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At least 559 records · Page 31Linked to original sources
PubMed2000

Monitoring of the pesticide levels in some water supplies and agricultural land, in El-Haram, Giza (A.R.E.).

Monitoring of pesticide residues were conducted at different locations in the El-Haram region Giza, Egypt. The water samples were collected from El-Haram Giza, canal water supplies (El-Zomor, Abd-el-aal land and seaside and El-Mansorya), in addition to El-Moheet drainage water. The soil samples were collected from the arable land that surrounds water canals. Water samples were obtained by solid phase extraction (SPE) and soil samples by gel permeation chromatography (GPC). The combination of gas chromatography and mass spectroscopy with different ionization techniques was used for determination and identification of the pesticides, which were quantitatively determined as 1 microgram 1(-1) levels in environmental samples. The residues of pesticides were varied between different locations. Also, organochlorine pesticide residues in El-Moheet drainage water were relatively higher than in the canal water. The concentrations of organophosphorous compounds (chlorpyrifos, dimethoate and parathion) seem to be low in water as compared to soil samples. Most findings were less than 1 microgram g(-1), which is considered a low-level finding. Sixteen organochlorine pesticides were detected in most of the water samples and the percent of positive samples followed the order drins > total BHC > total DDT > endosulfan > heptachlor epoxid > heptachlor. Pentachlorophenol (PCP) was detected only in El-Zomor and Abd-el-aal canal water. Results obtained confirm the presence of different pesticide residues representing different chemical classes in the canal waters. This means that the discharging of wastes in to the water supplies must be controlled. Drainage water was highly polluted and contains much more pesticide residues than different canal waters.

Agriculture↗
PubMed2006

Estimation of pesticide runoff from paddy fields to rural rivers.

The runoff characteristics of pesticides from paddy fields to rural rivers were investigated over a period of three years in Hokkaido Prefecture, Japan. High pesticide concentrations were usually observed in rivers during pesticide application periods. In one year, the growth of rice seedlings slowed down after transplantation owing to low temperatures and lack of sunshine, and many farmers delayed herbicide application. In that year, high-concentration runoff of herbicides in rivers was observed 1-3 weeks later than in average years. The pesticide runoff rates ranged from 0.3% for fenthion to 42% for benfuresate. The runoff rates of pesticides applied post-flood were large. Furthermore, the larger the water solubility of the pesticide, the larger the runoff rate. The highest concentrations of herbicides in paddy water were observed on the day of application or 1-2 days later, and the concentrations decreased exponentially afterwards. The half-lives of the herbicides ranged from 1.2 days for pretilachlor and esprocarb to 5 days for simetryn; the concentrations of the herbicides in paddy water had decreased to 1/10 of their initial concentrations by about 7 days after application. Therefore, the runoff amounts of pesticides from paddy fields could be decreased by improving irrigation-water management.

Acetanilides↗
PubMedDate not supplied

Interlaboratory comparison of pesticide recovery from water using solid-phase extraction disks and gas chromatography.

An interlaboratory study was conducted to assess the suitability of C18 solid-phase extraction disks to retain and ship different pesticides from water samples. Surface and deionized water samples were fortified with various pesticides and extracted using C18 disks. Pesticides were eluted from disks and analyzed in-house, or disks were sent to another laboratory where they were eluted and analyzed. Along with the disks, a standard pesticide solution in methanol was also shipped to be used for fortification, extraction, and analysis. The highest recovery from deionized or surface water using shipped disks was obtained for cyanazine (>97%), followed by metalaxyl (>96%), and atrazine (>92%). Although <40% of the bifenthrin, chlorpyrifos, and chlorothalonil fortified in surface water was recovered from shipped disks, recoveries from deionized water were >70%. From in-house eluted disks, bifenthrin and chlorpyrifos were recovered at 118 and 105%, whereas chlorothalonil showed 71% recovery, indicating that poor recovery from surface water was due to loss during shipping rather than low retention by the C18 disks. There was no consistent relationship between recovery from C18 disk and physicochemical properties for the pesticides included in this study. For most of the 13 pesticides tested, there were no differences in recovery between in-house extracted disks and shipped disks, indicating the suitability of disks to concentrate and transport pesticides extracted from water samples.

Chemical Phenomena↗
PubMedDate not supplied

Development of methods for determination of the residues of 15 pesticides in medicinal herbs Isatis indigotica Fort. by capillary gas chromatography with electron capture or flame photometric detection.

