Frequent Pesticide Research Articles

Health of Farming Communities Prior to Modification of the Occupational Environment through a Watershed Development Project in Kolar, India.

Background:Watershed development (WSD) projects, aimed primarily at enhancing soil and water conservation and supporting livelihoods in semi-arid areas, have the potential to impact health by modifying the occupational and household environments in agrarian communities. To identify and address potential health concerns arising from a planned WSD project in Kolar district, India, a health impact assessment (HIA) was conducted. This necessitated understanding the health status and concerns in the project villages.Objective:To characterize the health of farmers and their household members in close proximity of the planned WSD project.Methods:We carried out a cross-sectional survey between April and July 2019. The study comprised: (i) a household survey covering the four project villages and two comparison villages (e.g. socio-demographic characteristics, occurrence of vector-borne diseases (VBDs), access to safe water, sanitation and hygiene, and utilization of healthcare); and (ii) an anthropometric survey for children under the age of 5 years in the four project villages and four comparison villages.Results:Respondents (n = 333) reported household-level occurrences of VBDs (chikungunya, 3.3%; and dengue, 1.5%), consuming unsafe water (54.5%) and frequent pesticide application in fields (26.7%). The prevalence of child underweight was 23.8%.Conclusions:VBDs, poor water quality and child undernutrition were found to be important local health concerns, amenable for preventive and promotive measures through the planned WSD project. Occupational environments in agricultural settings affect the workers and their households, and comprehensive projects such as WSD can seize the opportunity for improving health of farming and other rural households.

Binary Logistic Regression Modeling on Net Income of Pagar Alam Coffee Farmers

Pagar Alam Coffee is a Besemah coffee originating from the Smallholder Plantation in South Sumatra, Indonesia. The majority of Pagar Alam coffee farming is a hereditary business. Coffee farmers' income is very dependent on coffee production, production costs, and coffee prices. This study aims to obtain a probability model of Pagar Alam coffee farmers income based on the factors that influence it. The independent variables studied were the number of dependents, economic conditions, number of trees, age of trees, frequency of fertilizer used, frequency of pesticide used, production at harvest time, production outside harvest time, number of women workers outside the family, minimum price of coffee, maximum price of coffee, farmers' gross income, and land productivity. Modeling used binary logistic regression method on 179 respondents. There were three methods used, i.e. enter method, forward and backward methods. The model using enter method results the greatest prediction accuracy which is 87.7%. The factors that have a significant influence on the net income of Pagar Alam coffee farmers are gross income, land productivity, and the number of women workers from outside the family. The most influential variable is gross income.

Pesticides and their degradates in groundwater reflect past use and current management strategies, Long Island, New York, USA

Long Island, New York, has a mix of urban/suburban to agricultural/horticultural land use and nearly 3 million residents that rely on a sole-source aquifer for drinking water. The analysis of shallow groundwater (<40 m below land surface) collected from 54 monitoring wells across Long Island detected 53 pesticides or pesticide degradates. Maximum concentrations for individual pesticides or pesticide degradates ranged from 3 to 368,000 ng/L. The highest concentrations and most frequent pesticide detections occurred in samples collected from the pesticide management (PM) network, set in an agricultural/horticultural area in eastern Long Island with coordinated pesticide management by state and local agencies. The other two networks (Suffolk and Nassau/Queens) were set in suburban and urban areas, respectively, and had less frequent detections and lower pesticide concentrations than the PM network. Pesticide detections and concentration patterns (herbicide, insecticide, or fungicide) differed among the three networks revealing broad differences in land use. The predominance of fungicides metalaxyl, 1H-1,2,4-triazole (propiconazole/myclobutanil degradate), and 4-hydroxychlorothalonil (HCTL, chlorothalonil degradate) in samples from the PM network reflects their intensive use in agricultural settings. Total fungicide concentrations in the PM network ranged from <10 to >300,000 ng/L. The widespread detection of imidacloprid and triazine herbicides, simazine and atrazine, reveal a mixture of current and past use pesticides across the Long Island region. Low concentrations (<200 ng/L) of the triazines in the Suffolk and Nassau/Queens networks may reflect a change in land use and application. Acetanilide herbicides and aldicarb have been discontinued for 20 and 40 years, respectively, yet the concentrations of their degradates were among the highest observed in this study. Acetanilide (total concentrations up to 10,000 ng/L) and aldicarb degradates (up to 270 ng/L) are present in the PM network at much lower concentrations than previous Long Island studies and reflect changes in agricultural practices and pesticide management.

