Recent developments in capillary electrophoresis of carbohydrate species

Pesticides are important and diverse environmental and agricultural species. Their determination in pesticide formulations, in feed and food, and in complex environmental matrices (e.g., water, soil, sludge, sediments, etc.) often requires separation methods of high efficiency, unique selectivity and high sensitivity. As shown in this comprehensive review, capillary electrophoresis meets these requirements and has proved to be a suitable microseparation technique for the analysis of a wide variety of chiral and achiral pesticides. It is also shown that by combining selective precolumn derivatization schemes, sensitive detection methods (e.g., laser induced fluorescence detection) and trace enrichment techniques, capillary electrophoresis (CE) is capable of determining pesticides at trace levels as those usually encountered in environmental samples.     

Organochlorine and organophosphorus pesticide residues in food from Egyptian local markets

A market basket survey was conducted to monitor organochlorine and organophosphorus pesticide residues in potatoes, citrus fruits, and fish collected from local Egyptian markets. Maximum Residue Limits (MRLs) of the Codex Committee on Pesticide Residues for gamma-hexachlorocyclohexane (HCH) in potatoes were exceeded in 8 samples and for DDT in 2 samples. The aging of HCH and DDT indicated a recent use of both pesticides during the potato storage period between cultivation seasons. However, such use is illegal because HCH mixture isomers (gammaxane) and DDT have been officially prohibited from agricultural use in Egypt since 1980. The highest residue levels of fenitrothion (3.8 ppm) in potatoes may be due to its repeated use before and after harvest. No organochlorine pesticide residues were found in citrus fruits. None of the detected organophosphorus pesticides exceeded their MRLs. HCH and DDT residue limits were exceeded in 5 and 7 fish samples, respectively, collected from 12 markets throughout the country. The heptachlor MRL was violated in only one fish sample (3.9 ppm).     

Pesticide poisoning: a major health problem in Sri Lanka

Acute pesticide poisoning is a major public health problem in Sri Lanka. In several agricultural districts, it precedes all other causes of death in government hospitals. Most of the acute poisoning cases are intentional (suicide) and occur among young adults, mainly males. Poisoning due to occupational exposure is also common, but less well documented. In an irrigation area in Sri Lanka a very high incidence of serious pesticide poisoning was observed, with 68% due to intentional ingestion of liquid pesticides. It is argued that the easy availability and widespread use of highly hazardous pesticides is the most important reason for this high number of poisoning cases. The frequent application of highly hazardous pesticides in high concentrations was often irrational and posed serious health and financial risks to the farmers. Sales promotion activities and credit facilities promoted this excessive pesticide use, which was not counteracted by an agricultural extension service. Hazardous practices when spraying pesticides were due to the impossibility of applying recommended protective measures under the local conditions, rather than to lack of knowledge. Current emphasis on programs that promote the safe use of pesticides through education and training of farmers will be ineffective in Sri Lanka because knowledge is already high and most poisoning cases are intentional. Instead, enforcement of legislation to restrict availability of the most hazardous pesticides would result in an immediate health benefit. Improved agricultural extension services to promote alternative non-chemical methods of pest control is the most important strategy, in the long term, to prevent acute pesticide poisoning.     

Immobilized liposome chromatography for studies of protein-membrane interactions and refolding of denatured bovine carbonic anhydrase

