA-20 was carried out at the FAMV/UPF to evaluate the influence of fungicides, rates, and spray volumes on the efficacy of the chemical control for crown rust. The tested treatments combined two fungicides (tebuconazole, Folicur, 0,75 L ha-1; epoxiconazole + pyraclostrobin, Opera, 0,5 L ha-1), four rates (40; 60; 80 and 100% of the commercial rate), and two spray volumes (100 and 200 L ha-1). The field plots were arranged according to a factorial block design (2×4×2) with four replicates. The assessments included the disease severity, disease control, grain quality and grain yield. The net profit of each treatment was also determined based upon the application costs and the sale price ...

Background: Between 1955 and 2011 there were marked fluctuations in suicide rates in Sri Lanka; incidence increased six-fold between 1955 and the 1980s, and halved in the early 21st century. Changes in access to highly toxic pesticides are thought to have influenced this pattern. This study investigates variation in suicide rates across Sri Lanka's 25 districts between 1955 and 2011. We hypothesised that changes in the incidence of suicide would be most marked in rural areas due to the variation in availability of highly toxic pesticides in these locations during this time period. Methods: We mapped district-level suicide rates in 1955, 1972, 1980 and 2011. These periods preceded, included and postdated the rapid rise in Sri Lanka's suicide rates. We investigated the associations between district-level variations in suicide rates and census-derived measures of rurality (population density), unemployment, migration and ethnicity using Spearman's rank correlation and negative binomial models. Results: The rise and fall in suicide rates was concentrated in more rural areas. In 1980, when suicide rates were at their highest, population density was inversely associated with area variation in suicide rates (r = −0.65; p < 0.001), i.e. incidence was highest in rural areas. In contrast the association was weakest in 1950, prior to the rise in pesticide suicides (r = −0.10; p = 0.697). There was no strong evidence that levels of migration or ethnicity were associated with area variations in suicide rates. The relative rates of suicide in the most rural compared to the most urban districts before (1955), during (1980) and after (2011) the rise in highly toxic pesticide availability were 1.1 (95% CI 0.5 to 2.4), 3.7 (2.0 to 6.9) and 2.1 (1.6 to 2.7) respectively. Conclusions: The findings provide some support for the hypothesis that changes in access to pesticides contributed to the marked fluctuations in Sri Lanka's suicide rate, but the impact of other factors cannot be ruled out.

Over the years, the emergence of pesticides practice has prevailed to be the most intricate environmental turmoil amongst the scientific community. Specifically, pesticides constitute an accumulative, persistent and detrimental impact towards the survival of flora, fauna and environmental matrix. This has inspired a developing research with a variety of treatment technologies. Adsorption is recognized as the most efficient and promising approach, due to the ease of operation, simplicity of design, insensitivity to the toxic substances and superior capability for removing a broad range of pollutants. Its diverse applications, however, are retarded by the high cost of adsorbents and difficulties associated with regeneration. Montmorillonite and its derivatives, a unique group of under-utilized clay-based minerals has been proposed to be a suitable candidate for the treatment of contaminated wastewater. It plays a key role as the natural scavenger of pesticides, due to the abundantly a...

Many farm workers in South Africa continue to live and work under adverse conditions that are the legacy of apartheid policies. Despite its ocial prohibition, the arrangement by which workers are given alcohol as a bene®t of employment, known as the`dop' system, appears to persist. Even though it is a minority of farms that currently actively practice the dop system, the rami®cations of the historical institutionalisation of massive alcohol consumption are widespread. Heavy alcohol consumption is not only directly injurious to the health of farm workers and their families, but places them at risk to various social and environmental hazards. This is illustrated in a case of pesticide poisoning in which 24 workers were poisoned when given wine contaminated with the carbamate insecticide aldicarb. The case illustrates (i) the ongoing application of the dop system on farms in South Africa and (ii) the interaction between social factors and chemical exposures amongst farm workers. Public perceptions about the natural tendencies of`coloured' people to drink heavily have much to do with perpetuating the dop system, and reinforcing a system geared towards the social control of rural farm workers and their families. The dop system poses a major challenge to the public health authorities in South Africa who are charged with the task of restructuring health services to address the human rights and health needs of marginal farming communities within a primary health care framework.

A method was validated for the multi-residue analysis of 82 pesticides in grapes at ≤25 ng/g level. Berry samples (10 g) mixed with sodium sulphate (10 g) were extracted with ethyl acetate (10 mL); cleaned by dispersive solid phase extraction and the results were obtained by liquid chromatography–tandem mass spectrometry. Reduction in sample size and proportion of ethyl acetate for extraction did not affect accuracy or precision of analysis when compared to the reported methods and was also statistically similar to the QuEChERS technique. The method was rugged (HorRat < 0.5) with <20% measurement uncertainties. Limit of quantification was <10 ng/g with recoveries 70–120% for most pesticides. The method offers cheaper and safer alternative to typical multi-residue analysis methods for grape.

An optical biosensor based on vegetal cells entrapped in an inorganic translucent matrix and fluorescence detection has been developed. The biosensor uses Chlorella vulgaris immobilized in a translucent support produced from sol–gel technology. The translucence of the structure enables the algal active layer to be placed directly in contact with the optical fibers for fluorescence detection. This configuration has many advantages over the use of an opaque support because no space between the optical fibers and the active layer is required to collect fluorescence. This reagentless biosensor allows determination of diuron as an anti-PSII herbicide and its long term activity is assessed.

The thermal decomposition of Fenitrothion [phosphorothioic acid O,O-diethyl O-(3-methyl-4nitrophenyl) ester] was investigated. Results obtained by different scale calorimetric techniques show that the thermal decomposition of Fenitrothion involves two main steps. Intermediate and final thermal degradation products formed during isothermal and adiabatic thermal decomposition experiments were identified. The eco-toxicological profile of the decomposition products was assessed experimentally and compared to results obtained with a predictive software (ECOSAR). A specific index was defined to assess the change in ecotoxicity profile of decomposition products with respect to the original compound.