Multiresidue Analysis of Pesticides in Moringa Pods by GC-MS/MS and LC-MS/MS.

Moringa pods are known for their nutritional and health benefits. The cultivation of this crop receives frequent pesticide applications. In the absence of risk assessment data, maximum residue limits of pesticides in this crop are considered at the default level (0.01 mg/kg). However, there exists scarcely any validated method for pesticide residue analysis in this matrix. This study was undertaken to develop and validate a multiresidue method for the simultaneous analysis of multi-class pesticides in moringa pods by gas chromatography-tandem mass spectrometry (GC-MS/MS), and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The homogenized sample (10 g) was extracted with acetonitrile (10 mL). The extract was cleaned by dispersive solid-phase extraction using a combination of 50 mg primary secondary amine, 5 mg graphitized carbon black, and 25 mg C18 sorbents, and was directly analyzed by LC-MS/MS. Another portion of the extract was reconstituted in ethyl acetate before GC-MS/MS analysis. The method was validated as per the SANTE/12682/2019 guidelines using GC-MS/MS (180 pesticides) and LC-MS/MS instruments (203 pesticides). The method provided a satisfactory analysis of the targeted pesticides with good calibration linearity (r2>0.99), high precision (RSD < 20%), and accuracy (recoveries, 70 to 120%). The reconstitution of the acetonitrile extract in ethyl acetate significantly reduced the matrix effects on GC-MS/MS analysis. The use of matrix-matched standards could correct all recoveries. The method offered a large-scale analysis of multi-class pesticides with high accuracy, and precision at 10 ng/g, and higher levels. The method performance complied with the regulatory requirements, and thus, can be implemented in routine testing purposes. The study reports a validated method for large-scale multiresidue analysis of pesticides in moringa matrix for the first time. The method provided a high throughput analysis of multi-class pesticides with satisfactory selectivity, sensitivity, accuracy, and precision.

Photoselective exclusion netting in apple orchards: effectiveness against pests and impact on beneficial arthropods, fungal diseases and fruit quality.

Frequent pesticide treatments in fruit orchards increase hazards for workers, consumers and the environment. Moreover, the indiscriminate and excessive use of pesticides often induces resistance in pests. In the past few years, physical exclusion strategies have been proposed as an alternative for the control of insect pests. The goal of this study was to evaluate the effectiveness of anti-hail photoselective netting in protecting apples against key and emerging pests, as well as the impact on beneficial arthropods, fungal diseases and fruit quality. In netted plots, a significant reduction in pest populations, i.e. fruit moths, Halyomorpha halys (Stål) and Drosophila suzukii (Matsumura), was recorded in comparison with un-netted controls. Moreover, the damage on fruits caused by H. halys was reduced up to 62% compared with insecticidal treatments. The net did not negatively affect the abundance of predators and the incidence of post-harvest rot. In addition, the incidence of bitter pit on apple was reduced up to 52%. Furthermore, fruit quality was unaffected by the net coverage (both at harvest and after 4 months of storage). Anti-hail photoselective pearl netting proved a promising exclusion system that can prevent attack by more than one insect pest at a time, allowing for a strong reduction in insecticide treatments and relative costs. At the same time, the netting did not negatively influence the presence of predators, the incidence of fungal disease or fruit quality. © 2019 Society of Chemical Industry.