Seasonal variations of pesticide residues in surface waters and ground waters of the Imathia area of Central Mecedonia (N. Greece) were determined for the period from May 1996 to April 1997. The sampling cruises included eight sites in rivers Aliakmon, Loudias, Tripotamos, Arapitsa and Canal-66, seven water springs in the mountain Vermion, seven rainfall water collection stations and one hundred underground points. Solid-phase extraction disks followed by gas chromatographic techniques with flame thermionic detection, electron capture detection and mass-selective detection were used for the monitoring of various pesticides their transformation products in environmental waters. The most commonly encountered pesticides in underground waters, were alachlor, atrazine, desethylatrazine (DEA), metolachlor, molinate, propanil, simazine, carbofuran, diazinon and parathion methyl. The above compounds including propazine, trifluralin, malathion, parathion ethyl, lindane, alpha-benzene hexachloride (alpha-BHC), beta-BHC, 4,4'-DDE and heptachlor were determined in river waters. The higher concentrations in underground waters were measured during the period from May to August, 1996, following seasonal application and diminished significantly during the autumn and winter. Water pollution by triazine and chloroacetanilides was highest in the estuarine areas; showing that many of these compounds are transported significant distances from their application sites. The major inputs of atrazine, alachlor, simazine and metolachlor occurred in May and June just after their application. Atrazine, DEA, diazinon and metolachlor were also detected in spring waters at concentration levels below 0.006 microgram/l. Finally, atrazine, DEA, carbofuran, simazine, diazinon, parathion ethyl and parathion methyl were detected in rainfall water samples collected in the agricultural area of Imathia (central part of the plain).     

A lateral view: the news reporter and conflict recovery

The inhibition of pseudocholinesterase (butyrylcholinesterase) activity is a valid and sensitive biochemical indicator of exposure to anticholinesterase insecticides and is often mandatory of the agricultural use of these pesticides. In the present work we developed a modification of an easy and sensitive technique to detect the pseudocholinesterase inhibition due to pesticide exposure. Small amounts of head tissue are needed and low concentrations of the enzyme can be detected. The determination of pseudocholinesterase inhibition is a useful biomonitor of anticholinesterase pesticide exposure for bees in the same way that it is useful for the determination of exposure in humans.     

Correlation analysis of pesticide use data and cancer incidence rates in California counties

California, the leading agricultural state in the United States, has maintained a population-based cancer registry since 1988, and it also maintains a comprehensive, state-wide pesticide reporting system. Data on cancer incidence and pesticide use reporting are available, by county, for all 58 counties in California. Average annual age-adjusted cancer incidence rates (1988-1992), on a county-, sex-, and race/ethnicity-specific basis, were obtained from the California Cancer Registry (CCR), which maintains the population-based cancer registry throughout California. Pesticide use data (i.e., pounds of active ingredient applied annually in each county) were obtained from the California Department of Pesticide Regulation for 1993. Investigators used Pearson product-moment correlation coefficients (r) to correlate age-adjusted incidence rates for selected cancers with the use data for selected pesticides. For most sex- and race/ethnicity-specific groups, the correlation coefficients were very close to zero or negative in sign, indicating no correlation between pesticide use and cancer incidence. There were, however, several exceptions, particularly in Hispanic males for whom the following correlations were observed: leukemia and atrazine (r=.40), leukemia and 2,4-dichlorophenoxyacetic acid (r=.41), leukemia and captan (r=.46), atrazine and brain cancer (r=.54), and atrazine and testicular cancer (r=.41). For black males, we observed the following: atrazine and prostate cancer (r=.67) and Captan and prostate cancer (r=.49). In females, only a few of the correlations were elevated. Although most of the correlations examined in this analysis were not elevated, several of those in the Hispanic and black male populations were. These segments of the population have traditionally been employed as farm workers in California and have had the greatest potential for exposure to pesticides. This was an ecological study for which no data about exposure to pesticides at the individual level were available for analysis. In addition, no latency period was allowed between potential exposure and diagnosis with cancer. However, the results obtained in two minority groups who represented the majority of farm workers in the fields suggested that additional research studies, in which more rigorous study designs are used, should be conducted in those groups.     

Gas chromatographic detection of class I pesticide residuals in olive oil. Preliminary data for a project on food pollution and children's health

The data are preliminary findings in order to study the possible pollution of fresh olive oil with Class I Pesticides, often misused by olive farmers, and it's effect on children's health. The oil produced from the olives of 8 farms in a small town of Southern Italy was collected at the mill in 1992, with no previous notice to the farmers, and was analyzed by Head Space Gas Chromatographic technique. The research for organophosphates and chlorinated pesticides was negative. The Kreis test excluded oil rancidity and the index of refraction confirmed the oils being fresh olive oil. The fact that the oil samples resulted free of pesticide residuals, however, might be explained by the unusual season weather not favourable to the olive parasites and the consequent reduced amounts of pesticides used by the farmers. The work will be repeated in 1993 and completed by a dietary semiquantitative questionnaire and epidemiologic evaluations on the children's health.     