Two multiresidue methods were developed for the determination of 15 pesticides (organochlorines, organphosphorus compounds, pyrethroids, and fungicides) in medicinal herbs Isatis indigotica Fort. and its formulations. The analytical procedure is based on ultrasonic assisted extraction and liquid-liquid extraction (LLE). After solvents were added, the raw material or granule sample was sonicated in an ultrasonic water bath and then centrifuged, filtered, and cleaned up by LLE. The infusion sample was extracted with petroleum ether by LLE. The pesticide residues were determined by capillary gas chromatography with electron-capture or flame photometric detection. Recoveries with the method at concentrations between 0.4 microg/kg and 10 mg/kg ranged from 70.2 to 119.5% for raw material, 73.2 to 105.1% for granule formulation, and 72.8 to 113.3% for infusion formulation. The relative standard deviation values were <20% for all of the pesticides studied. The pesticide detection limits were within the ranges 0.3-0.5 microg/L for endosulfan, 3-7.5 microg/L for pyrethroids, 0.7-32.5 microg/L for organophosphorus pesticides, and 0.1-0.6 microg/L for the other pesticides. The proposed methods are simple and rapid and provide simultaneous determination of pesticide residues in Isatis indigotica Fort. with acceptable recoveries and repeatability and an adequate limit of determination.

Chromatography, Gas↗
PubMed2001

Determination of pesticides in drinking water by micellar electrokinetic capillary chromatography.

A new analytical procedure using a two-step sample preconcentration (solid-phase extraction (SPE) and field-amplified sample stacking) prior to separation by micellar electrokinetic capillary chromatography was developed for the determination of 14 pesticides such as aldicarb, carbofuran, isoproturon, chlorotoluron, metolachlor, mecoprop, dichlorprop, MCPA, 2,4-D, methoxychlor, TDE, DDT, dieldrin, and DDE in drinking water. Good recoveries of pesticides were obtained using SPE with sample pH adjusted to 2-3. Field-amplified sample stacking was found to give enrichment factors up to 30-fold preconcentration of various pesticides under reversed polarity at -2 kV for 50 s. The optimized background electrolyte (BGE) consisted of 50 mM sodium dodecyl sulfate (SDS), 10 mM borate buffer, 15 mM beta-cyclodextrin (beta-CD), and 22% acetonitrile at pH 9.6, running was under 25 kV and detection at 202 nm. Good linearity was obtained for all pesticides with detection limits down to 0.04-0.46 ng/mL and a working range of 0.1-40 ng/mL. The repeatabilities of migration time and peak area were satisfactory with relative standard deviations (RSDs) between 0.66 and 13.6% and 4.1 and 28%, respectively. All pesticides except dieldrin were found to be detected at concentrations at least tenfold lower than the World Health Organization (WHO) guideline values. The analytical procedure developed offers an economic method for fast screening of multiple pesticide residues in drinking water for health protection. It had been applied to determine carbofuran and MCPA in agricultural run-off water samples, giving satisfactory repeatabilities of 10 and 12%, respectively, with n=5 for the determination of pesticides in contaminated water samples.

Electrophoresis, Capillary↗
PubMed2002

Reclamation of pesticides in New York State.

BACKGROUND: Unwanted agrichemicals pose a unique threat that many states now address this with statewide collection programs. In New York, this is done at the discretion of individual counties. METHODS: We compiled and analyzed registration inventories from five separate county-based pesticide collections located in three different agricultural regions. Telephone surveys of thirty-one of New York's leading agricultural counties gathered information on their strategies for disposal of unwanted pesticides. RESULTS: The combined collections yielded 54,214 pounds of pesticides from 123 farms (441 lbs/farm). The most common active ingredients collected included older (and often discontinued) agents such as organochlorine (5,355 lbs, 9.8%) and arsenic (3,832 lbs, 7.1%) compounds, as well as more modern and commonly used active ingredients such as organophosphate pesticides (3,200 lbs, 5.9%). Disposal costs ranged from $2.03 to $2.86 per pound. Data from three collections indicated that 27% of the recovered pesticide (13,123 lbs) was stored in "unacceptable", "leaky", or "poor" containers. Of 31 agricultural counties, only 17 (55%) have hosted at least one farm pesticide collection event in the past. Planning for future collections is quite limited. CONCLUSIONS: There is a potentially large amount of toxic chemicals, some in decaying containers, that poses a risk to soil and groundwater in the state. The planning of future collections in New York State is haphazard. Carefully designed pesticide collection projects can be effective and should be a priority for local and state health officials.