Comparison of the epiphyte Tillandsia bergeri and the XAD-resin based passive air sampler for monitoring airborne pesticides

The aim of this study was to assess if the epiphyte Tillandsia bergeri is feasible to be used as a biomonitor of pesticides in the air by comparing with the results of the artificial XAD-resin based passive air sampler (XAD-PAS). Biomonitors and XAD-PAS were deployed at 10 sites of Quequén Grande River watershed (Buenos Aires province, Argentina) during three exposure periods. Endosulfan was the main pesticide found in T. bergeri as well as in XAD-PAS, even after the ban was in effect. Higher endosulfan levels were observed during pesticide application period in XAD-PAS, while T. bergeri showed a decreasing trend during this period. Chlorpyrifos concentrations were in the same order than endosulfan in XAD-PAS, while T. bergeri showed significantly lower levels. Concentrations of legacy pesticides (hexachlorocyclohexanes, chlordanes, dieldrin, heptachlors) registered a low contribution to total pesticides analyzed both in T. bergeri and XAD-PAS, reflecting the past use of organochlorine pesticides in the region. Trifluralin showed the lowest concentrations in T. bergeri while XAD-PAS exhibited a higher proportion in some sites. Even both samplers showed that endosulfan was the most frequent pesticide found, environmental processes such as volatilization and photodegradation, as well as biological processes in T. bergeri have probably occurred and therefore pesticides accumulation was altered. Results demonstrate the importance of taking into account the type of sampling media when analyzing atmospheric pesticide composition. Nevertheless, the use of T. bergeri and XAD-PAS allowed discriminating efficiently the relative contribution of currently used pesticides versus legacy pesticides to air pollution.

High-resolution QTL mapping in Tetranychus urticae reveals acaricide-specific responses and common target-site resistance after selection by different METI-I acaricides

Arthropod herbivores cause dramatic crop losses, and frequent pesticide use has led to widespread resistance in numerous species. One such species, the two-spotted spider mite, Tetranychus urticae, is an extreme generalist herbivore and a major worldwide crop pest with a history of rapidly developing resistance to acaricides. Mitochondrial Electron Transport Inhibitors of complex I (METI-Is) have been used extensively in the last 25 years to control T. urticae around the globe, and widespread resistance to each has been documented. METI-I resistance mechanisms in T. urticae are likely complex, as increased metabolism by cytochrome P450 monooxygenases as well as a target-site mutation have been linked with resistance.To identify loci underlying resistance to the METI-I acaricides fenpyroximate, pyridaben and tebufenpyrad without prior hypotheses, we crossed a highly METI-I-resistant strain of T. urticae to a susceptible one, propagated many replicated populations over multiple generations with and without selection by each compound, and performed bulked segregant analysis genetic mapping. Our results showed that while the known H92R target-site mutation was associated with resistance to each compound, a genomic region that included cytochrome P450-reductase (CPR) was associated with resistance to pyridaben and tebufenpyrad. Within CPR, a single nonsynonymous variant distinguished the resistant strain from the sensitive one. Furthermore, a genomic region linked with tebufenpyrad resistance harbored a non-canonical member of the nuclear hormone receptor 96 (NHR96) gene family. This NHR96 gene does not encode a DNA-binding domain (DBD), an uncommon feature in arthropods, and belongs to an expanded family of 47 NHR96 proteins lacking DBDs in T. urticae. Our findings suggest that although cross-resistance to METI-Is involves known detoxification pathways, structural differences in METI-I acaricides have also resulted in resistance mechanisms that are compound-specific.

Análisis de residuos de plaguicidas en el agua superficial de la cuenca del río Ayuquila-Armería, México

The application of chemical products for pest control is one of the most widely used methods in agriculture worldwide despite their adverse effects on humans and the environment. This is a topic of interest due to the growing number of chemical products and their toxicity. The objectives of this research were to identify the most commercialized pesticides in the Ayuquila-Armería River basin (Mexico) and to determine their concentration in the surface water of the basin. The hypothesis of this work was that the current system of agricultural production in the basin is causing degradation of water quality due to the presence of a wide variety of pesticides. For the f irst objective, we visited 27 outlets of pesticides located in the main municipal capitals within the basin, obtaining a total of 143 commercialized active ingredients, mainly of chemical origin. For the second objective, we carried out two samplings in the dry season and two in the rainy season, in 30 sites distributed within the basin. The sampling sites were chosen in a directed way according to the problem of existing contamination and trying to cover the largest agricultural areas within the basin. The analyses were carried out through liquid chromatography coupled to mass-mass spectrometry. The results showed that 66% of the samples contained at least one pesticide. The most frequent pesticides were ametrine, dimethoate and diazinon. The sites that presented the highest number of pesticides in the four samplings were Palo Blanco, Antes Manantlán, Tuxcacuesco and Ayuquila. The sites near the area of intensive agriculture had a higher number of pesticides than those located in areas with rainfed agriculture. This study is the f irst to analyze the presence of pesticides in surface waters of the basin.