1,2 Dibromo-3-chloropropane (DBCP) and ethylene dibromide (EDB) in well water in the Fresno/Clovis metropolitan area, California

Ground-water contamination with the pesticides 1,2 dibromo-3-chloropropane (DBCP) and ethylene dibromide (EDB) affects Fresno/Clovis city in California. The spatial and temporal distribution of DBCP and EDB in public wells in Fresno/Clovis was examined, using mapping and time-series analyses of chemical test results, during the time periods 1979-1980 and 1992-1993. Health risks were estimated from mean concentrations, lifetime cancer risks were estimated, and monitoring and control programs were reviewed. Mean DBCP concentrations in selected wells declined from 0.56 ppb in 1979-1980 to 0.18 ppb in 1992-1993. Closure of wells and wellhead filtration caused levels to be reduced further (i.e., to 0.06 ppb). Mean EDB concentrations declined from 0.25 ppb to 0.15 ppb during the same time periods. The estimated lifetime cancer risk for DBCP was 1 excess death per 125 000 population in 1992-1993, but this risk varied within the city. The risk for EDB was 1 excess death per 2.2 million. Recommendations were made for the modeling of pesticide movement in ground water and for epidemiological studies.     

A qualitative field method for monitoring pesticides in the edge-of-field runoff

A field method is described, which allows the qualitative estimation of pesticide contamination in the edge-of-field runoff. The method employs cheap and easy-to-use runoff sampling bottles, which were installed in an agricultural stream catchment over a period of three growing seasons. During this time 18 runoff events were detected, in nine of which insecticide contamination was measured (maximum concentrations: lindane 0.7 microgram l-1 and 12.7 micrograms kg-1, parathion 20 micrograms l-1 and 728 micrograms kg-1, fenvalerate 18.4 micrograms l-1 and 924 micrograms kg-1). These insecticides were detected mainly as particle-bound chemicals. On about 80% of the occasions the presence or absence of runoff measured in the field was in agreement with a simulation of runoff presence or absence using the runoff model KINEROS.     

In vitro study of pesticide hematotoxicity in human and rat progenitors

Some pesticides are hematotoxic and cause aplastic anemia, agranulocytosis, neutropenia, and thrombopenia. In order to evaluate hematopoietic progenitor cultures in the exploration of pesticide hematotoxicity, human and rat colony-forming unit-granulocyte and macrophage (CFU-GM) were cultured in the presence of different concentrations of pesticides, known to be either hematotoxic or innocuous for blood cells. The results were compared to the control culture of the same sample. Four insecticides (lindane, azinphos, mevinphos, parathion methyl), three herbicides, (2,4,5, T, bromacil, MCPA), and two fungicides (fosethyl-aluminum, DNOC) were tested and exhibited the following data: 1) Pesticides, known to be hematotoxic, inhibited the development of progenitors. Different phenomena were observed and suggested different mechanisms: cell destruction, block in mitosis, decrease or delay in mitosis. 2) Difference in sensitivity to molecules between human and rat progenitors was observed. Human progenitors were more sensitive to pesticides, except for 2,4,5 T.     

Comparison of pesticides and other compounds in carpet dust samples collected from used vacuum cleaner bags and from a high-volume surface sampler