Hazardous Waste↗
PubMed2006

Acute pesticide-related illness among emergency responders, 1993-2002.

BACKGROUND: Emergency responders are among the first to arrive at a pesticide-related release event. Magnitude, severity, and risk factor information on acute pesticide poisoning among those workers is needed. METHODS: Survey data collected from the SENSOR-Pesticides, CDPR and HSEES programs between 1993 and 2002 from 21 states were reviewed. Acute occupational pesticide-related illness incidence rates for each category of emergency responder were calculated, as were incidence rate ratios (IRR) among emergency responders compared to all other workers employed in non-agricultural industries. RESULTS: A total of 291 cases were identified. Firefighters accounted for 111 cases (38%), law enforcement officers for 104 cases (36%), emergency medical technicians for 34 cases (12%), and 42 cases (14%) were unspecified emergency responders. Among the 200 cases with information on activity responsible for exposure, most were exposed while performing activities related to a pesticide release event (84%) and not involving patient care, while the remainder involved exposure to pesticide-contaminated patients. A majority of cases were exposed to insecticides (51%). Most had low severity illnesses (90%). The incidence rate was highest for firefighters (39.1/million) and law enforcement officers (26.6/million). The IRRs were also elevated for these professions (firefighters, IRR = 2.67; law enforcement officers, IRR = 1.69). CONCLUSIONS: The findings suggest the need for greater efforts to prevent acute occupational pesticide-related illness among emergency responders.

Adolescent↗
PubMed2005

Modulation of the genotoxicity of pesticides reacted with redox-modified smectite clay.

Pesticides are toxic agents intentionally released into the environment; their use raises public health and environmental concerns. In recent years there has been much attention to the biotic degradation of pesticides. Abiotic mechanisms in the soil can contribute to pesticide degradation yet the toxicological impact of such degradation is unclear. This study combines for the first time an investigation into abiotic mechanisms of degradation coupled with toxicological endpoints in mammalian cells. The genotoxicity of three commonly used agricultural pesticides was assessed before and after exposure to redox-modified clay minerals. The objectives of the study were to determine the genotoxicity of 2,4-dichlorophenoxy acetic acid (2,4-D), dicamba, and oxamyl, using single cell gel electrophoresis with Chinese hamster ovary (CHO) cells, and to determine the effect of the iron oxidation state in clay minerals (ferruginous smectite SWa-1) on the genotoxic potency of the pesticides. 2,4-D alone or following reaction with redox-modified clays did not induce DNA damage in CHO cells. Oxamyl alone induced a concentration-dependent increase in genomic DNA damage; however, its genotoxicity declined after reaction with reduced clay minerals. Dicamba was not genotoxic when directly analyzed. When dicamba was reacted with reduced clay, a concentration-dependent increase in genomic DNA damage was observed. This is the first reported case of a pesticide being converted into a genotoxin after exposure to redox-modified smectites. These data introduce a new paradigm on the interaction between redox-modified clays and pesticide-related environmental genotoxicity.

2,4-Dichlorophenoxyacetic Acid↗
PubMed2006

Variation in pesticide hazard from vegetable production in Great Britain from 1991 to 2003.

Pesticides pose a difficult problem for policy makers as society generally seeks to reduce any adverse impacts of their use, while industry claims they are important contributors to economic success. Attempts to direct policy according to scientific findings are hampered by the multidimensionality of the potential impacts of pesticides which may affect consumers, operators, wildlife and the environment. Pesticide risk indices seek to reduce these multidimensional impacts into a single dimension and have been increasingly used to understand variation in the hazard posed by pesticides at both field and regional level. This study uses one such risk index, the environmental impact quotient (EIQ), to estimate the hazard posed by pesticide usage from 1991 to 2003 on several vegetable crops grown in the UK. Results are reported for the EIQ and for the environmental impact (EI) for brassicas, peas, beans, onions, leeks, lettuce and endives. The EIQ is a dimensionless estimate of the toxicity of a product, while the EI, which combines the EIQ with data on actual usage, estimates the overall hazard of the use of a product. The exact trends in EIQ and EI varied with crop over the period 1991-2003, but overall the EIQ decreased by 19% and the EI decreased by 34%. However, the mean EI per hectare decreased by only 3%. This suggests that some of the observed reduction in EI at the national level may be related more to decrease in crop area than changes in pesticide use and management. If these observed losses in crop area are being replaced by vegetable imports from overseas, then this raises the possibility that the UK is effectively exporting any problems related to pesticide use. The ethics of this remain unclear.