Agroecological farming practices promote bats

Intensive agriculture is a major driver of biodiversity loss, and a critical part of creating sustainable food systems is finding ways to balance production and conservation. While practices characteristic of agricultural intensification tend to erode biodiversity, agroecological farming practices can potentially support biodiversity and enhance pest suppression services. Bats are important predators of agricultural pests, yet little is known about how prescriptive management practices can be used to support bats and their associated pest-suppression services. We investigate how bats use natural habitat and conventional and organic farms in an agricultural landscape, ask which on-farm management practices may benefit bats, and examine how these management practices influence bats by mediating changes in habitat quality. We conducted acoustic surveys at 54 sites in the California Central Coast Region, a productive region with high ecological and economic value. We found higher bat activity in natural habitat compared to farms for total bat activity and clutter-adapted, but not open space bats, and slightly higher bat diversity in natural habitat compared to conventional farms. We found no effect of habitat type on species richness and a weak effect of habitat type on bat diversity, although bat community composition differed significantly between natural habitat and farms. Crop diversification increased the activity of all bat species and clutter-adapted, but not open space bats, regardless of the amount of semi-natural habitat surrounding farms. Both crop diversification and less frequent pesticide applications increased prey biomass, and the activity of clutter-adapted bats was positively correlated with greater Lepidoptera biomass. We suggest that improving habitat quality (increasing abundance of insect prey) through vegetative diversification and/or less frequent pesticide applications offers flexible management options to growers by considering both bat ecology and the constraints of regional agricultural management practices.

RESIDU PESTISIDA GOLONGAN ORGANOFOSFAT KOMODITAS BUAH CABAI MERAH (Capsicum annuum L.) PADA BERBAGAI LAMA PENYIMPANAN

PESTICIDES RESIDUAL OF ORGANOFOSPHATE CLASS OF RED CHILE (Capsicum annuum L.) ON VARIOUS STORAGE DURATIONIn order to control pests and diseases in red chili plants, farmers use pesticides was over as impact leaving residue in the chili. The purpose of this study was to determine type, dose and frequency of pesticides used by the farmers, as well as to determine the organophospate residual in chili on different storage times. This study was conducted in two phases namely survey to 10 respondent farmers in Baturiti district, Tabanan regency used questioner and treatment pilot study used different storage time from 0, 1 and 3 days samples took from Apuan Village, Baturiti, Tabanan. Class of organophosphate pesticide residue analysis conducted in Denpasar Branch Police Forensic Laboratory. The results showed dominant pesticides used was organophosphates profenofos (curacron) 60 % and klorpirifos (kaliandra) 20 %. Dose pesticides used was &gt; 40 ml (&gt; 4 bottle cover volume 10 ml) and &gt; 40 gram (&gt; 4 spoon) for tank volume 17 liter and also &gt; 30 ml (&gt; 3 bottle cover volume 10 ml) and &gt; 30 gram (&gt; 3 spoon) for tank volume 14 liter. Frequency of pesticides used by farmers on 1 plant season was 90 % more than 12 times and the other 10 % used frequency 10-12 times. Farmers do not comply dose and frequency with the pesticides used regulations. Analysis result showed that the treatment effect of different storage time is not real to organophosphate pesticide residues groupon red pepper. The average residues detected are indicating a trend with residue storage profenofos on day 0, 1 and day 3 for 1,20 mg/kg, 2,70 mg/kg and 1,37 mg/kg and the amount of chlorpyrifos residues on the storage day 0, day 1 and day 3 is 0,0027 mg/kg, 0,0039 mg/kg and 0,0021 mg/kg. Profenofos and chlorpyrifos residue content is still below the Maximum Residue Limit (MRL) under the provisions of MRL profenofos on red pepper, which is 5 mg/kg and chlorpyrifos, which is 0,5 mg/kg.