Epidemiologic studies of the association between residential pesticide use and cancer risk require an assessment of past pesticide exposures. Pesticide levels in carpet dust are believed to reflect long-term pesticide use. Recent epidemiologic studies have found collection of dust samples using the high-volume surface sampler (HVS3) to be expensive and cumbersome. We compared the levels of pesticides and other compounds in dust obtained from subjects' personal used vacuum cleaner bags to that collected by the HVS3 to see if this simpler method could replace the HVS3 in epidemiologic research. We visited the homes of 15 subjects, took the used bags from their vacuums, and collected carpet dust samples with the HVS3. The samples were analyzed for 42 target compounds: 26 pesticides, 10 polycyclic aromatic hydrocarbons (PAHs), and six polychlorinated biphenyl (PCB) congeners using GC/MS in selected ion monitoring mode. The two methods agreed in detecting the presence of the target compounds between 80% and 100% of the time. Neither sampling method was consistently more sensitive. The median target compound concentrations were similar, and a paired t-test showed no significant differences. For many compounds, the concentrations of compounds in the HVS3 samples were higher than those in the used bag samples at the upper end of the concentration ranges. However, the Spearman rank correlation coefficients were 0.85 or higher for most compounds, indicating that homes would be ranked similarly using both methods. Overall, there appears to be no clear difference in the quality of the pesticide, PAH, or PCB concentration data for the two dust collection methods.     

Assessment of the reproductive and developmental toxicity of pesticide/fertilizer mixtures based on confirmed pesticide contamination in California and Iowa groundwater

Pesticides and fertilizers, as used in modern agriculture, contribute to the overall low-level contamination of groundwater sources. In order to determine the potential of pesticide and fertilizer mixtures to produce reproductive or developmental toxicity at concentrations up to 100 x the median level found in groundwater, we prepared and studied two mixtures of pesticides and a fertilizer (ammonium nitrate). One mixture containing aldicarb, atrazine, dibromochloropropane, 1,2-dichloropropane, ethylene dibromide, and simazine plus ammonium nitrate was considered to be a representative of groundwater contamination in California (CAL). The other, containing alachlor, atrazine, cyanazine, metolachlor, metribuzin, and ammonium nitrate, simulated groundwater contamination in Iowa (IOWA). Each mixture was administered in the drinking water of either Swiss CD-1 mice during a Reproductive Assessment by Continuous Breeding study or pregnant Sprague-Dawley rats (gd 6-20) at three dose levels (1x, 10x, and 100x) where 1x was the median concentration of each pesticide component as determined in the groundwater surveys in California or Iowa. Unlike conventional toxicology studies, the purpose of this study was to evaluate the health effects of realistic human concentrations. Thus, the testing concentrations are probably well below the maximally tolerated dose. Propylene glycol was used as the solubilizer for the pesticides in drinking water formulations in both studies. In the reproductive study, neither mixture caused any clinical signs of toxicity, changes in food or water consumption, or body weight in either F0 or F1 mice at doses up to 100x the median groundwater concentrations. There were no treatment-related effects on fertility or any measures of reproductive performance of either the F0 or the F1 generation mice exposed to either CAL or IOWA at up to 100x. Similarly, measures of spermatogenesis, epididymal sperm concentration, percentage motile sperm, percentage abnormal sperm, and testicular and epididymal histology were normal. In the developmental study, CAL- or IOWA-exposed females did not exhibit any significant treatment-related clinical signs of toxicity. No adverse effects of CAL or IOWA were observed for measures of embryo/fetal toxicity, including resorptions per litter, live litter size, or fetal body weight. CAL or IOWA did not cause an increased incidence of fetal malformations or variations. In summary, administration of these pesticide/fertilizer mixtures at levels up to 100-fold greater than the median concentrations in groundwater supplies in California or Iowa did not cause any detectable reproductive (mice), general, or developmental toxicity (rats).     

Report of a panel on the relationship between public exposure to pesticides and cancer. Ad Hoc Panel on Pesticides and Cancer. National Cancer Institute of Canada

BACKGROUND: Pesticides, which by their nature are biologically active compounds, continue to raise public concern regarding their possible role as important etiologic agents in the development of human cancer. METHODS: To examine this potential role, the National Cancer Institute of Canada convened an Ad Hoc Panel on Pesticides and Cancer to examine the possible contribution of pesticide exposure, particularly in the general population, to the development of human cancer. RESULTS: The Panel focused primarily on exposure in the general population and reviewed a range of studies that addressed issues related to dietary exposure as well as incidental home and garden uses. In addition, the Panel examined the regulatory framework that exists to safeguard the public from potentially carcinogenic pesticides and also reviewed some potential benefits of pesticide use, including the availability of an abundant and low cost supply of fresh fruits and vegetables as an important strategy in the overall mitigation of cancer risk. CONCLUSIONS: The Panel concluded that it was not aware of any definitive evidence to suggest that synthetic pesticides contribute significantly to overall cancer mortality. The Panel also concluded that it did not believe that any increased intake of pesticide residues associated with increased intake of fruits and vegetables poses any increased risk of cancer. The Panel further concluded, among other things, that tobacco use continues to be the most important preventable cause of cancer and premature mortality and thus is an appropriate focus for cancer control strategy.     