Agriculture↗
PubMed2006

Exposure risk assessment and evaluation of the best management practice for controlling pesticide runoff from paddy fields. Part 1: Paddy watershed monitoring.

Rice pesticide concentrations in surface water along with hydrological balance and water management conditions were investigated in a paddy watershed of about 100 ha at the Sakura river basin in Tsukuba, Japan, for 3 years from April 2002. Monitoring on different hydrological scales ranging from a paddy plot up to a watershed determined the importance of water management associated with rainfall events and the cyclic irrigation for reducing pesticide discharge into aquatic environments. Surface drainage significantly increased as a response to rainfall events greater than about 1.5 cm day(-1). A total of 16 herbicides were detected in the stream water and their peak concentrations mostly occurred from early to mid-May following the pesticide application period. Two water management factors influencing the pesticide runoff from paddy fields were defined: excess water storage capacity (EWSC) and water holding period (WHP). Uncertainty analyses of pesticide discharge from a paddy plot for dymron (daimuron) and imazosulfuron (IMS) were performed using Monte Carlo simulation (MCS) with prescribed probability of rainfall and water management practice from observations over a period of 3 years. Application of an intermittent irrigation scheme with shallow water depth practice and high drainage gate to maintain the EWSC > 2 cm and increasing WHP from the current Japanese Agricultural Chemicals Regulation law of 3-4 days to at least 10 days were recommended for reducing the pesticide runoff from paddy fields in a monsoon region such as in Japan. The combination of good water management in field plots and small-scale water cycling is the best management practice for controlling pesticide discharge from paddy watersheds.

Agriculture↗
PubMed2002

Pesticide soil sorption parameters: theory, measurement, uses, limitations and reliability.

The soil sorption coefficient Kd and the soil organic carbon sorption coefficient KOC of pesticides are basic parameters used by environmental scientists and regulatory agencies worldwide in describing the environmental fate and behavior of pesticides. They are a measure of the strength of sorption of pesticides to soils and other geosorbent surfaces at the water/solid interface, and are thus directly related to both environmental mobility and persistence. KOC is regarded as a 'universal' parameter related to the hydrophobicity of the pesticide molecule, which applies to a given pesticide in all soils. This assumption is known to be inexact, but it is used in this way in modeling and estimating risk for pesticide leaching and runoff. In this report we examine the theory, uses, measurement or estimation, limitations and reliability of these parameters and provide some 'rules of thumb' for the use of these parameters in describing the behavior and fate of pesticides in the environment, especially in analysis by modeling.

Adsorption↗
PubMed2003

Parameterisation, evaluation and comparison of pesticide leaching models to data from a Bologna field site, Italy.

Effective prediction of pesticide fate using mathematical models requires good process descriptions in the models and good choice of parameter values by the user. This paper examines the ability of seven pesticide leaching models (LEACHP, MACRO, PELMO, PESTLA, PLM, PRZM and VARLEACH) to describe an arable field environment where sunflowers are grown in the Po Valley, northern Italy. Two pesticides were considered, aclonifen and ethoprophos. The models were evaluated in terms of their ability to reproduce field data of soil water content and pesticide residues in the soil and ground water. The evaluation was based on a combination of calibrated and uncalibrated runs. The results from the models were compared with each other to explore the differences between the models. The models varied in their ability to predict soil water content in the summer: the capacity models PRZM, PELMO and VARLEACH predicted less drying than MACRO, PESTLA, PLM and LEACHP. The models varied in their ability to simulate the persistence of the pesticides in the soil. Differences in the simulated pesticide degradation rate were observed between the models, due to variations in the simulated soil water content and soil temperature, and also differences in the equation linking degradation rate to soil water content. There were large differences among the predictions of the models for the mean leaching depth of ethoprophos. PRZM, PELMO, PESTLA and LEACHP all showed similar mean leaching depth to each other, whereas VARLEACH predicted lower ethoprophos mobility and PLM and MACRO predicted greater mobility. All the models overpredicted dispersion of ethoprophos through the soil profile, as compared to the field data. None of the models was able to simulate the field data of rapid leaching of pesticide to ground water except PLM after calibration of the percentage of macropores in the mobile pore space. More work is required in the parameterisation of macropore flow for those models that include this process.