Levels of serum cholinesterase in coffee growers from the Caldas Department, Colombia

To determine the levels of serum cholinesterase in coffee growers from the Caldas department and its association with demographic and labor factors. A descriptive study was carried out in a sample of 1 098 farmers from the Upper East and South Center of the Caldas department, through a survey that analyzed characteristics such as sociodemographic, labor, and clinical conditions, as well as cholinesterase levels, determined by Ellman's method. Regarding the occupational aspect, 90.8 % of farmers reported a risk of direct exposure to pesticides. 3.8 % of the analytical determinations of cholinesterase were abnormal, which was related to the fact that 75.6 % of the farmers themselves prepare the mixture of the insecticide, 22.2 % spread the insecticide over their crops more than twice a week, and 37.8 % do not wear protective clothing during the fumigation. The last fumigation was within the range of one to ten days, revealing that the shorter the time of application of the insecticide, the greater the inhibition of the enzyme. The most frequent pesticides were organophosphates (58.6 %). Controlling pesticide exposure is difficult because most workers are self-employed. It is necessary to strengthen training programs and awareness campaigns regarding the effect of pesticides on health, as well as health and safety measures at the workplace. Low levels of serum cholinesterase indicate the absorption of a minimal amount of cholinesterase inhibiting insecticides.

Identification and Natural Parasitism ofTrichogrammaSpecies onOstrinia nubilalisHübner (Lepidoptera: Noctuidae) Eggs in Düzce, Turkey

Small corn fields are intertwined within hazelnut orchards as main crops in Düzce province, located in the Black Sea Region of Turkey. In recent years, the fall webworm, Hyphantria cunea (Drury) reached outbreak levels in hazelnut orchards and chemical agents represented the primary means used to control the population of H. cunea in those orchards. Frequent pesticide spraying against H. cunea may have an adverse effect on beneficial insects and may also disrupt biological control of the European corn borer (ECB), Ostrinia nubilalis (Hübner) by Trichogramma species. Trichogramma specimens collected from corn fields of Düzce provinces in the West Black Sea region in Turkey were identified as T. brassicae Bezdenko based on morphological and molecular characteristics. As a result of this study, natural occurrence of the parasitoid, T. brassicae is still important in successfully suppressing the ECB population in Düzce province of Turkey. It seems that this wasp species adapts well to corn fields. Two years following the initial incidence of parasitism, T. brassicae parasitized more than 90% of the eggs of ECB. A second generation borer attack had not caused stalk or tassel breakage and/or boring into the ear shanks in 2014 and 2015. In both years, larvae were extremely sparse. It would appear that T. brassicae was responsible for the total collapse of the host population. Parasitization of host eggs by T. brassicae in 2014 and 2015 were correlated with the time of collection (r=0.71 and 0.26, respectively). Reasons for the high incidence of parasitism by T. brassicae possibly may have been overwintering survival and alternate hosts of T. brassicae being available prior to August.

Accelerated Microbial Degradation of Nematicides in Vineyard and Orchard Soils

Accelerated microbial degradation (AMD) of organophosphate and carbamate nematicides is a phenomenon whereby biodegradation in the soil is increased, leading to a dramatically shortened persistence of nematicides. More intensified agriculture practices in South Africa in response to the future demand for food may lead to increased pest and disease pressure, which in turn will lead to more frequent pesticide application. The same principle applies to plant-parasitic nematode control practices, and the overuse and misuse will have a pronounced effect on the enhancement of AMD. With limited management options available, the responsible use of nematicides becomes more pertinent. Producers should be aware of the problems associated with multiple soil applications of organophosphates and carbamates against plant-parasitic nematodes. This article reviews factors contributing to the AMD of carbamate and organophosphate nematicides in soil and makes practical recommendations to avoid the occurrence of AMD in vineyard and orchards.

The Status of Honey Bee Health in Italy: Results from the Nationwide Bee Monitoring Network.