Probabilistic Approach to Estimation of Urban Storm-Water Total Maximum Daily Loads: Unregulated Catchment

This work examines the basic processes and functions behind urban storm-water pollution delivery into surface waters and develops a set of tools that allow the estimation of pollutant load dynamics on receiving waters. In particular, the group of expressions developed in this paper allows the calculation of runoff parameters (volume, discharge rate and pollutant load) on an event average basis for an unregulated catchment. Using Monte Carlo simulation techniques, the runoff pollutant concentration probability distribution (as event averages) are obtained. Merging these runoff statistics with the stream parameters allows the receiving water pollutant concentration characteristics to be obtained as well as the probability of exceeding threshold pollutant concentrations in the mixing zone of a stream. The simulation can be performed with allowance for different levels of complexity with respect to catchment hydrologic representation and pollutant load functions. As a result, the magnitude of influence of urban runoff on a surface water body can be determined, pollutants of concern can be identified, and certain remedial measures recommended.     

Nerve-plasty interventions on the facial nerve in the elderly patient--morphological evaluation of disappointing functional results]

Acute pesticide poisoning is a global health problem, especially in developing countries. Although Taiwan has quickly industrialized during the last several decades, pesticide use is still prevalent in the agricultural sector. We reviewed 187 consecutive hospitalized cases of the Provincial HsinChu Hospital from January 1989 through December 1995 to explore the determinants of acute pesticide poisoning in Metropolitan HsinChu. The annual incidence rate of acute pesticide poisoning was 3.2/100,000 with an overall fatality rate of 23% which was more severe than the rates found in developed countries. The major agents involved were organophosphates, and the major cause of poisoning was suicide. Alcohol abuse, history of major medical illnesses, and history of suicide were significantly associated with suicidal poisoning; quarrel was the immediate risk factor. Causes of poisoning (suicide vs non-suicide) and selection of the pesticides were major determinants of lethality. More stringent legislation and enforcement regarding the sale and distribution of extremely toxic pesticides are needed to reduce fatalities due to acute pesticide poisoning.     

Impact of the Delaney Clause in the EPA

The U.S. Environmental Protection Agency serves as the lead agency of the Federal government for the regulation of pesticide use in the United States. Regulatory responsibilities are mandated in the Federal Insecticide Fungicide and Rodenticide Act (FIFRA) and several sections of the Federal Food Drug and Cosmetic Act (FFDCA). In order for a pesticide to be used in the U.S., it must either be granted a full registration under Section 3, or offered special consideration under Section 18 or 24 of FIFRA. Tolerances (maximum allowable residue limits) for pesticides to be used on agricultural commodities meant for human consumption or animal feed are established under Sections 408 and/or 409 of FFDCA. This presentation will describe the underlying conflict between Section 409 of FFDCA and both Section 408 and FIFRA, the recommendations made by the National Academy of Sciences in its 1987 publication Regulating Pesticides in Food--The Delaney Paradox, EPA's attempts to implement these recommendations, the true impact of "Delaney" on the ability of EPA to grant tolerances on raw or processed foods for chemicals determined to meet the "induce cancer" criterion and the status of legislation designed to "fix" Delaney.     