Aniline Compounds↗
PubMed2004

Integrated modeling environment for statewide assessment of groundwater vulnerability from pesticide use in agriculture.

Atrazine, a herbicide widely used for corn production in the Midwest, has been detected in groundwater of several states, and has been identified as a possible human carcinogen. With the widespread use of pesticides in crop production, and the frequent detection of these chemicals in groundwater, large-scale risk assessments would help water resource managers to identify areas that are more susceptible to contamination and implement practices to ameliorate the problem. This paper presents an integrated, visual and interactive system for predicting potential environmental risks associated with pesticide contamination at spatial scales ranging from fields to landscapes and regions. The interactive system extends the predictive ability of the Pesticide Root Zone Model Release 2.0 (PRZM-2) to a landscape and statewide scale through integration with a geographic information system (GIS), graphical user interface and environmental databases. Predictions of statewide (Iowa) vulnerability of groundwater from atrazine leaching below the unsaturated zone were made to demonstrate the utility of the system, and the results were used in risk assessment. In the example application, atrazine fate and transport were evaluated using long-term climatic data (1980--1989) in combination with several environmental databases (eg STATSGO soils database) and exposure risks were expressed in terms of the probability of the predicted pesticide concentrations exceeding the maximum contaminant level (MCL) for drinking water. The results indicate that the predicted pesticide concentrations were significantly lower than the EPA-established MCL. In addition to providing an interactive environment for landscape-level assessment of potential risks from pesticide leaching, the system significantly reduces the time and resources needed to organize and manipulate data for use with PRZM-2, and provides an analytical framework for evaluating groundwater-leaching impacts of pesticide management practices.

Agriculture↗
PubMed2001

Rating systems for pesticide risk classification on different ecosystems.

A novel approach is proposed to quantitatively assess the environmental risks associated with the use of plant protection products. Different ranking indexes for the classification of pesticide risk in various environmental systems at different time and space scales have been developed: PRIHS-1 and PRIHS-2 (Pesticide Risk Index for Hypogean Soil Systems), PRIES-1 and PRIES-2 (Pesticide Risk Index for Epygean Soil Systems), and PRISW-1 and PRISW-2 (Pesticide Risk Index for Surface Water Systems). Such indexes identify the risk for each environmental system immediately after a pesticide spraying (PRIHS-1, PRIES-1, and PRISW-1) or in a wider time--space scale scenario (PRIHS-2, PRIES-2, and PRISW-2). Moreover, a general index (ERIP: Environmental Risk Index of Pesticides) was developed for quantifying the comprehensive risk for the environment. The indexes were calibrated by applying to a large number of pesticides for which data were available. The results of the different indexes are compared and the value and limitations of the approach are discussed.

Animals↗
PubMed2002

Pesticide environmental indicators and environmental policy.

A current concern in many European countries is the environmental impact of agricultural pesticide usage and appropriate policy development to reduce impact. Currently, relatively hazardous pesticides that might be targeted for replacement by other products or management practices are not positively identified, with consequently few incentives for farmers to choose the least environmentally-risky chemicals. There is a lacuna in terms of widely-agreed operational environmental indicators, and an urgent need for comparative environmental assessment tools for pesticides, for use by both agriculturists and policy-makers. Such a system could, for example, provide a basis on which to differentiate an eco-tax according to the environmental threats posed by each product, and thus improve policy effectiveness. The heterogeneity of pesticide chemicals should be taken into account more explicitly in policy design. Through a comparison of different approaches covered in the literature on pesticide environmental classifications, this paper assesses the feasibility of developing environmental banding to improve the effectiveness of pesticide policy. A more pragmatic approach lies in the development of pesticide groupings rather than a continuous scale of environmental burden, i.e. focusing on broad similarities and differences rather than precise individual ordering. In particular, hazard indicators should be considered further, as a first stage in progress towards comprehensive environmental impact measures.

Agriculture↗
PubMedDate not supplied

Educational and informational strategies to reduce pesticide risks. Council on Scientific Affairs.