In Italy a nation-wide monitoring network was established in 2009 in response to significant honey bee colony mortality reported during 2008. The network comprised of approximately 100 apiaries located across Italy. Colonies were sampled four times per year, in order to assess the health status and to collect samples for pathogen, chemical and pollen analyses. The prevalence of Nosema ceranae ranged, on average, from 47–69% in 2009 and from 30–60% in 2010, with strong seasonal variation. Virus prevalence was higher in 2010 than in 2009. The most widespread viruses were BQCV, DWV and SBV. The most frequent pesticides in all hive contents were organophosphates and pyrethroids such as coumaphos and tau-fluvalinate. Beeswax was the most frequently contaminated hive product, with 40% of samples positive and 13% having multiple residues, while 27% of bee-bread and 12% of honey bee samples were contaminated. Colony losses in 2009/10 were on average 19%, with no major differences between regions of Italy. In 2009, the presence of DWV in autumn was positively correlated with colony losses. Similarly, hive mortality was higher in BQCV infected colonies in the first and second visits of the year. In 2010, colony losses were significantly related to the presence of pesticides in honey bees during the second sampling period. Honey bee exposure to poisons in spring could have a negative impact at the colony level, contributing to increase colony mortality during the beekeeping season. In both 2009 and 2010, colony mortality rates were positively related to the percentage of agricultural land surrounding apiaries, supporting the importance of land use for honey bee health.

Early Life Factors Associated with Adult-Onset Systemic Lupus Erythematosus in Women.

Exposure early in life can influence adult disease and immunity, but the role of early life exposures in risk of systemic lupus erythematosus (SLE) is not established. Women in a national cohort (ages 35-74) provided data on perinatal, maternal, and sociodemographic factors, longest residence to age 14, and residential farm history of at least 12 months to age 18. Cases (N = 124) reported SLE diagnosed age 16 years or older with use of disease modifying antirheumatic drugs. Non-cases (N = 50,465) did not report lupus. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by logistic regression adjusting for age and race/ethnicity. SLE was associated with low birthweight (data on 84 cases and 36,477 non-cases; <2,500 versus 3,000 to <3,500 g OR = 2.2; 95%CI 1.2, 3.9) and preterm birth (57 cases and 22,784 non-cases; ≥1 month early versus full-term OR = 3.4; 95%CI 1.6, 7.4). Considering longest childhood residence to age 14, SLE was associated with more frequent pesticide use (e.g., at least monthly OR = 2.3; 95%CI 1.3, 4.1). SLE was associated with having an early and extended childhood farm residence (i.e., prenatal/maternal farm exposure and longest childhood farm residence OR = 1.8; 95%CI 1.1, 3.0 versus neither). In those with a childhood-only farm residence of 12+ months, agricultural pesticide use was associated with SLE, with the strongest associations for direct personal exposures. The association of SLE with preterm birth is consistent with studies in other populations and with an observed association with low birthweight. The associations of SLE with childhood exposure to residential and agricultural pesticides warrant further study.

Household pesticides and their practices in Dhaka City

Abstract not availableBangladesh J. Zool. 43(1): 137-139, 2015

Biotech Potatoes in the 21st Century: 20 Years Since the First Biotech Potato

Potato is the world's most important vegetable crop, with nearly 400 million tons produced worldwide every year, lending to stability in food supply and socioeconomic impact. In general, potato is an intensively managed crop, requiring irrigation, fertilization, and frequent pesticide applications in order to obtain the highest yields possible. Important traits are easy to find in wild relatives of potato, but their introduction using traditional breeding can take 15–20 years. This is due to sexual incompatibility between some wild and cultivated species, a desire to remove undesirable wild species traits from adapted germplasm, and difficulty in identifying broadly applicable molecular markers. Fortunately, potato is amenable to propagation via tissue culture and it is relatively easy to introduce new traits using currently available biotech transformation techniques. For these reasons, potato is arguably the crop that can benefit most by modern biotechnology. The benefits of biotech potato, such as limited gene flow to conventionally grown crops and weedy relatives, the opportunity for significant productivity and nutritional quality gains, and reductions in production cost and environmental impact, have the potential to influence the marketability of newly developed varieties. In this review we will discuss current and past efforts to develop biotech potato varieties, traits that could be impacted, and the potential effects that biotech potato could have on the industry.