Health care for pesticide applicators in a locust eradication campaign in Kuwait (1988-1989)

Pesticide applicators in the Plant Protection Department of the Agriculture Affairs and Fish Resources Authority are monitored regularly by the Occupational Health Section of the Ministry of Health. The aim is to protect them from the adverse effects of pesticides and to prevent acute poisoning by removing from exposure those who have low cholinesterase (ChE) activity levels or low white blood cell counts. Thirty-eight workers routinely examined in July 1988 were reexamined at the onset of the locust invasion in Kuwait in November 1988; also examined were 36 farmers recruited for the first time to fight locusts and a matched control group of 38 firefighters. After 2 to 3 months, when the locust invasion decreased markedly and pesticide spraying nearly stopped, the exposed workers were reexamined. The pesticides used to control locusts were five organophosphates and one organochlorine (lindane). Sixty percent of normal for red blood cell (RBC) ChE activity and 50% of normal for plasma ChE activity were used as threshold levels for removing workers from continued exposure to ChE-inhibiting pesticides. The different reactions of study groups during the locust control period are described, including results from tests of pulmonary function, RBC and plasma ChE activity, and nerve conduction velocity.     

Acute work-related poisoning by pesticides in The Netherlands; a one year follow-up study

The National Poisons Control Centre of the National Institute of Public Health and the Environment in the Netherlands conducted a prospective study on acute poisoning arising from exposure to pesticides in agricultural workers. The study was performed to determine the extent and severity of acute pesticide poisoning in the Netherlands and the working conditions that lead to these poisonings. All cases of potential acute occupational intoxication by pesticides in which the Poisons Control Centre was consulted in 1991 were thoroughly studied by an occupational hygienist and a specialist in internal medicine. With the consent of the patients and their physicians, the patients' medical condition and the working conditions leading to exposure were investigated on the spot. After the exclusion of 73 patients (27 non-occupational exposures, 7 occupational exposures in non-agricultural workers, 1 accident occurred abroad, 32 patients with illnesses unrelated to pesticides and 6 who could not be traced for follow-up), 54 cases of possible acute work-related pesticide poisoning remained for study. In 37 of the 54 events there was a direct relation between exposure to pesticides and acute health problems. In one patient doubt remained about the origin of the complaints and in 16 of the 54 cases pesticide poisoning was highly unlikely and the complaints could be attributed to other diseases. In the 37 remaining cases symptoms consisted of skin and/or eye lesions (23 cases) and systemic health effects (14 cases). Exposure to the soil disinfectant 1,3-dichloropropene resulted in severe skin damage. Direct contact of pesticides with the eyes invariability resulted in local irritation. Severe systemic poisonings occurred after exposure to organophosphate and carbamate insecticides and the soil disinfectant methyl bromide. Investigations at the site of the exposure revealed 43 cases of clear exposure to pesticides, in which, except for two cases, 1 worker per incident was involved. In 67% of the cases exposures took not place during pesticide dissemination, but during preparatory activities (35%), repair of application equipment (14%) and during re-entry (14%). In 79% of the cases splashing of pesticides or spray drift led to the exposure. In most accidents (74%) imperfect technical design or technical defects were important risk factors for exposure. Although most workers were aware of the risk of using pesticides, they were still careless in taking adequate protective measures. Especially during preparatory and reparations activities the wearing of protective clothing has to be emphasized.     

Analysis of pesticide residues in drinking water by planar chromatography

Planar chromatography is described in the field of water analysis. The principle of automated multiple development (AMD) technique is mentioned, the strategy of the whole procedure which became a German standard is demonstrated and separations of pesticide mixtures, as well as water samples containing pesticides are presented. The suitability of this method was proved for 283 pesticides and the corresponding ISO Standard has been applied for.     

Structure of a DNA base-excision product resembling a cisplatin inter-strand adduct

Little data on the prevalence of acute and chronic pesticide exposure among farmers and the frequency of protective gear use are available. This report presents results of a cross-sectional study of pesticide behaviors among dairy farmers certified to apply pesticides to field crops. Private dairy farmers residing in six adjacent Wisconsin counties were randomly selected and contacted by telephone for interview. One hundred ninety-one farmers completed the interview (response rate, 76.4%). Twelve percent reported never or almost never wearing gloves during application, and 53.7% reported never or almost never wearing other protective gear. Thirty-two percent reported dermal exposure, and 32.0% reported inhaling pesticides during last application. Findings suggest that exposure to pesticides was frequent in this sample, whereas use of personal protective equipment was not routine.