BACKGROUND: In 1993, the American Medical Association (AMA) requested its Council on Scientific Affairs to investigate issues and concerns related to (1) improving public notification of pesticide applications and (2) improving educational programs for commercial and farm pesticide applicators and increasing enforcement of licensing examination requirements. This report was presented at the 1994 Interim Meeting of the AMA House of Delegates as Report 4 of the Council on Scientific Affairs. METHODS: Information for the report was derived from published literature and from personal communications with state and federal regulatory officials, physicians, and representatives of pest control, lawn care, and farm organizations. Some information about state certification and training programs was obtained from telephone conversations with pesticide applicator training program coordinators from California, Florida, Illinois, Iowa, Michigan, Missouri, Nebraska, New Jersey, New York, Texas, Washington, and Wisconsin. These states were selected because they contain large agricultural or urban populations that are likely to require the services of trained professional pesticide applicators. RESULTS: Current surveillance systems are inadequate to characterize potential exposure problems related either to pesticide usage or to pesticide related illnesses. The effectiveness of applicator certification and training programs and public notification programs could not be determined because of a lack of federal and state survey data for making useful assessments. CONCLUSIONS: Considering current data gaps, it is prudent for homeowners, farmers, and workers to limit pesticide exposures to themselves and others.

Certification↗
PubMed1996

Limits for pesticide residues in infant foods: a safety-based proposal.

A review of safety procedures for regulating pesticide residues in food commodities has demonstrated that maximum residue levels established by national and international bodies may not be suitable for direct application to finished infant products. We have developed a safety-based strategy specifically aimed at setting limits for pesticide residues in baby foods. The approach is based on the acceptable daily intake (ADI) together with the application, when necessary, of an additional uncertainty factor to account for the potential higher sensitivity of infants to toxicants. The need for this extra factor is dependent on the toxicological information available and may be particularly important for pesticides with a neurotoxic potential. Using this strategy we have evaluated safety-based residue limits for finished products based on a standard food intake pattern of a 4-month-old infant. For most of the pesticides examined the estimated limits fell within a range which can be controlled through existing quality assurance systems. This scientific approach appears usable in practice and is intended as a basis for stimulating discussions aimed at evaluating the need for new limits to ensure the optimal quality of infant products with respect to pesticide safety. This assessment demonstrates that for a number of pesticides there is a need for adequate developmental studies to provide assurance that the current ADI is appropriate for infants. A consequence may be the necessity for enhanced analytical sensitivity for the determination of pesticide residues in infant foods which would be compatible with limits based on an infant-adjusted ADI.

Child, Preschool↗
PubMed2002

Effects of currently used pesticides in assays for estrogenicity, androgenicity, and aromatase activity in vitro.

Twenty-four pesticides were tested for interactions with the estrogen receptor (ER) and the androgen receptor (AR) in transactivation assays. Estrogen-like effects on MCF-7 cell proliferation and effects on CYP19 aromatase activity in human placental microsomes were also investigated. Pesticides (endosulfan, methiocarb, methomyl, pirimicarb, propamocarb, deltamethrin, fenpropathrin, dimethoate, chlorpyriphos, dichlorvos, tolchlofos-methyl, vinclozolin, iprodion, fenarimol, prochloraz, fosetyl-aluminum, chlorothalonil, daminozid, paclobutrazol, chlormequat chlorid, and ethephon) were selected according to their frequent use in Danish greenhouses. In addition, the metabolite mercaptodimethur sulfoxide, the herbicide tribenuron-methyl, and the organochlorine dieldrin, were included. Several of the pesticides, dieldrin, endosulfan, methiocarb, and fenarimol, acted both as estrogen agonists and androgen antagonists. Prochloraz reacted as both an estrogen and an androgen antagonist. Furthermore, fenarimol and prochloraz were potent aromatase inhibitors while endosulfan was a weak inhibitor. Hence, these three pesticides possess at least three different ways to potentially disturb sex hormone actions. In addition, chlorpyrifos, deltamethrin, tolclofos-methyl, and tribenuron-methyl induced weak responses in one or both estrogenicity assays. Upon cotreatment with 17beta-estradiol, the response was potentiated by endosulfan in the proliferation assay and by pirimicarb, propamocarb, and daminozid in the ER transactivation assay. Vinclozolin reacted as a potent AR antagonist and dichlorvos as a very weak one. Methomyl, pirimicarb, propamocarb, and iprodion weakly stimulated aromatase activity. Although the potencies of the pesticides to react as hormone agonists or antagonists are low compared to the natural ligands, the integrated response in the organism might be amplified by the ability of the pesticides to act via several mechanism and the frequent simultaneous exposure to several pesticides.

Animals↗