Spatio-temporal patterns of pesticide residues in the Turia and Júcar Rivers (Spain)

A study was conducted on the occurrence of 50 pesticides in water and sediments of Turia and Júcar Rivers (Valencian Community, Eastern Spain) for a period of two consecutive years each, 2010/2011 and 2012/2013, respectively to assess the contribution of agriculture and urban activities on pesticide pollution. The results showed that mean concentrations of pesticides ranged from <LOQ up to 200ng/L. Chlorpyrifos was the most frequent pesticide whereas imazalil, thiabendazole, tolclofos methyl, ethion and carbofuran were those found at higher concentrations. Ubiquitous pesticides are those with long half-lives. The most polluted parts of the rivers were the headwaters and the mouth, which could be related to the agricultural practices and rainfall. Contrarily, in the abrupt part of the rivers of difficult access the contamination is low. Other quality parameters monitored in this study also corroborate the worst water quality in the alluvial plains that coincides with higher anthropic pressure. The temporal variations also indicated a strong relation of pesticide concentrations with hydrology, the higher the river flow, the higher number and frequency of pesticides but at lower concentrations. On the contrary, at lower river flows higher pesticide concentrations were detected. The risk assessment for aquatic biota pointed out that organophosphorus and fungicides are a threat to fish and daphnia and herbicides and fungicides are hazards for algae. Thus, the strict control of pesticide concentrations is important to preserve the aquatic ecosystems health.

Effect of pesticide exposure on immunological, hematological and biochemical parameters in thai orchid farmers- a cross-sectional study.

Various studies have found that many Thai orchid farmers used excessive amounts of pesticides without proper protective gear, but no toxicological study has been made. This cross-sectional study aimed to evaluate the immunological, hematological and biochemical statuses of these farmers. Sixty four orchid farmers and 60 controls were studied. Plasma cholinesterase activity, the percentage and absolute number of B lymphocytes (CD19+) were significantly lower in the farmers group (3966.32 ± 1165.48 U/L, 11.61 ± 4.09% and 312.26 ± 164.83 cells/mm3, respectively) as compared to those of controls (5048.85 ± 1139.40 U/L, 14.32 ± 4.23%, 420.34 ± 195.18 cells/mm3, respectively). There was a statistically significant higher level of serum IgE among the orchid farmers (0.031 ± 0.011 mg/dL vs. 0.018 ± 0.007 mg/dL) but not IgG, IgA and IgM, levels. Serum lysozyme level, lymphocyte proliferative responses to mitogens, hematological parameters and kidney function test, were not significantly different between the two groups. The liver function profiles showed significantly lower levels of albumin and serum protein in the farmer group. Thus frequent pesticide exposure resulted in subtle changes of some biological parameters. These changes, though may not be clinically significant, strongly indicated that caution in handing pesticides by these farmers is warranted.

Detection of residual organochlorine and organophosphorus pesticides in agricultural soil in Rio Verde region of San Luis Potosi, Mexico

Organochlorine pesticides were intensively used in Mexico from 1950 until their ban and restriction in 1991. However, the presence of these compounds is commonly reported in many regions of the country. The aim of the present study was to identify and quantify residual organochlorine and organophosphorus pesticides in agricultural soil in Rio Verde region, San Luis Potosi state, which has been identified as possibly polluted by pesticides. Composed samples from 24 zones covering an area of approximately 5,440 ha were analyzed. The most frequently found pesticides were p,p´-DDT followed by ,p,p´-DDE, heptachlor, endosulfan and γ-HCH whose frequency rates were 100, 91, 83 and 54%, respectively. The concentration of p,p´-DDT in the crops grown in these soils was in the following order: chili > maize > tomato > alfalfa. The results obtained in this study show that p,p´-DDT values are lower or similar to those found in other agricultural regions of Mexico. Methyl and ethyl parathion were the most frequent organophosphate pesticide detected in 100% and 62.5% of the samples with average concentrations of 25.20 and 47.48 μg kg–1, respectively. More research is needed to establish the background levels of pesticides in agricultural soils and their potential ecological and human health effects in this region.